http://californiageology.net/botany daily 0.75 2025-12-31 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1623977834152-M1EYCGOWDAJZYNDUVWLS/asclep2intermsharper.jpg Botany - Asclepias speciosa I MUST CONFESS THAT THE ORGANIZATION OF THIS FIRST PLANT PHOTO BLOCK IS RATHER PERVERSE—A MIXTURE OF GENERA, THEMES, AND AREAS. …closeup in my garden... The little dark spherule at the bottom is the corpusculum, which is atttached to translators, which are attached in turn to pollinia. Honeybees visit these flowers so frequently, apparently just by chance enough affect pollination to make a difference, even though these bees are not as good at pollinating milkweeds as bumblebees are. Taken with my old Nikon D70s. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1591595281544-SUHQDJQLOZAVN6Y72PEL/hybridinterm1.jpg Botany - giant form of Asclepias speciosa I have been growing this stately and magnificent plant obtained from the Regional Parks Botanic Garden plant sale. Beyond that, nobody remembers its source. It probably came from Suncrest Nurseries. I propose that their field collecting got into the inner North Coast Ranges where Asclepias latifolia was last seen in California (1912), and that introgression with this species gave my speciosa giant, lily-pad-like leaves plus hybrid vigor and consequent gigantism. The plants are extraordinarily tall. Furthermore, the plant is caespitose but not rhizomatous. It forms tight clumps and reproduces largely by seed. Never was such a speciosa seen, even though its flowers cause it to key out there. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1593824274356-CG20G3IB075V567QAXXS/combo2.jpg Botany - Asclepias comparison “typical” Asclepias speciosa, left, the giant nonrhizomatous form, right. Both key to speciosa by the flowers. Same chair. All examples of the broad-leaved form are tall; this individual may have a slight aggrandizement from espalier effect. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1591595308757-8XH26NAQO1B25VNZAT31/DSC_5225interm1.jpg Botany - speciosas compared on the left, “typical” speciosa, medium-statured and markedly rhizomatous. on the right, a leaf of the giant form, with plants caespitose but not truly rhizomatous, and very tall. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1762642580146-YPYH0ESJJYZC1RHOTR7K/A.sespiosa+big+lvs.jpg Botany - two stages of seed pods of A.speciosa w. giant leave At left, the beautiful white hairy coma; at right the seed pod just opening….FANTASTIC! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740535891212-O61WP81J6H0XCMHQS6MG/Asclep+calif+copy.jpg Botany - Asclepias californica on Mt Diablo ….a little above Turtle Rock… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740535917079-JV2H9KZLNPEAXWNG8JCP/Asclep+calif+flowers+copy.jpg Botany - Asclepias californica on Mt. Diablo, closer view https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1461463635097-I897OJYTN1FLGZKOVS8Y/Acordinterm2.jpg Botany - Carquinez Asclepias cordifolia Here's one up close, 23 April 2016. The chewing was done by monarch caterpillars. E.L. Greene found this species near Martinez in 1889, when John Muir lived there. It would be strange if Muir did not know this wonderful Sierran plant was growing near his home. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1461463614032-1QYLPY96MZMA8THHTJN5/acordinterm1.jpg Botany - Asclepias cordifolia Carquinez Dean Kelch discovered a large population of Asclepias cordifolia in the Carquinez Strait Regional Shoreline. Here is a small part of it in bloom, 23 April 2016. The habitat--exotic grassland dominated by Avena--is highly anomalous for this milkweed. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763855839708-PE7JXC1OIA1Z831EW9PL/A.+cordifolia+in+G.jpg Botany - Asclepias cordifolia …in our garden…photographed with a D70s, which made the leaves look as blue as they were!…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1591595067753-EHHM4JTVPMYGLF07RZMD/cordifolia6-7-20interm1.jpg Botany - Asclepias cordifolia flowers This tiny bee visited the flowers in my garden on a windy day in early June 2020. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748571523176-0T918LX917C3D3VJM24C/Asclepis+eriocarpa+MiddletownR-sharper.jpg Botany - Asclepias eriocarpa …along Butts Canyon Road in the outskirts of Middletown, after the fire that incinerated parts of the town, before the pandemic….Beautiful plant!…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1614151281954-FU35GUTDAF4B0IAKH3FC/Acryptoceras2.jpg Botany - Asclepias cryptoceras This amazing milkweed occurs in western states but in California only in Mono County. I’ve seen it east of Bodie (left) and at Aldrich Station in Nevada (right). The species has very large flowers for a milkweed, which I have never seen in the field. There are great photos of them on Calphotos. But I think we should step back and admire that fabulous foliage! The plant at left is in bud. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1726706253721-K2V1S9IIBHHMY1DWLIIR/JV+w+A+albicansSharperR2A.jpg Botany - Asclepias albicans ...in one of the palm canyons in Anza Borrego SP--but it was long ago, so I can't recall which one. Its chalky shoots TOWER over my old friend Jimmy Vale. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653509272434-3UA4BCC0ORB72SRLW54O/PFlatAsclepR.jpg Botany - Asclepias solanoana in Sonoma County Though scanned from an old slide, always an unsatisfactory process, this is still one of my favorite pictures of this serpentine-endemic milkweed, showing how by coloration and by plastering itself onto the scree, it blends in. Now THAT is satisfying! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653843812301-SSYMPIO0ZA6POAYEANMC/AsclepBestR+copy.jpg Botany - Asclepias solanoana Observed in late May 2022 at almost the same locality as the last photo. Such beauty in such a raw place! This plant wants only the most barren serpentine scree. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653950398649-NO2S94QU8BH9T0EWZBWP/brach1stcombo+R2copy.jpg Botany - Socrates Mine jewel flower This collage shows the very endangered Streptanthus brachiatus on summit serpentinite of the Mayacamas Range west of The Geysers Geothermal complex. Upper right, first-year rosette of this biennial species. Left, characteristic flowers—both in the end of May 2022. Lower right, scan of a slide taken in the 1980s at the same site, when this species was much more common there. However, most of the population has been eliminated by uncontrolled bulldozing. Equipment operators rarely work with botanists, and rarely care. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1674613787813-RYBGYRNA097H30ZBC0B1/geysers+combo3R2.jpg Botany This view to the east from where the preceding milkweed and jewel flower were photographed, shows that we are right on the edge of The Geysers Geothermal Field. Left, 1986, right, 2022, after a fire. Mt. Cobb, over 4700’ high, rises in the background, its wonderful sugar pine forest devastated. The facility at left is a condenser array. Thermal water plus steam rise in production wells from the geothermal reservoir, which is situated above a cooling and probably largely solidified magma chamber. Steam is piped to turbines, which power generators. After that, the steam is piped to condensers such as this one to cool, inducing a phase change to liquid water. This water is then piped to injection wells to replenish the reservoir, the water of which is supplied by rain. In the 1990s this circulation was found to be insufficient to replenish the reservoir, and energy production declined. Stability was attained by pumping in large amounts of treated waste water from Santa Rosa and Lake County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1662015390044-7PKHZ1Z0R3FQXBV9SEWB/nervBestcomboR1.jpg Botany - Eriogonum nervulosum This very rare buckwheat lives on Snow Mountain in Mendocino National Forest, but it skips south to isolated serpentine scree sites in Lake and Napa Counties. This pair was on raw scree on forbidden ground north of Western Mines Road in southern Lake County, that I dared when I was young. Roger Raiche found them first, and told me of the existence of this wonderful site. It is farther south along the ridge upon which the preceding Asclepias and Streptanthus grow. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1716426989193-F1B521KUBFUG64OZ7CUG/E.+cedrormR.jpg Botany - Cedars Buckwheat Eriogonum cedrorum was discovered by Roger Raiche. Its habitat is giant ultramafic scree slides at The Cedars in Sonoma County. Roger at first compared it with E. ternatum, but ultimately concluded it was a new species. He published it with the late great Jim Reveal. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1682313459678-8KMIAW3W5I5A8EO4KX0I/Borax+combo.jpg Botany - SE of Borax Lake, Lake County There is a barren on siliceous tuff with obsidian blocks SE of Borax Lake. A site nearby is famous for the obsidiand fluted points it produced. This site on Acacia Road needs to be protected. It is small, but packed with botanical “items.” E.g., here are four annual monkeyflowers that were growing there: going clockwise from lower left, Mimulus layneae, M. bolanderi, M. kelloggii with its long throats, then M. androsaceous (which is tiny). I love annual monkeyflowers, and this site was notable for having four species, all pink to reddish. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1682313486177-UY9OCLVBREMKJPR2WUA0/Mlayneae+BoraxR.jpg Botany - Mimulus layneae Se of Borax Lake On the Acacia Road obsidian barren, which should be protected. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1742533936661-2WGAABQO4KE7P46V99R4/Eriatrum+brandegBlorax+L+copy+2R.jpg Botany - Brandegee's eriastrum Eriastrum brandegeeae, named by Herbert Mason, one of my botanical heroes, grows on the same obsidian barren as the monkeyflowers in the preceding photos. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1760405670556-R8QFMWGVQ9AABJS2YLF4/tricanthum.jpg Botany - Centaurium tricanthum Butts Canyon, Napa County. Twisted anthers; I don't know why! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1600410506662-68CQVTLNH0KZL2O8SZLE/WK3.jpg Botany - Walter Knight Walter was my botanical mentor. He loved to take photos of noted botanical colleagues, but he was very camera-shy himself, so there are few known pictures of him. Here he is studying a huge Arctostaphylos manzanita, while working on the Sonoma Flora. He did most of the work on that flora, and I was his field assistant. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653172974142-I7X45GI1AFSRPP2RO3NC/chinquapinR2.jpg Botany - giant chinquapins on Mt. Tamalpais They are stiil there , though very drought-stressed. The Marin Flora says the trees here reach 60’ high, but many are taller than that now. They have to fight for light with adjacent tanoaks. This grove is along the Benstein Trail high on the west side of Mt. Tam, and it is the southernmost grove of tree-form chinquapins in California. Farther south one only finds the shrubby form, var. minor. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1683162217539-7LQ3ZUFKPEH9L7INMT5X/shrevei%26bay%2C+Cone+Peak+RdR.jpg Botany - Laurel-leaf oak on Cone Peak Road, Santa Lucia Mts. Quercus parvula shrevei, left, compared to Umbellularia, right. As we drove up the road to Cone Peak with Wayne Roderick at the wheel, probably in the early 1980s, I was amazed that I was seeing live oaks that looked much like bay laurels. I was stunned to discover that the oaks had longer leaves than the laurels. At that time I don’t think shrevei had been named yet… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435698825078-5D083K18HQIBXESGGYGW/frit1interm.jpg Botany - Fritillaria liliacea near Mt. Diablo https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435698846861-SAR58DRVODPCD37RKZ29/frit2interm2.jpg Botany - Fritillaria liliacea near Mt. Diablo https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1551494431995-2KG7K66VC5BU8YIS74A6/olympia12+128ps4.jpg Botany - Checker Lily on Mt. Diablo In early spring 2012 I found this rare, nearly yellow form of Fritillaria affinis. The crinkled tepal margins do nothing to detract from the exquisite beauty. Elsewhere on the mountain I have only found boring greenish forms with smaller, less elegant flowers. The locality I will withhold, lest by giving it I inspire some moron to go out there with a shovel. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1680054028734-D2WHK8ML6SGN0ZSZOS42/BrionsResyellowFritRsharperR.jpg Botany - Fritillaria affinis yellow form Encountered near Briones Reservoir in a late March a few years ago…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1680054049612-FKDIQS6WSUMICM53LBTT/Briones+frit+3-13+002R.jpg Botany - Fritillaria affinis in Briones Regional Park A classic checkerspot form, and these flowers were also fairly large. Encountered in oak and bay laurel forest east of Maricich Lagoons. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1662410233836-2BDWFI4RE1X9TZVCZW64/tristulus2psR1A1cleaner.jpg Botany - Fritillaria "tristulus" This was the subject of Jim Roof’s “somber monks of Pt. Reyes,” by which term he meant these frits. They grow at the Lighthouse and on Chimney Rock, where this old slide was taken. These frits hardly ever produce seed, and the “taxon” is thought to be a largely sterile triploid. It is lumped with F. affinis in Jepson. Roof’s essay was perhaps the last piece he ever published, and certainly one of the most impressive things he ever wrote, in his long, eloquent, beautiful and productive writing career. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1662410254771-6SN74MSLR02WNF4KNWWU/spine2R1Aclean2.jpg Botany - Chimney Rock to the lighthouse Here is the habitat of Frtillaria “tristulus.” Tristulus means sad, and the somber moods of this place in fog and rain, combined with the subdued/dark coloration of the flowers, probably led Adele Grant to that name. But the place is glorious! Not sad! Abuses that have been committed there are sad, as Roof details in his essay. Anyway, this is the granodiorite spine of outer Point Reyes. There is more of it up at McClures, and of course Inverness Ridge constitutes inner Pt. Reyes, and it is held up by granodiorite too. Between the two spines is a broad lowland swale underlain by Miocene marine sedimentary formations: Laird, Monterey, and Purissima. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748734413057-W4MKTJ0CPQOD8MLXO04T/BEST+F.+atropurpureaPS-R2.jpg Botany - Fritillaria atropurpurea ….on the road to Haskell Peak one June…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653290109124-VMD2BL3YATH0E3KVD9EB/FritrecurvR1A.jpg Botany - Scarlet Fritillary Fritillaria recurva in the 2014 Butts Creek burn. These plants are extremely difficult to capture photographically. I took pictures of many, and many of this one, but only one photo was worth saving! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1662410204715-TYYC4IJMSG0CBLWNOZYZ/FpurdypsRi2.jpg Botany - Fritillaria purdyi A colony of especially tall, robust specimens grows (or grew; the site was for sale last time I saw it) on serpentinite west of Lakeport, Lake County. This is one of them. Note that it resembles F. falcata, but its corollas tend to be nodding rather than facing outward. It can also range to nearly white with purple pinstripes, which falcata never does. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1647987131228-E58DT6GC9TT4CB3D47GJ/Feastwoodiae2R3+copy.jpg Botany - Fritillaria eastwoodiae, Butte County I encountered this rare frit on serpentinite in the far northern Sierran piedmont east of Paradise, Butte County. The colors are extravagant in many individuals, and what you see is the real deal. The flowers are very small though, and you have to get down and get dirty to pay the plant the homage it deserves. A macro lens helps! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1663802903395-PXO7LXUCVHGY3GI5SKR1/Frenchmanpudica2.jpg Botany - Fritillaria pudica Shot by Bob Case one late March on an andesite flow at Frenchman Reservoir in far eastern Plumas County. That county has the southernmost populations of this species in California. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1727220563879-VN5LJ1R5T6HJBAKDXJ1F/F+glauca2A.jpg Botany - Fritillaria glauca in Humboldt County On serpentinite near Red Lassic. Beware—these plants never survive in a garden. Never try to dig them, as you are simply destroying them. Growing from seed will fail, too. Their survival essence does not accompany them to a garden setting. Here in this howling wilderness of parched and barren scree, where it looks as if nothing could survive, is the only kind of place they can grow. They need infertile rock and scree, though they are not found only on ultramafic substrates. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653461559224-47YZEUUPTFOLFMR1P04J/Frit.+falcataDPCbacklitR.jpg Botany - Fritillaria falcata, Del Puerto This species has a very limited range on bare ultramafic scree of the Coast Range Ophiolite in and near Del Puerto Canyon, and on comparable substrates above New Idria. This one I caught backlit. Scan of an old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653461609614-154BLWMLKZG33F1JC91G/ChamiltoniiRsharper4.jpg Botany - Coreopsis hamiltonii off Mines Road I found this endangered sunflower in this delicious ultramafic scree. It was above the Los Mochos boyscout camp along Mines Road in Alameda County, and that was the first time this entity had ever been found in Alameda County. I was allowed only the most fleeting acquaintance with this place—just enough time to take this photo. Interesting how the peduncles droop, as if they are determined to drop their seed down among the rocks so birds won’t get them. Scan of an old slide. There were too few plants for me to take a specimen for the herbarium, so let this picture serve as a record. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1675284344242-I85SHLVAEDG85VFBCJSC/hamiltonii+Arroy+Bayo+comboR2+copy.jpg Botany - Coreopsis hamiltonii in the Arroyo Bayo The largest colony of this endangered sunflower, The Mt. Hamilton Coreopsis, that I have seen is on a very sleep slope of splintery shale derived from disintegration of Franciscan turbidites up slope. The type locality is listed by Abrams as Mt. Hamilton, and this site is close enough to the mountain to qualify. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1675285073481-A54KXQD4YCXYC2LZD2JJ/C.+stillmaniiDPC2R2+copy.jpg Botany - Coreopsis stillmanii There is yet another diminutive Coreopsis in the Hamilton Range, C. stillmanii. Wayne Roderick pointed out this site to me probably near the end of the 1970s. There is a small population between the head of Del Puerto Canyon and San Antone Junction. This species seems to have only a tenuous foothold in the coast range, whereas it is very abudant on serpentinite in the foothills of the southern Sierra. Can you see the differences between this one and C. hamiltonii? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1717551440206-5ZCZH8ZKUKETZ46F6LVE/Clarkia+breweri.jpg Botany - Clarkia breweri One of most spectacular clarkias, can be found along Mines Road, in Del Puerto Canyon, and in the Arroyo Bayo--all easterly from Mt. Hamilton. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654463043209-E8L6A1BFUGYE2T5MW2EA/CTFrick3.jpg Botany - Frick Lake, Alameda County This is an alkali pan south of Brushy Peak. Here Chris Thayer is studying a very large specimen of the endangered Atriplex joaquiniana. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654463116438-3WFK1MR72GXFRV6T9ERY/palmatus1A.jpg Botany - Springtown Another famous endangered species at Springtown is this Palmate Salty Birdsbeak Chloropyron (aka Cordylanthus) palmatus. It deals with excess salt by excreting it onto the surfaces of its leaves, where it appears as conspicuous white crystalline dots. Note the tightly held white corollas. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654463158502-POVV59HYBKTV0R9XLLQL/linoides3R.jpg Botany - Springtown In June 2022, Leptosiphon liniflorus, the flax-flowered Linanthus, which so resembles Hesperolinon, was a thousand times more abundant than I have ever seen it there. We were frankly stunned. The worst drought in California’s recorded history still had some impressive displays of native annuals—while uor forests are dying. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654463202301-I2QVXGQAA8SB648XOPAD/DbachR.jpg Botany - Springtown, Bacigalupi's tarplant Deinandra bacigalupii is an endangered Livermore endemic. It is abundant in one area at Springtown, but its native range is miniscule and parts of that are being eliminated. The plant is recognizeable by its largish flowers, rays that tend to be separated like blades of a windmill, yellow anthers, and very harry disc corollas that consequently appear fuzzy (blurry through a camera lens!). Rimo Bacigalupi was director of the Jepson Herbarium, and a close friend of Jim Roof, with whom he had worked at the legendary gigantic US Forest Service native plant nurseries in Berkeley in the 1930s. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1739411856217-OL5NABOT6ZA6WCMAQUWU/covilleaanumR.jpg Botany - rare annual buckwheat on Mt. Diablo Eriogonum covilleanum occurs very sparingly on the upper parts of Mt. Diablo. David Gowen told me how to find a few plants on the Devil’s Pulpit Trail. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1532213591297-ALZPLLN0LKCU2QYU80IP/OpinorumFINAL.jpg Botany - Orobanche pinorum on Mt. Diablo Chris Thayer and I found this plant near the summit of Mt. Diablo in July 2011. It is parasitic on Holodiscus. It is now known from three occurrences on the mountain, but it is disjunct there all the way from the Snow Mountain region in Lake County west of Willows. There are a couple of old reports from Santa Cruz County, and one from 1923 near Lagunitas in Marin County. The taxon is rarely seen anywhere. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1561098493885-4J8TG3V8ZPN2XPIXWGHY/bulbosaMBTr.jpg Botany - Orobanche bulbosa on Mt. Diablo This exquisite parasite attaches exclusively to the roots of Chamise, and it may be encountered within pure dense stands of this shrub, where often little else grows except after fires. Mary Bowerman Trail, June 2019. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1561098669248-35W6TFRIXDZVR0ZJTZFP/OvallicX2.jpg Botany - Orobanche vallicola in Walnut Creek This beautiful parasite attaches exclusively to the roots of elderberries, and it was still abundant in June 2019 among old Sambucus mexicana in Civic Park, in Walnut Creek. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1755387183686-W66EOL1GF8O8YSNVQ5W4/O+grayana+SHARPER.jpg Botany - Orobanche grayana …on the Ten Mile Dunes north of Fort Bragg. Wherever I have seen this on the coast, it has always been on Grindelia. Scan of a slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435699543073-DAG63SWPM1LDLW6TJLUM/meconinterm.jpg Botany - Meconella oregana A very interesting distribution, disjunct between southern Oregon and the SF Bay Area https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435694431530-YG5PVO0ENJ2DVZO550GL/DSC_8097pinterms+copy.jpg Botany - Meconella oregana closer https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1710484750539-M2FH4QK8S3GZ3FIFI2XI/California+macrophyllaR.jpg Botany - California macrophylla …at Black Diamond, east of Sidney Flat. The picture of the flower was contributed by my colleague Kevin Dixon. I’ve been to this population many times, but always too late to see flowers. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1477442603197-2NTNUOSETRHCLWQUKX84/dodecs.png Botany - shooting stars compared Dodecatheon clevelandii patulum, left, Dodecatheon hendersonii, right, blooming near each other at Black Diamond Mines, March 2015. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1717292562245-LQTHA9XIDUQ0O3YE7T2W/S+peramoenus1A.jpg Botany - Streptanthus peramoenus on Mt. Diablo It was having a wonderful year, I forget the year, but it was early in the 21st century. On the serpentinite of Long Ridge. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1717292584171-9KYQZ8WEBHFQMGZ7F0O9/211.jpg Botany - Streptanthus peramoenus on Long Ridge ...a closer look. This entity has been IGNOMINIOUSLY lumped with S. glandulosus. But I can ignore that. It will always be peramoenus to me. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1477198441145-ID8QITRHUUT3KTLNNA2U/tarplants_edited-2+copy+3.jpg Botany - Briones tarplants Four tarplants in the Briones Hills 2016, displaying differences in glandulosity. L to R, Layia hieracioides, Madia elegans, Holocarpha heermanii, Hemizonia congesta. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1477198597825-19JI3NJGG9BA7TE62PTK/Lagophyllaram.jpg Botany - Lagophylla ramosissima in Briones Branched Hareleaf blooms last, after almost all the Holocarphas have withered, yet it is the least glandular of the Briones tarplants, so must protect itself from water loss other ways. The hairs on the leaves may collect dew or condensed fog. Compared to Holocarpha, the leaves are smaller and fewer, the stems thinner and very woody, and the plants much smaller overall--all likely advantages for surviving drought. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1477198933667-VTCEJ4GGH76EQ31G4Y6W/Lagoramo1interm+copy.jpg Botany - Lagophylla at Briones Lagophylla ramosissima bloomed sparingly in the Briones Hills in the drought year 2016. I saw a few open heads one morning in September, then nothing for weeks until the first October rain, which encouraged a few more morning blooms. Between bloomings, the plants looked dry and barely alive. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1477442202712-ZYY8TZZ3EBS8KVZWAZV4/bleph2.jpg Botany - Blepharizonia This Blepharizonia laxa head on a plant growing at Black Diamond Mines Regional Preserve is well defended by a profusion of tack-shaped resin glands. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1494307218933-FIQR6M4AMYIBNC2RXGPR/ODP2+interm-1.jpg Botany - The Oakley Dunes Primrose These gorgeous plants used to bloom abundantly all along what is now called Main Street in Oakley, a town that is underlain by sand and so very favorable for plants that like desert conditions. The unique and beautiful flora and very diverse endemic fauna of Contra Costa's original mini-desert has been almost completely wiped out by housing and vineyards. What a beautiful place Oakley still was in the 1970s! All gone now, except for two or three tiny spots like this one on Rose Avenue. Four years ago we saw three burrowing owls in this small patch. There are a few remaining bluehead gilias and suncups here, too, but the site has been repeatedly disced. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701029705505-AZ3AU4QLWDPCQAN3A00E/Oenothera+cognata+Rose+AveR.jpg Botany - Oakley Primrose Oenothera deltoides cognata in a disturbed sand patch surrounded by development in Oakley, Contra Costa County. This robust form of the subspecies deserves to be named the Oakley dunes primrose. It lives near its more famous cousin, the Antioch Dunes primrose and is an extra robust form of cognata. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1571551576801-Y5T2N3U1CN0L7ETXYI0W/MZScirpusinterm2.jpg Botany - Seacoast Bulrush at Martinez Waterfront Our brackish marshes have glorious fall color. Here Bolboschoenus robustus, formerly Scirpus robustus, foreground, has begun to light up the scene, October 19, 2019. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1571292059305-QH5I423EXAEKFI9CY2YM/Typha.jpg Botany - fall color of cattails Martinez waterfront, mid October 2019. Cattails have glorious fall color, but few notice it. I might never have noticed, had Bert Johnson not shown me. But the colors are ephemeral—fleeting. The orange is created by backlighting, the sun shining through leaves that have just turned light brown, not the dark brown or gray that are both coming. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435814885750-SFMLZARDK1UJH0A8CQQ7/biloba2.jpg Botany - Clarkia biloba This species is common in the Sierra foothills, but it jumps thence to Contra Costa County, where it is rare. Despite the severe drought, this species had a great year in 2015 on the Carquinez Strait and at Martinez Waterfront (above the RR switching yard). https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711846233701-OUFVD0R6PKJR0CC0W7ZH/Hamptonlunaris1+copysharperR.jpg Botany - Bent-flowered fiddleneck Amsinckia lunaris is rare, with a limited distribution. It is also heterostylus, with pin and thrum flowers, promoting outbreeding. There is, in good years, a great abundance of these beautiful annuals along the trail from the end of Hampton Road in Contra Costa County. The flowers are larger than those of other local Amsinckia species, so they make you stop in your tracks. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1746340298391-1WMU1OGY730VIIFSZQOQ/Cystopteris+fagilis+Briones+comboR.jpg Botany - Brittle Fern This dainty fern has disjunct and rare occurences in the Berkeley Hills and the east side of Briones RP, where I discovered in a deep-shaded canyon—and where I shot these photos. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748760831386-5E8F3GJPY3V0LGU8Q5RL/sharper3+copyR.jpg Botany - Eriogonum truncatum …was thought to be extinct until a UC Berkeley botanist discovered a small population on or near Mt. Diablo. Then Heath Bartosh and Kevin Dixon found two much larger colonies in Black Diamond Mines Regional Preserve, in places I’ll not specify…This was the find of the century for SF Bay Region botany. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1683144837847-P8YI8UG2SUY8J5LKAUHC/Tiburon+PaintbrushR.jpg Botany - Tiburon Paintbrush: rarest of the rare This entity has been most frequently reported near old St. Hilary’s church, on serpentinite; but even there it is exceedingly rare and akin to searching for a needle in a haystack. It has since been found a small number of other places, for example in American Canyon in southern Napa County, and on the amazing serpentine terrain above Nicasio Reservoir. The current fad assigns it to Castilleja affinis ssp. neglecta, but I think simple C. neglecta better reflects the reality of this entity. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1744933250963-BP72IUVCE1S09M46P3K6/Calochortus+umbellatus+sharperRing+Mtn2+copy+3.jpg Botany - Oakland Star Tulip …an especially lovely form of Calochortus umbellatus high on Ring Mtn. in Marin County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763187564675-TDTYLWKKGMY66N1ZXZ06/Calochortus+tiburonensis+5-10-14+.jpg Botany - Calochortus tiburonensis The BEST time to this is May. It is endemic to Ring Mtn., and was only discovered in the 1960s… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763253670103-YLM5DE1CS2MSBHHH4VDU/D+caespitosa+Ring+MtnR.jpg Botany - Deschampsia caespitosa on Ring Mtn This is the Sierra form of Mountain Hairgrass, which lives on serpentinite at lower elevations. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725480923259-MT2CCY7Q6H2CVLMB6BET/Cast+humbolt+Limantour.jpg Botany - Humboldt Bay Owl's Clover at Limantour Castilleja ambigua ssp. humboldtiensis is endangered. Here, it's in the salt Marsh at Limantour Beach, a hemiparasite apparently attached to pickleweed. The only other place I've seen this entity was in a very similar setting at the Elk River Dunes near Eureka in Humboldt County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653204174826-3UNHIB6MV3P1PHES6UMB/PtReyes+CamassharpR.jpg Botany - Camass I have to admit a partiality for blue. That’s why I think Camassia quamash linearis, shown here in a backdune wetland at Pt. Reyes, is one of the loveliest flowers in the park. This taxon reaches its southernmost limit in the coast ranges here in Marin County, though it grew in similar situations in the fabulously rich lost wetlands of San Francisco until they had a city planted on them. I’m addtionally attracted to the combination of blue petals with yellow anthers. I wonder why. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1656745545804-2HM4EEH44X9EP4LJ9PHZ/Monardella+undulata2.jpg Botany - Monardella undulata In dune sand at Abbott’s Lagoon, Pt. Reyes, with Poa douglasii. I love this uncommon plant, especially those big, wide, windowed bracts. How it gets sufficient nutrition to bloom like this in salt-sprayed dune sand, I do not know. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1714854760259-JUMBHLHI1V62ZSD0BCTG/Lathyrus+littoralisR.jpg Botany - Lathyrus littoralis at Abbott's Lagoon …3 May 2024. One of showiest coastal dune plants. Although it must have multiple adaptations to moving sand, salt, and drought in surficial layers of sand, I’ve seen two for this species. It’s roots go VERY deep, down to where the sand holds water. And its hairy vestiture no doubt helps with water loss. As Dan Axelrod pointed out many years ago though, dunes are actually mesic because surfical sands prevent efficient capillary action, thus water is retained at depth. That’s why many coastal dune plants have deep roots. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1714854782856-D052PLHM0AZXTMXX47II/Layia+carnosaR.jpg Botany - Beach Layia …on the dunes at Abbott’s Lagoon, 3 May 2024. Layia carnosa (carnosa means fleshy and refers to succulence) is more succulent than any other Layia. Note how it mimics more common inland tidy tips by having yellow disk flowers and white rays, whereas larger inland species, like platyglossa, have rays yellow at their bases and white at their tips. Curious! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1716517256402-ZNXYCE948E6NMVPNU3AP/L+tidestromii+Abbott%27sRsharper.jpg Botany - Lupinus tidestromii at Abbot's Lagoon ...in a May of long ago. Scanned from a slide. There are several herbarium collections from the same place, in the southern dunes near the south end of the brackish lake. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1712878536303-AG1VUMTAIDS22OHC164K/rubella+comb.jpg Botany Minuartia rubella only grows high in the Sierra and the Klamaths. But it’s disjunct to ONE place right on the coast-near the Pt. Reyes lighthouse. This is a cold-wind-blasted and frequently fog-drenched site. This extreme disjunction is still remarkable. Left, M. rubella ca. 9.000’ along Rock Creek, Inyo County, on the east side of the Sierra. Right, the same species near the lighthouse at Pt. Reyes. The latter probably has more succulent leaves. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1693089957538-UMENJDE8CFH44104ZDOQ/A+umbellata+breviflora+DrakesR.jpg Botany - pink sand verbena at Point Reyes Pink sand verbena in any form is very uncommon on the north coast of California. I found this one, Abronia umbellata var. breviflora, at Drakes Beach, which has long been considered its southernmost station. CNPS has classed it as list 1 rare and endangered. It occurs at but few localities between Drakes Beach and south coastal Oregon. I love sand verbenas, but I like the pink ones best! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1717551420418-G9TX5LJIG2FHWMSHKX10/Lupinus+grandiflorus.jpg Botany - Lupinus "grandiflorus" ...grows in freswhwater wetlands up from Abbott's Lagoon and Kehoe. It used to be called Lupinus grandiflorus, but got lumped with polyphyllus. In any case, it's the grandest of any polyphyllus. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1750744975282-RKZ4E5FEGZ522MOXWG91/soldanella+improved-cropped.jpg Botany - beach morning glory On the Ten Mile Dunes north of Fort Bragg. This is one of the best displays of Calystegia soldanella I’ve ever seen. Left, in glaring full sun; right, in fog. So beautiful. This is one of my top favorite dune plants. Scans from slides. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667874559686-6L6YNZZFYA6SDTPWARVS/E+supplexR2A+copy.jpg Botany - Supple Daisy Erigeron supplex is one of the rarest and most endangered plants on California’s north coast seabluffs. In my many years of botanizing the Fort Bragg area, I’ve seen only two plants (I think!)….Scanned from a slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719793976862-TPIIN6TAAF0DYR60ML4W/L.+macrantha+Abbott%27sRsharper2.jpg Botany - Lasthenia macrantha at Abbott's Lagoon ...last days of May, 2024... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1683145378704-EW99M8ZBVHJYHCLK1OHC/PuccicomboR2.jpg Botany - Puccinellia nuttalliana, Solano County Chris Thayer and I found this when he was working on the flora of Solano County. We were on Wilcox Ranch, part of the Solano Land Trust, in June 2010. Beecher Crampton had collected this species twice in the same area, decades before. Few people notice these grasses. They are medium-sized perennial bunchgrasses that tend to grow in or adjacent to alkali pans. I have seen the same species in Surprise Valley, Modoc County, also on an alkali pan. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1683145820043-PUHVA0UXNF9LH0Y1IBXC/NeostapfcomboR.jpg Botany - Neostapfia colusana in Olcott Pool Olcott Pool is in Solano County at Jepson Prairie. But to see this remarkable little endangered grass, discovered and named by Beecher Crampton, one must go after the flower fields have vanished, when the surface of this large pool is dried and cracking, It’s usually HOT, especially if you have to get down close to the ground to examine this plant closely. Scans of old slides. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1683145840987-KLMXB3JOWQ2GX7NZD70A/Neostapfia2R2B.jpg Botany - Neostapfia colusana inflorescence, magnified I shot this with a film camera attached to a bellows and enlarging lens—-a setup that duplicated Jimmy Vale’s setup. This small endangered annual grass of dried surfaces of vernal pools has extremely distinctive inflorescences. Glumes are lacking, and lemmas are expanded into fan-like structures bearing reddish teeth. A remarkable grass! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766354007840-MQBNN5EH5WIQXJZF73OS/E.+lobbii+landscape2R.jpg Botany - Escholschia lobbi ….in a front yard in the Red Hills of Tuolumne County…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766354071532-6EQMTW6W4GNHCGCS0YMP/Eschschozia+lobbiiR.jpg Botany - E. lobbii …in the same place… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766356285434-Z1ANVS992IXJ2O1NKL1E/Nemophila+maculataR.jpg Botany - Nemophila maculata …in a meadow in the Red Hills… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653290385328-WZ9U294LH7X9JVFIGAE2/calo%26Mim.jpg Botany - meadow east of Middletown Therer is a huge serpentine wet meadow east of Middletown in Lake County. It is crammed with all sorts of wonderful plants, and makes great displays in good years. Here we have Calochortus uniflorus and my favorite monkeyflower, Mimulus tricolor. I refuse to call them anything other than Mimulus. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748297484976-WLVME1SK39HP7YRPQLWY/Pogogyne+E+of+MiddletownR.jpg Botany - Pogogyne douglasii ….growing across HWY 29 from the previous scene… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1746166137443-9U5BNY6TNAODPEQK17PO/Pogogyne+doulasii+Lake+CoR3+copy.jpg Botany - Pogogyne douglasii …a closer view… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1629836496795-L34JL4MBY1O0M9USEGI9/Yolo1pS2+copy.jpg Botany - Water-hyssop I found this Bacopa eisenii in the Vick Fazio Yolo Bypass wildlife area a few years ago. This is one of its rare occurrences in the Sacramento Valley. It’s native to the San Joaquin as well as Owens Valley, and into Nevada, but it has been slowly spreading north in our Great Central Valley. It used to be a scroph, but it has been ignominiously thrown into Plantaginaceae, which I suspect will ultimately turn out to be a scrap-basket taxon that gathers distantly related taxa from hither and yon. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1714715312559-PE8ZNQPN20L85D3C92JR/Montara+Mtn+Anemone.jpg Botany - Anemone oregana on Montara Mtn., San Mateo County What a delight to find this right along a trail on Montara Mountain. This is a superlative blue form of what used to be called Anemone quinquifolia in California. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711936729574-XLKZHQ8I4O62Q9E2USPG/Clavatus+Tumey+Connolly+May+2010.jpg Botany - Calochortus clavatus in Corral Hollow I found the northernmost site for this species in May 2010, on the former Connolly Ranch near the mouth of Corral Hollow, in San Joaquin County. There were two previous records for clavatus in Stanislaus County, a little south of this location. I consider this one of the most beautiful mariposas, with its deep, chalice-like corolla, squared off at the base owing to protruding glandular eminences, and with red anthers. C. luteus, in contrast, has shallow more rounded bowls and yellow anthers. The plant in these photos was high in the Tumey Hills, a lone individual protected from large herds of sheep by this forbidding dead shrub. I published a picture of one I found in Corral Hollow (part of a group) in the December 2010 issue of The Four Seasons. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1710548192032-CADYI18HTAEQB3776HAD/C.+inflatur+triptychR2cleaner.jpg Botany - desert candle triptych …in the Tumey Hills of western Fresno County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1710740763008-B0J0LD4RAB17227YPEV1/Isomeris+at+PanocheResR2.jpg Botany - Bladderpod scrub at Panoche Reservoir This is the northermost I’ve seen this plant formation. All the shrubs in view are Isomeris arborea. I’ve also seen this plant formation west of Tehachapi Pass. I know it’s been put in a new genus, but one of the benefits of retirement is not keeping up. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1710740786604-L5J8AOCXJHJFHA7MKC82/Isomeris+bladders+at+Panoche+Res.jpg Botany - Isomeris arborea laden with bladders …again at Panoche Reservoir…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1710740811595-AKE7TNRU0UD0Z36JLSN0/Hollisteria3-14-15sharperR2.jpg Botany - Hollisteria lanata …in the north part of the Panoche Hills. I’ve also seen this rare species in the Ciervo Hills. The farthest north it ranges is Corral Hollow—where so many plants and vertebrates have their northernmost range limiits. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711521274430-HIBBPPFV8EXBQR43AWP4/Lembertia+CarrizoR.jpg Botany - Monolopia congdonii on the Carrizo Plain A very endangererd entity, formerly known as Lembertia congdonii. This inconspicuous composite is almost restricted to the southern part of the inner South Coast Ranges, though it also ranges into the far southern San Joaquin Valley and even east of Bakersfield around Caliente. It’s hard to find, so there may be much more of it out there than hitherto suspected. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711522267058-30G6A44B6UQSCUK8OD4Z/Amsinckia+vernicosa+TumeyR.jpg Botany - the most beautiful Amsinckia Here Amsinckia vernicosa grows on gypsiferous shale barrens in the Tumey Hills. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711521839167-85PLTDKQXB5TGOV2WH4C/Eriog+indictum+comboR.jpg Botany - Eriogonum indictum in the Tumey Hills I think this is one of our handsomest buckwheats. And it’s tough. Here in the Tumey Hills it’s growing on barrens of gypsiferous shale. At McKittrick it grows on asphaltum. In the Big Blue Hills it grows on serpentinite. Its tolerance of extreme soils has always impressed me. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711522727789-5GYEV3LIXBTUU375QWGM/Salvia+carduacea+E+of+McKittrickR2.jpg Botany - Thistle Sage east of McKittrick Salvia carduacea is an annual. But it has some of the most beautiful flowers in the genus. See next photo for a closer view. It once ranged as far north as the Antioch Dunes. It has been deleted there as well as in much of its range. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711522749732-IISALBPJ1SEGRI94GFUA/S+carduacea+closer.jpg Botany - Thistle Sage east of McKittrick …a closer view of the spectacular flowers…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735713196061-6XYRO1QG5LSXY95H8JZU/Coreopsis+giganteaIMPR-Rsharper-cleaner.jpg Botany - strange landscape at Pt. Sal, N. Santa Barbara County Doctor Seuss plants, i.e. Coreopsis gigantea, in extreme NW Santa Barbara County at Pt. Sal. I adore this landscape. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1614584889212-SI43URGA7Y86D4PSRXUB/combo4.jpg Botany - Hermidium in Owens Valley Hermidium (=Mirabilis) alipes grows on the dessicated floor of Owens Valley. Like Asclepias cryptoceras, it inhabits extremely arid settings in the rain shadow east of the Sierra. Both have large, leathery, blue-glaucous leaves. To maintain such large leaves close to the ground where temperatures are highest, requires the plants to hold them vertically so that they present their edges to the scorching mid-day sun. Something akin to this happened when hominids became bipedal in Africa. Unfortunately hominids are not blue, but you can’t have everything. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1614152245492-M68OUQJCFJPQ4E9FDAOL/Aroth3.jpg Botany - Nama rothrockii This lord of all Namas, and perhaps of all borages, forms large colonies of rhizomatous perennials high in the Sierra, in well-drained dry places. This colony was photographed above Ravona in Pine Creek Canyon, Inyo County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737758744523-2VSLBFEVJRAQN517D7SZ/inyos2%2Bravona+003+copy+2.jpg Botany - Pine Creek Canyon Shows the almost vertical escarpment of the eastern front of the Sierra, which forms the west wall of the Basin and Range. The Pine Creek Tungsten Mine was up this canyon. They mined scheelite from a complexity of skarns. Here’s a link: https://pubs.geoscienceworld.org/segweb/economicgeology/article-abstract/77/4/823/19608/Tungsten-bearing-skarns-of-the-Sierra-Nevada-I-The?redirectedFrom=PDF#:~:text=The%20Pine%20Creek%20mine%2C%20located%2027%20km,core%20logging%20have%20suggested%20that%20skarn%20formation. The summit of Mt. Tom is to the left, but out of view…. at over 13,600’ , while Owens valley is at ca. 4,000’….That makes the relief here nearly 10,000’. This is where we found Nama rothrockii—where I stood to take this photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1741586446468-PX1FXUUHGL94M9EVKRIW/best+tungsten+Hills1R.jpg Botany - Tungsten Hill skarn This is a view of a thin section loaned me by my colleage Ryan Fay, in XPL with the 4X objective. The dark concentrically zoned xtals are barite. These are imbedded in calcite. Many of the small colorful xtals are probably diopside, a calc-silicate pyroxene. (I know I see a pyroxene, probably mixed with epidote.) The Tungsten Hills are west of Bishop, not far south of Ravona and Pine Creek Canyon. Definitely a calc-silicate skarn. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1464633905277-Z78J9NKAHV3V62YPVK5H/MatherCalos.png Botany - Mariposas near Mather Variants of Calochortus venustus in the Rim Fire burn area, May 2016 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1618553441934-SGOWTGBIV5XOB1CLOGB4/W.bolanderi+BlacksCKRdRed.jpg Botany - Wyethia bolanderi This very rare plant was in early bloom and early leaf in buckbrush chaparral on serpentinite between Moccasin and Coulterville in early April in a year of extreme drought. It is such a lovely plant, but very hard to find. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1619398994414-TWT2YB8PV2FA06X2MXN1/pallidaR+PM.jpg Botany - Grayback Fern Few people have seen this fern, and thus few know how lovely it can be in spring. Pentagramma pallida is sparingly distributed in the Sierra foothills and inner south coast ranges. The only place I’ve seen it is near Knights Ferry in the former. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1746497492715-3W9ONTKFPTUWXPJRVMDY/Junip+occidentalis+almost+the+diam.+of+the+Bennet.jpg Botany - Sierra Juniper Some people are calling this Juniperus grandis rather J. occidentalis now…The name is no consequence…This juniper at Carson Pass has nearly the girth of the famous Bennet Juniper, near Kennedy Meadows and Pinecrest in Stanislaus NF, Tuolumne Co…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1684910185448-7U6MOD95K28FHTO7OWLR/Idahoa+HWY+108.jpg Botany - Idahoa on andesitic debris-flow barrens You must go to the mountains in early spring to catch the fruits still fleshy and mottled green and brown on Idahoa scapigera. But it’s really the see-through silicles, each with usually three seeds, that are the most charming parts of these tiny plants in the Brassicaceae. Few people notice them, as you have to be right down on the ground to get a good view. On an andesitic debris-flow barren along HWY 108, May 2023. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1762878285196-XCLBS3OIB8511RK2125K/Allium+tribracteatumSHARPER.jpg Botany - Allium tribracteatum …along HWY 108 in Tuolumne County where the Idahoa was… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1714373172880-OLNZZKY4CFVXHQVLOWAQ/Claytonia+cfR.jpg Botany - Claytonia crawfordii …on. andesitic debris-flow barrens along HWY 108. Left, too early, right, too late. Imagine if all the buds on the left were open. They do, just not when I’m there. This rare and endangered species is very hard to find. I believe it’s endemic to a limted part of Tuolumne County. I love the “twayblade” effect. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1734934526014-ANI73V3YFEFKBC1T5Y30/C+crawfordiiR.jpg Botany - Claytonia crawfordii along HWY 108 ….still too early! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735194053864-Y571KB8F36JIT2G1H3WQ/Claytonias.jpg Botany - Claytonia rubra ssp. depressa I like these charming rosettes. Left from NE Plumas County; right from west of Sonora Pass… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1573454871900-T0FC6BX3REG0QYV1280U/sonorapass.jpg Botany - Anemone drummondii For proof that angels in choir may be heard in our mountain passes, get on the ground and receive the benediction of these beauties. Near the summit of Sonora Pass, a June long ago. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1720055816131-M8JJ01T27AEXOIF2PB1U/Pheonicaulis+Sonora+Pass2.jpg Botany - a wonderful sight in early June at Sonora Pass The place-the summit of Sonora Pass-- is sparsely visited when there are still patches of snow. So, few notice Pheonicaulis cheiranthoides in bloom. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1720221297943-J5M9XY88XPFAN8LSDP1M/L+humboldtii+at+Gring+Rock.jpg Botany - Lilium humboldtii humboldtii ...growing among bone-dry Arctostaphylos viscida chaparral at Indian Grinding Rock State Park off HWY 88, I think some time in the 1990s... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1720055689183-ERXWBNQ3UOPUHSNSP09U/Elepant+back+showSharper%3F.jpg Botany - Elephant's Back at Carson Pass ...once in July.... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1720055718259-PVWGLSX5NKU10VDPVNCR/MertensiaCarson.jpg Botany - Mertensia ciliata ...part of the mix..... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1720055750775-S881MSLR4COPUQ6AXZAO/F+speciosa++Carson.jpg Botany - Frasera speciosa ...called Tower plant....another part of that mix... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1720055787478-7HSDTDO123MNYVEW86FO/Ranunc+escholzii.jpg Botany - one my most favorite buttercups Ranunculus eschscholtzii was growing on a ledge of the north face of Round Top at Carson Pass. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1720136811106-8L8GUSNY69DCJEEG6WUM/Cerast+beer+Roundtop.jpg Botany - Cerastium beeringianum ...is a circumboreal species. I've only seen this on a north-facing ledge on Round Top at Carson Pass. Jimmy Vale had tipped me off that it was on Round Top. I found only one plant--truly a needle in a haystack. This species is very rare and seldom seen in California. Global warming will eliminate it. Carl Sharsmith reported it from the Dana Plateau, but Roger Raiche and I searched all over up there and could not find it. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1655314098962-X9FA6QPVSI481J4JDZDC/Peavine+Mimuli2.jpg Botany - annual monkeyflowers on Peavine Ridge left, Mimulus bicolor, right, M. torreyi, on the sharply drained andesitic mudflows atop Peavine Ridge in Eldorado County, approx. 5200’ elevation, early June 2022. I love annual monkeyflowers. In this case, as in many places in northern California, drought-tolerant annuals of open places did well in the severe drought, while nearby forests struggled for survival, with their very existence threatened. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1700181111348-IAJXT3C6JX3SUZOFKS2H/D.+asterophera.jpg Botany - Tahoe Draba Draba asterophora is a abundant on Freel Peak SW of Lake Tahoe, but otherwise of limited distribution and considered endangered. Look at the lovely coarse grus this plant is growing in high up on Freel. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1700181160701-QGMY2SVKVGF30YWDCAG4/Freel+habitat.jpg Botany - Tahoe Draba habitat on Freel Peak Freel Peak has the most extensive whitebark pine krummholz I’ve ever seen. And these mini “trees” are still healthy, while in all the western states, taken collectively, upwards of 50% of standing whitebark pines are dead. Draba asterophera grows on open barrens up there. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701113613478-TBS2DY7YJKQO90R9TGIZ/albicaulis+groundcoverR+copy.jpg Botany - whitebark pine groundcover In some places on the north flank of Freel Peak, the Pinus albicaulis krummholz assumes the habit of a groundcover only a few inches tall on its fringes. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1716490446278-0OLVPA2JKZIPOM8KK6P2/freel+pkRcleaner.jpg Botany - Freel Peak Freel has the most enormous extent of granitic scree I've ever seen---habitat for many wonderful cushioned alpines, plus Tahoe Draba. Scanned from a slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1696313440683-LBNQNXCXY74EGVU275PS/Audrian+1R.jpg Botany - Lake Audrain near Echo Summit This was in September 2023 after the ravages of the immense Caldor Fire. Much of the lake was still covered by Brasenia. On some maps the spelling is “Audrian,” but I’m going with Gladys Smith, who uses the name Audrain. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1696313462143-0C4JRXU18Z83W641RCWE/Audrian2R.jpg Botany - Lake Audrain The leaves of Brasenia turn red late in the season. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1661123543823-FI5B1M0XXS0M6P7W0UFD/Audrain4R2.jpg Botany - Brasenia Brasenia shreberi, here at Lake Audrain near Echo Summit, is in the Cabombaceae, a family closely allied to the water lilies (Nymphaeaceae). Together these two familes, based on DNA, are a sister group to all other flowering plants, which means they branched off as early as or earlier than all other angiosperms, Of course, they have had a lot of time to evolve in their own rights since then. I think this is the greatest of all our aquatic plants, though it is endangered in California. Gladys Smith was, I believe, the first to record this occurrence. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1628470529144-BIMSACGTE2UIQTMDS7GR/alnifoliaR2.jpg Botany - Rhamnus alnifolia This very rare California shrub is restricted in the Sierra to Placer to Plumas counties, in all of which it occurs very sparingly, though it also grows in the Rockies. It should never be confused with Frangula purshiana, which is a tall shrub with large leaves that are less alder-like. Frangula lacks winter bud scales and has sepals that are fleshy, erect, and keeled adaxially. Rhamnus (which includes the ilicifolia alliance) differs in all of these. Left, Jim Roof’s old 1941 locality along Silver Creek, a small tributary of the Truckee River south of Truckee. Here it is in too much sun in a dryish soil and very stressed. Right, just below Donner Lake, an even older locality going back to Sonne in the 1880s, in part shade and moister ground, therefore pretty lush. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1727245374216-SDJ8F74W3DMURG7WCCN3/Eroig+at+CiscoLessPinkR.jpg Botany - pink Eriogonum ursinum at Cisco In 2015 we discovered that Eriogonum ursinum populations on ultramafic rocks at Cisco Butte and on nearby Monumental Ridge have deep-pink inflorescences, both at anthesis and in seed. This character is supposed to be restricted to two populations in the Klamath Mts., named E. ursinum erubescens. The Placer County entity is either disjunct erubescens or a new subspecies. I'll be working on this problem. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601707140133-ZMR0U6AFS9BCO4WZXJ8Q/peridoRED.jpg Botany - Monumental Ridge peridotite We hoped to find Polystichum scopulinum on north-facing peridotite outcrops here. It is a fern that prefers ultramafic substrates. It is a diminutive sword fern that prefers diminished competition. Note the characteristic blocky jointing of this rock type. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601707171587-BFK68NDHUDC95DYNGDC0/scopulinumRED.jpg Botany - Monumental Ridge dwarf sword fern And there it was. What a thrill. These dwarf sword ferns are uncommonly lovely. They are also impossible to keep alive in a garden, so don’t bother collecting them. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601707195546-V4GX0RROKGBOXHO2UHQ8/scopcloseRED.jpg Botany - Polystichum scopulinum frond Note the basal lobe of the pinna is separate, as in its much larger cousins, P. californium and P. dudleyi. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708634848614-ZRYZ5DPNMEFC3H6GEVHL/14+copyPS.jpg Botany - Mimulus lewisii This large, wet-growing pink monkeyflower was along Castle Creek in Nevada County. All of this species I have seen in the Sierra is pink like this. In dramatic contrast, all I have seen in the Warner Mts of Modoc County are much darker-one could almost call them red. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763854169084-87O5YJBN8LD5P73P3ZMW/G+ovatifolia+L%2C+G+humifusa%2C+R-.R2jpg.jpg Botany - Gaultheria ovatifolia & Gaultheria humifusa G. ovatiflolia left, in the Placer Grove of giant sequoias…..G. humifusa left, just outside the south entrance to Lassen NP. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708634871625-8DQ57JYDGANWZNDEJZKX/e+torreyanumR.jpg Botany - Eriogonum torreyanum in Placer County Chris Thayer and I discovered this population of this endangered entity on Foresthill Divide in Placer County. At that time, it was known from only two or three tiny populations in Nevada County. The Foresthill Divide population was growing among a run-of-the -mill form of Eriogonum umbellatum, WITH NO INTERGRADATION. I think allocating torreyanum to subspecific status under umbellatum is ludicrous. Perhaps this lumping was to denigrate Gordon True, who originally discovered this good species on Castle Peak, because he was not an academic botanist, and he was associated with Cal Academy, which Berkeley Herbarium botanists long looked down upon. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708654503747-0APMBUC8OA29D2DQM6HN/monkeyflowertrailtoCastlePkR2.jpg Botany - Mimulus jepsonii near Castle Peak Steve Schoenig is my go-to-guy for Mimulus. I keyed this out improperly, but Steve bailed me out. This little massed beauty is M. jepsonii, which has its southern terminus at HWY 80—which less than a mile south of where I took this picture. From there it reaches into Oregon. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708654530862-EZU4G0Z3M57REB4ZQWA6/Agoseris+glauca+below+CastlePk.jpg Botany - Agoseris glauca near Castle Peak I love this plant. It’s unusual for the genus with its glaucous and entire-margined leaves….South slope of Castle Peak, ca. 2012. It grows in the northern Sierra, thence far to the north and the east, but is rare in the central and southern Sierra https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1663568217344-2VUWZ0PHI3W62KLJET39/crysolepis+WA.jpg Botany - laurel-leaf form of canyon live oak Quercus chrysolepis at middle elevations in the Sierra has a strong tendency to be a laurel-leaf form with large long leaves, all with entire margins—in great contrast to almost all occurrences in the coast ranges, which typically have smaller, shorter leaves often of two types on the same tree: entire vs. spiny-margined. I really like the Sierran forms. At higher elevations in the Sierra, in montane chaparral, one gets a shrub form called var. nana, which resembles Q. vaccinifolia. Canyon Live oak actually includes some of California’s largest individual oak trees. I’ve seen huge ones along the flume trail above the Yuba River north of Nevada City, and truly gigantic ones in the notch at the top of Mt. Konocti in Lake County. This photo was taken between Washington and HWY 20 in Nevada County. Scan of an old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1718923598346-9I6T2X0259X9KQHT33NX/Keystone+landscape.jpg Botany - Keystone Gap ...looking at the south face of Sierra Buttes, over the scree on which I found the first isolated plant of Tauschia howellii, the first time Chris and I went there. So many other nice plants there, too--including the largest and densest colony of Lewisia kelloggii--by a long chalk--I've ever seen. The rocks here are thinly divided slate or phyllite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1602363756876-YNZQ1JZ9PP9BGHVNWBB5/AA+Tauschia2ARED.jpg Botany - Tauschia howellii in the northern Sierra I found this with Chris Thayer in July 2004 at Keystone Gap on the Henness Pass Road in Tahoe National Forest. That was the first time this plant was ever found other than in the Salmon Mountains in the Klamath Mountains province far to the NW. Later that month Kathy Van Zuuk of the USFS found about 100 more plants close nearby. Chris and I then found many hundreds more at a separate site at the head of Big Avalanche Ravine, about a half mile east as the crow flies, in 2005. Scan of a slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1718923572825-01BJYH9YIR81R6X1Y50S/Thartweggii+brighter.jpg Botany - Taushia howellii is still there ...in June 2024. This time we caught it in bloom. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1691448820436-M6HTWTOIIZRW7F4AL5RH/Shasta+Lily+along+Round+Lake+TrailR.jpg Botany - Lilium pardalinum shastense along the Round Lake Trail, south edge of Lakes Basin, first week of August 2023…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601706319742-E403LTZ4XELC4HTHSB12/kelloggiiRED.jpg Botany - Lewisia kelloggii near the PCT above Lakes Basin. In this country of metamorphic rocks, where the foothills metamorphic belt climbs to the very crest of the Sierra, every pebble or rock fragment is interesting, as the rocks are so varied. Scan of an olde slide, ca. 1980. I was led to this site by Toni Fauver. A wonderful field trip. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1539502393388-JH279M5KG3BSAXIL50OT/SilverLVAcciniumInterm.jpg Botany - Dwarf Bilberry Vaccinium caespitosum between Silver Lake and Round Lake, Lakes Basin, Plumas County, first week of October 2018. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1660002946595-5ZULIXFRCV3WNY8348UL/start+of+RLTR.jpg Botany - paintbrush and yampah, Round Lake Trail Castilleja miniata making an outrageous show near the start of the trail, in the very southern edge of Plumas County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748734632620-QSLX1N6WZL1KV8ONTQ5D/Ribes+hallii.jpg Botany - Ribes viscossimum hallii This is the most fragrant of currants, shot on the road to Haskell Peak one June. Jim Roof called it “that sweet-smelling sister of its perfumed tribe” or something like that! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1660002920799-SIUBJ1CK9MIHJ3ALEMKK/natheciumPS2R.jpg Botany - Bog Asphodel on Graeagle Creek Narthecium californicum is profusely abundant at one place on Graeagle Creek, at the edge of Lakes Basin, Plumas County. This is something I’m used to seeing in fens in the Klamath Mountains. Formerly in the Liliaceae, it has more recently been placed in its own family, Nartheciaceae. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735603108694-EDP6RKBQNZUH014HG5GH/Plum-Eureka+fen+comboRsharper.jpg Botany - fen along Jamison Creek above Plumas-Eureka SP I have always loved this fen. Displayed here are Platanthera orchids, Tofieldia, Helenium bigelovii,Allium validum, corn lilies, Castilleja miniata, Senecio triangularis, Ranger’s Buttons, and much more… Parnassias in September… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1603605912731-BA5CM4VL3DANAEOHZ6VJ/ParnassiaCF.jpg Botany - Parnassias in Plumas County These beauties grow about a mile apart in one canyon, P fimbriata (on the left) on a moist north-facing cliff, P. palustris (on the right) in a sunny wet meadow. The funny things between their stamens can be called staminodes or false nectaries. The real nectar sources are out of view deeper in the flowers. But the staminodes appear brightly colored to bees and thus help direct them to the real nectaries. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737266290624-P4RP4EGIMSTBD06MARHE/Viola+sheltoniiR+copy.jpg Botany - Viola sheltonii This especially nice form of this species, with petals red on their backs, has to be sought in early June in the northern Sierra. By July there is no trace left. This was in the first few days of the second week of June in a very heavy snow year. In fact, there was snow blocking the road ca. 20’ away. In Jamison Canyon above Plumas-Eureka SP in 2011. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653172947488-WEHEKYMF74W3MI6X4ZHU/AllotropComboR.jpg Botany - Sugar Sticks Allotropa virgata is a non-green ericad that I assume connects to roots of green plants via mycorhizae. I have only seen it three times, in each case in red fir forest with few other understory plants. So I’m guessing it’s often parastic on red fir. These were on Haskell Peak east of Sierra Buttes, the non-flowering candy sticks in June on the west side, the flowering plants, left, in July on the east side of that peak. Note how the anthers (ten per flower) open by slits. They appear to have scattered pollen onto their own flowers. It’s impossible not to admire these plants! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1661151038564-ZLJNTGPCAOIH0I4Y9J9P/Utricmacro2R.jpg Botany - Bladderwort in Carman Valley Carman Valley is north of Calpine and west of Sierra Valley. We came upon two ponds there in July 2022 that were covered with Utricularia macrorhiza in bloom. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1661151061334-Q8XCD27MB5JGFJRRR01G/bladdersR.jpg Botany - bladders The bladders are legion, and borne on much-branched stolons. They are able to evacuate water, thereby generating a negative pressure relative to the outside. They have sensitive hairs that tiny invertebrates like mosquito larvae or rotifers can trigger, in which case the bladder opens instantly and sucks the unfortunate creature into the bladder, in a flash. There digestive enzymes and commensal organisms break down the prey. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719694981281-2K1XCC74Q5OF1HU682WL/Beckmania+combo.jpg Botany - American Slough Grass in Sierra Valley ...near the headwaters of the Feather River in a small richly vegetated canal...The squat florets of Beckmannia syzigachne look like stacked purses or castanets. I don't know any other grass that resembles this one, but perhaps, in some ways, Paspalum. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1627414311567-3E06CEXTHNOXWHDO8PKU/NamaDone2.jpg Botany - Nama aretioides forms The white one is from sand dunes along the road from Chilcoot to Frenchman Reservoir NE of Sierra Valley. This site is threatened by encroaching development and swamping brush. The purplish-pink form is at Aldrich Station at the south end of Coal Valley in west-central Nevada. This site is sufficiently remote to be relatively safe for a while. The white one is Nama aretioides var. californica. The pink one is the nominate subspecies. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719639454281-C47LGGPDHX4Y7AD6JZNZ/frenchman1+062+copy+2.JPG Botany - granitic sand dunes north of Chilcoot This is the same place we found the white Nama in the previous photo. The ridges both east and west are crumbling granitic rocks, and this area tends to get very windy. ...a scene straight out of the Mohave with Oenothera deltoides, but in Plumas County! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719639476172-V69WFVT4SBCU1C45T4PU/frenchman1+060+copy+2.JPG Botany - Desert primrose Oenother deltoides at that same site. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719639505812-I1N5AWPMZ9RGSQ1PLP9F/I+baileyi+baileyi+sharper%2BimprovedMORE.jpg Botany - Ivesia baileyi baileyi ...on an andesitic cliff face in the narrows on the way from Chilcoot to Frenchman Reservoir. This is a very rare plant. The only other place I've seen it is on the summit of Dixie Peak. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719639530859-RMXBAC63VEMAGLNCYOGK/Polemonium+pulcherrinum+Frenchman.jpg Botany - Polemonium pulcherrimum This was on an east-facing shaded cliff face two feet above the water flowing fast out of Frenchman Reservoir, hence refrigerated. It was growing about 2,000' lower than the minimum elevation given in The Jepson Manual. I have to wonder how it got here.... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1627414429518-5PPGBNW5F9WAQ1VQAD2M/RanuncCombo.jpg Botany - Sagebrush Buttercups left, Ranunculus glaberrimus; right, R. andersonii. Photos by Bob Case, on volcanic outcrops at Frenchman Reservoir. You have to go in late March or early April to see these most spectacular of buttercups—while there’s still a lot of snow on the ground in the passes and sometimes even here. I’ve not been able to get there that early in the year, but it’s on my list! These plants are ephemeral. Get there in June or July and all you find are dry skeletons. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1663802869129-2V8IRIX0QWWPOEPGLBQA/Frenchmanbecwithii2.jpg Botany - Viola beckwithii Shot one late March by Bob Case near the preceding ranunculi, on an andesite flow at Frenchman Reservoir in far eastern Plumas County. Note this is not named for the famous mountain man Jim Beckwourth, even though the trading post he settled down to in late age is along the Feather River very close to this site, and the pass he discovered is even closer. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763697055822-0940892SPZN64L4SN3T1/Horse+Mtn.+Viola+beckwithii.jpg Botany - Viola beckwithii from Horse Mtn, Humboldt County …this version has more glabrous leaves—and MAYBE less divided—than plants from the E side of the northern Sierra…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737006641891-QMPV0EUMV97UTE4C6XKG/frenchman1+260+copy.jpg Botany - Allium platycaule ….at Frenchman Reservoir north of Chilcoot in Plumas County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1656534651379-4CP1MW4NNFAW3DD81D29/RedHillpano3+copyR.jpg Botany - Red Hill, Plumas County This view, looking NNW, shows peridotite and serpentinite of Red Hill plummeting into the canyon of the North Fork of the Feather River along Caribou Road. Much of the scene here was scorched by the western part of the 2021 Dixie Fire, but the “forest” of Jeffrey pines on the ultramafics was apparently protected by the wide spacing of the trees. This nutritionally severe and dry rocky landscape is habitat for Frangula purshiana ssp. ultramafica—so different from the requirements of typical purshiana, which is mostly a tall, thirsty riparian shrub. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738281486284-0MNH1M62SGOBK7OBAE96/F.+ultramaficSawyer.jpg Botany - Frangula purshiana ssp. ultramafica John Sawyer, God rest his soul, sent me this photo of this Frangula with leaves nearly white. He photographed it a locality in Plumas County I’ve never been to—alas! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1663222655625-3J2TKG8TE7LXQBHAQVK8/pachystigmacomboR1.jpg Botany - Dentaria pachystigma, Red Hill I encountered this beauty near the summit of Red Hill in late April 2005. There was stil snow on the summit. The plants bloom early, and are already finished. How glorious it would be to see them in full bloom! But the superb gray, very leathery leaves befit its sunny habitat on raw peridotite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1662332150913-IY3L9WQL78LX51GKRGFD/polyst1.jpg Botany - Polystichum scopulinum, Red Hill I have always found This dwarf sword fern only on ultramafic rocks. Here it is between boulders in a megatalus of peridotite on the NE flank of Red Hill, Plumas County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1662332169106-1O5Z9RFRD9FQ0FEX6SG6/red+hill+trees1.jpg Botany - the Polystichum scopulinum site Here is a view just across the road from the P. scopulinum. You can see some of the megatalus on that slope. I was interested in the fact that the forest is much richer than what would usually be expected on serpentinite or harzburgite peridotite. The two trees at left, including the big one, are doug firs. Next to the right is a Jeffrey pine, than a white fir, then an incense cedar, then another doug fir. Doug firs and true firs are generally intolerant of ultramafics owing to their dearth of calcium. So I predicted it must be a lherzolite, a type of peridotite that contains calcium-bearing clinopyroxenes. A thin section (next two slides) supports that. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1662332200089-ORORMGNF4TK382ZO2U1L/lherzoRed+Hill2.jpg Botany - Red Hill wehrlite This is a view of a thin sectiuon in PPL with the 4X objective, from the Poiystichum scopulinum site on Red Hill, Plumas County. The light-gray streaky crystal occupying most of the view is a clinopyroxene, which by definition contains calcium. Weathering will make this available to tree roots. Jason Mayfield and Howard Day mapped this substrate as wehrlite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1662332218315-C46ATNVI1IA7L6QNY3OR/lherzolite+Red+Hill1R.jpg Botany - Red Hill wehrlite Here is another view of that same thin section, this time in XPL, showing that olivine, criss-crossed by serpentine veinlets, dominates parts of the rock. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1689581815444-H6PJXM3IPYLLXGQS7H6Z/23N18+.jpg Botany - serpentine site SW of Bucks Lake This is part of the site where Frangula purshiana ultramafica grows SW of Bucks Lake, Plumas County. The understory of this open woodland is dry montane chaparral, of which the Frangula is a component. VERY different from the moist/riparian habitats where the nominate species grows…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1665431270242-5BWPE3WSJKZ7D6PYSDKA/Fultramafica+Bucks1+sharper2R.jpg Botany - Frangula purshiana ultramafica again This is in a second region, namely SW of Bucks Lake (west of Quincy), where the small population of these shrubs grows on both serpentinite and serpentinte metasomatically transformed to carbonate. Scan of a slide taken in September 2005. Thayer and I were exploring the area. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1698025758803-20QY22IUSQTNK9LSJM6R/ultramafica+color+blazingR.jpg Botany - Frangula purshiana ultramafica in brilliant fall color, on same site as the prior photo. The leaves of these shrubs, growing in full scorching sun mostly on serpentinite, seem to start out bright yellow, then turn salmon pink to red as they age. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1663380567611-VPI3J1F7NFJII6OSKUCK/FRgrandiflorus3R.jpg Botany - azalea-flowered monkeyflower, Feather River canyon This is the largest-flowered of all the azalea-flowered monkeyflowers, growing in the Feather River canyon, where the most impressive plants can be encountered. This is from a scan of a slide taken in June 1985. These plants were once called Diplacus grandiflorus, but have been ignominiously thrown into Mimulus bifidus. I can’t criticise the specific epithet taxonomically, I just find it distasteful. However, getting rid of the genus Diplacus, which is a very good genus, was simply stupid. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740274667310-Q3PMHW2YROS44U5IOH9B/Diplacus+grandiflorus+Feather+Riv..jpg Botany - DIPLACUS grandiflorus …growing on the Feather River, but not on serpentinite. This the GRANDEST of all diplaci. Diplacus is a very good genus, and should never had been sunk in Mimulus. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735601563164-T7M536QO8DRIDRZTQ0LJ/Sedumalbomarginatum1+copyR.jpg Botany - Sedum albomarginatum I have only seen this endangered species growing on peridotite or serpentinite at localities I won’t specify in Plumas County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667166280609-NAMSVC3LOUO1ITK2RFFJ/crystalL1.jpg Botany - Polystichum kruckebergii, Crystal Lake, Plumas County The cliffs at right drop almost vertically from the summit of Mt. Hough. This is where Tom Howell found Polystichum kruckebergii long ago, and where I found it in September 1987. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1698015959720-O4VNVIM57DXLRE6QSTPP/Pkruck1R.jpg Botany - Polystichum kruckebergii at Mt. Hough, 10/23 First found this rare fern on Mt. Hough in 1987—long after Tom Howell found it there. The fronds are generally narrower and smaller than those of P. scopulinum, and the basal pinnae are deltoid rather than lanceolate. The Jepson Manual suggests this is a fertile hybrid between P. lonchitis and P. lemmonii, a suggestion I find scarcely credible. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1698015983197-XZ51WVIMNMRMTPCP5BPU/ferns+cf.jpg Botany - comparison of two scarce sword ferns P. kruckebergii at left, P. scopulinum at right. Another difference between these is that scopulinum is nearly or entirely restricted to ulramafic substrates. I don’t know of any localities for kruckebergii on ultramafic rocks. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1716063388782-7LF8TKJW4FXHXCPAM4IF/Wades+LakeR.jpg Botany - Wades Lake, Plumas County Wades Lake is to the west of Plumas-Eureka SP, high up with the crest of the Sierra forming its western wall. We used the note in Glen Clifton's unpublished flora of Plumas County to find Polystichum lonchitis there. He only says Wades Lake, so we had to hunt around a bit. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1716063412903-V7X1QW6NRH39V1TNFGFP/P+lonchits+whole+plantR.jpg Botany - Polystichum lonchitis at Wades Lake We only found this one plant. There were likely more on unscalable cliffs (at least for me) above this plant. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1716063437317-U1IM5N7JWWRKPKYG4FDL/Ploncitis+closeR.jpg Botany - Polistichum lonchitis at Wades Lake, closer The morphology of the fronds is much like plants I've seen in the Siskiyou Mts. It gets it's common name, Holly Fern, from the stiff pinnae with spinescent margins. A wholly admirable plant. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1712524450510-BFTRRE2O2AU1I3CZ35RY/Eriogonum+cfR.jpg Botany - buckwheat comparison Eriogonum douglasii in Dixie Valley, Plumas County, left; Right, Eriogonum umbellatum bahiaforme near the summit of Mt. Diablo on nutrient-starved metachert. These are in different groups of the genus, as evidenced in part by the whorls of bracts midway up the fower stalks in douglasii, which umbellatum lacks. However, it is very common to see heads first yellow then aging red, and this happens in both instances here, an example of parallel evolution. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1712635666336-3WNMR3IJGZT64L2I0UQP/pratteianum108R.jpg Botany - Eriogonum prattenianum HWY 108 Here you can see the transition in one plant from pale yellow to strikingly red heads. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708894947163-HG3OF3WZ6V6LAJNKKFUT/Leucrinum+JV--ModocR.jpg Botany - Sand Lily in Granger Canyon South Warners Leucocrinum montanum was unceremoniously yanked out of Liliaceae and dumped into Agavaceae. Whatever the family, it’s just as beautiful. Jimmy Vale and I found this in sandy scree in Granger Canyon, on the east side of the South Warners a little south of Cedarville. This is Jimmy’s slide, which I scanned. Sand Lily goes as far south as Sierra Valley. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708896471427-VKZ49BBAKSX7V3DYVBNG/Dimerezia+Granger+CnR.jpg Botany - Doublet in Granger Canyon Jimmy Vale and I found this Dimeresia howellii in volcanic scree in Granger Canyon. It’s in the Asteraceae, and all the flowers are discoid. I call it the Diadem Plant. It has a very limited range in for NE California and close by in adjacent states. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708930664655-POBG5GN01N8S4EQ1017Q/Cordyl+combo2A.jpg Botany - a SURPISE in Surprise Valley I was thrilled when I found Cordylanthus [maritimus ssp.] canescens in a saline-alkaline seep on the east side of Middle Alkali Lake across from Cedarville. Astonishing if this is really part of maritimus. It bears little resemblace to that species. Looking at these plants in Surprise Valley, maritimus never came to mind. Canescens also occupies the Alvord Desert in the rain shadow of Steens Mountain. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1594508524130-QECDT5PB7M6ND569SIA4/conehomolgies2.jpg Botany - red fir cone homologies right, a cone of Abies magnfica shastensis at Mt. Eddy; left, cone parts and seeds of Abies magnifica magnifica in the northern Sierra. The former has bracts exerted. In the upper left photo the included bract of Sierran magnifica is the green, toothed item in the middle. We are looking toward the top of the cone, so the bract subtends the scale and is homologous to a needle-leaf. The scale is a seed-bearing short shoot that arises in the axil of the bract and expands into the wide structure that is the largest component of most conifer cones. The seeds that grew on this scale are on the far side in this view. Their wings are not visible but the seeds, wrapped in a pterostegium of wing tissue, are exposed. The pterostegium is only found on the adfacial side of the seed, the side that faces the scale on which it grew. At lower left the abfacial sides of magnifica seeds are displayed. Note the characteristic hatchet shape of fir seed wings, and the prominent resin vesicles in the distal parts of the seed bodies. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1602363672268-L4TC6970SQCV4GGTVF7P/DSC_0238.JPG Botany - Shepherdia canadensis near Mt. Eddy This taxon is disjunct to two California sites so far known, ultramafic seep areas near Mt. Eddy in the Klamath Mountains. The nearest populations are in the Blue Mountains of NE Oregon and the Ruby Mts of eastern Nevada. I discovered this in the 1980s, but was only able to identify it after Janet Haden looked at it in the 90s and exclaimed: “That looks like a Shepherdia.” This was truly the thrill of discovery. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1602363696864-DAUAO561DUSKQD7ONG3M/DSC_0246.JPG Botany - Shepherdia canadensis near Mt. Eddy a closer view of a fruiting branch at the same site as the last. These sites are botanically extremely rich but also extremely delicate, and only a few individuals of this shrub have been found so far. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1705112174557-JMJ2C8VVXEJVA322IK9L/Eriog+siskiyouensis.jpg Botany - Eriogum siskiyouense …at the summit of Park Creek grade, Siskiyou County. How lovely the foliage of this endangered species can be—so like the best forms of Sedum spathulifolium. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1705112198107-ULYC20GVOLKLQ3LWT5Q1/F+idahoensis+cfR+copy.jpg Botany - unnamed perrenial grass …on ultramafic scree at the summit of Park Creek grade. As I recall this keyed to Festuca idahoensis. However, it’s caespitose, which F. idahoensis is not. Around this area, F. rubra on ultramafic substrates is green. I believe this exquisite gray entity needs a new name. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735970535398-PRBIF08R0V9RTG4VETSE/F.+idahoensis+Pilot+RidgeR+copy.jpg Botany - Festuca idahoensis …in “magic” light on Pilot Ridge serpentinite on the crest of the Sierra along the Laporte-Quincy Road in Plumas County. So lovely! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1436672754493-VNU3VVZ6V91C9I3JCIOL/kelloggiiinterm2.jpg Botany - Lilium kelloggii This incredible lily, photographed near Arcata in Humboldt County, is the queen of all lilies to my taste. This is a very rare species with variants in serpentine chaparral in Del Norte County and shadier places in the woods in Humboldt. It likes its roots to be cool, but it is not a wet-grower like the widespread and better-known L. pardalinum. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653596486103-TNK0PW7IFR4HTK64MKQC/primopsRsharperR2.jpg Botany - Rare yellow lily north of Weitchpec I’m not going to advertise the location of this rare yellow lily that has been intepreted as part of a hybrid swarm between Lilium columbianum and L. rubescens. I’ll only say that is was north of the cofluence of the Trinity and Klamath Rivers. If one is lucky, one can see this once in a lifetime. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735535155092-PQ97VJV995IM7GM0HVHG/Lilium+rubescens+on+way+back+fromPSLassicks+copy.jpg Botany - Lilium rubescens, Humboldt County …along the Eel river coming back from the Lassicks in the dark, many years ago—pre-pandemic….. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653592078009-HV4FC98MRB1TEOJI1MF5/GeraniumoreganumR2.jpg Botany - Geranium oreganum We encountered this knockout-dragout beautiful geranium along the Bald Hills Road in Humboldt County in June 2014. It extends sparsely in California northward from northern Mendocino County, thence into Washington state. It has been little collected for herbaria in California. The flowers in these were each about two inches wide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763658955366-WH7ZDYEZ8TL16HEJNRTY/V+chrysatha+R%26E.jpg Botany - Vancouveria chrysantha This lovely endangered species is found only in Delnorte County and SW Oregon. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763489981572-QBE8HBDONQ61D2QAFHZJ/locality+ofSHARPR2.jpg Botany - locality of Emptrum nigrum Facing directly into the wind, like a ship’s prow, at Elk Head, Humboldt County…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763488481298-TWIMH16VMB3CK1KCVTCM/Empetrum+nigrumSHARPER.jpg Botany - Empetrum nigrum at Elk Head This taxon, so far as known, occurs at only two localities in California: here at Elk Head in Humboldt County, but the Del Norte County locality on Point Saint George, N of Crescent City, may have been extirpated. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702085350863-ZASSDODGM8I6T5BNEOWN/R.+bracteosumR.jpg Botany - Ribes bracteosum in Fern Canyon This was in Fern Canyon in Prairie Creek SP in 2014. This canyon is right on the coast. It’s a very moist place. This was the first time we had seen this species, and at first, from a distance, we thought it was Acer macrophyllum. It’s HUGE for a currant. Here Ribes bracteosum is showing off Katie Colbert. It turns out this entity is very hard to grow, which probably accounts for Jim Roof not having it in the RPBG. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702085372827-MFTD7JRXYQIAYKWFV46G/bracteosum+cfR.jpg Botany - Ribes bracteosum leaf comparison R. bracteosum, left, and Rubus parviflorus (thimbleberry), right. Thimbleberry has very large leaves, especially in Fern Canyon. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1675753055892-BD4GQMJG13YXG9JWO4OY/Cycladenia1R.jpg Botany - Cycladenia humilis This strikingly beautiful perennial, photographed in grus along the county line road west of Redding, represents, to my mind, one of the saddest failures in California horticulture. It has never been successfully cultivated. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1675753075788-DUGVAEUHWXJV10ORG03H/Cycladenia2.jpg Botany - Cycladenia humilus A close view of another plant in the same grus. This genus is in the Apocynceae, and very Apocynum-like fruits. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1675752378822-I9PNMA25IM4Y210CH2LK/Collomia+larsenii.jpg Botany - Collomia larsenii I’ve only seen this species three times, always high on Cascades volcanoes. This was high up Lassen Peak. I’ve also seen it high on the north face of Mt. Hood in Oregon, and on the top of one of the smaller silicic volcanoes in the Medicine Lake highlands. To me it’s one of the most delightful plants. This one was growing in coarse, unstable dacitic talus which probably had more airspace than soil. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1700983830202-BDPX4F0QRMBCKAKMHCRG/Chaenactis+nevadensis+Lassen+Peak.jpg Botany - Chaenactis nevadensis Way up on high on Lassen Peak. I think this species is the loveliest thing. It’s uncommon though. It occurs sparingly in the northern Sierra and western Nevada, then jumps to Lassen Peak and Bully Shoop west of Redding. Shot with my old D80, which had much less resolution than more recent Nikon SLRs. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1700983855143-8IYSFOUWKP7NTF657I13/Campanula+scabrell+Ski+Heil.jpg Botany - Campanula scabrella On the summit of Ski Heil Peak in Lassen NP. This plant is only rarely seen in California, in the far north, but extends into Washington State and Montana. Shot with my old D80, which had nowhere near the resolution of later Nikon SLRs. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1676014329979-P3NRK36ZPJKI5S4MTF6X/M+jonesii+combo2R.jpg Botany - Muhlenbergia jonesii I encountered this lovely small ceaspitose bunchgrass north of Lake Almanor in Lassen County, with the aid of Forest Service personnel. It’s a rare species, so they were monitoring it. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1676014372339-HNWOZFZPCB2UBZ378SOF/Bet+gland+comboR.jpg Botany - Resin Birch in Lassen County We encountered this in a wet meadow east of Lassen NP. This is an exceedingly rare item in California. However, it is widely distributed from Alaska across Canada to Greenland, coming down to some northeastern states in the US, and even down to Colorado. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1685431904003-NGIVWHEAKJ3XM0NX9OW0/Ash+Valley+combo1R.jpg Botany - Lassen-Modoc endemics of high degree I photographed one of these (at left) in Ash Valley, NE Lassen County—long ago! These are scans from old slides. Left, Ivesia paniculata, right, Eriogonum prociduum. The slide of the buckwheat was kindly given to me by someone of whom I have no memory. So I have to make an anonymous acknowledgment! There’s even some Ash Valley Milkvetch Astragalus anxius scattered about. Both the Ivesia and the Astragalus only grow in and close to Ash Valley. The buckwheat also occurs in Modoc County. These lovely plants bring back such memories—such memories! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748848270287-UXOKWF0UXDO3NZD4553P/Anthony+Peak+Larkspur.jpg Botany - Anthony Peak Larkspur This was scanned from a slide I took on the summit of Dubakella Mountain, west of Red Bluff, in 1987, when I was still but a poor photographer. Photography has been a lifetime of learning! Delphinium antoninum takes its name from Anthony Peak east of Covelo, about which Jim Roof wrote so brilliantly. This a pale form of the species. D. antoninum is uncommon, restricted to higher elevations in the north coast ranges and Klamath Mts., usually in talus. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1645599819963-8SWRWWN99WAERL2BXFSS/PattersonL%2CWheelerRpsR2A.jpg Botany - Sweetwaters, north of Bridgeport Wheeler Peak, left, Patterson Peak, right, both well over 11,000’, in the Sweetwater Mountains, looing westerly into California from Nevada. The Peaks are capped by young dacite and rhyolite, part of the protoCascade volcanism of the Miocene, according to one intepretation. Phil Olrich and I got up into the alpine tundra on Wheeler, a long time ago. It was wonderful. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1722186163093-UHBJITWYM9SN2AYOB1MS/Mt+OPatterson2.jpg Botany - Mt. Patterson in the Sweetwaters ...and the deep, steep canyon between Wheeler and Patterson. Both have rhyolite at their summits, that's why the colors are so bright. Probably hydrothermal alteration is involved too. Both are well over 11,000'. I couldn't believe the astonishing beauty I beheld. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1645602245807-AW4ARIO95RH9X84YSTNO/sweetwaters+231.psjR2.jpg Botany - Wheeler Peak in the Sweetwaters The rhyolite of which the peak is composed is 6.6-5.3 my old. The cabin is a remnant of past mining days, when silver, gold and copper were recovered in alteration zones along faults. The deposition was contemporaneous with and slightly after volcanism, related to hydrothermal fluids heated by the magma chamber. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1722187095328-BRTFSCBSILOPBZX8VYNV/talus+on+WheelerR2.jpg Botany - rhyolite talus on Wheeler Peak in the Sweetwaters ...Bridgeport Sierra in distance... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1722206861658-Q1F9P4O5JTCCWG2TDARQ/Brassicaceous+combo.jpg Botany - alpine plants of talus & scree high on Wheeler Peak Left to right, Draba densiflora, the Sweetwater Mts. endemic Draba incrassata, and, far right, "Physaria," aka. Lesquerella, kingii. All seen blooming on the same day in June. I was up there with my friend Phil Olrich, ca 2008 or 09. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740019566065-RZHSC1P76ZKY87Q69HQ0/Eriogonum+rosense+sweetwatersR2.jpg Botany - Eriogonum rosense …on Frying Pan Peak in the Sweetwater Mts. Photo by Michael Uhler in 2023. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740019592013-36F02GI4TYYGDXHHWHGJ/Alpine+gold+in+the+SweetwatersR.jpg Botany - Alpine Gold in the Sweetwater Mts. The dark peak in the left background is Wheeler Peak, 11,663’. Photo by Michael Uhler, 2023. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1722296762693-Y4G3YDDGFKZ3BMJ0T5I6/Oxytrops+parryi+PSR.jpg Botany - Oxytropis parryi? This charming thing must be a young individual of that taxon. I encountered it high on Wheeler Peak 25-30 years ago, and came away with no specimen because there were very few of them. I'm unable to key it out from the photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1736373983970-A3WU90XCNNIM76W7V14S/Oxytropis+sp.++SweetwatersR.jpg Botany - Oxytropis sp. A spectacular False Locoweed I photographed in the Sweetwater Mts. If anyone can recognize the species, I’d like to know the name. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1573611191764-L2EE1SWVBMFEMLAO29J3/sweetwatersinterm.jpg Botany - Paintbrush in Sweetwaters Either Castilleja applegatei or C. chromosa, attached to Artemisia tridentata, with Purshia and Pinus monophylla in background. East side of the Sweetwater Mountains, NE of Bridgeport, CA. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1712987859787-CW3KWS2TSE8FCP8TZL6O/Bodie+settingR.jpg Botany - Bodie, Mono County Bodie is high desert county.… Sharp snowy peaks of eastern Sierra in far distance…. There are lots of exciting plants in open places among the shrubs. Residents of Bodie lived with a great many native wildflowers. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1712987908276-3CTT60QUOF9N7EU6F3OU/Bodie+E.+caespitosum+comboR.jpg Botany - Eriogonum caespitosum in Bodie This was one of the wonderful plants that Bodie residents lived with. It may the tighest buckwheat (with the smallest leaves) in California. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1758424066578-WF499JRZH7WOBLSSHZ2L/trealesei1RA.jpg Botany - Opuntia "trealesei" …along the old Tehachapi Pass HWY. This one my favorite cacti. It used to form near-monocultues E of Bakersfield, but now is federally endangered … https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435699305426-N014VS15ENYPB3KC5Z8O/sageinterm.jpg Botany - Salvia dorrii, Walker Pass An unusually good display of this species, on the east side of Walker Pass, with ericamerias. Scan of an old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1762994661603-EG8QE937QFX6L28WQZB7/Baileya2+copy+3a.jpg Botany - Desert Marigold I found this Baileya multiradiata growing along the HWY west of Ridgecrest. It’s one my favorite desert perennials. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1668465027053-CR8HKVBB2HD4VO43NOL9/Glyptopleura3+copysharper.jpg Botany - Glyptopleura marginata I’ve seen this amazing composite only in a few places, in the Mohave. This was in sandy soil on Mazourka Canyton Road east of Independence. These are small annuals that get only 2.5 inches wide at maximum. Is the extravagant white margining of the leaves there to make up for the relatively inconspicuous flowers? Then perhaps the whole plant would look like a flower to insects. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738131954975-6IN9B3U2KTL04BK7P6RX/M+palmeri+w+Dove+CK+fm+.jpg Botany - Mimulus palmeri …in Redrock Canyon SP, Dove Spring Formation in background… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1672714676495-KFXVBOBTXV7687BCB0WX/rupicolacombo1R1A.jpg Botany - Mimulus rupicola, Death Valley It’s odd to find a herbaceous monkeyflower growing on rocks in triple-digit weather, but this Death Valley region endangered endemic survies that way. It’s specific epithet, rupicola, means growing on walls. We found this in the Cottonwood Mountains, growing on Pennsylvanian Bird Spring Formation limestone, close to the scene at right, which is the entry to the narrows of Marble Canyon. Scans of old slides… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1627506043268-YPPGIFG9FD6K6GKAZND4/DVHesperocomboR.jpg Botany - Hesperochiron pumilis in Death Valley These photos were taken long ago and I scanned them. Hesperochiron pumilis is a lovely small perennial that is nearly always found in moist places in the mountains—Klamaths, Cascades, Sierra, etc. Here it is WILDLY disjunct at a mound spring on the floor of Death Valley north of Ubehebe crater, presumably along the northern Death Valley Fault Zone, which would allow deep waters to rise. The ground all around is crusted with salt. This situation seems like finding a nice dish of ice cream sitting on a rubble pan in the middle of the Sahara Desert. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1619765404872-RACZXQ1AWHJI4FWLGSY0/Styrax1.jpg Botany - Styrax My shrub at home was loaded with flowers in April 2021. They are not only surpassingly beautiful; they are also highly fragrant. The otherwise wonderful book, California Native Plants For the Garden, by Bornstein et al., is grossly marred as a result of omitting this species. It is not only beautiful and fragrant, it is also useful medium-sized shrub that will thrive on clay loam or a sharper soil, is easy to grow from seed and easy to grow in general, needing little or no irrigation, and should be at the head of anyone’s list as one of the greatest California native plants for the garden. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1745793624318-4O7B21JDOPNR1AXSYTMZ/Viburnum+Butte+CoR1sharper.jpg Botany - Western Viburnum from near Frenchtown, Yuba Co. Viburnum ellpticum is one of the rarest shrubs in California. We found one shrub there, but not in bloom. The one in the photo is from the same location near Frenchtown, Yuba County, but in bloom in our little home botanic garden—collected by seed by someone whose name I can’t recall. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1717361981217-4LESPXGVDD3FDQ2HSV6A/Mmacranth5-26-24Rimpr.jpg Botany - Monardella macrantha ...in our garden at home. Most of the collections in the Consortium are from San Diego County, but it jumps up to Naciemento-Ferguson Road east of where it passes over the Santa Lucia Mts. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1739772126706-V8KCTAETTSTUORU9Y5LT/dogwoodat+bot+gardenSharper.jpg Botany - Cornus nuttallii at the RPBG…caught backlit…so lovely. JIm Roof tried over 50 years to grow this species, planting it in various places in the bot garden. All failed but this one. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1739772150688-D70CLRSVOWU8BR5YVQL6/T+chloro+at+Bot+GSharper.jpg Botany - Trillium chloropetalum This was in the RPBG. I shot this photo of the elegant leaves and buds long before I retired in 2013. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740205338339-9QQE380JYHEPJ345OPSV/E+revolutum.jpg Botany - Erythronium revolutum in the RPBG Nuff said? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1621803469657-RDI86WOT8S31LZNT7JZH/coulters.jpg Botany - Coulter Pine variants The natural range of variation in morphology of Coulter Pine cones is amazing. These are from a planted (long ago, and naturalizing) grove in the Briones Hills of Contra Costa County. The cone on the right is basically like P. sabiniana, but more elongate. The range of variation is so great, it makes me wonder if ancient introgression with P. jeffryi was involved. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1736314997896-5IFDUBJWR25GXNZULGF3/Mara+horridaRsharper2A.jpg Botany - Marah horrida …from the lower Sierra foothills of Fresno County. These are the largest fruits of any California manroot, with heavy armature protecting very large seeds. Swiss army knife for scale, and not a small one. The fruits were at least six inches long. The seeds of Marah macrocarpa, closely related to horrida, were mashed by some California Indians to make a binder for pigment. Interesting comparison with the Coulter Pine cones in the preceding picture…Scanned from a poor slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1746207496090-72JB8BSL786L910TU1CK/AvirgaDeiner+combo+copyR.jpg Botany - Anthirrinum virga …along Deiner Drive near Mt. Konockti in Lake County… This species is much more abundant after fires. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1543282733729-XPNAZV4BQVR016SCS03I/argem09.jpg Botany - prickly poppy on Walker Ridge Argemone munita ssp. rotunda appeared in abundance on Walker Ridge in Lake and Colusa counties for two years after a huge fire in 2008. These stunning plants, with their six-inch-diameter flowers, are seldom seen in the coast ranges except after fires. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611088643825-F35325DOZNUXPY56O2VM/amwhite.jpg Botany - prickly poppy on Walker Ridge the second year after the big fire. In the central and north coast ranges, this plant is almost strictly a fire follower. Photo by Bob Case. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1586052104790-E2EYS727HB5YFZEWEMKE/Hesproshar1interm.jpg Botany - Hesperolinon sharsmithiae O'Donnell Enhanced to clouds of bloom by the Butts Canyon Napa County fire of 2014 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1586052387234-FVLHF05KT2U2X4YUM3J7/DSC_5740Aintyerm2.jpg Botany - Long-rayed Brodiaea Triteleia peduncularis enhanced by the Butts Canyon fire of 2014 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1586052411348-JG19ZYIRNODEY6DTP6T9/DSC_0295interm.jpg Botany - Long-rayed Brodiaea on the Butts Canyon fire of 2014 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748297909057-4IOQOROOZVO1F4X401SW/COLOR+in+Butts+Cn+burnR.jpg Botany - color in a Butts Canyon burn …at the junction with Snell Valley Road, a place that’s always flowery…burn or no burn…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1586052437376-ID2BSHLJIBC6TLQS2022/DSC_1102ps3interm.jpg Botany - Erythronium helenae Along Butts Canyon Road in a Lake County fire of 2015. For decades, we saw only a handful of these plants here between the chaparral and the road. And this is only a third of the display. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1586052465359-D5VQ20VFR0GNJ915QYVD/DSC_1042ps1interm.jpg Botany - Erythronium helenae Along Butts Canyon Road in the 2015 fire. What nearer an angel floating down to visit us? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1746763697373-25FMQ1R4DVY31S4M3FES/display+in+burn+along+MV+Rd-r-SHARPER.jpg Botany - display in burn along Morgan Valley Rd. …in NE Napa County, April 2015… goldfields, what used to be called Linanthus dichotomus, and Gilia tricolor… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1621664110292-W0NDZNRJ6E9OMLGMJXC7/Helianth6R2.jpg Botany - Helianthella, Howell Mtn Road This glorious colony of Helianthella californica nevadensis was in surge mode within an incinerated chamise stand in the 2020 burn along Howell Mountain Road west of Angwin in Napa County. Like zigadenes, these plants bloom much more after a fire, though they were there all along under the chaparral, blooming shyly. The photo was taken at sundown under very low light conditions, which limited sharpness, but the overall effect is pleasing. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1538197862598-ZXPY7HNUQVI5SQRHM3B8/Cavedalerubescens+interm.jpg Botany - Lilium rubescens in Sonoma County Lilium rubescens had a banner year in the 2017 chaparral fires of Sonoma and Napa Counties. Would you replace this rare gem with vineyards? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531258627424-U8LO07R6EVC3E3TW2982/Atlas1+copyinterm.jpg Botany - Atlas Fire of 2017 The 2017 Atlas Fire in Napa County gave rise to some wonderful displays in 2018. Here owls clover, larkspurs, and leptosiphons are nicely framed by the stone wall made of local volcanics. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1681886174929-5XX9QH19Z2ZOA4VE8QCW/CpurpCRr2.jpg Botany - Ceanothus purpureus on Atlas Peak Road This endangered species is almost totally restricted in the wild to Napa County. This one was part of a large colony that extended up onto private property. There was a giant fire up there in 2017. The following spring we found just 3 or 4 live plants, since mature plants can be killed outright by fire. But the second spring we found lots of small seedlings. By 2023 they were making a grand show. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1681886140830-OK8J5MR0CQS899J73CDT/C+purpureus+flowers+macroR2.jpg Botany - Ceanothus purpureus flowers closeup Shot on Atlas Peak Road in mid April 2023. So stunning! Roger Raiche and I together discovered this species in 1985 on the summit ot Twin Sisters, just into Solano County, where we were permitted to hike that day. That is still the only known record in Solano County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531258656503-CU2WPH93R1RUTOJVMF0W/SodaCn2+copyinterm.jpg Botany - Napa Atlas Fire of 2017 Here along Soda Canyon Road in May 2018, in the Atlas Fire zone, Diogenes Lantern Calochortus amabilis never had it so good. Fire removes competition, allows more light to reach the soil, fertilizes the soil with phosphates, kills seed of exotic annual grasses, and stimulates more of our native bulbs to bloom than would bloom in the same place without fire—though the bulbs were there all along. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1619764886749-K7CEH3UTZDWIECKDX1JU/burn2R.jpg Botany - 2020 Hennessey Fire, Vaca Mts This is just a fraction of the huge fire of August-September 2020, followed by extremely severe drought. But there were still lots of lovely flowers here in April 2021. Even this landscape of devastation has an austere beauty, like the desert. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1619764910759-4DXX21FFKKDABYXLGJHY/CamabilisR.jpg Botany - globe lilies in the Hennessey burn East side of the Vaca Mts in the burn area, April 2021. This is the densest patch of Calochortus amabilis I’ve ever seen. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1647498377167-QZM31UCP1JUVH1X2UF6V/poppiesR.jpg Botany - upper Mix Canyon two species of poppies, E. californica and E. caespitosa, in uper Mix Canyon in the Hennessey Fire, mid March 2022. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1647498398171-M5BAQ3P0CE8CA2XXSKN6/Salv2R.jpg Botany - Mix Canyon hummingbird sage Mix Canyon, Solano County, on the east side of the Vaca Mts in the Hennessey burn area, had, in mid-March 2022, the largest and most spectacular patches of Salvia spathacea I’ve ever seen. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1647498417949-9U0PADLBR5Z6ANRBJSIX/Salv1R.jpg Botany - Mix Canyon Hummingbird Sage One almost wants to dive into it. Mid-March 2022. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1619764930434-HL7P7JOTS2B350GQKF5M/suaveolensSharp.jpg Botany - Phacelia suaveolens in the Vaca Mts burn Phacelia suaveolens is a true fire-follower. I have seen it only in burnt chaparral. It was abundant in such settings along the crest of the Vaca Mts in April 2021. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735705974126-QXEWDV0U0VHI53EI79LQ/zigadenes+in+Oakland+fire1991R2sharper+copy.jpg Botany - zigadenes after the Oakland Hills firestorm of 1991 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531866036838-S0K6WSM2RIBTPHSIGUEF/popinterm.jpg Botany - Fire Poppy on Mt. Diablo 2014 This is the true California poppy, Papaver californicum, very different from Eschscholzia californica, which is called California Poppy, when it should be called the California Eschscholzia. Chris Thayer and I found the Papaver in the burn area on the SE flank of Mt. Diablo overlooking Perkins Canyon in spring 2014. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610239797271-UWL1GDUG7AU8KHIOD2PA/windpops2a.jpg Botany - Wind Flower in Perkins Canyon Populations of Wind Flower Papaver heterophyllum are always enhanced by fire. Note in the closeup that this species has a style between the stigma and ovary, unlike P. californium. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1532239357684-QSN6EBE7C3Y7R5XWUEI4/Dicentra2015Ainterm5_edited-2.jpg Botany - Yellow Bleeding Hearts 2015, second year after the 2013 fire on Mt. Diablo. This huge patch of Dicentra (now, alas, Ehrendorferia) chrysantha, growing near Green Ranch Road high on the SW flank of the mountain, was very extensive by Mt. Daiblo standards. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610239749164-DROP7UM0XK05Q5QL1ZBM/Bestcombo1.jpg Botany - Mt. Diablo strict fire followers in 2014 These species appear only in the first year or two after a fire, except the Ehrendorferia, scattered individuals of which can hang around for many years. Clockwise from upper left, Calandrinia breweri, E. chrysantha, Phacelia phacelioides in bloom, same in rosette stage. The Phacelia is a very rare endemic of the south coast ranges, and normally it appears for only one spring after a fire. Then it waits as seed under chaparral for decades until the next fire. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610239774199-POXZTN8RIKAOQKG1GVG1/combo2a+copy.jpg Botany - Mt. Diablo strict fire followers in 2014 clockwise from upper left, Monolopia gracilens, not known elsewhere in the East Bay and seldom seen on the mountain except after fires, rosette stage showing wooly leaves; same in flower; Malacothrix clevelandii—Chris Thayer and I searched all over the mountain after the fire and only found two individuals of this, in one place; Antirrhinum kelloggii, which I found blooming for three years after the fire, as chamise chaparral grew back to entomb it. Drought conditions caused the shrubs to grow back slowly; otherwise the snapdragon may not have persisted so long. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1739412661027-K8A8FZEYXAZ7VVYYCND6/Malacothamnus+hallii.jpg Botany - Malacothamnus hallii …only peters out without fires, is likely abundant after fires on Mt. Diablo, and is abundant after fire on Lime Ridge. It is distinguished from M. fremontii by geener leaves and sepals not invested by shaggy hairs—-hence VISIBLE…These individuals were along South Gate Road, but I think they all died out. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768960918560-3BVMKM794M7RBBN6QQMM/Diablo-fireBreak2-5-28-14+017+copy.JPG Botany - Emmnanthe penduliflora …came up in abundance after the recent holocaust on Mt. Diablo… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768962536637-NC8735WNYTPDBXF3O2AE/E+pend.jpg Botany - Emmnanthe pendulifora …closer view… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1628141390285-BWP3XN73VMH2INWLPU0K/Streptanthus+hispidus+2014PS2RED.jpg Botany - Mt. Diablo Jewel Flower Streptanthus hispidus occurs at many sites on Mt. Diablo, almost always on metavolcanics. It is a Mt. Diablo endemic. I’ve only seen it on serpentinite once, south of Prospector’s Gap, in 2014 after the giant fire cleared away inpenetrable chaparral. Without that fire, nobody would ever have seen this. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1747511437691-JGCDIPIK73WMLMJAMWCM/helinthella+castanea.jpg Botany - Mt. Diablo Sunflower Helianthella castanea was exposed by the fire too. It had hidden under chaparral that burned off. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610743351415-PE5V8H9A3Y17QLJLT5LG/DVwindpops3RED.jpg Botany - wind poppies at Del Valle These were in a burn area along the Cedar Mountain Trail in Del Valle Regional Park, southern Alameda County. Fire always enhances populations of this species. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1616133691151-FT4H7FN7K2D2EMLSCEJ0/combo3R.jpg Botany - monkeyflowers in the Arroyo Bayo A huge fire in 2020 burnt a large part of the Mt. Hamilton region. These small annual monkey flowers are not fire followers, but here they were growing in chaparral and very hard to find. The fire cleared away the brush and made them easy to find. David Gowen was the first to discover Mimulus congdoiii, left, in the Hamilton Range. On 17 March 2021 we found it in bloom beside the locally common but always surprising M. douglasii, right. Pictures not to scale; congdoiii is actually relatively smaller. We only found the latter because David told us where to look. It is rare in the Hamilton Range and tends to be secreted in small open patches of scree hidden in brush—until fire exposes them. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653499261132-SM6BJEGJKTV9Q3HR1ZMN/anticomboR.jpg Botany - native snapdragons on Mt. Hamilton An immense field of Antirrhinum multiflorum sprang up in a remote area of a burn on the east side of Mt. Hamilton. Scanned from slides taken I think at the end of the 1990s… The flowers were so densely swarming with bumblebees that the whole field was humming. It was intoxicating, both for them and for me. We’re looking NE out over the legendary Arroyo Bayo to Red Mountain in the distance. In the near distance, ponderosa pines that somehow survived the fire. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653507564895-6LNF167Z8LY4QESMS95Y/hulsea+HsharperR2.jpg Botany - Hulsea heterochroma The only time I’ve seen this species in the Hamilton Range was later in the same burn and just below the Antirrhinum multiflorum field. Profsuely sticky glandular hairy, and favored by fires, it has some of the strangest-looking flowers of any composite, with rusty-red rays and orange disk. This plant is rare, and it’s always a thrill to find it. scan of an old slide… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1620800354138-FDU19W57MZUK4FWUYVSK/cbarts3r.jpg Botany - Collinsia bartsiifolia on Mt. Hamilton The higher parts of the west side of Mt. Hamilton have always had a lot of this striking Collinsia. But the 2020 burn, which swept across nearly the entire inner coast range, from the west side of Mt. Hamilton to within a stone’s throw of I-5, provided tremendous displays of this plant—despite one of the worst droughts in California history. Sorry the patch is not in good focus. It was late, light was lower than it looks, and I was tired after studying the fire starting at I-5. I stupidly did not take advantage of my camera’s capabilities. But it’s still a wonderful scene. The yellow is Helianthella californica. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1557294290677-7F2GO5YJLAEWVUL6SBV4/RHCbiloba98.png Botany - Red Hills, Tuolumne County Poor scan of an old slide, but the glory comes through. Clarkia blioba painted the hills in late spring 1998, following a fire in 1997 or 1996. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1557294328539-J315FNRNTUKBY5TYBXPZ/RH98atif.png Botany - Red Hills, 1998 Another scene of post-fire enhancement of Clarkia biloba (and I think popcorn flowers). Poor scan of a an old slide, but still delicious after all these years. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1747011536803-P521E2VF7BVDIHS1OIMG/display+in+1st+Mocassin+burn.jpg Botany - burn at Moccasin Creek, Tuolumne Co. ca. 2018 This view of the burn shows abundant Mentzelia lindleyi and Clarkia biloba. I caught a swallowtail in the frame too. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1747011568528-8PXZ0LQ0HD2NYQD5PNTO/2nd+display+in+1st+Mocassin+burnR.jpg Botany - burn along Moccasin Ck.--another view This view displays abundant Collinsia tinctoria in addition to the species shown in the prior frame. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1747011599321-GMSI3HAO0CIK0V4HG8DU/M.+lindleyi.jpg Botany - Mentzelia lindleyi in the Moccasin Ck. burn nuff said! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1747030544768-IY6LGLRZWRXGBXMGCXDO/Mocasin+bu+rn+%232R.jpg Botany - burn south of Mocassin Even in extreme drought years, displays in burn areas can be impressive, as much competition for water has been removed. Here is a small part of the burn, dominated by Eschscholziacaespitosa and Lupinus benthamii, in early April. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1747030575897-E78N23ELQYD7J6IQ7DE9/MOccasin+burn+%231R.jpg Botany - burn south of Moccasin This part was dominantly Eschscholzia caespitosa and Gilia tricolor. Early April. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766531915372-QGBNJVFXF1Z9E0ZVMHED/Streptathus+polygloidies+%26+metavolancis.jpg Botany - Strepanthus polygaloidies ….metvolcanics in distance…on a burn south of Coulterville many years ago… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1685312154693-0JM1BXDBUQWMCVOGZBXN/I+hartw+comboR.jpg Botany - Iris hartweggi stimulated by fire We encountered this display of Iris hartweggii in a burn along HWY 108 (the Sonora Pass HWY), in 2009. The Iris was obviously stimulated by the fire. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1656716328268-GX7K5247TNME6UE8R6EK/washingtonianum1A2.jpg Botany - Red Hill Washington Lily This lily benefited from the 2021 Dixie fire, which devastated this east flank of Red Hill north of the Feather River NW of Quincy. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1656483284182-7H4PUH61MU2096XP0YE0/wash2.jpg Botany - Lilium washingtonianum A closer view of one of the lilies on the east flank of Red Hill, NW of Quincy. Beauty from ashes. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1668465560601-5T2HDZ0A02GF9H6AHW1F/Red+Hill+2022+copy+2.jpg Botany - Dixie Fire devastation This was taken a bit up the road to Red Hill from the Washington lilies in the preceding pictures. The Dixie fire was the largest fire in California history, and it incinerating a large proportion of the coniferous forests of Plumas County. Owing to severe drought (the worst in history) there was little replacement of the conifers. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1689582245041-4I0C8AFGF6045PT4IV0K/McClennan+Canyon+RdR.jpg Botany - more results of the Dixie fire This fine display was on McClellan Canyon Road in mid july 2023. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1709087525743-SCBGGD6EMXPDLTGC2MS4/DSC_9358R2.jpg Botany - enhanced display E of Dixie Peak …in an easterly part of the Dixie Fire, June 2022. It was a year of severe drought, so were delighted to find this throng of Triteleia hyacinthina in small creekbed thta was drying out fast... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1709087557419-9OR6U51BKG5GZV4CF60D/DSC_9388R.jpg Botany - Mimulus pulsiferae …in the understory of the scene in the preceding picture…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1709087576778-Q68H4VE16JMMF0KQBU0D/M+pulsiferae+%26+M+breweri+E+of+Dixie.jpg Botany - 2 monkeyflowers, same spot M. pulsiferae, left, M. breweri, right.. Both were abundant owing to the fire. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1709087610544-C94H3VJL2QCZIXO76KM2/Dixie+Pk+Phacelia+comboR.jpg Botany - Phacelia humilis in openings in the understory, same place east of Dixie Peak, June 2022… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1709087639611-X746XHF1Y499EBGHR6B8/Arnica+cordR.jpg Botany - Arnica cordifolia …a grand display of this glorious but ungrowable plant, in burnt pine forest east of Dixie Peak, June 2022…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1734902364535-B5GSQHM9PK3L41ONQKSA/Crepis+%2B+Phacelia+hastata+S+of+Dixie+V..jpg Botany - Dixie burn area …a slope of Crepis sp. and Phacelia hastata… see next picture for slope opposite this… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1734902393306-WOBKPRR79GYRCB7N5SCN/across+from+flowery+slope+w.+CrepisR.jpg Botany - Dixie fire devastation …opposite the slope with Crepis and Phacelia… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1663381046902-0X4VRTVMX1XCDZLK949T/soapstonehill1AR2.jpg Botany - beargrass, Soapstone Hill, Plumas County This is from a scan of a slide taken in fall 2002. Oh how I wish I had been there in about June to see all the white torches blazing! Beargrass, Xerophyllum tenax, is stimulated to bloom en masse like this by fires. It seemed like there had been a fire at the site two seasons earlier. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1678068811227-X9LI9G1LDYFUHPCD3AVK/xero+comboR2.jpg Botany - Beargrass, Van Damme SP, Menocino County Xerophyllum tenax blooms en masse after fires. These I encountered on the uppermost terrace in Van Damme State Park, at the pgymy forest boardwalk across from the Mendocino Airport. This colony is among Bishop pines, the roots of which have penetrated the podzol hardpan which is the principal cause ot the pygmy forest. Adjacent vegetation is pygmified. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1721869491383-JP0QOG5FRQHMUQBE9QRC/poppies+S+of+WalkerR.jpg Botany - prickly poppies ...massed in a burn along 395 a bit south of Walker, July 2024. The burn looked two years old. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1532214023165-IFXAJI4GY55NKYML18PF/turinterm.jpg Botany - Poodle-dog Bush Eriodictyon parryi, formerly Turricula parryi, goes wild after burns. Chris Thayer and I found it at this site south of Lake Isabella in Kern County, roughly around 2007. http://californiageology.net/writing daily 0.75 2023-02-24 http://californiageology.net/home daily 1.0 2021-03-30 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435694930853-5BLI8BFVAK0WOFDWM0WK/sagesinterm.jpg Scientific Photos, Essays, and Poetry https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1434487102380-CCZOY50M61BWTJIJ5UBG/image-asset.jpeg Scientific Photos, Essays, and Poetry Geology, Botany and Conservation https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435631564297-0V73HK552QTX87V0PWPE/image-asset.png Scientific Photos, Essays, and Poetry Essays and Poetry https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1434485437336-3B20HCMZDFPNH2G0XKMY/%2Fphotos Scientific Photos, Essays, and Poetry Lithic Replicas, Landscapes, and Critters http://californiageology.net/photos daily 0.75 2025-12-31 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435768496462-WZ6W5GML7LQLUJM982ZC/DSC_1030+copysmaller+copy.jpg Lithic Replicas, Landscapes, and Critters - Acheulean handaxe replicas THIS BLOCK OF PHOTOS IS LOOSELY ORGANIZED BY THEMES. Franciscan chert on left, Farmington chert on right. The latter was part of my experimental program to replicate bifaces from Kalambo Falls in Zambia for J. Desmond Clark. It is illustrated in his monumental Kalambo Falls Prehistoric Site volume 3. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609362352208-BA34QLD6QONAWL5N71RU/Farm%26Fortunaps.jpg Lithic Replicas, Landscapes, and Critters - Farmington and argillite Left, a refined handaxe made in Farmington chert with antler percussion. Peak and Associates found a handaxe or preform of comparable refinement in their early Holocene or late Pleistocene excavations at Rancho Murietta. They donated all their collections to the University, but after that transfer the elegant handaxe was lost: a great tragedy. On the right is a refined handaxe made in argillite. The rockshop owners where I acquired the flake called it Oregon Wonderstone. I’ve not been able to track down the source of this material. The flaking was done with antler percussion at Desmond Clark’s cabin on Inverness Ridge, with Desmond watching. Talk about pressure! But he was a joy, and the results were respectable. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1629786951643-0RSGGR7NNF47MUUBTT42/KFbifaceR2+copy.jpg Lithic Replicas, Landscapes, and Critters - Refined Acheulean handaxe from Kalambo Falls This is a cast made from the original by the Wenner Gren Foundation for Desmond Clark, who kindly allowed me to photograph it. There are many highly refined handaxes at Kalambo, but this is the most impressive I’ve seen. It is arguably the most beautiful handaxe ever found in Africa. A design aesthetic is obvious to any experienced knapper. The camber is perfect in every section, the edge is perfectly straight all the way around, and this was worked with great care, as is evident from the small flake scars on the margin. The main flake scars are regularized to an extraordinary degree. In contrast, the other face received very limited attention, there are far fewer flake scars, and there was no attempt to regularize them. The knapper of this extraordinary piece was intent on perfection on one side. I believe this is a common feature of late Acheulean knapping, analogous to Egyptian predynastic (Gerzian) knives, which have the most regularized flake scar patterns ever achieved on one side, and where the other side is left with the original ground-stone surface, with no flaking at all. This hypothesis can be tested. The Kalambo handaxe was found on horizon 5 at site B, which produced many highly refined bifaces. Why? Were they all the work of one highly gifted knapper, or did a group of experienced knappers knap together and share their skills? I favor the latter idea. It may be testable at some point. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667598233869-L9U1F0ND42OUYJKD1UEP/kf2Rbest.jpg Lithic Replicas, Landscapes, and Critters - basalt handaxe and cleaver Here are a handaxe and a cleaver made from a coarse, challenging basalt from near Clear Lake. The cleaver is quite large, and a good “replica” of some of those collected at Gadeb on the SE plateau of Ethiopia in 1977. Some were excavated by me, under the direction of J. Desmond Clark. The latter are middlle Acheulean and approximately 1 my old, and they are as skillfully knapped as any anywhere in the approximately 1.5 my long record of the Acheulean. The handaxe was probably my last attempt to make a large refined one replicating those from Kalambo Falls. This basalt, however, is a much more demanding material than the fine quartzite that was used for the KF handaxe in the photo before this one. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1720385072172-GRVSSHEVXZCMWEBRJZ7M/GP+%2522dacite%2522R2.jpg Lithic Replicas, Landscapes, and Critters - dacite of Grizzly Peak, Lake County What I'm calling "basalt" of Lake County is just a field term, and it makes sense because this materail knaps exactly like coarse-grained basalt. However, Carter Hearn and Julie Donnally-Nolan found that this material I've been knapping is chemically dacite. The thin section, in PPL with the 10X objective, shows very small phenocrysts. The thin laths are mostly plagioclase, the blockier ones look like Kspar. The matrix is almost all isotopic glass, that seems to have spicular microlites—perhaps oxides—according to Howard Day and John Wakabayshi. However, this dacite has an abnormally high magnesium content. Perhaps it intersected serpentinite at depth. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1683441075104-17UZB52M6JGQYF9ECZQX/MVRdflakes+copyR.jpg Lithic Replicas, Landscapes, and Critters - basalt megaflakes These giant flakes of basalt from Lake County are ideal for making Acheulean bifaces. Homoerectus people learned to strike off giant flakes such as these, using hammerstones or throwing techniques. Earlier hominids were either unable to do this, or simply had not discovered the process. Striking off a giant flake like this is very satisfying (even thrilling), and some early Homo sapiens (who continued making Acheulean industries) seem to have been showing off by making the largest refined bifaces possible. …left, end-struck flake, right, side-struck flate, middle a cleaver made from such flakes…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748590090625-3Q2DO9L12HIEM8CPXNGP/GP+dacite2R2.jpg Lithic Replicas, Landscapes, and Critters - where I quarried those big flakes https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669101000952-00N7WDP5CAS8DLZUZ4LA/DSC_1354RED2.jpg Lithic Replicas, Landscapes, and Critters - elegant Acheulean cleaver from Gadeb 8E Here’s an example of a middle Acheulean cleaver from Gadeb 8E, more elegant than mine. Unpublished drawing by Betty Clark, generously provided to me by J. Desmond Clark. This drawing may be lost to science totally if I don’t display it here. The original is 8.5 inches long, not small, but of average size for a cleaver in the Acheulean of Africa, and its blank was a large ignimbrite flake. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669101020010-71WZCN1JHFK98SH582PT/8EexposedlessdustRED.jpg Lithic Replicas, Landscapes, and Critters - Gadeb 8E I helped excavate this site for two months in early 1977. With this clast-level view, it looks very much like a cobble layer in a point bar, and, although the site was the result of human occupation, it was clearly disturbed to some degree. Only 15% of the artefacts were in fresh condition; the rest were abraded to varying degrees. Many of the clasts you see are handaxes or cleavers. Most of the basalt ones were flaked cobbles, so they have that shape. The more elegant ones were made on large ignimbrite flakes. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1674717674823-I1SM21M58AUYORE6C7JH/shield+volcanoREDlessdust%2B.jpg Lithic Replicas, Landscapes, and Critters - shield volcano near Gadeb We could see from our 1977 camp this basaltic shield volcano, framing the east end of the plain of the Webi Shebeli River. I was told it was 12,000 feet high, but I don’t recall its name. It’s very likely alkali basalt, which would befit its proximity to the rift valley. Two prominent cinder cones can be seen in the middle distance. “Houses” of Oromo families can be dimly seen to the lower left of the volcano. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669101039527-Y692D1JXR65TQDBH2Z2W/JDC+at+GADEB.jpg Lithic Replicas, Landscapes, and Critters - Professor J. Desmond Clark Here Prof. J. Desmond Clark, whom I consider to be the greatest African prehistorian of the 20th century (though he accorded Glynn Isaac that accolade), is having a day off from the dig at Gadeb for fun socializing with the local Oromo people. He later rode that white horse. He was an excellent horseman. This trip was the first time I ever used an SLR camera. I was a subamateur! Consequently I had to sharpen, lighten, and darken the photo, and spent an hour deleting dust specks, to make it presentable. It came out of that process looking like a painting, but I like it. This is just how I remember Desmond. Behind most great men there is a great woman. Desmond’s wife, Betty, did superb drawings of artifacts for countless of Desmond’s publications, and played a critical role helping to manage his field camps. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606866987651-P3EYAV253TVV3J6NJHKL/Morgan1a.jpg Lithic Replicas, Landscapes, and Critters - Lake County basalt Here are an Acheulean handaxe and a cleaver made from the same material as that in prior photos...chemically dacite, but it flakes like coarse basalt. The handaxe was flaked with a copper billet, the cleaver with hammerstone. This material is very difficult to flake into flawless forms with hard hammer. I guess I got lucky on the cleaver, achieving an iconic form. I was originally taught to knap by Glynn Isaac, one of the most inspiring profs I ever had. Kathy Schick and Nick Toth were also in that class. Kathy went on to pursue taphonomy and site-formation processes, while Nick concentrated more on technology, becoming one of the best knappers of Acheulean forms. Both Kathy and Nick are deeply interested in cognitive evolution and Acheulean technology. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1522129775877-BP1WDPDCWUQ96IXGUH5U/hxs_interm.jpg Lithic Replicas, Landscapes, and Critters - Potential Acheulean materials For the handaxe at left I used an extremely tough basalt from Washington State, typical of the Columbia River flood basalts. For the handaxe at right I used a tuffaceous greenstone from the Sierra foothills. If Acheulean people had been able to come to North America, they would have found vast amounts of raw material suitable to their uses. But they never made it even to East Asia, though a crude, early-Acheulean-like technology was independently invented there. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606430949570-3AQX3U31P7FK8ARL3T03/cleavers.jpg Lithic Replicas, Landscapes, and Critters - Acheulean cleavers This shows an expedient cleaver at left, which took five minutes to knap, entirely with hammerstone and with minimal platform preparation, vs. a refined one at right, knapped with antler, with extensive platform preparation, and requiring about 40 minutes. The cleaver at left is in Jurassic metatuff from the Sierra foothills; the cleaver at right is in Lake County, CA coarse-grained basalt (chemically dacite). https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1607053731171-0ORPQGEFRL42F5FSR1LL/DSC_6343ps.jpg Lithic Replicas, Landscapes, and Critters - Martis dartpoint replicas Here are some of my middling replicas of Martis basalt dartpoints.. They are mostly at the upper end of the size range for real Martis points, because it’s the best I can do with my extra-large hands. The three at right were commenced with direct antler percussion on thickish flakes, then finished with pressure. The point at far left was commenced on a thin but wide flake with antler percussion, and finished with pressure. Second from left is the most interesting. This is all direct percussion with a wooden billet (Cercocarpus), except for finishing the tang with pressure. Differences in grain represent different raw material sources in the northern Sierra. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435768527502-CV0JPYEVWWDXB4ZWMPDT/martis.jpg Lithic Replicas, Landscapes, and Critters - basalt knife replicas In the northern Sierra Nevada of California, obsidian is not locally available. Middle Archaic (pre bow and arrow) lithic assemblages were dominated by locally available basalt. These are some of my replicas of "Martis" knives using various authentic Sierran basalts, except fourth from left, which is in basalt from Modoc County. Like most knappers since Acheulean days, the original makers of Martis bifaces often imparted much more beauty and refinement to their work than was required for basic functionality. My experimental program to replicate Martis bifaces appeared in The Journal of California and Great Basin Anthropology. To find that paper, try: https://escholarship.org/content/qt17p95410/qt17p95410.pdf https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763960211870-RK17WXJE8J9L43X32CM0/Alder+Hill+material+copy+2R2.jpg Lithic Replicas, Landscapes, and Critters - large fine biface made in Alder Hill trachyandesite All that looks like basalt may not be. All the toolstone at Alder Hill is trachyandesite. “Basalts” are often gunsteel blue. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606810860331-1BT8Z147HBHGFK1FVU5Q/AlderHill3.jpg Lithic Replicas, Landscapes, and Critters - Alder Hill basalt Two lanccolates I made in particularly coarse and miserable basalt from Alder Hill, Nevada County. Truckee, California is surrounded by very young mafic volcanoes but residents there are generally unaware. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1713420772481-SD601O9DYNR1RCNCRKBS/Bowmanknife1+copy.jpg Lithic Replicas, Landscapes, and Critters - Bowman Lake metasediment knife This material is much tougher than basalt, and much less brittle. It LOOKS like basalt, but it’s not. I made this ca. 4” knife with great difficulty. The percussion phases required powerful blows; the pressure flaking required all my strength. Martis knappers were smart enough to know this material should be reserved for cores and flakes, and maybe the odd scraper. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1628923354812-C6A18RHLIZ5LELDH59F5/MedicineCF.jpg Lithic Replicas, Landscapes, and Critters - Medicine Lake obsidian bifaces This grayish material collected from the Glass Mountain (mostly rhyolitic) obsidian flow on the rim of the Medicine Lake caldera is a joy to work, but it’s hard to find. The vast bulk of obsidian in this complex flow is unworkable, being already criss-crossed with fractures. These are two of my experiments in controlled percussion, the larger one like “blades” used for ceremonial purposes by Klamath River Indians, though not as large; the smaller one a mediocre attempt at a Solutrean laurel leaf: too thick, but a nice flake-scar pattern, all antler percussion. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1659939572883-0YKQAF7HZQ9UDIAFS1IQ/bifaceCF.jpg Lithic Replicas, Landscapes, and Critters - glass and glass Left, a lovely knife made from a thick bottle bottom I picked up in an old dump in the Sierra foothills. The aquamarine color may be from clarifying agents that were much used in the 1880s until 1920. At right is a large lanceolate biface in so-called mahogany obsidian from Davis Creek in the Warner Mountains generously donated to me by Phil Olrich. I had one shot at this, as I knew I would never again get a flake of reddish obsidian large enough to do this. I had to stop before most knappers would call it finished, for fear of ruining my one opportunity with a rash desire for perfection. The view is very much foreshortened, as I had to get the camera down low, as close to end-on as possible, to get the color to show in the bottle glass. Anyway, these I put up just for their sheer beauty. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1554877405952-O9196I8195V7SIJXYLT2/DSC_0008+copy.JPG Lithic Replicas, Landscapes, and Critters - Farmington chert associate A reddish cherty ?argillite occurs with green Farmington chert in the latest Pleistocene or early Holocene artifact assemblages from Rancho Murietta east of Sacramento. Both materials were used extensively and seem to grade into one another. There are hints that pieces like this “replica” were a goal of the prehistoric knappers, even though no such finished artifact has been found—yet. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701806769698-SYZXWNMHHJ1HIYVXFY9B/10l+lined+june+beetle+combo.jpg Lithic Replicas, Landscapes, and Critters - Ten-Lined June Beetles at Samoa Dunes …in Humboldt County…Left, a beetle showing off its magnificence on a shoot of Pinus contorta. Right, another in flight. Presumably the flags on the antennae are for detecting pheromones. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740468215965-V9OOVW61WAXPANHBAAWL/PVcatR.jpg Lithic Replicas, Landscapes, and Critters - Pipevine swallowtail …on our Aristolochia a few years ago… The striking colors are to ward off predators. All parts of the plant are poisonous, and the caterpllars become poisonous by eating the leaves. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748910039481-RFZXRR09O8MQ71K6WK5P/monarch+caterplilarR.jpg Lithic Replicas, Landscapes, and Critters - Monarch caterpillar in Briones …on Ascepias fascicularis in the Alhambra Creek watershed, I believe in June….Regardez the silken holdfast at the posterior end. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1750641637716-50T0W3M9DNBO1F2XDWLZ/sphinx%26+bumblebeeon+MonardellaR2LT.jpg Lithic Replicas, Landscapes, and Critters - sphinx moth on Monardella odoratissima This was on the Round Lake trail, just north of the ridge separating Gold Lake from Lakes Basin. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1713239111424-YDJ95BWW360SUZWA2JUU/Van+Damme+combo+copy.jpg Lithic Replicas, Landscapes, and Critters - on a drizzly day in Van Damme State Park Lungwort Lobaria pulmonata, left; Pacific Giant Salamander Dicamptodon sp., right. The taxonomy of the latter is complex. It’s in the Ambystomatidae, with Tiger Salamander Ambystoma being the type genus. The Lobaria grows on logs and high in conifers, and it falls to the forest floor often. It’s a partnership of a fungus, an alga, and a nitrogen-fixing cyanobacterium, and when it falls to the forest floor and decomposes it contributes a significant amount of nitrogen to the soil. The pitted surface of the thallus has reminded some of lung tissue, so herbalists once recommended it as a remedy for tuberculosus. The thallus reminds me of a staghorn fern. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1729311517033-2QKIGHEC34LSK9UCKVX1/Rana+cascadae.jpg Lithic Replicas, Landscapes, and Critters - Cascades Frog near Mt. Eddy I won’t disclose the locality, fearing collectors. Note the dorsolateral folds, which related Yellow-legged frogs lack. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1445707364631-SSWF488DZGSI294LXPVY/RLfrogs_edited-1.jpg Lithic Replicas, Landscapes, and Critters - frogs in a box In a spring box in a remote part of Contra Costa County, October 2010, the western toad was whispering "Today I'm a red-legged frog. I'm so sleek, so stylish, so beautiful, so RED! If I don't move, they'll never know." https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1614585811777-LGH53X424C9CN17XSXZR/LassenSnake%26trout2.jpg Lithic Replicas, Landscapes, and Critters - garter snake with trout It may come as a surprise that garter snakes can catch trout, and that they can do so in chill waters of streamlets in mountain meadows, as was the case here, east of Lassen National Park. Photo by Katie Colbert. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1501911862541-LSZZUWNKAQR9JDVZEFS9/leopardlizardShortCanyonInterm_edited-1.jpg Lithic Replicas, Landscapes, and Critters - Collared Lizard, Short Canyon This collared lizard MAY have been part of a population adapted in coloration to the granitic rocks they inhabited in the Owens Peak area of the southeastern Sierra. This was the most beautiful lizard I’ve ever seen. Look at ALL the green dots and orange stripes! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1736229104116-X1L0JICEM5A1XC59STTI/P8150067+%2B%2B%2B+%28983x1024%29+copy.jpg Lithic Replicas, Landscapes, and Critters - Long nosed leopard lizard Photographed by my good friend Mike Uhler at Taboose Pass Trailhead near Big Pine. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738190104976-H8QW600HJDU7C7HTAVVU/BN+leopard+lizard1.jpg Lithic Replicas, Landscapes, and Critters - blunt-nosed leopard lizard I photographed this lizard on the Elkhorn Plain, which is immediately east of the Carrizo Plain, in the 1980s. The next photo, a closer view of the same lizard, makes the source of the name obvious. I was using a macro lens for both photos, so I had to get very close. I learned that, if I approached slowy with my face concealed by the cyclopean camera, lizards would not consider me a mammalian predator. LOOK AT HE DISPROPORTIONATELY LONG HIND LEGS. THIS LIZARD WAS MADE FOR SPEED. I saw it running on its hind legs! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738190140398-47Y6ZSXFJCSXL0OZI34N/BN+leopard+liz2.jpg Lithic Replicas, Landscapes, and Critters - blunt-nosed leopard lizard …the same critter as that in the previous photo… This closer view makes the source of the name obvious https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1743552982138-XD26HQYR4Y6GXITHFNIL/even+better2A-R.jpg Lithic Replicas, Landscapes, and Critters - desert iguana …coming and going as it pleases, living wild on the grounds of the Maturango Museum in Ridgecrest, CA….Desert iguanas are almost entirely vegetarian, especaily favoring flowers and leaves of creosote! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706910704092-4UIKM1GZNDHEPSAE3XBW/whiptail+N+Pk+copy.jpg Lithic Replicas, Landscapes, and Critters - whiptail on North Peak North Peak is consort to Mt. Diablo. It’s common to encounter whiptails around the summits of both Mt. Diablo and North Peak. Note that this wonderful reptile has very long toes on those legs, analagous to the collared lizard in the preceding picture. But the amazing armored plating on those legs contrasts starkly with the hind legs of the collared and leopard lizards, which are smooth and unemcumbered by armor, and probably built for speed. Collared and leopard lizards are ferocious predators, usually in attack mode, so defense can be de-emphasized. That’s my two cents. Note the impressive scimitar-like claws on the front feet of the whiptail. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1445646317714-IJ9SXC98VZICAWG3VZUA/buckeyeA.jpg Lithic Replicas, Landscapes, and Critters - buckeye with bark stripped Two buckeyes in the eastern part of Briones Regional Park were stripped of their bark during the summer of 2015 by ground squirrels, the population of which has been increasing dramatically despite drought. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1445646844897-5CT1C2O9CMU6HRRZ3KU1/buckeyeB.jpg Lithic Replicas, Landscapes, and Critters - buckeye bark close-up You can see the bite marks left by squirrel incisors. Climbing trees makes ground squirrels vulnerable to predators. It would be a fair guess that these terrestrial rodents at Briones were hungry. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435728530108-R8W5LS5N7FK8F88ETC87/otter2-14Davis+018.jpg Lithic Replicas, Landscapes, and Critters - river otter caught in action pulling a carp out of the Putah Creek canal at U.C. Davis https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1436649469798-CWK03ELFF3Q8MEKBGZMC/foxesps.jpg Lithic Replicas, Landscapes, and Critters - Gray Fox cubs Urocyon cinereoargenteus in a woodpile at the Regional Parks Botanic Garden https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1739490537204-2FS9GDI91JXKM10VY45Y/Coyote+in+Owens+ValleyR.jpg Lithic Replicas, Landscapes, and Critters - Coyote singing in Owens Valley My Mom was for many years the official artist of the California Wildlife Federation. This painting and the next one, of a wolverine, are two of my most favorite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1739490566857-BOEAN4BQRYV520JMPAAT/Gulo++gulo+copy.jpg Lithic Replicas, Landscapes, and Critters - Gulo gulo …is the Latin name for the wolverine… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611544332049-44GCHNRN9OFCTPYN4RYJ/Param.jpg Lithic Replicas, Landscapes, and Critters - Paramylodon mandibular cheekteeth Our largest Pleistocene ground sloth was Paramylodon harlani. Its dietary adaptations have become clearer in recent years after long uncertainty. This is addressed in my “Oops to the Oops” essay in my essays and poetry section. These photos of a specimen in a private collection show the open roots of the cheekteeth. Just as in rodent incisors, this indicates they were ever-growing, which suggests an abrasive diet. The two teeth in the right photo are the same as the two on the left in the left photo. In the right photo we are looking into the roots of the teeth from below. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1613186432558-PJH6RLVF2IR5SWX1C7ZH/uppersexposedRED.jpg Lithic Replicas, Landscapes, and Critters - Equus cheek teeth This is the right upper cheek tooth series of a modern horse, with the bone peeled away to expose anatomy. The teeth are P2 at left through M3 at right. Horses have hypsodont teeth adapted to grazing grasses, which with their silica phytoliths wear teeth down quickly. The teeth are not ever-growing, but ever-erupting. You can see that M1 erupted earlier than P3-4 or M2-3. The cracking stuff is cementum, the outermost mineral coating of the tooth, but it is also a living tissue. It has cementoblasts, blood supply, nerve bundles, and is surrounded by periodontal ligament which helps attach the tooth to the alveolar bone (the porous bone between the teeth). Cementum is thickest near the base of the tooth and near the top where the tooth is most subject to wear. At the time of eruption, cementum covers the entire tooth, and remains on parts of the chewing surface throughout the life of the animal. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1657093637763-1MHRL0BE8GGLQ84JELRF/horsemaxescfR1.jpg Lithic Replicas, Landscapes, and Critters - horse upper cheek tooth series CF Here we have left upper P2-M3 of modern Equus, above, and a Miocene hipparionine, below.. The cementum fills the two main fossettes and surrounds the protocone. It has about 50% hydroxyapatite, and is slightly softer than dentine with about 70%, and much softer than enamel with about 95%. The P2 and M3 are transversely narrower than the other teeth because the skull contour there is narrowing. I study fossil horses, which are best represented in the record by teeth. These teeth have an elaborate terminology that takes some time and practice to learn. The biggest thing that distinguishes Equus from its ancestral genera is that the protocone extends BOTH anterior and posterior to the isthmus connecting it to the protoconule. The anterior extension is what is unique to Equus. In striking contrast, the protocone in the hipparionine (an unrelated group) makes a separate ellipse connected only in P2-P3, though in many hipparionines there is no connection at all. Sorry for the jargon! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1671522907692-VJKY7PBX8CWVIB6IZ0P6/Miracinonyx.jpg Lithic Replicas, Landscapes, and Critters - American Cheetah A spectacular skull of American Cheetah Miracinonyx trumani, from the terminal Pleistocene of Crypt Cave, east of Winnemucca Dry Lake, Nevada. American cheetahs were built like old world ones, and probably closely related, an earlier North American species than this one possibly ancestral to old world forms. This skull is in the Nevada State Museum in Carson City. I consider it one of the most wonderful fossils of any kind ever found in North America. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735796318862-UOBITUT8WXKX375V506P/badger+skull.JPG Lithic Replicas, Landscapes, and Critters - ground squirrels' nightmare In the anterior dentition of a badger skull, the upper lateral incisor is caniniform. Together with the upper canine, it embraces the lower canine so that wriggling and struggling prey is firmly clamped. Wolves share this feature. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1709338486129-TCBDZGU5N4O78EK743LG/Pongo-Pan+combo-sharperimproved.jpg Lithic Replicas, Landscapes, and Critters - Pongo and Pan skulls compared Pongo differs from both Pan and Gorilla by its concave face, reduced supraorbital torus, lack of frontal sinuses (thus the reduced brow ridges), very narrow interorbital space, orbits higher than wide, and upwardly oriented (rising forward) neurocranium relative to palate and toothrow. All but the last feature can be seen in these pictures. Sivapithecus shares with Pongo several of these very distinctive features and is thought to be ancestral to Pongo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740018753802-MFQUV5K2SL67ZSLZ2HPV/Proconsul+cf+best%3FR2.jpg Lithic Replicas, Landscapes, and Critters - ancestor-descendent? Proconsul heseloni, left, type specimen from Rusinga Island, ca. 18 Ma….Right, Aegyptopithecus zeuxis skull from high in the Jebel Qatrani Formation in the Fayum of the western desert of Egypt. 33.1-33.4 Ma. Owing to the striking resemblance of dentitions, I believe the latter was in the direct ancestry of the former, despite the great difference in age. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648879639465-U9CQAITB5FJCQCRIREVZ/major+male%26female+copyps2R.jpg Lithic Replicas, Landscapes, and Critters - early Miocene hominoids from Kenya These mandibles have been variously classified. Le Gros Clark and Leakey 1951 called the one at right, from Songhor, Proconsul major, but Martin Pickford renamed it Ugandapithecus major. The more gracile mandible at left, the size of a female chimpanzee, has also been called Proconsul major by Begun, but this would be a female. It hails from the Legetet Formation at Koru. Pickford made it his holotype of Ugandapithecus legetetensis, but Begun’s classification seems better to me. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1649139143502-RRGRRW088GWJMOQ3C2EB/Samburupithecus%26femaleGorillabetter.jpg Lithic Replicas, Landscapes, and Critters - Samburupithecus Above, a maxillary toothrow of Samburupithecus, from the Samburu Hills in Kenya and about 9.5 my old. Below, a maxillary toothrow of a female lowland gorilla, of fairly comparable size. Begun studied skull parts of the former and found that it looks just like Ekembo, and its teeth too are suggestive that it might be a late proconsulid, rather than a hominine like the gorilla. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648419839574-61WO7B31A75MKTYPD9Z8/Sivafr2A.jpg Lithic Replicas, Landscapes, and Critters - Sivapithecus and Equatorius left in both pictures is a partial dentary of Sivapithecus (sivalensis, indicus) from the Siwalik Hills, foothills to the Himalayas, from the Nagri Formation of Pakistan. Right in left photo is a juvenile mandible from Maboko Island, Kenya, referred by McCrossin and Benefit to Kenyapithecus africanus, a taxon originally called Sivapthecus africanus by LeGros Clark and Leakey. The striking resemblance of their thick-enameled first permanent molars suggests the affiliation, but these days this is regarded as a result of homoplasy rather than direct relation. The right hand dentary in the photo at right is part of the type specimen of Equatorius africanus from the Tugen Hills in Kenya. The same observations apply. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1649139122789-D1E7F4GKG623VBR17CN5/Nacholo.jpg Lithic Replicas, Landscapes, and Critters - Nacholapithecus and Sivapithecus africanus Both are from Kenya. On the right is a cast of the type specimen of Sivapithecus africanus from Maboko Island, named by Le Gros Clark and Leakey in 1951 and housed at the British Museum. They were impressed by its similarites to fossils from the Siwalik foothills. Left is part of the dentition of Nacholapithecus, ca. 15 my old, also from Kenya, which has similar characteristics. Thick enamel, relatively low cusps, and vestigial cingulae repeatedly appear in various taxa in Africa and Eurasia, and reflect diet more than genetic relationship, though Begun shows most of these taxa (Sivapithecus, Griphopithecus, Kenyapithecus, Equatorius, and Nacholapithecus) pretty close together in his family tree. So the jury is still out! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648534172313-TDJBL2TB7XQADEQ5CUV1/Indopih.jpg Lithic Replicas, Landscapes, and Critters - Sivapithecus and Indopithecus Another interesting comparison. Left, a robust Sivapthecus dentary, and right, a mandible of Indopithecus giganteus (aka Gigantopithecus bilaspurensis), both from the Siwalik foothills of the Himalayas. The close resemblance in morphology suggests the latter, ca. 6.5 my old, was derived from the former, around 10 my old. A skull of Sivapithecus looks very much like a modern orangutan, which suggests both specimens here are related to orangs, and so too is Gigantopithecus blacki, a polar-bear-sized ape found only in the mid-to-late Pleistocene of China. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648967501468-VOJZEOI1RT0IPBLP2GPY/OuranoR.jpg Lithic Replicas, Landscapes, and Critters - Ouranopithecus Ouranopithecus macedoniensis is an ape that has been found in strata ca. 9 my old in Macedonia (Greece), and perhaps from Bulgaria to Turkey. Its smallish canines compared to other apes, as well as its extremely thick-enameled and low-cusped molars have led some authors to claim it is ancestral to Australopithecus. But details of its skull are not a good fit; moreover, Ardipithecus and chimps resemble each other more than they do Ouranopithecus, and neither have such molars. Australopithecus would had to have evolved thick enamel and low cusps a second time after its ancestors had lost them. Chimps are NOT our ancestors, but our common ancestor with them probably resembled them gnathically, based on Ardipithecus. The dental adaptation of Ouranopithecus has evolved repeatedly as climates dried and mammals were forced to adapt to a more varied diet on the ground, with a lot of hard foods (such as seeds and tubers or corms with adhering grit). https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648572268112-CEC8IJ89W7CEDNVXQIQC/A.africanus+faceB%26W2+copy.jpg Lithic Replicas, Landscapes, and Critters - the face of Australopithecus africanus Here are five faces or fragments thereof of specimens from Sterkfontein that Ron Clarke has called Australopithecus africanus sensu stricto. I agree in every case. From left to right, STW 53, a skull Tobias referred to Homo habilis (which makes little sense: its teeth are too big for that taxon, and it has an embarassing amount of postorbital constiction of the frontal, while its face is confluent in morphology with the others); next right, Sts 5 (note the very strong canine pillars that rise to frame the nasal aperture); next, STW 13 (ditto); next, TM 1512 (with a more Homo-like configuration resembling STW 53); and, far right, a 3D scan of Sts 52a (which bridges the gap betwen more Homo-like and more strongly pillared faces). All are good, real casts, except the last. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1649139167007-6D1C70WCT4OY4EEFBMLT/postcrancf.jpg Lithic Replicas, Landscapes, and Critters - innominates and femora Left, left innominate and femur of Australopithecus afarensis, right, those of a modern chimapamzee. The latter is arranged as if the animal tried to stand erect bipedally. Note the smaller lesser trochanter and ischial tuberosity on A. afarensis. The larger counterparts on the chimp would tend to pinch soft tissues between them unless the chimp walks with feet widely apart—which it must do anyway because the gluteus medius is a hip extensor rather than a hip abductor as in bipedal hominines. The latter arrangement is provided for by the forwardly rotated, broad ilium of such creatures. The lesser trochanter in bipedal hominines receives the tendons of the iliacus and psoas major, both of which flex and laterally rotate the femur, while also helping with stability. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648534195156-HYP78H7D4C4QMRN1G923/promethmandcfR.jpg Lithic Replicas, Landscapes, and Critters - 2 species of Australopithecus from Sterkfontein mandibles of Australopithecus africanus (Sts 52b), left, and right, what Ron Clarke has called A. prometheus (Sts 36), using a name coined by Raymond Dart at Makapansgat. I’m going to go out on a limb and shamelessly admit that I think Ron Clarke is right. One essentially never gets to see high quality photos of these specimens, and virtually never side-by-side comparisons of important specimens. This has always frustrated me, and I am trying to remedy the problem. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1709341063015-OJAX4F0YV416T66S2169/406+cfd+robustusR.jpg Lithic Replicas, Landscapes, and Critters - Paranthropus crania compared P. boisei, left. P. robustus, right. Yoel Rak discovered many hitherto unsuspected things about australopithecine faces. For instance, what Yoel called the maxillary trigon (a depressed triangular area) can be seen well preserved on the right maxilla of robustus, adjacent to the nasal cavity. Also, the zygomatics on boisei are much more flaring than those of robustus, because in the latter the face is more perpendicular to the sides of the cranium, whreas in boisei the relation is much more rounded to make space for very thick masseters. Also the orbits differ in shape, and the supraorbital torus is flatter in boisei, while dipping more in the center in robustus. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1649206810815-4G3HIYGETR3EIN6799QE/boiseiR.jpg Lithic Replicas, Landscapes, and Critters - Australopithecus boisei variation in size in two male mandibles of A. boisei, left, KNM-ER 729 from East Turkana, right the Peninj mandible from near Lake Natron. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1671240321863-PCUYBTTA3NXLBUYKL0O0/boisei+vs.+NiauxRED.jpg Lithic Replicas, Landscapes, and Critters - boisei vs. Homo sapiens Left, perhaps the largest mandible and dentition of Australopithecus boisei ever found; right, Homo sapiens sapiens, and not a small individual, from Niaux Cave in France. This gives a sense of just how megadont australopiths really were. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1649574507176-X4L8EJQF1ZTU2JQVSQC1/1482%263230R2.jpg Lithic Replicas, Landscapes, and Critters - female and male A. boisei? KNM-ER 1482, left, from a bit below the KBS tuff at East Turkana, and KNM-ER 3230 from a bit above it. 3230 is a very robust male A. boisei (or, if you wish, Paranthropus). The identification of 1482 has long been in doubt, and Coppens et al. 1976 just called it Hominidae indet. I think it’s a female mandible of A. boisei. Skulls have demonstrated great sexual dimorphism in size of this species. The V-shaped mandible, extreme crowding of the canines and incisors, and relatively large size of P/4 compared to M/1 (compared to Homo) move me in that direction. There are also resemblances to A. aethiopicus, namely the V shape, the crowding, a low corpus, and a deep fossa on the posterior aspect of the symphysis.. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1651881112618-RI5674N7CM37DAIPPV7Z/OH5%26PeninjCROPR.jpg Lithic Replicas, Landscapes, and Critters - OH 5 with Peninj mandible This imperfect fit between two large male individuals of Paranthropus boisei demonstrates something universally true of australopithecines: They were all face (or, if you want, all jaws and teeth). https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1651881137857-TV8F85BU0D2VC3THYVJ2/Sts71%2636CRopR.jpg Lithic Replicas, Landscapes, and Critters - Sts 71 & Sts 36 Another imperfect fit, but the mandible and cranium here are from one individual, from Sterkfontein, that Ron Clarke has referred to Australopithecus prometheus, and others to A. africanus. Both pieces were severely distorted by settling of cave breccia. This is the only perspective from which they almost articulate. But the fit is close enough to give the general sense: again, all face! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648534214433-U6XH3HD90O4D99UW0F0R/promethcf2R.jpg Lithic Replicas, Landscapes, and Critters - 2 Australopithecus and...? from left, A. africanus and the juvenile type specimen of A. prometheus, both from Makapansgat. Right, KNM-ER 1802, which has been assigned to Homo rudolfensis, even though it bears little resemblance to a much more complete mandible that seems clearly to belong to that taxon. I find the resemblance beween the dentition of 1802 and the type specimen of A. prometheus, center, striking. One would merely have to delete the labial cingulae in the latter! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648880462123-FQUG2YEAX7WEF3JYGJ9M/habilis.jpg Lithic Replicas, Landscapes, and Critters - Homo habils KNM-ER 1813 from East Turkana, left, and OH 16 from Olduvai, right, showing their striking similarity. OH 16 is part of the hypodigm of Homo habilis, and I do not believe 1813 can be called anything else. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1672727657045-RNM9QF5112ATQR5CT2Z4/1813comboRbest.jpg Lithic Replicas, Landscapes, and Critters - comparison between Homo habilis and A. africanus This is a comparison between Homo habilis, represented by KNM-ER 1813, gray, and STW 53, ochreous, which Philip Tobias referred to Homo habilis, but Ron Clarke referred to Australopithecus africanus. I agree with Ron Clarke, and here are some of my reasons. The face of 1813 is flat, with no trace of nasal pillars, and the beginnings of strong brow ridges. Also the root of the zygomatic is much more horizontal in 1813, though these pictures do not show that feature well. In every case STW 53 is, in contrast, like any A. africanus. The teeth of STW 53 are too big for Homo habilis. The postorbital constriction in STW 53 would be embarassing for any Homo. And the well-preserved mastoid region of STW 53 is hypertrophied, almost like A afarensis, with which it is compared at upper left. The mastoid region in 1813 is much reduced. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1672367899847-UWAD6BUO1M83923CQ04I/naledi+vs+TelanthropusR2.jpg Lithic Replicas, Landscapes, and Critters - naledi vs Telanthropus Left, 3D print of Homo naledi mandible from Rising Star Cave; right, cast of type specimen (SK 15) of Telanthropus capensis from nearby Swartkrans. The latter was later transferred to Homo erectus. The subequal lengths of second and third molars contrast with the usual situation in Homo erectus, where the 3rd molar is always or almost always smaller than the second. The strong resemblance between these two mandibles at least suggests that they belong to the same taxon. This, among other things, really makes me doubt the young dates for naledi. At the very least, the resemblances here are intriguing. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1649206855163-FZK85C8OQDTI6MQ468C5/rudolph%26platyR.jpg Lithic Replicas, Landscapes, and Critters - Two skulls from Kenya Homo rudolfensis, left, and the much older Kenyanthropius platyops, right. Tim White argued convincingly that the platyops skull was too crushed for its reconstruction to be of much use. Meave Leakey and Alan Walker made a compelling case that their reconstruction is good. The answer? Find a better specimen! rudolfensis is about 2 my old, platyops closer to 4. The former is from East Turkana, the latter from West. The flat face of platyops, so surprisingly reminiscant of that of rudolfensis, suggests to many that the former could be a direct ancestor of the latter. Time will tell. It took clse to 40 years for additional fossils to be found that virtually clinched acceptance of rudolfensis as a species in a separate lineage than H. habilis. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1649206830685-29C6TMMSMRXI5F2U8I93/HEX2AR2.jpg Lithic Replicas, Landscapes, and Critters - Homo erectus calvaria This is an interesting comparison, showing left, skull 12 from Choukoutien, and right, OH 9 from Olduvai. The latter, at about 1 my old, is at least twice as old as the former, but it is already showing suggestions of African early Homo sapiens that shows up around 600 ky. Note the charateristic eminence that runs fore-aft along the top of CKT 12, and the heavy, less bipartite brow ridge of OH 9. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648419892203-O4D10V0M8WFE0QLOF78P/SolovsCKT.jpg Lithic Replicas, Landscapes, and Critters - Solo skull 11 vs. Choukoutien skull 12 Left in each pair is Solo Skull 11, right in each is Choukoutien Homo erectus skull 12. The Solo skulls have been referred to Homo erectus, and they do have a strong morphological resemblance, but the larger brain of the much later Solo form has expanded the skull so that the vault is slightly higher, but in particular there is much less postorbital constiction and the sides of the vault are closer to vertical. I’m on the fence regarding whether the Solo skulls truly represent H. erectus—I lean toward early sapiens. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1671239891264-CZCDK78HBFS9BVMOVDBB/naledi+vs.+CKTRED.jpg Lithic Replicas, Landscapes, and Critters - Homo naledi vs. H. erectus Homo naledi, a 3D print, left, and Homo erectus from Choukoutien, right, a brilliant reconstruction from original specimens by Tattersal and Sawyer. This should dispel any notion that naledi is actually a form of erectus. In my view naledi is unique. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648968661227-YBQZEJQRYPJT7JQNP3WH/megan.jpg Lithic Replicas, Landscapes, and Critters - Meganthropus left, what has been called Meganthropus paleojavanicus; right, Homo erectus. Both specimens are from Sangiran in Java. The corpus of the mandible in the former is extraordinarily thick compared to any Homo erectus, and the teeth are larger too. Most workers consign Meganthropus to synomymy under Homo erectus, but I’ve always found the differences intriguing. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648534233022-RF8SG12PQOE6P6J8SSI0/SkuhlcfR.jpg Lithic Replicas, Landscapes, and Critters - Skuhl skulls V and IV Another comparison one never sees in papers or books. These are skull V, left, and skull IV, right, from Mugharet es-Skuhl, Mt. Carmel, Israel. This was some of the first material of Homo sapiens sapiens recognized to be very old—though, at ca 100ky, it seems young now, as a modern skull from the Omo region of SW Ethiopia, twice as old, has been dated more recently, and two skulls from Djebel Irhoud in Morocco, nearly modern, are thrice as old. It was once thought that the skulls from Skuhl show very recent mating with neandertals, but I don’t buy that. The cheek bones on skull V, left, are heavily (but very reasonably) reconstructed, but those on skull IV were more or less intact. In each case they are very flaring, and thus very different from those of neandertals, which are swept back. I think the original thought was Mendelian, and these would be F1 or F2 hybrids. Though the skulls retain some robust features that are primitive retentions, they do not seem to be F1 or F2 blendings of ssp. sapiens and ssp. neandertalensis. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1671239180914-580YVY3GRMFJRHKRA31O/Shanidar+vs.+Skuhl+4Red2.jpg Lithic Replicas, Landscapes, and Critters - neandertal vs. modern human faces Shanidar i, left, a reconstruction by Tattersal and Sawyer using original specimens, and right, Skuhl IV, the face of an early modern Homo sapiens sapiens. The neandertal’s midfacial prognathism (“fish face”) is striking. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1631255364968-24FD3X35Q0QOQL6IWGPM/NShellpelicansR2A%2B.jpg Lithic Replicas, Landscapes, and Critters - Sonoma coast pterodactyls We got into a throng of pterodactyls (actually, brown pelicans) on the Sonoma coast in September 2021. Many were diving for something evidently schooling beneath the surface. My camera could only catch a fraction of them, so I chose the one photo I like best. Can you see the brave little cormorant in the water? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531859730585-7FZBKIMVCSIQ9JIFB5XG/DrakesBeachSandForest+Interm.jpg Lithic Replicas, Landscapes, and Critters - sand forest Something like a Carboniferous coal forest has been created by water retreating down the shoreface of Drake’s Beach, winter 2017-18. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1594427612038-Y6SOAL4TYGLBCJQ5NXXT/OlivellaLiveinterm.jpg Lithic Replicas, Landscapes, and Critters - Olivella biplicata live These snails distribute themselves in intertidal sand with smaller animals in deeper water and larger ones in the wet beach sand, typically just a few inches beneath the surface. Run your fingers through the wet sand and you can find these beautiful shells. Looking at California prehistoric beads bleached white by weathering gives no sense at all of how beautiful the shells were when the animals were alive, as in this photo taken on Drakes Beach. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1758667412865-79E8DSD98Y5LTA86LHXR/kehoe+RR.jpg Lithic Replicas, Landscapes, and Critters - by-the-wind sailor at Kehoe 8/25 The Irish for this jellyfish is: smugairle nagaoithe, which can be translated as “snot of the wind.”—-perhaps in this case, with more decorum, “spittle of the wind.” This beautiful shot was taken by Katie Colbert. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1752361986187-NY2Q2YMWLG97NAU04MSL/Armeria+maritima+at+KehoeR.jpg Lithic Replicas, Landscapes, and Critters - Armermia maritima …on a N-facing slope on the seabluff at Kehoe… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1752796474001-ZW65LE17O97IPV0D2MT3/looking+NW+from+N+end+of+KehoeR+copy.jpg Lithic Replicas, Landscapes, and Critters - looking NW toward MaClures from N end of Kehoe ….early June 2024…The sky turned darker blue before sunset… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1752795782513-YD9UDSVHZ8YG41U899CN/sand+figurescroppedR+copy.jpg Lithic Replicas, Landscapes, and Critters - sand figures dancing on Kehoe Beach …..July 2025….not the “melancholy long withdrawing roar” of Dover Beach, but jolly…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1712879441127-0ME3NPNWLPQR6RLCFSR6/DSC_5293R.jpg Lithic Replicas, Landscapes, and Critters - Laird Sandstone at Kehoe Fresh water draining and dripping of this cliff of Miocene Laird Sandstone at Kehoe in early April 2024 created these stripes. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1754955775929-Z0LTW42G8CHJSBN5X65P/sunset+at+Kehoe-2R+cropped.jpg Lithic Replicas, Landscapes, and Critters - sunset at Kehoe I caught the slate blue-gray ot the ocean…..my favorite color in Nature… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1755468406069-NPX0J3F5E8BOZO3A8RYY/gull+from+Tennessee+Pt.jpg Lithic Replicas, Landscapes, and Critters - sunset with gull from Tennessee Pt. Marin County I really caught the slate-blue-gray of the ocean with this one! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611438454702-6FDIBUA7O8OWGT1SGV44/interm.jpg Lithic Replicas, Landscapes, and Critters - Franciscan chert, Marin headlands This view north from Tennessee Point shows huge dip slope, at least on the left side of the cliff, in Franciscan chert. Wouldn’t it be fun to be there during a temblor that causes a huge sheet to detach all at once? There is also a normal fault cutting down from the high point, right side down. This photo by Katie Colbert captures the thrill of the place. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1726272154425-D8H4C0H6HTH5WO49PE72/Tenn+PtR.jpg Lithic Replicas, Landscapes, and Critters - Franciscan chert, Tennessee Point This tightly folded Franciscan chert is on an inaccessible beach at Tennessee Point in Marin County. Photo by Katie Colbert https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708902545948-5152GCYPJ492W6QRZFG4/N+Warners+across+Goose+Lr.jpg Lithic Replicas, Landscapes, and Critters - glorious North Warner Mts. …viewed looking east across Goose Lake in June… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765072800240-BYXQ2Q1C5NGLGO7M3AOP/Cypripedeum+motanum2.jpg Lithic Replicas, Landscapes, and Critters - Cypripeum montanum …in those glorious north Warners. I will not disclose the location, as some jackass with a shovel would be likely to go there and dig it up. Since these plants are not growable, it would be phytocide—in short, murder; and the act of a moron. Scanned from a slide I shot in 1989. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1734901737587-T2R1X63IHG79Q3MS5NN5/meadow+in+granite.jpg Lithic Replicas, Landscapes, and Critters - green meadow in granitics, NE Plumas Co. I was entranced by this landscape. “Magic light” is overrated. You can take wonderful pictures in all kinds of light. Devastation of Dixie fire in distance. Ceanothus velutinus in bloom in abundance at left. This was between Dixie Valley and Thompson Peak, but closer to the latter, hence in the NE part of Plumas County, near Lassen County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748735199017-ARX1X2S2Z0D81SX40EIP/meadow+at+start+of+Haskell+rd.jpg Lithic Replicas, Landscapes, and Critters - beautiful meadow …at the start of the road to Haskell Peak June 2023…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1731564300499-7S31IIRPBGKJENSFXEYI/Spencer+Lks+cropped%26+sharper2.jpg Lithic Replicas, Landscapes, and Critters - Spencer Lakes, north of Sierra Buttes Upper Spencer Lake, left, Lower Spencer, right. This was taken during the first week of August, 2023— a heavy snow year. Check out the snowbank at an inlet to Upper Spencer. That’s where the following photo was taken about 30 years ago. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1444453030356-5K1K1I2EPAH9AEL39ION/SorbustrailtoWadesL.jpg Lithic Replicas, Landscapes, and Critters - Mountain Ash I didn't key out this Sorbus on the trail to Wades Lake in the northern Sierra, photographed on an overcast day in early October 2015, but a rose by any other name... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435698530239-UBMLZF8MV81LVA49YWDQ/graeinterm.jpg Lithic Replicas, Landscapes, and Critters - seep near Graeagle Falls Helenium bigelovii, Madia bolanderi, Castilleja miniata etc. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737318629974-DD1JMOJPPMC1X2CZO1ZM/Frazier+Fallsjpg.jpg Lithic Replicas, Landscapes, and Critters - Frazier Falls, early June 2011 The waterfall was roaring, owing to a very heavy snow season. It was awesome! Glacial striations across the way demonstrate that a glacier moved down this canyon. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719553847652-SFXHLXEIHE78LWNP9GIC/PDT+rock+gardenR+copy.jpg Lithic Replicas, Landscapes, and Critters - natural rock garden along the PCT This marvellous natural rock garden, along the PCT above Round Lake in Lakes Basin, has attracted my attention for decades. The rocks are metavolcanics in the Sierra Buttes Formation, but they resemble to a remarkable degree the “moss rock” used by people making rock gardens in the East Bay’s botanic gardens. The view is looking to the south. The dip of the rocks is not bedding but jointing, as the Sierra Buttes Formation dips easterly. The rocks in this complex outcrop are nature’s perfect model for a botanic garden bedrock outcrop garden. With its all-important spaces, it resembles the wonderful Phil Johnson type of design. Scanned from a slide I shot long ago.... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1734731193421-E1VHC4EUUNP9O83YYKYK/IMG_9023+copy+2PS-R.jpg Lithic Replicas, Landscapes, and Critters - another view of that …shooting into the sun, with Sierra Buttes backlit, showing the walls where they are low—they get much higher. It must have been a lucrative mine, with many injuries to the mountaineers who constructed the walls on such steep slopes…The Pharoah Akhenaten worshipped the disc of the sun, and he was often potrayed with rays of the sun coming down to him. This photo puts me in mind of that. Photo by Katie Colbert. Katie and I found this marvellous rock-cut and rocked-walled road to nowhere high up the SE flank of Sierra Buttes. A local we met right here told us it went to a deep mine shaft, mostly obscured at this point. I’ve been trying to find the name of the mine and when the road was cut, w/o success. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748137479279-WN1ECGC9AT6RPDDUP1KH/NYuba+cataractR.jpg Lithic Replicas, Landscapes, and Critters - near the headwaters of the North Yuba The winter of 2015-16 a great deal of snow fell, breaking records. This view from a bridge along the PCT shows a cataract near the headwaters of the North Yuba. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719555938744-4QJBC0KLGFIOVF66EYK7/Young+America+LakeR2+copy.jpg Lithic Replicas, Landscapes, and Critters - Young America Lake ...seen from high on Sierra Buttes. Forest is mtn hemlock, red fir, and Pinus monticola. This is the real color of the lake seen from above, but not at the shoreline. A trick of the light, algal, or glacial flour? Scanned from a slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719555956895-E85MCKR4R9NXFKQYYX4X/YAL+combo2clean.jpg Lithic Replicas, Landscapes, and Critters - Tough going off trail The left side shows the gap at the top of the exceedingly steep slope where I was obliged to slide down on my bottom end. The right side shows the black chert blocks I then had to balance across, which gave off razor-sharp flakes as they struck each other as they teetered. Young Americe Lake is considered one of the hardest hikes in the area. I could not do it now! Scanned from slides. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1697335829476-DLOAV26BLQ9MUDUTSTLS/Jam1C+copyinterm+copyR.jpg Lithic Replicas, Landscapes, and Critters - north fork of Jamison Creek I’ve always loved this creek, here shown well up canyon from Plumas-Eureka SP. The fall color is mostly willows, Acer macrophyllum, Cornus sericea, and thimbleberry. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1734415335645-OVNN0VPUHZIY8HRNTCSG/sericia+copyR2.jpg Lithic Replicas, Landscapes, and Critters - fall color in Lakes Basin Cornus sericia and willows along the trail from Grass Lake to the north end of Long Lake, in 2023? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735601156767-LZ8Z1H51MBM5XI3IWI2Q/RLT+fall+colorR2cleaner.jpg Lithic Replicas, Landscapes, and Critters - fall color along Round Lake Trail …on the southern fringe of Lakes Basin. Red is Cornus sericea, yellow is willows with a substratum of Thimbleberry. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1728690826095-G9EUHYMTS0CQBFNIG0P2/Lup+sel+FrenchmanR.jpg Lithic Replicas, Landscapes, and Critters - lupines massed display at Frenchman Res., Plumas Co. Lupinus lepidus var. sellulus bloomed in huge sheets at the north end of Frenchman Reservoir in late June 2021. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1688085743676-HH3H8UR425I3DNM4K4OY/W+mollis+BeckwourthR.jpg Lithic Replicas, Landscapes, and Critters - Wyethia mollis a little north of Beckwourth Beckwourth is in the north edge of Sierra Valley in Plumas County, CA. These soft mule ears were a short distance north of that village in June 2023. I’ve seen this plant all over higher elevations in the state, but neve like these. These were about four feet tall—the largest I’ve ever seen. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1688084521129-JYG9S5CT3YTMN36PUD9J/Senecio+hydrophilus+copy.jpg Lithic Replicas, Landscapes, and Critters - Senecio hydrophilus north of Beckwourth This is only a small part of the complex of meadows filled with Senecio hydrophilus, well north of Beckwourth on the road to Janesville (which is in Lassen County), in Plumas National Forest. One could well imagine that most of the world’s stock of this species is here. It is widespread but generally spordic in meadows of the northern Sierra. It also jumps down to the Delta, where it is much taller, stouter, and the stem is more colorful. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1688085247047-Q76ULDQV9OXYZAU2TAF8/Phlox+croppedR.jpg Lithic Replicas, Landscapes, and Critters - Phlox speciosa right across the road from the complex of meadows filled with Senecio hydrophilus, we found the best display of Phlox speciosa I’ve ever seen. June 2023 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737596344701-JTGRU08Q7XVSHFJ3D8OB/Pike+redbuds.jpg Lithic Replicas, Landscapes, and Critters - Pike redbuds The vicinity of Pike in Sierra County has the reddest redbuds I’ve ever seen. This was backlit, but not photoshopped. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1678948299320-UA93JK8327CZSCJEXZ78/Castle1.jpg Lithic Replicas, Landscapes, and Critters - Castle Peak, Nevada County In a July long ago. Mostlycommon things, but the whole scene lustily lovely. Wyethia mollis, Castilleja applegatei, Ipomopsis aggregata, Monardella odoritissima, and lupine I can’t recall. High up on the west flank of Castle Peak. The firs are Abies magnifica… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708636156830-48CM0OH52MTBVPNEOEWN/116+copyPS.jpg Lithic Replicas, Landscapes, and Critters - gnarled storm veterans on Castle Peak The NW side of Castle Peak just below the summit has abundant Mtn Hemlock Tsuga mertensiana. These were in a very exposed site, so they are wind-flagged (by blowing ice crystals) and generally beat up. LIGHT, COMPOSITION, MOMENT. June 2010. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1733086237678-7QA89MIXMWXW26YD2PMV/RED+RX+FREELps1+copyR+copy.jpg Lithic Replicas, Landscapes, and Critters - oxidized cobbles in a rushing stream …well aerated too…This was shot in the late afternoon, with a modest shutter speed to show motion of the water. These rocks were SO beautiful! Near the bridge at the Luther Pass trailhed to Freel Peak. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1757183849148-V1K7A49Q4DQ3YJK5G3DF/MacGinitea+nobilis+copy+2.jpg Lithic Replicas, Landscapes, and Critters - MacGinitea nobilis …named for my dear friend Harry MacGinite, “MAC” by Jack Wolfe… It’s a sycamore relative from the early mid Eocene. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1757194224394-50C4RHV5GECY7FE2OF3O/Hammelites5.jpg Lithic Replicas, Landscapes, and Critters - Hammelites voyana …from the Sailor Flat florule in Nevada County….I presume this has been long lost from the UCMP collections. Despite extensive searching, I could not find it there. This is the most beautiful leaf fossil I’ve ever seen. Hammelites is related to Hammelis, the modern witch hazel of many uses… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1729321481804-3PVEZY25ER5NBMKAHOHV/aspens+Hope+ValleyR.jpg Lithic Replicas, Landscapes, and Critters - aspens in Hope Valley 2024 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601100935525-0R1ME20P73Q5UNLX9CLN/Carson3.jpg Lithic Replicas, Landscapes, and Critters - Round Top at Carson Pass In summer 2014 we found this lovely patch of flowers at the NE base of Round Top. Castilleja lemmonii is the main event. The view is northeasterly, with open subalpine woodland of whitebark pines in middle distance, and Meiss Ridge, where Bob Case found Townsendia in the last century, in the farther middle distance, with Freel Peak on the far-distant skyline at right. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1729320629877-59ECZ7CWIN5DKH8KIXZ7/Carson-Luther10-13+091R.jpg Lithic Replicas, Landscapes, and Critters - western juniper at Carson Pass https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1728171012885-DLQ4YM6M6TQ9OOKBKW93/Frog+Lake+snowberries2PS-R.jpg Lithic Replicas, Landscapes, and Critters - a snowberry patch SW of Frog Lake …at Carson Pass… I don't normally think of snowberries as having wonderful fall color, but it was definitely the case here. I'm calling this Symphoricarpos albus. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763011920033-ZCR0ZQ2OOWTQ8O2C3F8R/Round+Top+post+sunsetRR+copy.jpg Lithic Replicas, Landscapes, and Critters - Round Top after sunset Round Top is just SW of Carson Pass. There’s a bit of alpenglow up there. Alpenglow always looks better on granite than on drab andesites. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1754876025814-2AXVIQB7XHTW2AZNI82T/Cat%27s+photo+of+her+lakeR2.jpg Lithic Replicas, Landscapes, and Critters - magic light …at an unnamed lake near Carson Pass…. Photo shot by my dear friend Cat Daffer. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1757961300369-V8NT7FM8GK6V818VACN3/KW+LK+cloudsRbrightened+up+dark2.jpg Lithic Replicas, Landscapes, and Critters - reflections of clouds …at an unnamed lake near Carson Pass, shot by my dear friend Cat Daffer…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1684910922229-RCTE5ET0VGPEY8CYNQUR/Marshes+Flat+Road.jpg Lithic Replicas, Landscapes, and Critters - Marshes Flat Road, Tuolumne County a scene of Calochortus superbus and royal larkspur in May 2023 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1684910942063-C0EXVO4CHBPZ6PAKBJ2V/Two+Mile+Bar.jpg Lithic Replicas, Landscapes, and Critters - Harvest Brodiaea Brodiaea elegans on the road to Two Mile Bar near Knight’s Ferry, May 2023… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737938370786-P8UWGC3CK2WTHDASLTRJ/Dana+from+D.+plateauR+copy.jpg Lithic Replicas, Landscapes, and Critters - Mt. Dana from Dana Plateau Mt. Dana, at over 13,000’, is composed of the Ritter roof pendant, consisting of Paleozoic and Mesozoic metasedimentary and metavolcanic rocks. The Dana Plateau is floored by granitic rocks and thought to be unglaciated owing to plant list it supports, including Podistera nevadensis. And the granitic rocks show no glacial striations—that I could see anyway. Scanned from a slide I took in the late 1980s. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738713169132-RUPSV581PJ6X9V126K4C/TR+to+Timber+Gap%2C+cleaned+up2A2Mineral+KingcleanerRsharpercleaner+copy.jpg Lithic Replicas, Landscapes, and Critters - beautiful Mineral King in Sequoia NP I have always loved this scene. It shows a much younger, much stronger, and completely relaxed me, on the Trail to Timber Gap. Scanned from a slide shot by Al Seneres ca. 1979 or 1980. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1742275535907-WVO8A95RU4SSN42Y75H6/342+diff+viewR+copy.jpg Lithic Replicas, Landscapes, and Critters - skarn from Mineral King I don’t know who collected the sample, but the thin section shows calcite left and upper right; the brighty colored crystals are epidote; and some of the jet-black crystals at right are isotropic, probably andradite garnet, a calcium-bearing mineral. Epidote is also a calc-silicate. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1742275585236-42TUV2V7EF7QA97JOITG/min+king+342R2.jpg Lithic Replicas, Landscapes, and Critters - a closer view of the Mineral King skarn ….in XPL with the 10X objective….The brightly colored xtals are epidote. They have greatly inclined extinction, and they are pale green in PPL, thus likely epidote rather than clinozoesite. Isotropic probable andradite garnet can be seen above and below the epidote. The tan/pink xtals are calcite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1682639557872-WNPAWQBVV6DR4ZN67BG9/Bear+Valley+4-26-23R3.jpg Lithic Replicas, Landscapes, and Critters - Bear Valley, Colusa County, April 2023 April 26, 2023. There was only one big field like this, in the same place it usually occurs. The deep yellow is Layia gaillardioides, the pale yellow is some combination of platyglossa and chrysanthemoides. The blue is Gilia tricolor, and the cream is Platystemon. It was an above average year, but with emphasis on average. Spring 1995 was a hundred times better. Instead of one field like this, the entire (huge) valley was filled with flowers, and every half mile you drove or walked brought you a different color combination. 1995 was a TRUE “superbloom” year in Bear Valley. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1682639576289-6E0SEOAUBM0W45L6B225/Bear+Valley+two+4-26-23R.jpg Lithic Replicas, Landscapes, and Critters - Bear Valley April 26, 2023, closer … a closer view, with my camera lens between the strands of barbed wire… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1745978241046-WJGW2MY1EV9ZHTS7D67J/eastofMiddletownR2.jpg Lithic Replicas, Landscapes, and Critters - awesome display of Calochortus superbus …east of Middletown in Lake County along HWY 29, 10 June 2016…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1746684948121-ETVFF2JU7VIK120JTACD/Delphinium+uliginosum+MV+Rd.jpg Lithic Replicas, Landscapes, and Critters - Delphinium uliginosum …on U.C. Davis land in NE Napa County, along Morgan Valley Rd…..There must be a lot of moisture in this meadow to support this rare California endemic. …May 2015… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1532495921295-9VXGFF6GIJ5AYQP4P64J/NapaburnpsInterm-1.jpg Lithic Replicas, Landscapes, and Critters - meadow in 2015 Napa Co. burn This luminous meadow, in April 2016, on BLM land north of Lake Berryessa, seemed like an island of life in a sea of devastation. Valley oaks, too—so strange, as all the hills right and left are serpentinite and will not support such oaks. The rocks at the south end of the meadow are serpentinite, but the rocks beyond those are metasediments. Perhaps these are intermingled at depth beneath the meadow. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765063012795-4IQFJYYII7S7UIVHKCGJ/metased+on+Hunting+CKRsharper.jpg Lithic Replicas, Landscapes, and Critters - cliff of sandy mudstone S of meadow This seems to have lots of mafic grains. Shot in XPL with the 4X objective… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765060767874-59BWGMY70503F1RDN2ZO/Hunting+Ck+metased+SharperR.jpg Lithic Replicas, Landscapes, and Critters - sandy mudstone S of meadow Shot in PPL with 4X objective. The red grains may be iddingsite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1731038153904-3RISOZHEBS88R9BT3K4S/SnellVlupes%2BR2+copy+2A2.jpg Lithic Replicas, Landscapes, and Critters - Snell Valley, Napa County …in the first week of April ca. 2020… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1673421239533-Y5D73DSKDXZJ0V3N2GRC/conjugensNewBetterR2.jpg Lithic Replicas, Landscapes, and Critters - Contra Costa Goldfields My friend Celia Zavatsky found this giant field of the endangered Lasthenia conjugens in Solano County. It is threatened by agricultural practices and invading ryegrass. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1743970132467-B40NYP9IPONAFKEU4P0H/RioVistaTritels+enhanced.jpg Lithic Replicas, Landscapes, and Critters - Ithuriel's Spear near Rio Vista …in an April long ago…..I’ve looked for this display in subsequent years—but I think it got trashed. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1652656265465-DF0WE479IW0BM4SK1LUM/BullPTDeschampsia2R+copy.jpg Lithic Replicas, Landscapes, and Critters - Hairgrass prairie at Drake's Estero This is a small part of the vast prairie of Deschampsia caespitosa holciformis at the head of Creamery Bay at Pt. Reyes. It has long been cattle pasture (beef cattle, not dairy). This species thrives with livestock grazing both on the coast and in the Sierra. I believe it must have provided a major part of the forage of the Pleistocene megafaunal grazers—horses, bison, mammoths, and others. If not grazed, this pasture turns into a low-diversity jungle of tall coyote brush wrapped in blackberry, mixed with Carex barbarae, as shown by exclosures around the area. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1438372249108-XJFQ3Y8ZV0T347I3Y68M/vasco2.jpg Lithic Replicas, Landscapes, and Critters - purple needlegrass in summer Stipa pulchra in summer at Vasco Rocks, Contra Costa County. The annual grasses between the needlegrass tussocks die off while some green growth persists in the stipas, but, by the time fire season arrives, all the grasses are brown. That most of the bunchgrass-covered hills in lowland central California were green through the summer because these perennial grasses stayed green is a popular myth that is simply wrong. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708481376472-27HHGC2XMINZKAK8J6G5/Layis%2C+Hartford+Rd.cleaner2R2.jpg Lithic Replicas, Landscapes, and Critters - tidy tips in north Livermore Part of a field of Layia chrysanthemoides along Hartford Road in north Livermore in April 1991. This field is reliably great in decent rain years, because it has been grazed but not plowed. It is a last remnant of the glory that was Livermore Valley. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708395442249-JICVDTOWBOEBRFI4TYPT/Vpendunculasharper+2.jpg Lithic Replicas, Landscapes, and Critters - Viola pedunculata in Sunol-Ohlone Some March in the 1990s. Poor scan of a poor slide, but still compelling. I was taken to this scene by Dan Reasor. Many of he tops and upper slopes of the hills were painted like this. It might have been ’95, which was the best year for wildflowers in northern and central Californis I ever witnessed. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708481089536-65S2A16UVKZCRBC6UW4K/SAV+PscleanR.jpg Lithic Replicas, Landscapes, and Critters - Cream Cups in San Antone Valley This is a portion of a huge field of cream cups in San Antone Valley, east of Mt. Hamilton, late April 1989. Scanning old slides yields very unsatisfactory results, even as tiffs at maximum resolution. But at least this picture gives a sense of the grandeur of this valley as it once was. Invisible from this view is the understory of blue Phacelia ciliata and red Calandrinia menziesii. This field was regularly grazed, which was probably helpful, but also occasionally plowed, which was not. I've not seen a display like this there since 1989. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611451434140-6VB6CC1T6S55UEJOHP2N/San%2BAntoneVA2a.jpg Lithic Replicas, Landscapes, and Critters - San Antone Valley, near south end This photo of San Antone Valley east of Mt. Hamilton was taken somewhere around 2005. Looking north, you can see Red Mountain with its magnesite mine fills. The flowers are pure simplicity: just the common small lupine, L. bicolor, and goldfields. From these most humble common elements a lovely and soothing scene was created. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1615448250543-IKAXG2PBJG2QBIC9IGUV/panoramaR.jpg Lithic Replicas, Landscapes, and Critters - Del Puerto A view north from Del Puerto Canyon Road in the dry January of 2021. The scene is occupied by Cretaceous-Paleocene Moreno Formation except for the ridge at far right, which is early Eocene Tesla Formation with Oligocene Valley Springs tuff overlying it. The latter erupted from a caldera far out into Nevada. Overlying the Valley Springs is late Miocene fanglomerate. Note there is an unconformity within the Moreno, with beds in the dark hill left of center dipping more steeply than those in the light one right of center. So there must have been some uplift of the former before the latter was deposited. A deceptively simple scene, but one with a true Californian character, and one that anyone who wishes to be a true Californian must love and protect. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1554271753454-T44Q187926QUTTX8TWL6/owlscloverinterm2.jpg Lithic Replicas, Landscapes, and Critters - Panoche Road owls clover along Panoche Road in western Fresno County, late March 2019. Looking +/- south https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1554271792799-F87CHJREI0J0ID5FUWVL/goldfields1interm.jpg Lithic Replicas, Landscapes, and Critters - Panoche Road goldfields along Panoche Road, eastern San Benito County, late March 2019. View +/- south https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1554529504542-QVQ2IT9WWLS90VKCK9CJ/PanocheK-T+copy.jpg Lithic Replicas, Landscapes, and Critters - SE Panoche Range A moody view, late in the day, of the SE flank of the Panoche Range. It’s summer, a time when flowers have passed, but still the landscape is entrancing. The famous Cretaceous-Tertiary boundary, time of extinction of the dinosaurs, is to be found in the strata across the gorge. Note the numerous light-colored sandstone dikes cutting across the overall dip of the beds. The dikes were plumbing for Paleocene cold-seeps and cold-seep communities. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1558486693776-0MKOSC59OLR5KJPASXK5/Griswold.jpg Lithic Replicas, Landscapes, and Critters - Griswold Hills Chris Thayer and I found this delicious frosting on Great Valley Sequence sandstone in a side canyon in the Griswold Hills of eastern San Benito County. This is not an atypical scene for the GVS, but it’s a nice one. Springs issue from deep sources in these rocks, and transport saline and calcareous waters to the surface. The saltgrass at left reflects saline pore waters from the Cretaceous ocean; the numerous concretions manifest calcium carbonate cement. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1590648277823-M36F3HZ3JCI4C4VGEX50/NewIdriaps23interm+copy.jpg Lithic Replicas, Landscapes, and Critters - New Idria At the New Idria quicksilver mine in the 1990s. Scan of an old slide. Looking east from among Artemisia tridentata to the San Joaquin Valley. The dominant feature of the scene is the angular unconformity between brown Creatceous and Paleocene sandstones of the Panoche and Lodo Formations in the middle distance, and lighter-colored Tertiary units beyond. Faulting, folding, and possibly detachment have all contributed. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1554271844932-QGTQ1DI76POLY7PA144O/Temblors2010.jpg Lithic Replicas, Landscapes, and Critters - Temblors A very small part of the vast display of flowers on the SW face of the Temblor Range in March 2010. Monolopia, Phacelia, Mentzelia and/or poppies https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711436828704-2HUYFAP1JW35IWSH5WJZ/TemblorsgreatR+copy.jpg Lithic Replicas, Landscapes, and Critters - a closer view of the Temblors in March 2010. This was up a ravine just south of the preceding view. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1590800317640-YBRUN89Q8249PZ49KRV7/Temblors2014intermA.jpg Lithic Replicas, Landscapes, and Critters - Temblors 2010 Another site on the SW face of the Temblors in 2010. The pale purple is actually Eremalche parry, which is pink but looked pinkish-purple in this light late in the day. To right are Ericameria linearifolia and monolopias. A dash of Coreopsis and Mentzelia comes in at upper left. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1703555001790-C1VAILFSASBEARJ6RXJJ/Coreopsis2R2.jpg Lithic Replicas, Landscapes, and Critters - A fragment of the Carrizo Plain, March 2010 A tiny amount of the vast flower fields filling the Carrizo Plain in March 2010. Coreopsis, beyond that Layia, beyond that goldfields; in the far distance the Temblors, covered with diverse flowers throughout, but Monolopia dominant in this view. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1703555043979-P0CPYTZVZQD43HPD91A4/Layia+munziiR.jpg Lithic Replicas, Landscapes, and Critters - Layia munzii on the Carizzo Plain That’s the light color in the foreground, March 2010. On the low hills in the distance, monolopias dominated, rising up into the Temblor Range in the background. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1663827221828-6VYCUHJSZ41MIDJUND7F/Carizzo+baby+bluesR2.jpg Lithic Replicas, Landscapes, and Critters - another Carrizo field This too was near the north end of the plain in March 2010—that glorious year…tidy tips, baby blue eyes, and goldfields. Heaven must be like this. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1721869767937-IEJ19W7TGR6UMS4AQ3LT/collapsing+stamp+mill+along+Masonis+Rd.jpg Lithic Replicas, Landscapes, and Critters - Chemung Mine ...along Masonic Road above Bridgeport Reservoir, caught in "magic light..." https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1722027310468-IXA9BWFKD4UUH5B0XO4R/red+rx+and+gray+rabbit+brushR+copy.jpg Lithic Replicas, Landscapes, and Critters - down the road a bit from Chemung Mine ...again, magic light...gray rabbit brush against blood-red gravel from mining activities makes a stunning but simple picture. It was getting dark, and that's why the colors or so saturated. To get this, I probably shot at ISO 3200. One of the Great Courses photography instructors repeatedly states "ISO is your friend." So true! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725312396330-DW2A9NZZ8GT3XGDPHA7N/507+4XR.jpg Lithic Replicas, Landscapes, and Critters - alunite? ...from the red mine dump down Masonic Road from the Chemung Mine. The needles have parallel extinction and are clear in PPL. This was shot with a 4X objective in XPL. The needles SEEM to be alunite, and the pervasive matrix looks like a host of cryptocrystalline silica in some places andesite fragmen†s in others. This rock could have begun as a glassy andesite that became partially devititrified; and the needles, rather than being alunite, might be sericite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738982901257-LJLVJDXOXDSKCEKX5EJJ/fishslough+053+copyPS-R.jpg Lithic Replicas, Landscapes, and Critters - north end of White Mts ….with shamanic symbols in foregound… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1661553849719-CULKDQ6NLZD3I05O4DUA/Whitesps2R.jpg Lithic Replicas, Landscapes, and Critters - Pinus longaeva looking north to the Patriarch Grove, 2003. One can see that the bristlecones are concentrated on the white-to gray Precambrian Reed Dolomite, but some impressive individuals grow on the darker, warmer noncarbonates—as is the case with the one in the foreground. One can perhaps understand the preference of bristlecones for the nutritionally demanding dolomite, as they need to stay in one place for thousands of years, and they don’t get very tall—so theoretically they would benefit from the reduced competition on the more demanding substrate. Scan of an old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1661582529923-5CRHSBZ3QEQY23P49L2O/Whites2Rclean.jpg Lithic Replicas, Landscapes, and Critters - Pinus longaeva in the Schulman Grove, 1986. Scan of an old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738114301957-37YRBNZVKG4FV30QMB8I/viw+N+from+MT-Rsharper.jpg Lithic Replicas, Landscapes, and Critters - view N from Metheusela RTrail Here is a classic subalpine forest, defined by its very open canopy. View north along the Reed Dolomite on the east side of the White Mts, showing a mix of bristlecone and limber pines—buit mostly the former. 1986. scan of an old favorite slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1717889889572-24XDPAU6GRAE09LQEX7X/WMtn+Pksharper+copyR.jpg Lithic Replicas, Landscapes, and Critters - White Mtn. Peak ...view north to White Mtn. Peak (14,252'--only ca. 250' shorter than Mt. Whitney) from the north flank of Sheep Mtn. (12,497'), which I climbed to the top with Roger Raiche some 40 years ago. The broad expanse of alpine fell-fields at the north base of Sheep Mtn., shown here, is the only place I've seen any species of Androsace. See next picture. Ironically, White Mtn. Peak is composed mostly of dark Jurassic metavolcanic rocks. Scanned from a slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1717889911140-W9HUSU4B298P0FFPGONC/Androsacesharper2cl2R.jpg Lithic Replicas, Landscapes, and Critters - Androsace septentrionalis ...on the alpine fell-fields shown in the prior photo. I was there alone that time, trying to work my way around altitude sickness. Staff at the Crooked Creek Research Station gave me a clue: alka-seltzer as a prophylactic. It worked! A.septentrionalis can be an annual or short-lived perennial (Primulaceae). I suspect the latter in this case, with a very short growing season at this high elevation. Scanned from a very poor slide. In those days I shot everything au naturel--never used flash--and paid the price! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737598149959-0JREPUMWEXC935GHIHJD/KT+Inyo+Mts+copy+3R.jpg Lithic Replicas, Landscapes, and Critters - my mountain goat wife Katie Colbert climbed this cliff I would not dare in the northern Inyo Mountains to see Wagon Wheel Mirabils Mirabilis froebelii. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611470992663-BU4P5WP68WCM6PIVWO6P/Mazourkainterm5.jpg Lithic Replicas, Landscapes, and Critters - cottontops Cottontops Echinocactus polycephalus on limestone near the mouth of Mazourka Canyon in 2011, with the great western wall of the Basin and Range in background, and Green Monster Hills in middle distance. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609831721035-GW2JUEZRIAK9ADUW2OTZ/SierranWave2RED.jpg Lithic Replicas, Landscapes, and Critters - Sierran wave over Independence, CA An evening in April 2011, taken from the mouth of Mazourka Canyon. A foehn wall or cloud cap can be seen on the crest of the range, with a zone of lenticular altocumulus (or “lee wave”) above us. Between is the foehn gap. It is the selfsame wind that causes all three. The wind generates them by traveling in a wave-like form. Moisture-laden Pacific winds climb the west flank of the Sierra and cool, so their moisture condenses. They drain down the east flank of the range, warming at lower elevations. Warmed, they rise again eastward, creating the cloud bank overhead that most people call a Sierran wave. But it’s only the wind that travels in a wave-like form, and the cloud bank, at the crest of a wind-wave-form, can remain stationary for hours while the wind blows through it. Water vapor condenses while rising on the way to the crest from the west, and evaporates on the way out while warming with descent to the east. Photo by Katie Colbert. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708123922148-FREH6355HD4CS9J506FA/Antelope+Valley2.jpg Lithic Replicas, Landscapes, and Critters - Antelope Valley 2008 …. scene in the first week of April, 2008. Looking southerly... The occasional gray Atriplexes really enhance the scene. Unfortunately it was early in the AM so the poppies were still closed, and I didn’t think I could take time to wait for them to open. I’ve kicked myself ever since, and also because I shot this with a very low-res digital camera. Alas and alack—it’s still a lovely scene. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1600378638518-5Z5TSB9II6TXLE85V2UG/AV2.jpg Lithic Replicas, Landscapes, and Critters - Antelope Valley, northwestern part Get down, get dirty with the poppies. En masse they tend to overwhelm your camera’s sensor and you lose some detail. No matter. It still takes my breath away. south fringe of Tehachapi Mts in background, 2014. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611451410200-MNHIGXGYYG0J9UX687G2/NeolloydiaF2b.jpg Lithic Replicas, Landscapes, and Critters - forest of pygmy barrels This backlit forest of miniature barrel cacti illuminates the scene as the sun goes down. They are Sclerocactus johnsonii. Here, at a place not to be named in the Death Valley Region, they are concentrated on quartzite while the hundreds of square kilometers of dolomite all around only support very sparsely scattered individuals. Ca. 1980, poor scan of an old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1703555023266-WOUAT7BG8M5TH7XMI54T/Lake+Manly.jpg Lithic Replicas, Landscapes, and Critters - Lake Manly, Badwater Basin 2005 In winter 2004-05, there was much rain in the Mohave. Flower fields were everywhere, and Death Valley had a minor “superbloom.” Meanwhile Pleistocene Lake Manly, which had occupied much of Death Valley, sometimes to a depth of about 3oo feet, was renewed, but only in Badwater Basin, which is below sea level. This lake was very shallow, but people were canoeing on it. It was really a treat to see this. View is across the lake looking westerly to the Panamints, the highest point being Telescope Peak, a bit over 11,000 feet high, with bristlecones pines. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1569997168300-IV2O0GX1PYLHFLCTKQEE/RedHills.jpg Lithic Replicas, Landscapes, and Critters - sunset in the Red Hills Taken near the west edge of the Red Hills of Tuolumne County, west of the serpentine area, September 2019. Photo by Katie Colbert with her iPhone. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1642747616446-4BLL0EPDEQJWIB9OCEKW/Woodbridge+copyPSR2.jpg Lithic Replicas, Landscapes, and Critters - Woodbridge, February 2012 silhouette of Mt. Diablo seen from the east after sundown. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1642747639304-6X7AFETL6RDMUH4CUAEJ/woodbridge2-12+126psR.jpg Lithic Replicas, Landscapes, and Critters - Woodbridge, February 2012 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667874074793-AJUKSJ7TJIDFJ2M4H03Q/sunset+from+homeR+copy.jpg Lithic Replicas, Landscapes, and Critters - sunset at Fort Bragg, Mendocino County This was taken with a film camera from the edge of the bluff where my parents used to live. It is NOT photoshopped! The deepest saturation of sunset colors occurs AFTER the sun goes down. I saw this kind of thing countless times. This was one of the best. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763444752497-OYKMESS4XROWJYK4944S/Samoa+Dunes+BeachRcropped.jpg Lithic Replicas, Landscapes, and Critters - sunset at Samoa Dunes beach, Humboldt Co. ….NUFF SAID!…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765233103334-UERYPBWJ6RN8EZDEV4H7/rainbows+over+Pittsburg+%26+Brown%27s+I%3F.jpg Lithic Replicas, Landscapes, and Critters - dual rainbows over Pittburg …Contra Costa County…Chipps Island & Van Sikle Island in the distance…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763617205274-R1O49GX8EASXOBH023IB/wave+splash+Trinidad+BayR.jpg Lithic Replicas, Landscapes, and Critters - Trinidad Bay Humoldt County NUFF SAID! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735366157348-0M2Y2DNY0443ZS0SRGR4/Opuntia+bigeloviiRsharper-cleaner2.jpg Lithic Replicas, Landscapes, and Critters - Teddy Bear Cholla Opuntia bigelovii after sundown, backlit, as I recall, somewhere N of Joshua Tree NM in the mid 1980s, scanned from one of my slides. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1714853580963-4MH3A0YYEGI3U1MLMUUE/Abbots+surf+bestR.jpg Lithic Replicas, Landscapes, and Critters - tormented sea …shot off Abbott’s Lagoon at Pt. Reyes with my Nikon D7000 (a DX camera) at ISO 1000 and setting called cloudy. It was just an experiment, but the picture gives a good sense of the awesome torment of a powerful ocean on a foggy day. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667874310528-Y023KK5X0K6F4RCNC98B/Cabrillo1R+copy.jpg Lithic Replicas, Landscapes, and Critters - Pt. Cabrillo lighthouse at nightfall This grand old lighthouse is near Caspar, which is between Mendocino and Fort Bragg. Taken with a film camera in 1995. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1717550962995-K0PRW4QRCR6F3TICYXJQ/RJM+Big+BasinSharperR.jpg Lithic Replicas, Landscapes, and Critters - my old friend at Big Basin This is my wonderful old friend, the late Dr. Raul J. Madrid, a superb geologist who did much to elucidate the geology of the Basin and Range. He's leaning against a large coast redwood in Big Basin State Park--maybe 30 years ago. The Oakland Hills had coast redwoods even larger than this one--all cut down by 1860, by selfish ignorami. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1739930852007-AL549WNUZ87CR52QEG7L/rpbg+sceneR.jpg Lithic Replicas, Landscapes, and Critters - Regional Parks Botanic Garden When I was director there, and there were still a few nice-looking noble firs…Alaska Cedar at far left, and a smaller one in front of the Port Orford cedar center left…center right, another Port Orford cedar…The purplish red shrub at lower left is Cornus sessilis. The bright red near the center is vine maple. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740119536418-3QQO028XQ9LBP304FT0W/lodge%26bulb+bed+copy.jpg Lithic Replicas, Landscapes, and Critters - Juniper Lodge and bulb bed …in the RPBG. I took care of the bulb bed, lavishing attention on it. Juniper Lodge in background, showiing off Fremontodendron ‘Margo,’ named for the wife of Al Seneres. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740120480505-XN0AFZ8DBDFRXQH9LOBG/Wildcat+Ck+in+RPBG+copy.jpg Lithic Replicas, Landscapes, and Critters - Wildcat Creek in RPBG …Looking upstream when I was director….. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740984717554-CJS440GJ7EW5UGU5B0CQ/JBRwith+fieldnotesR2A.jpg Lithic Replicas, Landscapes, and Critters - Jim Roof with field notebook This was on San Bruno Mtn.— a place he loved and fought to preserve, in the 1960s or 70s. He was the first director of the RPBG. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1762836854857-YJD0LY5ZLDP1YPQUUSY4/Stew+Winchester+and+Ledyard+Stebbins+at+Butts+Ck.jpg Lithic Replicas, Landscapes, and Critters - Stew Winchester & Ledyard Stebbins It was some time in the 1980s….Ledyard was a sour mood that day. Over a hundred people showed up at Pope Station for his field trip! Stew is holding a stem of Epipactis gigantea. …..very poor scan from a slide…… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1744608780678-JYOZ39T18NKHX24D6RBG/WK+Garin.+1972cleaner+copy.jpg Lithic Replicas, Landscapes, and Critters - Walter Knight in Garin RP, 1972 I followed Walter as he got away from Jim Roof. This is year 3 in my knowledge of Walter, who became my career and botanical mentor. The young lady is wearing a sweatshirt reading Gregory Gardens, where I lived for ca. nine years. The photo was probably taken by “Monty” Monteagle… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1742183036710-YGFXKFD925K17OKNZ69U/WR+%26+Irja+copy+2A.jpg Lithic Replicas, Landscapes, and Critters - Irja Knight and Wayne Roderick …are here on a beach on the north coast. Irja was my very dear friend…Wayne ultimately became the 2nd director of the RPBG. I was the 3rd. I worked for both Jim Roof and Wayne. Wayne was a JOY to work for! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1762995338663-B9WCXWEAKIHDNWERNYNI/giant+bluegum+at+Ft.+Ross+copy+2A.jpg Lithic Replicas, Landscapes, and Critters - largest girth blue gum This Eucalyptus globulus is/was growing at Fort Ross. It has the greatest diameter I’ve ever seen in that species. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1734131498155-PWM8JOYDLVMEMWT34S0X/fall+colorR.jpg Lithic Replicas, Landscapes, and Critters - fall color in our yard The yellow shrub at right is Styrax. The red one at center is Viburnum ellipticum from northern Sierra. The red vine is Roger’s Red. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763350652839-R512UYYI3DBBVRCOFXB5/Roger%27+Red-R.jpg Lithic Replicas, Landscapes, and Critters - Vitis california 'Rogers Red' …a closer view of the leaves….actually hybrid with Vitis vinifera ‘aliconte bouche’… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1762926765355-USD4ZI4BOURXPZDG1AWT/turkey+tails.jpg Lithic Replicas, Landscapes, and Critters - turkey tails They were growing our back yard—on bark… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1742447076698-P2FEX6618H42S94GPDM8/Aloe+garden+BEST-R.jpg Lithic Replicas, Landscapes, and Critters - my African Acheulean rock garden All replicas of African Acheulean handaxes and cleavers, with all African succulents to look real. The LCTs are scattered about like on a real lithic scatter. The only problem with this arrangement is that basalt toolstone was not available where these plants grow in the wild! So, it’a art! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1742106084907-9OQG30LBKDLHLY1PFLAI/Aloe+peglarae+combo.jpg Lithic Replicas, Landscapes, and Critters - Aloe peglerae …at an earlier stage of my African Acheulean rock garden... This plant is blooming today—March 2025. This species is rated as endangered owing to habitat loss and overcollecting. It grows only on two ‘reef-like” ridges of quartzite in northern South Africa: the Magaliesberg and Witwatersrand. I think it is the most lovely of all aloes… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1745732385112-Q4VG9V7MQW0T71X4RZ95/color+echoesR.jpg Lithic Replicas, Landscapes, and Critters - color echoes …in my African Acheulean rock garden…. The Aloe with the tall, odd inflorescence is from South Africa, named after the great Robert Broom, student of mammal-like reptiles and pioneer paleoanthroplogist; only Aloe broomii is recognizeable in bushman rock art, owing to its distinctive inflorescence… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740463671784-825K2VNNQAHP1ZO0L0C7/pipevine--ours%2Ccropped%26sharper.jpg Lithic Replicas, Landscapes, and Critters - our pipevine GLORIOUS! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1762987338620-S6XSPKIZFAG73XLOI9YZ/buckeye+ballsR.jpg Lithic Replicas, Landscapes, and Critters - buckeye in our garden This reminded of Rolf Bensaler’s lecture long ago in the Wayne Roderick Lectures, his title: BUCKEYE BURLS, BALLS, AND BUTT SPROUTS! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1747779644715-QNVC00W1OZE1M9AT15HS/Lewis+Dent+houseR.jpg Lithic Replicas, Landscapes, and Critters - Dent House in Knight's Ferry U.S. Grant visited his brother-in-law, Lewis Dent, here in Knight’s Ferry along the Stanislaus River when he was mostly stationed at Eureka, but came down to San Francisco. U.S. Grant is on my short list of the greatest Americans… not just for his civil war victories, but also for Reconstruction… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1731314204824-5HV5NGV0A1JEW5606LZS/monitor%2B%2B2.jpg Lithic Replicas, Landscapes, and Critters - well preserved monitor at Malakoff Kings Saloon is the closest building; beyond it is the Smith and Knotwell drug store—an ironic juxtaposition! It’s a rare sight to see such a well-preserved monitor. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1736534559480-3AFQU4MYDKISDDTAKOGI/Clover+Valley+RanchR.jpg Lithic Replicas, Landscapes, and Critters - Clover Valley Ranch building …in a side valley to the west of Dixie Valley, Plumas County. KT and I have fantasized about restoring these buildings, in their beautiful valley. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1736488680003-1ZUQLM55M0R2A4BDJJG5/our+ranchR.jpg Lithic Replicas, Landscapes, and Critters - view north …from the Clover Valley Ranch buildings… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738354170263-KW1BYP37AM9G897E0LRQ/Treadwell+Mansion+at+CCof+Arts.jpg Lithic Replicas, Landscapes, and Critters - The restored Treadwell Mansion at CCAC John and James Treadwell bought the coal mines at Tesla, after making a fortune draining gold mines in Alaska, like Sutro did in Virginia City. The mansion served as an administration building at California College of the Arts, known as CCAC when my mother attended art classes there when she was very young. I wonder if she was aware that the mansion once belonged to the Treadwell family, who owned Tesla, where her grandfather worked as a carpenter, her grandmother died from complications of childbirth, and her father lived as a boy. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740515754090-RRAMWGO4Z3FGHJCIM7ER/Empire+mine+shaft.jpg Lithic Replicas, Landscapes, and Critters - where my great great grandfather worked My great great grandfather worked at the Empire Mine near Grass Valley starting in 1880….He went down this shaft to work 12 hour days deep underground. He came to San Francisco in 1875, as a “cousin Jack” from Cornwall, with hardrock tin-mining experience. The Bourns, who owned the Empire Mine, hired a lot of hardrock miners from Cornwall. My great great grandfather’s name was Thomas H. Jenkins. The shaft is steeper than it looks in my photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1747780205279-J21B4U8ZZS6APDCGC14L/Aetna+Mine+retortR.jpg Lithic Replicas, Landscapes, and Critters - retort at Aetna Mercury Mine I don’t know if this was saved from the fire in place. I don’t recall seeing it here before the fire, so it must have been brought in from some place else. In any case, it’s RARE to see mercury retorts so INTACT. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1740898574838-QPHEICWGN6CXDMA09QO9/old+truckR+copy.jpg Lithic Replicas, Landscapes, and Critters - Model A Ford pickup …at the Aetna Mine, Napa County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1762916521680-2AGBX7BEIA1ZN4AX027B/blocks+of+mineralized+Si-carb+rxR.jpg Lithic Replicas, Landscapes, and Critters - highly mineralized blocks of Si-Ca rock ….at the Aetna Mine next to the model A Ford….with debris of ages all around….Could the green be Chrysocolla? It’s a copper-hydroxide silicate, with a bluish green or green color. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735970895349-D37AW13OQIC1MH0EPSZA/hydrophobic+soil+on+Laporte+-Quincy+rd+copy.jpg Lithic Replicas, Landscapes, and Critters - Dixie Fire A view along the Laporte-Quincy Road of such devastation of the Dixie Fire that the soil became hydrophobic, and there was no understory…. http://californiageology.net/geology daily 0.75 2026-01-03 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1628121662987-HIQ8FXT35I0W6OJEZZGR/Vollmer1rectbetterPLUS+copy+2RED.jpg Geology - view south from Vollmer Rocky and Las Trampas ridges at left, St. Mary’s College nestled at their north end. Snow on the far Hamilton Range. The ridges in the East Bay are held up usually by steeply dipping resistant rocks, or by anticlines that include resistant rocks, like marine sandstones or chert and hard volcanics. In contrast, the valleys tend to be formed by synclines and/or eroded into soft nonmarine mudstones that are younger than the bedrock in the ridges. The softer sediments are in stratigraphic continuity with the bedrock in the ridges, but erode more easily. The same thing has happened throughout the western states. If you want to look for fossil terrestrial mammals, you go to the flanks of the ridges or right out into the basins. The desecration of the south end of Siesta Valley, gruesomely ugly from this far vantage, even uglier close up, is irreversible now. The south end of the valley was cynically renamed “Wilder,” when wildness is exactly what was removed. A tragic product of a great sin: greed. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610851941944-6PFHQGGAIIK14ZKYH3BY/MoragaRidge2B+copy+2PS.jpg Geology - Moraga Ridge and Indian Valley We are standing on Moraga Ridge, looking SE. The ridge is held up by Moraga Formation volcanics. Indian Valley is to the right. Ridge at far right is held up by Claremont Formation. The valley between is in type Orinda Formaton, which thins to the south and peters out beyond the saddle at the south end of the valley. There are thin marine sandstones interbedded with fluvial Orinda near the base of the formation south of the saddle, and also south of Round Top. Near HWY 24 and Round Top the Orinda is thickest, and Ross Wagner has suggested that a releasing structure in the local fault network thinned the crust, allowing magma to come to the surface and also causing subsidence, accounting for the greatest thickness of the Orinda there. Unless public agencies step in to prevent another glaringly ugly development, you can kiss this beautiful scene goodbye. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531871786353-95OLVUI20GQI03E1J41N/tuffsps2.jpg Geology - lovely Sibley sequence This rock face in Robert Sibley Volcanic Regional Preserve is a little deceiving owing to quarrying and the angle of view, but there appears to be a basalt flow at the botttom, brecciated and reddened at its top, and a basalt flow at the top, brecciated and reddened at its bottom, with light brown basaltic tuffs sandwiched between the flows. There is also a fault left of center. I consider this to be one of the loveliest outcrops in the Berkeley Hills. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738280861501-7OVGSAPVUJSFKT49AX8I/Sibley+autobrecciaR.jpg Geology - basalt autobreccia This is a block that fell from the cliff shown in the previous photo, or very near it. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1628121534955-LDSON7NIE33L3XVICGGW/IMG_0608+copyPSred2.jpg Geology - just around the corner A few steps north of the prior view a quarry road cut right through the ridge, exposing a partial cross sectiion. The sequence, here looking south, looks much simpler here, with statra dipping steeply east, and lava at right overlain by red-baked basaltic tuff, overlain by purplish lava at left. One intepretation considers this flow about 150 feet thick, but the upper parts are obscured by quarrying. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707350917795-JLSE2OPGVPNDYLNRUX54/Sibley+SCORIA+better.jpg Geology - welded scoria landscape at Sibley Garniss Curtis visited this site with me, and told me he and Dick Hay were working on this unit in the Miocene Moraga Formation. He said at the time that this was the world’s largest known deposit of this kind. I can’t believe that’s true, even though Ross Wagner found in his mapping of the Berkeley Hills that this unit is much more extensive than I had imagined. See next photo for a closer view. Scan of a slide taken in the early 1980s--or late 70s. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707350948844-S0HBD7GO8PNCR04Y058G/Sibley+welded+scoriaR.jpg Geology - welded scoria at Sibley, closer view The welding proves that the scoria remained hot and plastic as it erupted from Round Top, still remaining that way when it landed. Thus the welding. It’s a wonderful deposit! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1547337737022-FY6HYGT3C4JGDBMM9RI5/Sibleytuffsps.jpg Geology - Sibley tuffs This oxidized sequence of tuffs or tuffaceous sediments was probably deposited in water. To the far right is a dark basalt flow, which may have still been hot when the tuffs began to settle, which might account for the deeper red tone of the tuff adjacent to the flow. The hard, resistant bed that is offset close to the flow is an indurated tuff that was probably “welded” as a result of landing while still very hot. Two views of a thin section of this unit follow. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1547338216759-IBILYZVHUVGCUCFJGDF5/combo2a+copy.jpg Geology - basaltic or andesitic tuff These are two views, in plane-polarized light, of a thin section of the indurated tuff shown in the preceding landscape view at Sibley. The left one is dominated by a volcanic clast full of plagioclase laths. Also present are some small fragments of reddish basaltic or andesitic cinder. Vesicles in cinder are easier to see in the view to the right. The right view also contains quartz crystals, and I have noted potassium feldspar elsewhere in the slide. These are almost certainly sand grains that were picked up from older sedimentary units through which the tuff erupted. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531262752771-3NJK8MM7P5YKCG1Z2LD8/BHT4ps.jpg Geology - Berkeley Hills rhyodacite tuff Near the south end of its outcrop area, the Moraga Volcanics marker tuff, dated at 9.8 my, was altered by hydrothermal action penecontemporaneous with volcanism. The beautiful aquamarine colors are probably from a smectite clay mineral, perhaps nontronite, produced by hydrothermal action. The chunks, varying in color, are all rhyodacite lava. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531262767915-NKMKSR1SIYN2KIGBSLNE/BHT1ps.jpg Geology - Berkeley Hills rhyodacite tuff Another aspect of the colorful rhyodacite tuff. The matrix, which was originally probably mostly glass shards, has apparently been at least partially silicified, probably by hydrothermal action. The brilliant clear crystals are sanidine, the principal target for argon/argon dating. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531257713141-8PL1RV4OX2B5K02KADNM/RPBGdaciteTuffpplinter.jpg Geology - Berkeley Hills tuff thin section Large blocks of the famous Berkeley Hills rhyodacite tuff, 9.8 million years old, lie about the Regional Parks Botanic Garden where a prehistoric landslide delivered them from near Grizzly Peak. This plane-polarized-light thin section shows big crystals of quartz (e.g., the largest one at lower right) and some sanidine feldspar. The quartz is embayed (moth-eaten), probably because the igneous melt heated up again after the quartz had crystallized, perhaps due to mixing with fresh basalt. The matrix betwen the quartz crystals is full of glass shards. Look for y-shaped pieces. You can picture these as parts of the walls of pumice cavities that have been blown apart. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531262727938-D5PGFB3YN43MAXRUA8NS/daciteinterm.jpg Geology - rhyodacite clasts from Berkeley Hills tuff These two chunks--the left one from a 10-inch diameter clast, are porphyritic rhyodacite eroded from the famous rhyodacite tuff in the Moraga Formation. Clasts so large occur only near the Round Top volcano, which is basaltic. Garniss Curtis argued that the siliceous source vent was therefore adjacent to Round Top, but carried north by motion on the Wildcat and Hayward Faults. I suspect that the siliceous vent was actually west of the nearby Hayward Fault, and that its remains may be in the Tolay Volcanics in Sonoma County--which include much flow-banded rhyolite lava. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1599162469320-YR2LSV1SATH5N3JHQG4M/biclastinterm1.jpg Geology - BHT clast thin sections Here are views of thin sections that correspond to the two clasts in the previous photo. The phenocrysts of the gray clast at left include abundant quartz and plag, little if any sanidine, and frequent pyroxene. I would call it a dacite. The yellowish-brown clast at right is crammed with quartz phenocrysts and has lots of sanidine, plus common plag. There is little sign of mafic crystals. I would call this a rhyolite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1569720414762-30OFZT0T4L0G86V66GG1/Sibleyvitrophyre%3FInterm.jpg Geology - hydrothermally altered dacite clast This fresh surface on a rhyodacite clast associated with the tuff of that composition near Round Top has abundant plagioclase and occasional quartz phenocrysts in a groundmass filled with iron oxides, some reddish in PPL and some black. The great abundance of these oxides, combined with extreme abundance of fluid inclusions in pervasive void fillings, suggest high oxygen fugacity in a hydrothermal setting close to the surface. That, of course, is the speculation of an amateur. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611872003561-MCR2CDGMGS5T4BH3DO3X/reasdy.jpg Geology - thin section view of the red and black dacite The pale tan coiled form at left (in PPL) is a cavity filled with fibrous chalcedony (fibers visible at high magnification in XPL). At right is a logjam of plag xtals and black oxides. The red in the matrix is probably hematite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611872047060-B5BGNSOUOSNSUF4PJJS0/finc1.jpg Geology - closer view At left, the coiled chalcedony cavity filling proves to be crammed with fluid inclusions, as are the voids in an extensively embayed plagioclase crystal, right. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611872070317-5ZLYHXBIFHO9OKGEL0HO/qtzready.jpg Geology - another view of the red and black clast Two seriously embayed quartz phenocrysts are center-stage. Note they have no fluid inclusions, while the pale tan chalcedony formed later is crammed with them. Everything about this rock says supergene hydrothermal alteration to me. The iron oxides must have been contributed by descending solutions, as there would not be enough intrinsic iron in a rhyodacite to make so much oxide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531263469091-ZMBGWRSX1H6X80GN55FJ/CeladoniteFinalinterm.png Geology - celadonite Celadonite is a micaceous mineral related to glauconite. In the Berkeley Hills we have found it in the Moraga Formation flows, but only on the east side of the Siesta Syncline. It's occurrences in basalt vesicles and in quartz veins, as shown here, suggest a hydrothermal origin. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531263487352-MVTF0X541RUJLUG8E5QO/celadps1interm_edited-1.jpg Geology - celadonite in thin section Part of a thin section of a specimen like that in the previous photo and from the same site, shows celadonite growing in basalt (top part) and invading quartz vein (bottom part) in vermiform fashion. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531263501046-8NP58E5MM4X9U42PN6YA/celad2intermps2_edited-2.jpg Geology - celadonite in thin section Same thin section as in prior photo. The celadonite (green) fingers seem to contain spheroidal subunits that resemble glauconite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531263556436-G693R35LXXRM2HZK0NKG/cavsinterm.png Geology - cavity fillings in Moraga basalt Many have seen the fascinating chalcedony amygdules that fill vesicles in many parts of the Moraga Formation basalts. Cavity fillings are less common, and these are two highly unusual ones. At left, exposed by recent bank-cutting, is a five-foot-wide cavity with quartz precipitated in various forms, and part of the basalt wall at right delaminating into the cavity, perhaps under hydrothermal pressure. At right is part of a cavity filling (geode) with clear quartz prisms around the margins and darker plates of calcite in the center, probably reflecting oscillating saturation of hydrothermal solutions with silica and carbonate. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531263528574-A389W8D330C83HUJ2OBZ/BBagatebestinterm.jpg Geology - Berkeley blue agate This cavity filling from the Moraga Formation basalt in the Berkeley Hills is in a private collection. It is the best I've ever seen. It was not cut by a rock saw, but rather split by impacts in a stream bed, then worn a bit. The banded outer layers (agate) are chalcedony (polycrystalline quartz). Larger quartz crystals fill the center. This is a common pattern that can result from higher silica saturation in early hydrothermal fluids, resulting in more frequent nucleation of crystals that consequently crowd together and remain small. With cooling of the waters and gradual reduction in silica satuaration, fewer crystals nucleate but now they can grow larger. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531263571539-GQY9K300ZGDBPECKRJGI/diffrColorsps2interm.jpg Geology - Iris agate Dr. Francis Jones, chemist and mineralogist, and the first docent at the Regional Parks Botanic Garden, worked out the microstructure of "Berkeley blue agates" that occur as vesicle fillings in basalt of the Miocene Moraga Formation. He showed that the "Iris agate" variant is caused by bands of varying refractive index in "turtleback" chalcedony (in thin section) acting as a diffraction grating. Something approaching what Francis studied can be seen in this siliceous vein in andesite from Peavine Mountain, Nevada. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1741109445434-PSUBW7ZVYEWME49KELRY/my+rigAA-R.jpg Geology - petrographic microscope This is the polarizing petrographic microscope rig I use to view and photograph thin sections…That’s a Nikon D90 on top. Most crystals are anisotropic, splitting light passing thru them into two rays, vibrating perpendicular to each other. The petrographic microscope has two polarizing filters, one below and one above the sample. The lower turns the light source below it to plane-polarized light (PPL). The crystals then split the light into two rays. The upper polarizer is perpendicular to the lower, and combines the two rays passing thru the crystals. How much out of phase the two rays are makes the colors. Chromatic abberation makes a little contribution to the colors also. When the upper polarizer is inserted that is called crossed polars (XPL). Crystals have color in PPL also, usually less emphatic than in XPL, but not always. These colors are often more useful for identifying the mineral than those with XPL. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596783547761-GW0U0GERX8HBM28PVITM/SibleyHX.jpg Geology - Acheulean handaxe in Moraga basalt This was the first refined handaxe I ever made in basalt. It’s very hard to find fresh flakeable basalt in the Berkeley Hills. Fresh surfaces of the best material tend to be gunsteel blue. I made this in Walter Knight’s garage in Petaluma. While I worked, he walked in and took one look at me, and said, softly, “I’d better not disturb you,” and backed out. He could tell instantly that flaking a refined piece, especially in basalt, demands intense concentration and single-mindedness. I was lucky he understood! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531264212317-6SN0PKDSE1E45A7FQKVP/EdgewoodGeyserite%26lichensinterm.jpg Geology - branching geyserite An example of Miocene geyserite within the Moraga Formation volcanics. Note the branching of the columns in this siliceous sinter formed at the vent of a geyser or at a boiling splash-pool. I tried to make this small slab inconspicuous, but it was stolen shortly after this photo was taken. The site is vulnerable to moronic vandals, so we do not give its location. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531264328804-ZMGKWF0IMF0648XAOOG8/cyanofinal.jpg Geology - filamentous cyanobacteria These two views of a thin section in plane-polarized light show filamentous cyanobacteria, likely thermophilic, that are embedded in opal that is part of a block of chalcedony found close to the geyserite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531264132852-G0RPBZE3B9ZBFS8GC220/geyserite2final.jpg Geology - geyserite Geyserite only forms around geyser vents or boiling splash-pools. It is a form of sinter. In cross section the hand specimen at left shows the characteristic appearance of stacked, convex poker chips. The thin section at right shows the layers magnified, and they consist of alternating bands of chalcedony and calcite mixed with chacedony. All of this has probably replaced original opal. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1726778350591-V7KJUXK71ZHGJH8MXMWJ/LS+breccia+near+geyseriteA.jpg Geology Further evidence for violent geothermal action associated with the geyserite is limestone-matrix breccia with chunks of chalcedony and volcanics. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531263701499-859HCCDRK49IMU4Y1IRJ/chert-matrixVolcBrecciainterm.jpg Geology - chert-matrix volcanic breccia This breccia has a lustrous chert matrix (the chert just below is banded and multicolored). The red chunks are microvesicular basalt, their vesicles filled with chalcedony amygdules. This is from a stratigraphic horizon near the geyserite site in the Miocene Moraga Formation, but about a mile away. The breccia suggests violent action where silica was likely being deposited by hotsprings, perhaps initially as opal. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707357052393-WXTUEL1L4JHW4DHVC1ON/Claremont1R.jpg Geology - Claremont Formation on Skyline Drive The Claremont Formation is frequently called “Claremont chert.” But it consist largely of porcellanite with shale interbeds. But see the following photos. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707357072035-LYERZE0ZYI3PUP2S8I8Y/Claremont2R.jpg Geology - Claremont Formation …a typical view: porcellanite (muddy chert) interbedded with shale. These couplets represent long-term fluctuations in sedimentation, in contrast to what can be observed in the next two pictures. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707357100302-J7JFMBDJOLUBWFO0WQD7/Claremont3.jpg Geology - a nearly white chert bed in the Claremont These fine bands were not disturbed by the dramatic folding seen on the scale of outcrops or roadcuts in the Claremont Formation. This is strong evidence that the folding was NOT produced by soft-sediment deformation. This is the closest one can get to “pure” chert in the Claremont, but such beds are rare. See next photo for a closer view. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707357119545-95M469HBR5AUM46JPORM/Claremont4.jpg Geology - varves in the chert I believe these fine laminae were produced by seasonal variations in sediment supply, hence I would call them varves—analagous to tree rings. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531262828066-LOYYQK8LSAQ1IOYJ5EGD/outcropinterm.jpg Geology - dike in Claremont Formation This brecciated dike along Grizzly Peak Blvd. is unlike any other dike in the Berkeley Hills that I have seen. Note the chunks of red Franciscan chert that the dike picked up from older rocks. Following photos show views of a thin section of the matrix between the larger volcanic clasts. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531262856851-PDI3X3R7IO13GGE6XPTW/PPLoverallinterm.jpg Geology - dike in Claremont Formation This view of a thin section of matrix of the dike is in plane-polarized light. Note the matrix is itself dominated by clasts, mostly andesite or basalt with aligned plagioclase crystals. One near the top has a dark glassy matrix and vesicles. The matrix betwen clasts has abundant angular quartz crystals. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1531263128339-8WVJTMGXZFSPZWZOVW5F/natrolitepsinterm.jpg Geology - zeolites in Claremont dike the vesicles are filled with a zeolite that is likely natrolite https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1743483152562-P68FAEDQLTXT25VQZ9NS/moraga+fmCROPPED-RsharperCONTRAST.jpg Geology - Orinda Formation at Sibley Volcanic Regional Preserve The Orinda Formation is thickest here, which Ross Wagner argues to be owing to releasing fault bend(s), and the overlying volcanics are owing to the releasing bend as well. You can see the not-so-subtle bands in the Orinda Formation grassland, reflecting composition of underlying strata. The grass is taller (lighter bands) on mudstone, with better surficial H2O retention; thinner (darker bands) on sandstone and conglomerate. Scanned from a slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1652665840324-GBTWFKYBVR4XQ7X9D30J/purpporhs1R+copy.jpg Geology - "purple porphyry pebbles" Pebbles like these, with black glassy groundmass and conspicuous pink K-feldspars, often also with embayed quartz phenocrysts, are very prominent in the Paleocene Carmelo Formation at Pt. Lobos and here at Pt. Reyes. Glynn Isaac gave them a nickname, “purple porphyry,” but they are not technically porphyry. They are porphyritic felsic volcanic rocks. Essentialy identical clasts occur in the type Orinda Formation as well as in younger sediments at Pt. Pinole—perhaps from streams that came off the Salinian terrain as it tracked north via San Andreas and San Gregorio Faults. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1652665865046-AF6CBO3ZAUZS3HMDNDE6/purpporhs2R+copy.jpg Geology - field site for the "purple porphyry" pebbles Here beyond the very west end of Drake’s Beach, the porphyritic pebbles, derived from Carmelo Formation conglomerate, are mixed with granodiorite pebbles from Salinian basement. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601683582908-2VJBFX4AI4G772XT8NQC/TOps2RED.jpg Geology - "purple porphyry" thin section 1 A view in PPL of one of the pebbles from the type Orinda Formation. The swirling flow banding was probably originally glass. It is much devitrified now and partially replaced with polycrystalline quartz. Quartz phenocrysts are predominate, but there are all also plenty of Kspars, very altered. There are also cavities lined or filled with polycrystalline quartz., one of which is the funnel shape in the middle. Left, a large quartz phenocryst. Upper right, a Kspar, much altered, with Carlsbad twinning. Mafic crystals are rare and small, broken up and altered. All of this presents a close petrographic resemblance to similar pebbles in the Carmelo Formation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601683605009-JXSAMD5UO10LF7GFHH66/Carmelo2ps3RED.jpg Geology - "purple porphyry" thin section 2 This view in PPL of a thin section of a Carmelo Formation pebble presents a polycrystalline-quartz-filled cavity at lower center, very altered Kspars left and top center, the latter accompanied by a quartz phenocryst. The alteration of the Kspars resembles the alteration in the Orinda Formation pebble. The matrix between the crystals again is finely convoluted flow-banded, and extensively replaced by polycrystalline quartz. There are frequent shapes that look like relict glass shards in the flow banding at higher magnification, though I am not certain of that as I see no clear vesicle fragments. It is hard for me not to compare this with similar pebbles in the type Orinda Formation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1545277096609-36JPV2530K6ICH8QHAWK/Temdual2300.png Geology - blueschist fault gouge in HFZ This smeared-out blue schist was exposed by a cut within the Hayward Fault Zone near Lake Temescal. The fault has scavenged this metabasite from Franciscan terrane west of the fault. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1545277139397-0FZ5H4QS32PHK3RXNHFZ/Temdualtsecs2.jpg Geology - Temescal area blue schist thin sections These thin-section views in plane-polarized light with the 10X objective reveal microscopically what is within the smeared-out rock in the previous photo. On the left, two different orientations of foliations may be S-C bands resulting from prolonged intense shear at great depth. The blue mineral in PPL is either glaucophane or riebeckite. It is composed of countless wavy needle-like strands and is thus asbestiform. Both glaucophane and riebekite can look like this. My guess is glaucophane, but I haven’t worked that out yet. With this much deformation it would be difficult in any case. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738201059262-18Z0ZDL37ERY8IBERM3R/GVS+overlying+CROsharper2.jpg Geology - GVS overlying CRO near Lake Temescal Davy Jones and Garniss Curtis discovered Leona rhyolite (actually keratophyre) of the Coast Range ophiolite overlain here by Knoxville Formation of the Great Valley Sequence, in depostional contact, the Knoxville dipping easterly. The same relationship can be found far to the south, in Del Puerto Canyon. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763513731389-DXPOVTEW1M9KYIIV15AE/Leona+%2522rhyolite%2522R.jpg Geology - Leona "Rhyolite" What lithology this really IS is explained in the previous photo. On old geologic maps this was classified as Plio-Pleistocine. Now we know that it’s Jurassic, by relations shown in the preceding photo, and radiometric dating. Prehistoric First Peoples used to quarry this material for RED pigment near the Lincoln Center at the base of the grade of Redwood Road. The ochreous parts are red; the fresher parts, on chipped surfaces, are gray. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1644457781718-HSO7YZBIV9PM8TOAV4A0/Seeno3A.jpg Geology - East toward Kirker Pass THIS BLOCK OF PHOTOS PROCEEDS LOOSELY FROM NORTH TO SOUTH IN THE EAST BAY. View looking east from Stoneman Park toward Kirker Pass and Black Diamond, late 1990s. Gray ledge under the left rainbow is top of the Neroly Formation; white above that is airfall part of Lawlor Tuff; pink above that is ashflow part. The Lawlor erupted from a vent immediately east of the town of Napa 4.8 million years ago. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765233917164-AS18ASW3SO16PP1UKS3K/Lawler+Tuff+%40+Grand+Cn.+of+Neroly.jpg Geology - airfall tuff in the Lawlor, lower left in the previous photo…It’ s WHITE! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596232479300-PECL8GWVH3D5INPAXG9I/Markleyinterm.jpg Geology - Markley Formation at Black Diamond Most of the thickness of strata underlying these hills consists of Eocene marine Markley Formation, mostly sandstone. Detrital zircon studies suggest one of the sources for the sand was a river arriving here from the Idaho batholith, though the geater source was the Sierra Nevada. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1664920727949-MNADDRI0B7OVU8AFKQ20/ridge1.jpg Geology - mid-Cenozoic sequence at Black Diamond This view taken looking NNW from near Somersville Road shows most of the mid-Cenozoic succession on the north flank of Mt. Diablo. The gray exposure in the foreground is Eocene siliceous Sidney Flat Shale, which is also responsible for the huge slump beyond. Ascending the steep slope beyond the slump, late Eocene upper Markley sandstone can be seen cropping out above the fenceline. Upper left of center a small gray zone conforming to the regional attitude (near EW strike, near north dip of 35-45 degrees) represents part of the middle Oligocene Kirker Tuff—which does not extend to the east of Somersville Road. Above the Kirker is Cierbo (in places calcareous, thus partly white), bracketed between about 12 and 10.9 million years. Capping the ridge is Neroly, which is locally nonmarine. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1679188217379-OGZAXDE7FYN2LGDTAKCR/UMss1R2.jpg Geology - Upper Markley sandsone This is Upper Markley sandstone that contains pumice clasts, as seen in the next picture. These sandstone outcrops belong to the late Eocene Upper Markley, which stratigraphically is between the Sidney Flat Shale below and the Cierbo Formation above. This exposure is north of the top of the pass east of Sidney Flat at Black Diamond Mines RP. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1623894269786-TY9DIU5FLY7W3ZKRTADZ/UMarkleywPumiceArata.23Rpg.jpg Geology - Thin section of Upper Markley This view of part of a thin section from the outcrop in the previous photo (collected during research for the GSA volume on the Mt. Diablo region) was taken with the 10X objective, in PPL. It shows that even as early as the late Eocene, rivers coming into California from the Nevadaplano were brining in volcanic detritus from silicic calderas (caused most likely by slab rollback and associated extension). These volcanoes were much farther east than those that contributed a huge volume of ash to the Oligocene Kirker Formation. There is an antler-like elongate glass shard at left, while at irght there is a large clot of pumice fragments and glass shards. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1622932327533-YSLIECGM1D3GSQLF5MB4/KikercomoRs.jpg Geology - tuff at Briones Reservoir Ron Crane mapped what he identified as Kirker Tuff on the Oursan Trail NE of Briones Reservoir. It would have been a submarine deposit, perhaps in a channel, as deep-water marine sediments are above and below. This would be the farthest west occurrence of the late Eocene to Miocene Nevadaplano caldera eruptions that stormed down Sierran paleochannels as ash-flow tuffs, the most famous of which is the Valley Springs Formation. The tuff here weathers buff, but it is white on fresh surfaces, and it has a brittle blocky fracture. Chris Henry from UNR sampled this outcrop but the grains were too small for Ar/Ar dating. So this MAY or may not be the Kirker Tuff. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954384195-VDVILLCSIVBO5AL8W9UN/D750areducedInterm2.jpg Geology - view west in Los Medanos Hills Obvious stratigraphy in the Oligocene-Miocene part of the homocline that is the upturned edge of the Sacramento Valley Tertiary depocenter. View from west of Sidney Flat west to and beyond Kirker Pass, March 2020. The unit with white patches in left foreground is part of the Kirker Tuff, which exploded from a silicic caldera in Nevada 29 my ago. The unit with white streaks at far right is the Lawlor Tuff, which exploded from a silicic caldera just east of the town of Napa 4.8 my ago. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954780606-BCQ7W04GLFO2OUYQ9OHD/Kirker2ainterm.jpg Geology - Kirker Tuff This thin section view of the upper part of the Kirker Tuff near Kirker Pass, at 100X in PPL, shows all glass. There are very few crystals and they are very small and only visible in XPL. The glass is pumice blown to smithereens during eruption. Everything you see here is glass of various shard sizes. There is some small-scale stratification in the tuff, but the glass shards in this view show negligible alignment, suggesting they came in quickly in a slurry and came to rest abruptly. The ball of coarser shards is a coarser-grained glob that got mixed with adjacent finer ones. The depositional environment was shallow marine. There are shark teeth in the Kirker. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1615772470326-NMZC1M4MP2FB1V9H2NH3/BDKirkerps1R.jpg Geology - Kirker Tuff west of Sidney Flat Here is a view of a thin section of Kirker Tuff exposed near where I stood to take the photo of the green Los Medanos Hills atop the ridge west of Sidney Flat, 2 pictures back. The flat dark crystals are biotite, showing alignment owing to currents in the water where this tuff came to rest, and on the way there. Al Deino used biotite and plagioclase to Ar/Ar date the Kirker Tuff to latest early Oligocene, equivalent in age to some of the ash-flow tuffs that roared down Sierran paleovalleys from calderas in Nevada, and with its own source there. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1626739669159-37OPBKBVAFAPMOBKRCOQ/ResKirkerX4R.jpg Geology - Briones Reservoir Kirker The Kirker here very much resembles the two samples shown in previous photos, looking as it does like a mass of bone fragments crushed and at times regurgitated by hyaenas, dominantly glass with only scattered crystals/sand grains. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597214298768-DX61NNIYLZBDTFNYKK37/ShellRidgetuffinterm1.jpg Geology - Shell Ridge tuff The obvious white tuff is near the base of the shallow marine Cierbo Formation. It has been Ar/Ar dated at 11.45 Ma. It thus correlates with a tuff Ross Wagner found of the same age near the base of the nonmarine Orinda Formation near Cull Canyon. This is one of a plethora of exciting discoveries by Ross in the Miocene Contra Costa basin. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596232515221-2HPR2UQ6CU042Y1WR4HE/StonemanTUFFinterm1jpg.jpg Geology - Tuff at top of Cierbo This impressive cross-bedded pumiceous tuff, dated via Ar/Ar at 10.93 my, is a conspicuous marker bed at the top of the Cierbo Formation in the Los Medanos Hills. The cross bedding is deceiving. It looks like the current flowed to the east, but because the entire section dips rather steeply to the east, if that section were horizontllized, these cross beds would dip to the west. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608348808093-SPPI4U4KBV6KMCWLREGJ/CierboStoneman3red.jpg Geology - tuff at top of Cierbo A thin section from the outcrop shown in the previous photo, in PPL with the 4X objective. It shows that the unit consists of sand made mostly of coarse grains of pumice. There are also plenty of feldspars, especially evident In the upper left quadrant, along with a crinkled biotite. There are also thin layers of more typical sand (not seen in this view). So the feldspars and biotite could have come in part from sources other than the eruption that put out the pumice. To get an accurate date, you have to date crystals enclosed within pumice clasts, therefore comagmatic with them. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1644694816583-UQ45H2OTZEB8ZJ2OWFQG/Neroly.jpg Geology - Neroly Here is part of what I call the Grand Canyon of the Neroly in Contra Costa County. I am keeping the location confidential. If it becomes known to the public, the rocks will be destroyed, just as similarly soft sandstones at Black Diamond Mines have been destroyed. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738199917205-T9NNOKOMOGJCM16S1H0O/Cierbo+S+of+PittsburgPS2Acleaner.jpg Geology - Cierbo in glory This is the Cierbo Formation south of Pittsburg, Contra Costa County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1614912315647-8WL26N8C93DNTD3SAUZ0/faultcomboRED.jpg Geology - fault cutting the Cierbo at Black Diamond Here a roadcut has exposed a fault surface (upper left) transecting the Cierbo. Lower left view shows part of the anatomy of the fault, which is not merely a plane, but has thickness. That thickness is partly occupied by fault breccia, right. Here blocks of sandstone float in a matrix of fault gouge, the latter apparently cemented by carbonate. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954882923-U91OW0EJ7BBNHDCUONXY/Neroly%2Binterm.jpg Geology - blue Neroly A closeup of the famous blue Neroly sandstone at Black Diamond Mines. This shallow marine to nonmarine sandstone, ca. 10-11 million years old, came from volcanoes in the Miocene Sierra Nevada. Volcanic mudflows rushed down stream channels into the shallow San Pablo Sea. The blue color is imparted by a coating of clay minerals covering sand grains, and derived from weathering of volcanic ash. The dark porphyritic pebble is a volcanic rock, and to its lower left there is a small chunk of granite eroded from Sierran basement. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765236957477-TIIP0ZP79WZIXRDTIPT7/blue+Neroly.jpg Geology - blue Neroly …at east end of Corral Hollow…The gray & white clasts might have begun as pumice floating on river(s), and weathered to clay. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1648533825550-D97TWQG7Z65IS1J208QU/Magnolia.jpg Geology - Neroly Magnolia This is a partial leaf of an evergreen Magnolia from the Neroly of the Los Medanos Hills. The Neroly contains abundant leaf fossils of a mixed evergreen-deciduous forest, with many genera in common with the SE US today. Taxodium (baldcypress), Persea (avocado) and alder are all common in the Neroly, though I have only found wood of the baldcypress. One can tell this leaf is evergreen because the inrolled margins betray its thickness. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954799032-TZT2TJ69XHKGWONF8PBA/Lawlernterm.jpg Geology - Lawlor Tuff at Black Diamond The hogback-forming Lawlor Tuff exploded out of a caldera at the west base of Mt. George, east of the city of Napa, 4.8 million years ago. Here it outcrops in the Los Medanos Hills part of Black Diamond Mines Regional Preserve. The steep dip, along with similar dips in beds overlying the tuff, suggests that Mt. Diablo as we know it today was not a mountain until after 3 million years ago. Immediately subjacent to the Lawlor here at Black Diamond is a conglomerate full of boulders of andesite or basalt, some of it vesicular. These clasts are too large to have been moved very far. The prime suspect for their source is the andesite flow(s) of the Concord Naval Weapons Station, the nearest possible source. Provisional Ar/Ar dates on the latter of 5.5-5.8 my fit nicely. However, there are remnants of what seems to be the same andesite stratigraphically above the Lawlor high in the Los Medanos Hills to the west of Black Diamond. My guess is that there may have been flows of different ages emanating from CNWS, but, without more field and lab work, this is only speculation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1651647656077-N3BI8QVXKUSXHZGAE1BW/LawlorCGcomboR3.jpg Geology - sub-Lawlor boulder conglomerate Immediately beneath the Lawlor Tuff at Black Diamond, there is a basalt- or andesite-boulder conglomerate. According to current evidence from mapping on the ground, the boulder conglomerate is older than the andesite flow(s) in the former Concord Naval Weapons Station, so the source of the mafic or intermediate volcanic boulders must be sought elsewhere. The base of the Lawlor is a cross-bedded pumiceous unit that contains pebbles, as seen at right. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765232222540-BAWOENMF1EB24XXY3M6Q/pebble+sub+Lawler.jpg Geology - purple porphyritc andesite beneath.... …the Lawlor Tuff….It vaguely resembles the “purple porphyry” pebbles in the Carrmelo & Orinda Fms….. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765232254390-5XYT26KWVCU2P5VZ7Q8I/pebble+sub+Lawler+%40+StonemanR.jpg Geology - thin section …of the purple porhrytic andesite pebble, which we found beneath the Lawlor Tuff at Stoneman Park above Pittsburg…..Shot in XPL with the 40X objective. Dominated by plagioclase; but there may be scattered small Kspars. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610840373544-UZUHNLJDIG1VEVUCVUBD/limeridgequarryRED.jpg Geology - Lime Ridge travertine quarry A view of one of the quarries made by the Cowell Cement plant operation, looking NW, south of Ygnacio Valley Road. There was a massive amount of travertine at and near the surface, but it did no go deep and the operation lasted less than 40 years. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610840399231-SKQWG1BI26Z9VSL7HOAC/travertine%2Climeridge+quarryRED.jpg Geology - travertine Travertine variants on Lime Ridge. Massive travertine deposits are generated by thermal springs where, at great depth, magma has charged circulating water with CO2, thus acidifying it (with carbonic acid). The acid waters interact with calcareous rocks at depth, liberating calcium and making more carbonic acid, and bicarbonate ions plus CO3 (2 minus). When such water reaches the surface, at temperatures up to 73 C, low atmospheric pCO2 allows the water to degas CO2, and the water becomes more alkaline. This favors precipitation of CaCO3, which makes travertine. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610840428493-YODLUBK98DFFY49O344Y/DSC_5793+copyRED.jpg Geology - Lime Ridge Domengine conglomerate The travertine quarries were in the Nortonville and Domengine Formations, and thermal waters may have made use of the contact between these formations for access to the surface. This conglomerate is in the upper part of the Domengine Formation, and contains some very interesting clasts—pyroxenite diabase and gabbro—suggesting CRO was subject to erosion at that time. At the base of the Domengine in Black Diamond, there is a conglomerate containing abundant red and green chert clasts, indicating Franciscan rocks were being eroded. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1664858179817-NSSGHQUT9CK633BC2WFB/Domengine.jpg Geology - Domengine The true glory of Black Diamond Mines is the Domengine sandstone, shown here, since, besides being beautiful, it is (or was) a fabulous subject for further resesearch as well as teaching. However, since this photo was taken, most of the best outcrops have been destroyed by graffiti vandals wielding, like Gary Larson’s tiny brained cretins, hammers and chisels. It is a great pity that geological organizations and Earth Sciences departments have little if any conservation ethic. If they did, they could see that the vandalism was stopped. Unfortunately for most of the outcrops, it’s too late now. I did my best. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1664858201494-1YNFOTNBZ5MCOI1ZIMV3/crossbedsEof+Stewartville+copyR2.jpg Geology - an example Here is part of an outcrop of Domengine that Ray Sullivan has studied and that I found with his help. Its bidirectional cross-bedding is evidence for a tidal influence, the oxidized mud drapes indicating tidal slack. I photographed this long ago and have since been afraid to go back, because I don’t want to discover that it has been destroyed. Surface outcrops of this kind at Black Diamond are getting very hard to find. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1664858222643-9GUOBCATZA3RKCA2WNKD/8d+copyR.jpg Geology - liesegang rings There were once many beautiful surface exposures like this in the Domengine at Black Diamond, but they are in the process of being eliminated by vandals and careless foot traffic. The banding is a diagenetic product the origin of which is not well understood. It probably involves precipitation of iron oxide from ground water moving through the rock. Precipitation at the migration front creates a band, while adjacent zones are depleted of the preciptates. When the next front passes through, another ring forms, but the creation of so many bands remains a mystery. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1670657133400-8WU0WQFQKFM3E7FPV62J/DomenginekaolARED2.jpg Geology - Domengine lower member thin section This is a view of a thin section, in XPL with the 10X objective, of lower member Domengine Formation quartz sandstone at Nortonville. Although the fine matrix is beyond the resolution of my scope, it is still possible to see vermicular kaolinite (looking like diced caterpillars). Kaolinite is usually produced by disintegration of Kspar (and/or micas), in which process potassium is lost, and the resulting clay contains only aluminum, silica, and hydroxyl. It is consistent with intense chemical weathering in a humid subtropical environment. I suspect that the weathering occured in the Ione Formation setting in the low Sierra foothills. The Ione is a lateral eqivalent of the Domengine. So then the kalonite in the matrix at Nortonville would be detrital. On the other hand, it may have formed in place after the Domengine sands came to rest and subtropical vegetation grew on them. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1743228756441-881P9SEMKT5PRQMNSLPY/mud+drapes+in+cross+bed+inR1+Hazel%3Aatlas+shaft+copy.jpg Geology - mud drapes in Domengine These mud drapes in cross-bedded sandstone of the Domengine Formation in the Hazel-Atlas shaft at Black Diamond Mines RP indicate tidal action in the early middle Eocene. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706899358248-FOSX267GYBI497NW3Z7Z/CastleRockR+copy.jpg Geology - Domengine at Castle Rock The sandstones of these outcrops were deposited in deeper water to the west of Black Diamond Mines, as turbidites in submarine fans. In contrast, the Domengine at Black Diamond was deposited in tidal situations—sometimes fluvial. Miserable scan of an old slide, but still compelling. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954952120-6FTUBQ7ELC5VJQQFY5EE/nortinter2.jpg Geology - Nortonville clinker The mysterious blocks of hard clinker at Nortonville invite investigation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597955007492-VS0ZRSWDTQFIQHVSSTWK/nortinter.jpg Geology - Nortonville paralava This was apparently a huge waste heap of mine debris full of coal and chunks of sedimentary rock. Exposed to oxygen, organic matter in such piles can spontaneously combust, and oxidation of pyrite, which is exothermic, can also cause combustion. Temperatures of 2,000 degrees C can be reached. Iron is oxidized to hematite, thus the reddish color, and rocks are melted, producing what has been called "paralava," which is evident in this photo. But it would be nice to know more of the actual history. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954475006-2L2ANDWXY3EAGYEFFL7P/DSC_5379%2Bcopy.jpg Geology - Hazel-Atlas red dog This mine dump is in the woods near the Hazel-Atlas Mine. The coal at Black Diamond was relatively sulfur rich, probably mostly in disseminated iron pyrite. On exposure, this combines with water and oxygen in a bacteria-enhanced exothermic process that produces sufuric acid, hematite, and oxygen, and which can get hot enough to ignite the mine dump. The red is from hematite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954670750-758U8F5G0WWRASXZ3P8C/formula2.png Geology - red dog chemistry This is a very simplified, summary formula for what goes on to produce red dog in a coal dump. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1627682002758-EKQHEHKETWAE3WXYQ7PS/Diablofrom+MorganTRP4-919PSRed.jpg Geology - Mt. Diablo in March What people call Mt. Diablo is actually a massif of two peaks, Mt. Diablo itself at left, and North Peak at right, here seen from Morgan Territory RP. Both are Franciscan, both topped mostly by greenstone, with lesser amounts of chert and sandstone. In the saddle between the peaks there is a sliver of melange that includes blocks of blueschist-bearing amphibolite. The Coast Range Fault runs diagonally from SW to NE, from Long Ridge west of Diablo to the north base of North Peak, wrapping around the base of the peak to the Mt. Diablo Mine. Overlying the fault is a band of serpentinite, and overlying that are sheeted dikes and pillow basalt. These and the serpentinite are components of the Coast Range Ophiolite, the basement for the Great Valley Sequence that filled the forearc basin between the Francisacn subduction zone ridge and the Sierran arc. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608230573840-HBBFNXFRLJEGNXTLE3W6/Markleydistant4red.jpg Geology - the north flank from Mt. Diablo The north flank of Mt. Diablo exhibits one of the thickest exposed Mesozoic-Cenozoic stratigraphic sections on earth. Right of bottom center is a Jurassic blueschist block—probably mid Jurassic—and, in the pool of light across the delta are the Montezuma Hills, underlain by the late Pleistocene unit of that name. Between these extremes , every epoch of the Tertiary is present, while between these and the Jurassic, there is a thick Cretaceous sequence. In the distant light-brown hills above the blueschist, it is easy to see the forested Domengine Formation, and, beyond that, grassy Markley Ridge. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1677721142464-IJXX14PDBQXQ2VZG2IIM/NPeak%26snow+for+M217.jpg Geology - Clayton west-side quarry Mt. Zion has been cut away on its west and south sides. Here the west quarry is viewed from NE of Lime Ridge, with snow on North Peak beyond. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1628122372281-VNDE0ARH4G96JDQR6KKF/Close%26ClearRED.jpg Geology - closer view of sheeted dikes The quarry owners will not allow geologists to take pictures in the quarries, which display the most spectacular on-land exposure of sheeted dikes on earth. So I use my FX. SLR, shoot from far away, then crop. The results are fair, and they clearly show deformation in the dikes at lower right. There is a conspicuous fault from upper left to lower right above that, which places metabasalt over the dikes. This has been intepreted as a normal fault, but the deformation in the dikes makes me wonder if it might be reverse. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1628122394680-MMO709J4OVOHNVHQ1MSX/Mitchell3RED.jpg Geology - sheeted dikes on the south side of Zion I was once given permission to accompany a quarry employee on to one of the ledges at upper right—without my camera, of course. We were able to get right beside the vertical quarry wall. The sheeted dikes were completely amazing, and took my breath away. One of the most marvellous geologic sights I’ve ever seen. Maybe the quarry operators could make more money charging admission on certain days of the week, AND LETTING PEOPLE BRING THEIR CAMERAS! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1642318716008-LPNEV6144J9SSHX6P0ZY/diabase1newR.jpg Geology - Mitchell Canyon sheeted dikes I got a little closer, but still had to crop the photo to magnify, so it’s a bit grainy. But this view does give a fair impression of the sheer splendor of this wall, which formed as dikes at the East Pacific Rise spreading ridge, or else in a suprasubduction zone extensional setting. The matter is not yet resolved. I believe they are both half dikes and whole dikes, as often a whole dike would go one way or rhe other, https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1644022131987-G7QBQLJE703S19RWITMN/diacomboR2.jpg Geology - Mitchell Canyon diabase thin section This is a combination of views of one slide, shot in XPL with the 4X objective. Holocrystalline dominance of augite and plagioclase is definitive of diabase. The brown mass lower left of center is anomalous brown chlorite (green in PPL). The needles are apparently actinolite (also green in PPL). At far right there is a brown hornblende crystal. Hornblendes are common in the Mt. Diablo diabase. This could be the result of hydrothermal alteration or just a result of a melt rich in H2O. The actinolite strongly suggests hydrothermal alteration at or near the seafloor spreading ridge under which these dikes were intruded. Many of the augites in this sample appear to be frozen in the process of replacement by actinolite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1677136771024-TY0FJ5AH2AUGOOGFMH1R/longridgeC+copyR2.jpg Geology - Long Ridge, Mt. Diablo This view is looking north. The top of the ridge is cappedby peridotite and serpentinite of the Coast Range Ophiolite. In the foreground is classic Franciscan melange, with mostly siliclastic matrix, and floating blocks of various lithologies, some of them high-grade. The Coast Range Fault lies between the CRO and Franciscan. This is a typical tectonic setting for Francisan melange with high-grade blocks. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1677136812097-3XWN9OJKDV60R3YOHRQJ/turtle+rock+comboR.jpg Geology - amphibolite block on Mt. Diablo This one, according to John Wakabayashi, is in a landslide. It’s difficult sometimes to tell landslide from melange! This block is a little way up the road from Turtle Rock. It’s amphibolite (very high grade) overprinted by glaucophane as the rock cooled in place, or rose to cooler depths. However, glaucophane itself is by no means low grade. Along with lawsonite, it is the most characteristic mineral of high pressure-low temperature paragenises in subduction zones. The blue in this block, and in the smaller block fallen from it shown at right, is from glaucophane. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706775455223-V9VQV3ZVYYK6FILNE7VB/north+peak+copy.jpg Geology - view from North Peak …looking westerly toward Eagle Peak, with dwarf California juniper woodland in foreground…ca.1990…This is Franciscan complex terrain, as the following images illustrate. The slde scanner available to me at the time I scanned this was an inferior machine. The scene is still compelling, even if the focus is poor… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706775480338-HOIRITEGS55AJQYDNKGK/pillow+LavaCliff%2C+N+PKR2.jpg Geology - pillow lava cliff near summit of North Peak North Peak is the main consort of Mt. Diablo. This magnificent cliff composed of pillow basalt is near the summit of North Peak. I once found red chert between some of the pillows here. All the pillow lava I’ve seen around the summit area of Mt. Diablo, in contrast, has been deformed by movement on fractures, many of them slickensided, and is hard to recognize those metabasalt outcrops as pillowed. Scanned from a very poor slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1743556802062-V0CDR14OUKKOHS9F9FFY/North+Pk.+pillowsR2sharper.jpg Geology - another view of the pillow lava outcrop on North Peak …scanned from a different slide…dramatic! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706775535737-7B4I8GOWK9OA4N4UCTN3/pillow+lava+closer+2.jpg Geology - pillow basalt on the top of North Peak very well-formed, too… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1628122306310-S28K9IY9O0VDMV3MMQ5L/fromLimeRidge.jpg Geology - view south from Lime Ridge Looking toward North Peak and Mt. Diablo from Lime Ridge, with one of the Mt. Zion quarries at left. The diabase in the quarry is made of sheeted dikes of the Coast Range Ophiolite. Between that quarry and its adjacent middle-distance hills on the one hand, and the Franciscan core at Mt. Diablo and North Peak on the other, a band of ultramafic rocks, bottom of the CRO, runs NE-SW, more or less perpendicular to most occurences of CRO up and down the inner coast ranges. This suggests Mt. Diablo was rotated counterclockwise about 90 degrees as it rose, mostly during the Quaternary, owing to a restraining stepover plus regional compression. The mountain sits between dextral strike-slip faults to its NE and SW, which must be the cause of both its uplift and rotation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1756771395714-1BUW9C0EIQQOSHQ30MTL/China+Wall+PS.jpg Geology - China Wall, Mt. Diablo SP West of the summit and SW of the Castle Rock Eocene, this relatively resistant sandstone in the Neroly Formation makes a lovely wall. It has been uplifted and dips steeply away from the mountain, and is part of the Mt. Diablo anticline, which consists of the erosional remnants of all the strata that once rested across the region where the mountain is now. The Neroly here is shallow marine; out in the Los Medanos Hills it is partly marine and partly non marine; and south of Altamont Pass it is nonmarine. Picture a large embayment with its western shore just west of Orinda and Moraga, and its eastern shore varying from Vacaville to the Los Medanos Hills. There were marine waters covering where Mt. Diablo is now essentially throughout geologic history, until about 9.7 my ago. At that point marine was replaced by nonmarine, but the area was still a sediment-collecting basin. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1613200226491-R754AXZ0LDBNWUG3ORWL/chblue2RED.jpg Geology - classic blue Nearly sandstone from Corral Hollow SE of Livermore. The blue is from montmorillonite that has replaced volcanic ash between the sand grains. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610840600258-34O358FH9YDIF8R8TCMZ/MarshCK1+copyRED.jpg Geology - Marsh Creek volcanic field Oliver Bowen suggested in CDMG bulletin 154 that the Lime Ridge travertines may have been caused by the same deep magmatic source that caused precipitation of quicksilver deposits here at the Marsh Creek volcanic field. Most of the wooded knolls in the foreground and middle distance are dike-like or neck-like intrusives, mostly siliceous, and dated by Ar/Ar at 7.6-7.8 my. Andesitic volcanics at the Concord Naval Weapons Staton, closer to Lime ridge, are dated provisionally at 5.5-5.8 my, but they could be as young as 4 my. Could the Lime Ridge travertines have begun to form this long ago? I hope that will be the subject of future research. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610921883914-RI2YYQ6Y6GGJMIY4LZ7B/PerkinsLith+copyRED.jpg Geology - Marsh Creek volcanic center outcrop Here is a typical outcrop of one of the siliceous intrusives, along Perkins Creek. What you see is jointing, not bedding. These rocks are best termed biotite rhyodacite, and Ar/Ar dating suggests they are 7.6-7.8 my old. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610921908632-GRHNXQ8GXBT8EFSJ9OTT/perkinsmacro2REDjpg.jpg Geology - Marsh Creek rhyodacite closeup This macro view shows that the rock is light-colored on fresh surfaces. The phenocrysts are plagioclase and biotite. Chemical analysis demonstrates that the rocks are more siliceous than the phenocrysts alone suggest. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610921933734-BRY4XJFI7UNCR2SW1N2K/perkinsxpl.jpg Geology - Marsh Creek rhyodacite thin section Here the large phenocrysts are plagioclase, and the needle-like golden-brown ones are biotite. It is not uncommon for the biotite to have grown over the plagioclase, crystalizing later. Broadly, the biotite can be seen to swim around the plag crystals. One plag is zoned, and both show simple basal twinning, while one also shows albite twinning. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610921951897-1GKFWQBC0YQVMOG9BOGF/MtDmine1+copy+2.jpg Geology - Marsh Creek metacinnabar Earl Pampeyan found cinnabar and metacinnabar in fractures in the Marsh Creek rhyodacites. This places a maximum age on mercury mineralization at the adjacent Mt. Diablo Mine. But that mineralization was probably concurrent with intrusion of the rhyodacite, as a hydrothermal system and heat source are required for mercury mineralization. This specimen is in a private collection and was photographed with permission. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654461867762-RL4X828V71NZ3RZ1N491/murieeta1.jpg Geology - Brushy Peak from the SE Again, sacred. The entire landscape here is underlain by Great Valley sequence sandstones and conglomerates. Shales can be expected in grassland, with minimal outcrop. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654461891805-TM64L9VUX9UJ3DN8I7P4/mrx2.jpg Geology - SE of Brushy Peak We were taken in by LARPD staff. This area is not open to the public without staff present. These cavitated sandstones are a very small part of the large area of such stupendous outcrops, traditionally known as Murietta Rocks ( not to be confused with rocks of similar character and the same name, also Great Valley Sequence sandstone, visible on the ridgetop west of I-5 in San Benito County. I regard these “wind caves” as created by the same process that makes tafoni: rainwater carrying carbonic acid seeps down through these porous rocks, dissolving the calcium carbonate cement. Where there is less cement, the process is more effective. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765734873227-3H6KOXBUEWD9N0LS9647/brushy5-13+165+copy+3r.jpg Geology - cobble conglomerate at Brushy Peak This was very low in the local Great Valley Sequence. The quartzite cobble and andesite cobble strongly suggest a source in the high Sierra—which was growing fast at that time. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654461911426-AAP0HVQHK16XW5EY78Z6/tafoni2.jpg Geology - tafoni and concretions at Brushy Peak This face is in the Murietta Rocks SE of Brushy Peak. See previous photo for description of how tafoni forms. Again, it’s hard to see why First Peoples, or anyone, would not regard this place as sacred. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738123617432-SA480ZB5UI3Q5YK0UC8S/vasco10+126+copy+2.JPG Geology - tafoni at Vasco https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954306402-AHBQUBWMX0KKZUZXPMIU/bluerockoutcroppsinterm.jpg Geology - Blue Rock, Ohlone Wilderness Blue Rock, a sandstone outcrop far out in the Ohlone Wilderness, is in a region monotonously dominated by Franciscan sandstone and chert, but all of it went part way down the Franciscan subduction zone. See next photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1632692596597-34D878H294EMT9JXCVDS/lawsSharpR2.jpg Geology - Blue Rock sandstone thin section The thin section shows sand grains and some interstitial fine-grained material, but the brightly colored, needle-like crystals are significant. They are lawsonite, and they grew across sand grain boundaries perhaps 20 km deep in the subduction zone. Lawsonite is a characteristic blueschist-facies mineral. Addditonal evidence that almost the whole of the Ohlone back country went down a subduction zone is provided by an amphibolite block near Blue Rock. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954696451-57KSP7IQY1I0DL939H7L/IndianJoeCaveRocksKT.jpg Geology - Indian Joe Rocks, Sunol A portion of Indian Joe Cave Rocks in Sunol-Ohlone Regional Wilderness, photographed by naturalist Katie Colbert. These are high-grade Franciscan metamorphic rocks, as demonstrated by the thin-section views that follow. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954722219-YSP9Y38EAC9HRC090A4J/IJoeXPinter.jpg Geology - Indian Joe Rocks thin section This cross-polar view shows larger, brightly colored hornblendes and lots of small narrow crystals of lawsonite. Thin section made on a naturally detached small fragment at request of park staff for their use in interpretive programs. These rocks are protected. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597954745906-QHTAMULASBZ56RJ64DNP/IJoePPLinter.jpg Geology - Indian Joe Rocks thin section, closer This plane-polarized view shows large greenish hornblendes with bluish glaucophane on their margins, and clear laths of lawsonite. Indian Joe Rocks are not all one thing, but this part at least was an amphibolite first, then glaucophane and lawsonite grew in it secondarily as the high-grade block in melange rose to regions of lower temperature or simply as it slowly cooled. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1672086575041-MI5VAUOLAEXCTZVTKW7B/Leyden+gabbro1A.jpg Geology - Sunol-Ohlone mylonitic gabbro At one locality there is an aggregation of blocks and chunks of mylonitized gabbro in Coast Range Ophiolite serpentinite. According to John Wakabayashi (written commun.) such pervasive ductile foliation usually occurs in extensional fault zones at magma-poor spreading centers. In any case, mylonites form in the brittle-ductile transition, where fault shear reaches down into ductile regions, roughly 20 km in depth. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707095807294-AQO6YIOYXO8AKEWU883N/Goat+and+TellesR.jpg Geology - Goat and Telles Rocks These are gigantic blocks in mostly siliciclastic/pelitic melange matrix. Left, Goat Rock, composed of Franciscan chert. Right, Telles Rock, composed of locally pillowed greenstone. I want to announce that one does not have to drive to Sonoma or Mendocino County to see classic Franciscan melange landscapes. These rocks are in and near Sunol-Ohlone Regional Wilderness. Telles is in the park, Goat is on SF Water Company land. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738123309085-FZC5KHWD2GQL8DEKVXU3/Goat+Rock+metachertsharper.jpg Geology - metachert of Goat Rock …in the large knocker at left in the preceding photo... Ain’t it lovely? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711091125472-61DW2CS2IVNEKV0WOOWK/Liv+Gravels+bestR.jpg Geology - Livermore Gravels wonderful cliff-outcrop of Plio-Pleistocene Livermore Gravels near the dam at Lake Del Valle. The formation includes the 4.8 my Lawlor Tuff in its lower part. The clasts are largely Franciscan, eroded from the Hamilton Range to the south. In views perpendicular to this face, one can see the beds dip rather steeply north, reflecting ongoing uplift of the range and perhaps thrusting of basement northward. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1675282511392-KF4824J02D7N3TWEGTXH/CedarCampdioriteblock2R2A+copy.jpg Geology - Livermore Gravels diorite Blocks and boulders of gabbro are occasional in the Livermore Gravels, but some of those that look superficially like gabbro are really diorite, as in this case. The mafic crystals (olive green) are all hornblende, and these are surrounded by plagioclase (white). View in PPL with the 4X objective. Both gabbro and diorite might suggest Coast Range Ophiolite was exposed in the upstream regions eroded to produce the Livermore Gravels, or that the the gabbro or diorite came from the Franciscan or the Sierra. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767936048371-OKQDLIIVI525JAMQANWT/pebelles+in+Liv+Gravels+copy.jpg Geology - pebbles in the Livermore Gravels They are diverse. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1760056851124-WJZKNODK63TUAY2BK0A6/Del+Valle+CK+white+cobble+BESTR.jpg Geology - white cobble from Del Valle CK. One can see carbonate overgrowing serpentine—which means serpentine is transforming into carbonate. …probably from the Livermore Gravels… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610744400255-FAPJE7S0PTX0NUFBMXVO/CCcomboRED.jpg Geology - Lawlor Tuff at Cedar Camp This pumiceous tuff in what I call the lower, thick mudstone part of the Livermore Gravels, east of Cedar Camp in Del Valle RP is the 4.8 my Lawlor Tuff that erupted from a caldera at the west base of Mt. George, Napa. The “gravels” here are almost exclusively fine-grained, overbank or paludal sediments, and “gravels” is misleading. However, I regard this unit informally as a lower member of the Livermore Gravels ss. Diblee called this Orinda Formation; but with the Lawlor Tuff near its base, the unit is far younger than the Orinda and the name is misapplied. Some have referred to it as Contra Costa Formation, also misapplied , as that name was long ago used to name a group, much older, in the Berkeley Hills. The North American Stratigraphic Code, in article 7, warns against duplication of names (same name used for different units). https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610744434485-VSD9DAXY01RJ472QDO9B/CedarCampLawlormacroCready.jpg Geology - pumiceous Lawlor Tuff at Cedar Camp This macro view of the tuff at Cedar Camp shows that it is almost all pumice. It is light as a feather, though too heavy to float on water. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1615768447222-ITWFIZVH29QH2QOKJHXZ/CedarCampcloserR.jpg Geology - thin section view of Lawlor Tuff This view of a thin section of the Lawlor Tuff at Cedar Camp, near the base of the Livermore Gravels, was taken in PPL with the 4X objective. The wonderful chunks of pumice that dominate are obvious. The blocky white things are feldspar crystals, both kspar and plagioclase, which abound in this rock. The kspar is sanidine, the main target for Ar/Ar dating. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711558586984-1E6RPXLYJAXHKY4MODRZ/CH+landscapeR.jpg Geology - Coyote Hills landscape The Coyote Hills are an anomalously isolated ridge on the southeastern Bay plain. It’s thought to be caused by the Silver Creek Fault, which starts well south of San Jose and goes north through Hayward. It’s on the east flank of tjhe ridge. There is thought to be another fault concealed by sedimentary cover to the west of the ridge. Both would be parts of the San Andreas-Hayward faults system, and they probably caused the Coyote Hills to squeeze up between them. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1730502883338-A3DXU0KWFCJ9DUCKA4NA/Coyote+Hills+chert.jpg Geology - contorted Franciscan chert at Coyote Hills Speaks for itself, I guess….so picturesque! The Coyote Hills rocks are part of the Franciscan Marin Headlands terrane, which extends northwesterly under the Bay, crops out in San Francisco, then richly blossoms in the Marin Headlands. Great places to see this in Marin are at the north end of the Golden Gate Bridge and north of Fort Cronkite. I have some pictures we took at the latter site in the general geology section. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711558652643-CQBRC0BYQPNWZH8J2ASO/CH+chert+brecciaR.jpg Geology - dramatic chert breccia in Coyote Hills RP I interpret this as a tectonite, formed by crushing of the chert in a fault zone at shallow levels where deformation is brittle. Check out how sharply angular the clasts are. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1693860075085-KU1OJ735QONCSEMDCM0I/Bucks+sceneR.jpg Geology - ultramafic area SW of Bucks Lake, Plumas County THIS BLOCK OF PHOTOS PROCEEDS GENERALLY FROM NORTH TO SOUTH IN THE SIERRA, BUT INDIVIDUAL AREAS SUCH AS LAKES BASIN TO SIERRA VALLEY HAVE NOT BEEN FULLY INTERNALLY ORGANIZED. This site, part of the Feather River Ultramafic Belt, has much serpentinite, but much more of an interesting carbonate rock, which I will show in the next three pictures. Chris Thayer and I found this site, which had the second known population of Frangula purshiana ultramafica (at that time yet to be named) ca. 30 years ago. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1693860433088-WWCNJARTE03TR4PSTFMK/carb+comboR.jpg Geology - most abundant rock type at that site In the ultramafic area SW of Bucks Lake, this is the most abundant rock type. Weathered surface left, fresh surface right. Obviously this is not serpentinite, though it does contain serpentine. I’ll speculate about its nature and origins with the following two pictures https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1693860466572-WDL0UMOZPHVC2ZDMI0GV/SW+Bucks+Lake1R.jpg Geology - "ophicalcite," sensu lato Here is a view of a thin section in XPL with the 4X objective. The tan to brown crystals with rhomboidal cleavage, on the edges of which can be seen many interference lines (better seen at higher magnification), are carbonate. They could be calcite, dolomite, or magnesite. I lean toward the latter two. I’ll give my reasons with the next picture. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1693860492242-DICZ4X8VV8KS4NAKG5YT/SWBucks+LakeR.jpg Geology - another view of the carbonate rock SW of Bucks Lake I got a lot of help from Howard Day and John Wakabayashi to understand this rock—tentatively. It was probably serpentinite to start. It was transformed via hydrothermal metasomatism in the presence of CO2, to mostly carbonate. I believe the carbonate is mostly either dolomite or magnesite, as serpentine would have flooded the system with magnesium. I’m guessing the serpentinite would mostly have been lizardite to start (remnants in dark areas), but the same hydrothermal fluids that created the carbonates also converted some of the lizardite to antigorite (radiating needles), which came in late in the process as it overlaps carbonate crystal margins. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1694288817101-49GZFP0E4IK4OXVTTYSU/antigorite+foliatedR.jpg Geology - serpentinite at the site SW of Bucks Lake This view of a thin section is in XPL with a 2X objective. I was sampling what was clearly serpentintie in outcrop and the thin section proves it. This view is especially interesting because it shows what one could argue is antigorite formed in a static environment in the upper part, while the lower part is actually foliated serpentine formed in a dynamic milieu. The static situation seems to have been later than the dynamic one, as some of the antigorite(?) crystals overlap the laminae below. Thanks again to Howard Day for helping me understand this. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1694288852479-RWJI0G8OCZXYO6IWRD3X/antigorite.jpg Geology - more serpentinite at the site SW of Bucks Lake This is a view of a thin section in XPL with the 4X obective. This was from yet another sample that was clearly serpentinite in outcrop. I believe the texture compares most favorably with antigorite, the highest-temperature polymorph of serpentine. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702345031710-QA40RF2CSO5H5LL3TVQC/Red+Hill+rd+lumprx.jpg Geology - limestone in the Feather River Ultramafic Belt Along Red Hill Road SW of Bucks Lake, Plumas County. See following three images. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702345054997-1MIFYVVTIUKV0PSOJBQP/lump+rx2.jpg Geology - that limestone again Here’s a closer-up view of the outcrop in the preceding picture. Surprisingly lumpy rocks—and they crop out extensively on the ridge NE of Redhill Road—apparently with intermittant soapstone. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702345115581-ZNF5PK1MZY08425NVDS3/258B2R.jpg Geology - that limestone in thin section This is an XPL view with the 4X objective. It shows dominantly carbonate. From the way it weathers, I’m guessing limestone, although there may be some dolomitic crystals here. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702345086981-ZOZP6EU6347GKWJ2F52D/258AR2.jpg Geology - closer thin section view of the limestone This is an XPL view with the 10X objective. The green at left is calcite or dolomite. I think the blue xtals at right are zoisite. My scope does not have sufficent power to resolve the yellowish area, but it could be epidote or tremolite or both. Both would be compatible with impure metalimestone—that is, containing siliceous mud. Zoisite is a hydrated calcium aluminosilicate. Tremolite is a hydrated calc-silcate mineral, with Mg and Ca in a 5:2 ratio. Epidote is a hydrated Ca, Fe aluminosilicate, with Ca:Fe two to one. Nobuaki Masutsubo, in his brilliant MA thesis at Fresno State, says the higher-grade metaultramafic minerals antigorite, tremolite, and talc are common in the Feather River ultramafic belt. As we have seen, all of these are distinctively present in the ultramafic area SW of Bucks Lake, which is part of that belt. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702350219152-XTT89YZX7B72NXVGSHPP/talc+block+w+ultramafica+copy+2R3+copy.jpg Geology - talc block in Feather River Ultramafic Belt This steatite block was near the limestone along Red Hill Road SW of Bucks Lake, Plumas County. There was more soapstone immediately associated with the limestone, but owing to the vegetation we could not see the structure. Frangula purshiana ultramafica Sawyer and Edwards in foreground. Photo by Katie Colbert. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735244965922-0T24IKHS32H5BTWBFQK9/xtal+lake+cliffs.jpg Geology - cliffs above Crystal Lake, Plumas County …These metasedimentary cliffs are at Mt. Hough above Crystal Lake. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735245181668-GV3CORZLC392QDZ7NG5P/xtl+lk+chert+breccia+2.jpg Geology - Crystal Lake chert breccia The part of this outcrop in view is about 6’ high. It’s composed of foliated chert breccia, in an argillaceous matrix. There is a thick lens of beautiful aquamarine chert in the upper part. Harwood says Diller named this the Arlington Formation, of Permian age, especially known for its conglomerates on the west shore of Crystal Lake, which refers to these outcrops. They are not conventional conglomerates. The sequence here dips to the SW, which is opposite the NE dip of rocks in the Sierra at Sierra Buttes and Lakes Basin. According to both Schweickert and Hardwood, and many other geologists, these beds are overturned. These strata are in the Hough block. Beds in adjacent blocks are overturned as well. All the blocks with overturned beds are well east of the Sierran crest, where normal faulting has prevailed—which may account for the overturning, especially if listric rotation was involved. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735245737175-LI0HDB3EGWGRMBSHOOEF/xtal+lk+chert+breccia.jpg Geology - foliated and brecciated chert at Crystal Lake …a closer view of the aquamarine and white chert clasts… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608793315894-AY517NXMDGNRJ5TWH25Q/Elwell%26LLakered.jpg Geology - Mt. Elwell over Long Lake Mt. Elwell is at the north end of Long Lake in Lakes Basin. It is composed of late Devonian Taylor Formation. The following photos are of a rock in the coarse talus you can see coming down from the peak. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608793340295-XAEI49QV323BY6H5M9K0/CPXrock1red.jpg Geology - Taylor Formation hypabyssal intrusive Woody Brooks has studied these rocks in great detail. This block is closely studded with augite phenocrysts up to about a cm in diameter. Woody explains that the green color is owing to high magnesium and low iron content. Unlike rather similar rocks along the Gold Lake Highway near the road to Sardine Lake, this rock lacks plagioclase. All the phenocrysts are augite. Their close packing suggests but does not prove that this intrusive tapped the lowest part of the magma chamber where early-crystallizing, heavy augite had settled. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608793365908-A5YHAFW742C5GLEGOE6P/twinlamella2red.jpg Geology - augite crystal in the Mt. Elwell talus block Just for sheer beauty (I love blue), it’s hard to beat clinopyroxenes. This one has a twin lamella crossing it, of different optical orientation than the rest of the crystal. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608793389067-Q212ADF47AGHSA7IIOE8/Elwell3reduced2.jpg Geology - corona texture in the Mt. Elwell talus block I would call this corona texture. The augite phenocryst at the bottom is interacting chemically with the surrounding matrix, in metamorphic solid state. Slow diffusion exchanges ions. Actinolite has been created by incorporating silica and water. A lawn-like band of actinolite crystals has formed close to the augite—in fact, many are actually touching it, but in this XPL view are in extinction. Outside the bright actinolite band the matrix has a lot of black in it, which consists of opaque oxides. A similar sequence classically occurs around reacting olivine crystals, and there it is called corona texture. Actinolite signifies greenschist facies metamorphism. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608793409159-VXO01U1AM2M3NYQB56VH/Elwell2reduced2.jpg Geology - corona texture, closer view It’s also just plain beautiful. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1604993667878-YT9YEVQCOBRYJMC0RO7N/SWLongLakerx.jpg Geology - SW corner of Long Lake For the thin section views in the next photo, I sampled the very white-weathering blocks in this scene taken at the SW corner of Long Lake in Lakes Basin, in what Woody Brooks has mapped as lower Taylor Formation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1604994811633-MZNDQ3ECL2IREDHY2RII/prehn%26pumpLLakeinterrmSharper2.jpg Geology - metamorphic minerals at Long Lake This combines two views of a thin section taken from the white-weathering blocks in the previous slide. I was intrigued because I could not identify the rock and it did not seem to fit well with the pillow lava and coarse-grained volcaniclastics that are supposed to be there. The thin section shows very altered feldspars, I think, but most enjoyable are the fascicles of brightly colored radiating prehnite, and the characteristically anomalously blue, bladed crystals of pumpellyite, which tended to grow within feldspar phenocrysts as seen here. Prehnite-pumpellyite facies metamorphism is the dominant grade in the northern Sierra. Because Woody Brooks states that north of Deer Lake metamorphism is greenschist facies, my IDs here have to be taken as provisional. My pumpellyite could be zoisite, and my prehnite could be actinolite—but, for now, I don’t think so. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608794256204-XNE3HZGEBJA8VVE173F6/Canonballred.jpg Geology - looking south from Prehnite Valley All the rocks in view are probably late Devonian, 359-374 my old. The geologist is studying the rusty-looking Canonball Tuff, part of the Elwell Formation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608861354095-5WCNOF1HRIOQ4NVEWQSI/qtz1.jpg Geology - the famous quartz porphyry of Diller The Devonian Sierra Buttes Formation is mostly silicic to intermediate volcanics and some marine sediments of an island arc that docked with North America during the Nevadan orogeny. Perhaps its most famous rock type—though far from the most common—is represented by this quartz porphyry that we found along the trail from Packsaddle Camp to Prehnite Valley. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1694127890007-4AZO5CCEIIKBDXHEYHBL/SBdike2R2.jpg Geology - siliceous dikes cutting Sierra Buttes Fm We observed large siliceous dikes cutting the Sierra Buttes Formation between Packer Lake and Tamarack Lakes, guided by a field guide by Michelle Roberts and several other geo-luminaries (2023). These are believed to have come from the Bowman Lake batholith, a finger of which extends north of the North Yuba—pretty close—and the Sierra Buttes Formation itself is considered to have been erupted from that batholith. All three— the batholith, the dikes and the Sierra Buttes Formation, overlap in age based on U-Pb dates. The reddish-brown to gray unit in the distance is the Taylor Formation, which overlies the SB Formation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1694127919096-1EDURC7K0FUN9NTH2LK6/SBdike1R.jpg Geology - closeup of siliceous dike in Sierra Buttes Fm This a closeup view of the dike in the preceding picture. It’s loaded with cm-scale quartz phenocrysts. Other parts of the same dike have a lot of intensely weathered plagioclase phenocrysts in addition to the quartz. These dikes must be one of the main sources of glacially redistributed blocks of similar lithology downslope, for example on the trail the Prehnite Valley. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608861372496-LSQQNQBIW5053RPSHMKJ/tamtuff1red.jpg Geology - Tamarack Tuff The Tamarck Tuff is an informal member of the Sutter Buttes Formation. This photo was taken on the west flank of Prehnite Valley. It was a subaqueous andesitic ash-flow tuff, with big chunks of pumice, characteristically very irregular in shape and size, and unsorted. That’s what the light clasts are. However, their air spaces have all been filled with quartz and chlorite, and, up close, many look chert-like. They don’t look like pumice up-close now. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601705741514-9LEZU8351ZN3AC95F7Y7/pepclose.jpg Geology - Elwell Formation peperite, closer Woody Brooks has analyzed and published this site near Packer Lake. This is part of an andesitic sill in the late Devonian Elwell Formation. It intruded chert that was still in the stage of soft silica gel. That cool mass chilled the sill and caused it to form fractures that the silica gel invaded. Thereby gaining access to the andesite, it caused a breaking up of the latter into sharply angular fragments, some with conchoidal fracture. The chert is black, the andesite weathered light brown. Brooks has called this “nondispersed” peperite. It is not a completely deranged breccia nor was the process explosive. Some of the pieces conjoin—look for example at the left and right ends. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1604805284205-2ZTOV561W55ISIBFHO82/peperite5+copyinterm.jpg Geology - Elwell Formation peperite A macro view is grainier but oh! how beautiful! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596232642255-XC2CEAV01D0HQZ5XA3Q9/GLHinterm+copy.jpg Geology - Gold Lake Highway outcrop These bluish-gray rocks near the turnoff to Sardine and Packer Lakes look unexciting in a quick drive-by. Closer inspection proves otherwise. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596232683929-IF02UNQXXH2ERKT1YCIH/DSC_2816+interm.jpg Geology - Gold Lake Highway closeup I think the Gold Lake highway rocks in the previous photo are hypabyssal, which means intrusions (dikes, sills) but they could also be flows. The big crystals (phenocrysts) are all augite (clinopyroxene). The concentration of these heavy minerals suggests the last eruptions from an island-arc volcano where the bottom of the barrel was coming up, where these heavies had settled gravitationally through the magma to the bottom of the chamber. The smaller, white phenocrysts are plagioclase feldspar. The matrix (between the phenocrysts) is probably entirely metamorphic though. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596672324212-NB4OVGNEJMR4E2D8GCZS/GLRdatSardineRdAinterm2.jpg Geology - Gold Lake Highway thin section . In thin section these rocks are really beautiful. There are parts of three phenocrysts shown, and you can see the matrix between is grainy. The xtal at right is a basal simple twin, which means you're looking at the prism end-on and it has divided itself into two parts with differing optical orientations. The other two xtals have lots of inclusions that I think are at least in part chlorite, a common mineral produced by alteration of mafic crystals. The matrix between the big xtals seems to be loaded with needles and blades of actinolite, a metamorphic mineral of greenschist facies metamorphism. I base this ID on crystal form, but also on inclined extinction. The black is largely opaque oxides. Howard Day and Woody Brooks believe that greenschist metamorphism in the region happened during the Jurassic Nevadan orogeny (let's say about 150 my ago), even though the original solidification of the rock from magma was much earlier. This is part of the Taylor Formation (Devonian). https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1705887855855-YXOT9RTACMIFF0COU8VN/Sardine+Rd+outcrop10XR2A.jpg Geology - actinolite in the matrix This is a view in PPL with the 10X objective of the matrix of the rock in the previous three pictures. Actinolite can be greenish or clear in PPL. The needles and blades are telling. There is abundant actinolite in the matrix of this rock. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707772477583-KP8YWQGA92O3UYT0TE3G/Frazier+pillows2R.jpg Geology - Peale Formation near Frazier Falls Well-formed pillows in this basalt have red radiolarian chert between the pillows. The top of this outcrop is domed and glacially striated. Cordell Durrell assigned this to the Mississippian Peale Formation, which overlies the Taylor Formation stratigraphically. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707772510814-K4N1BM7A6UBTWKDS1TWH/chert+X+Frazier+pillowsR.jpg Geology - chert between the pillows …on the glacially striated top of the outcrop in the preceding picture…The smooth maroon lith is chert, deposited in deep marine waters where pillow basalt could infiltrate it. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667285884396-9J8ABEELSDGM9GI9SDZC/LSXpillowsoutcrop.jpg Geology - green limestone adjacent to pillow basalt This odd rock, stratigraphically just below the pillow basalt in the previous photo, has clear carbonate weathering. The green is from chlorite, as can be seen in thin section. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667285907272-PI1V05ARK2SASWGYSSHB/carbXpillows%2CFrazier2R2.jpg Geology - thin section of green limestone near Frazier Falls Carbonate dominates this rock, seen here in XPL with the 4X objective. The black (green in PPL) is chlorite, and the small purplish gray patches within the chlorite may be clinozoisite. The chlorite is obviously sheared, and the twinning planes in the carbonate are deformed. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669790588283-A256MWAFFJR76EDJWH8J/FrazierFalls+sheared+carbonate.jpg Geology - calcite twin deformation Here’s another example of deformation of calcite twin lamellae from a foliated rock near the former one. This kind of deformation, producing curved, bold lamellae, happens with tectonic shearing and between 200 and 250 degrees C. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667285933139-DROEA9F6EE68I13HE0CQ/ch-shcomboR.jpg Geology - chert-shale sequence near pillows This too is closely adjacent to the pillow basalt near Frazier Falls. The gray and black are shale, the white and blue are chert. I’m guessing soft-sediment deformation from submarine slumping was involved, but all the other metasedimentary rocks in this area are also strongly sheared and foliated, so I would also infer that shearing was involved with this chert-shale sequence. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667285956371-4U2X8V8FQ3ZX6AUQ5BI4/grayLSR.jpg Geology - Peale Formation limestone The gray is crinoidal limestone, the black above it, which actually stratigraphically underlies it, is slate. Near Frazier Falls, stratigraphically higher than the pillow basalt. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667285976173-F0NE5815I80GZH95P5RG/FrasercrinoidalLSR3jpg.jpg Geology - crinoids in Peale Formation limestone That gray limestone is coarsely recrystallized and sheared. This has affected the crinoids, here seen as individual discs plus columns of discs, which cannot be brought into focus owing to their micro-deforming, especially from the coarse recrystzallization. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669837223512-4GXHAHKA10IJNGTZP7KR/FrazierFalls+green+in+qtz+veinR.jpg Geology - quartz vein cutting through crinoidal limestone Here is part of a quartz vein that cuts through the gray crinoidal limestone outcrop in the preceding picture. The dark green mineral is chlorite, as the next picture demonstrates. The quartz vein is probably of hydrothermal origin. There is an early Cretaceous tonalite stock (with an extensive associated dike swarm) near the east end of Gold Lake, which is only about a mile away from the limestone outcrop and its quartz vein. That intrusive is a possible cause of the hydrothermal system. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669837246748-3BDI96VKV737TYQ1B5JH/green+wormsR2.jpg Geology - chlorite in quartz Here we see a view of thin section (in PPL with the 10X objective) of the quartz vein in the preceding photo, including chlorite. The chlorite has grown into the quartz. It is exceptionally well-crystallized, which means you can see stacks of flat hexagonal prisms, much as in micas. These are just taller in proportion. R.A. Zierenberg told me that such well-crystallized chlorite is uncommon, and usually found in hydrothermal situations. That fits, as the quartz vein is likely hydrothermal. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1695519544169-HZ71DODT9W47S6F7VUIA/FF+Tuff.jpg Geology - Peale Formation metatuff Cordell Durrell interprets most of the low, glacially striated domes south of Frazier Falls as metatuff. From thin sections, I believe he is correct. Many exposures show soft-sediment and/or tectonic deformation. This outcrop is relatively undeformed. The next picture shows a view of a thin section from this outcrop. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1695519568069-CREASM0ISKJWPDGCGDYM/prehnite+tuffR2.jpg Geology - Peale Formation metatuff thin section A thin section from the outcrop in the preceding photo, taken in PPL with the 10X objective, shows an astounding amount of overgrowth by prehnite. These light green, acicular to bladed crystals, many in fascicles or bow-tie structures, are characteristic of prehnite. They also show relatively high relief in PPL, and incomplete extinction in XPL--all consistent with prehnite. Prehnite-pumpellyite is the most widespread metamorphic facies in the Sierra. Prehnite is generated by low grade metamorphism of mafic volcanics, but also in greywackes, argillites, and cherty rocks, and it can be seen here in what was presumably a metatuff. According to DH&Z, it’s not unusual for prehnite to replace plag, glass, and matrix wholesale—without altering the appearance of the rock in hand sample—which appears to be the case in this rock. Prehnite is lower grade than pumpellyite, and enters into complex dances with that mineral as well as epidote, quartz, actinolite, and clinozoisite, with varying temperature and pressure. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702857949631-LLWGNJF8OSYQ43QS54M1/pseudochertR.jpg Geology - pseudochert of Peale Formation This outcrop is west of the road to Frazier Falls from Gold Lake. Cordell Durrell places this near the base of the Peale Formation, which is Mississippian, and overlies the late Devonian Taylor Formation. Woody Brooks has the chert member of the Peale in this area, and there is a little chert in the vicinity, but I don’t think that’s what this block is. Durrell calls it tuff, and I think he’s right on. On closer inspection, the purple layers are mostly gray argillite beneath a thin oxidation rind. The rugose brown parts are limestone lenses. The green beds are wavily laminated, in my opinion silicified tuff. So there were tuff falls and quiet deposition of muds alternating. It’s a very lovely block! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667286000428-7MLCV1VSUWFDKO9Z1H56/Mills+PeakcliffR2.jpg Geology - Mills Peak lookout and cliff Durrell places these rocks in the Permian Goodhue Formation, which locally overlies the Peale, with a thrust fault apparently separating them. I have two thin sections from these rocks, and both suggest that the entire cliff is composed of mafic to intermediate volcanics. The thin sections, from samples near the top of this cliff, have all their plag xtals totally grungified. The mafic xtals are mostly cpx, but there is also an undetermined amount of hornblende—hard to tell how much, owing to the fact that the mafic xtals too are highly altered. Alteration minerals include chlorite, probably zoisite, and a little epidote… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609040103376-SYNHFTOV186MT8CSHUNZ/erraticIMPred.jpg Geology - giant glacial erratic This may be the largest glacial erratic I’ve ever seen. Probably plopped down here, near the NE corner of Long Lake, after a ride atop a glacier from the Sierra Buttes Formation up near the Pacific Crest Trail, well to the west. It’s made of nearly monolithologic breccia, and it testifies to the immense erosive power of glaciers. Because this student was trained in the geology program at U.C. Davis, she should be able to push the monolith over with one hand. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1691448523405-VLOTK7JVB2WRJSDILKO2/DSC_6190+copyR.jpg Geology - columnar basalt or andesite on Round Lake Trail The CGS Chico sheet maps a long ellipse capping the ridge between Gold Lake and Lakes Basin as Quaternary olivine basalt. This extreme simplification hides extraordinary complexity. There is indeed an extremely fine-grained black basalt exposed sparingly near the crest of the ridge, but there is much more to the story. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609028800473-JNRHHMD4J1YNF50IWXOP/bestps1.jpg Geology - hyaloclastite In the coarse talus down slope from the RLT columnar basalt, there are many blocks of what I believe is hyaloclastite. In this case we have a heterolithologic breccia, where, after two lavas were initially intermingled, the combination was erupted into a glacier or a lake, causing violent brecciation. In this view the white lava has a sharp border with the black, but often the border is transitional. This is my best call, but I have to study these blocks further in the future. I think the light gray/tan lith at lower left is weathered vesicular basalt in part, but one piece also shows flow banding and may be rhyodacite. Both the black and the white parts show some vesiculation, but the black is much glassier and more vesiculated. Both have lithophysae. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609028829123-FE0HV044HXQFNDYZUTFM/nextbestps1.jpg Geology - RLT hyaloclastite Here’s another example of the breccia that shows intermingling of two lavas. Note prominent flow banding in the darker chunk in the white lava at lower right. Note lower left of center how the white unit is breaking up and fraying and being invaded by the black. The black unit looks obsidian-like in places, but I believe it is basaltic glass. It has scattered olivine crystals, pervasive plagioclase laths, a few chunks of olivine basalt, and large quartz crystals that are significantly embayed, thus not in equilibrium with the more mafic glass. They are probably xenocrysts derived either from the more siliceous lava or from the Sierra Buttes Formation at great depth. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702778589084-ER0W3O12RA254UBW8CTL/Rnd+Lk+Mine.jpg Geology - Round Lake Mine at the SW corner of Lakes Basin. The geology here is very interesting! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702778569408-082VW2HC62N63UTDALY8/banded+blockatRLM-R.jpg Geology - banded block at Round Lake Mine Seems to have tumbled downslope from higher topographically in the Sierra Buttes Formation of Devonian age. I think it’s a bedded andesitic tuff sequence. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702778681226-QB7Y082FCYWKT4QG82BQ/coarser+band2R.jpg Geology - view of thin section in one of the coarser bands This was shot in XPL with the 4X objective. It shows one of the coarser strata in the block at Round Lake Mine. At left is the andesitic matrix. Occupying most of the image is a quartz vein overgrown by later epidote. Most or all the epidote crystals look zoned. This is common in epidote. DH&Z state that epidotes with an aluminum-rich inner zone an an outer iron-rich margin may be correlated with an initial prograde metamorphism that was followed by a retrograde event. Not sure if that’s what is going on here. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702778727503-83ETFHFPBFB4LX0EHV1Q/RLmine+finer+band1R2.jpg Geology - thin section of one of the finer bands This is a view of a thin section of one of the finer-grained strata in the wonderful block at Round Lake Mine. It was shot in XPL with the 2X objective, and shows a branching quartz vein with epidote overgrowth, plus a few actinolite needles, which would put this rock in the lower greenschist facies. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1702778747137-IIAA2ZZMDQS2YXTIOMHK/RLmine+finer+band3R.jpg Geology - closer view of thin section of one of the finer bands This is another view of the thin section taken from one of the finer-grained strata in that block at Round Lake Mine. It was shot in XPL with the 4X objective. Note the high relief and wonderful interference colors of the epidote. Also one can see the actinolite needles better in this view. The quartz is sutured and shows the beginnings of subgrain growth, indicating pressure during metamorphism. I think the quartz preceded both the epidote and actinolite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1630111444506-4LSSPFBQOFVX51LR0U8Q/KTHaskell.jpg Geology - Haskell Peak, Sierra County The dual summits of Haskell Peak are held up by two basalt plugs. The basalt splits into a platy talus and looks boring superficially. This day there was an actual REAL dish up there (my wife), in contrast to so many other peaks that are capped by the trashy accumulations of electronic junkmen. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1630111470348-YX4L5PKTP6DVSTA7USKA/Haskellsummitcombonewcrop2RED.jpg Geology - Haskell Peak basalt The basalt on Haskell Peak, probably Miocene in age, is an olivine basalt. The olivine phenocrysts are subhedral and abundant, as well as large compared to most of the plagioclase. I think this is extraordinarily lovely in thin section. At upper left is a sliver-like xenocryst of quartz, probably picked up from one of the many Oligocene ash-flow tuffs the basalt intruded. The quartz is fringed by a corona of minute crystals, probably pyroxenes, as a result of chemical interaction with the more mafic melt. Shot in XPL with the 2X objective. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1656537959325-5O9H05J8LLTJYIKQJMO2/tuff+H.jpg Geology - Tuff H on Haskell Peak This is part of the thick layer cake of multiple ash-flow tuffs, Oligocene to Miocene in age, that make up the bulk of Haskell Peak. This tuff and underlying tuff G (designations of Brooks, Henry, and Faulds 2008) are parts of the Nine Hill Tuff, which erupted down near Virginia City. Tuff H is a cliff-former with a platy fracture. This photo was taken looking southerly on 6-24-22—early in the season for a fire, but one can be seen in the distance. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1646120596184-C1LI9XX49H0SVDCEO0VE/blackClastsR.jpg Geology - Tuff H, hand sample Compressed and aligned black pumices are frequent clasts in tuff H. The alignment is probably a result of compression as the hot tuff settled when it came to rest, but the compression is not great, so neither is the alignment. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1646120618244-93MXP5Q8YKV65AKFGPSB/tuufHrecristR.jpg Geology - light-colored clast in tuff H I think this started as a clast of light-colored glassy, flow-banded rhyolite lava. It devitrified as it aged, and one can see both axiolitic (the white bar) and spherulitic devitrification. The spherulites are 1-2 mm. This clast sctratches easily with a knife, but it does not fizz in HCL, so I think it has also altered to clay minerals in part. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1646120640312-E3I7QT3VYN9E7EU776PB/TuffHcomboR.jpg Geology - thin section of tuff H, Haskell Peak Two views of a thin section are both in PPL, the left with the 10X objective, the right with 4X. The left shows a cavity with spars from vapor-phase crystallization common in rhyolites. The layers above and below, seen in XPL, prove to be turtleback chalcedony. The right image shows lots of devitrified glass shards, many of them folding around a sanidine crystal, with a layered pumice at lower right. And lots of opaque oxide. The latter may be part of the reason the tuff looks stony from a distance, although under a hand lens the matrix is glassy, and the unit probably qualifies as a vitrophyre. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1736535726095-BPZ4G9PQFKSF5OLXLGL5/Sugarloaf+MTn+near+Beckwourth.jpg Geology - Sugarloaf Peak near Beckwourth This andesitic plug, the remains of a volcano, is just north of Beckwourth, on the east side of the Beckwourth-Genessee Road. Dave Wagner has stated that is probably of Miocene age, and related to a volcanic center SE of Sierra Valley near Loyalton. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1624934156339-XPMT1DRM1SWKZP7LY2SK/LovejoyType1+copyr.jpg Geology - Lovejoy Basalt along Red Clover Creek Here is a view of Cordell Durrell’s type section of the Lovejoy, along Red Clover Creek in eastern Plumas County. According to Dave Wagner and others, the Lovejoy is a southwesterly extension of the Columbia River Basalt group, which covers much of eastern Washington and Oregon. All of this erupted from fissures, and commenced the Yellowstone hotspot track. The Lovejoy is 16 my old, erupted from a fissure or fissures at the Honey Lake escarpment and flowed all the way to Vacaville (see geology general section). In hand sample the Vacaville and Red Clover Creek lithologies are identical. Durrell counted nine flows stacked up at Red Clover Creek, but there are 15 elsewhere, sometimes making a thickness of about 500 feet. Durrell estimated that the Lovejoy eruptions produced 37 cubic miles of basalt. This is the largest known volcanic event in California’s geologic history. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737355406622-EAZ5Z83NX64CCWWOT2CP/LOvejoy+panoramaR.jpg Geology - south end of Stony Ridge …ca. 20 miles S of Honey Lake escarpment, source of the Lovejoy Basalt. Stony Ridge, seen in this photo, has one of the largest masses of Lovejoy, acc. to Dave Wagner et al. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1664761103608-K8D6DJFBEXJI56DYJ9CD/ThompsonPeakR.jpg Geology - source of the Lovejoy Basalt One of the many breathtaking views at the fissure-eruption source of the Lovejoy, here deeply eroded and deeply exposed on the Honey Lake escarpment/Sierran frontal fault zone. This is high on the east flank of Thompson Peak in the far NE corner of Plumas County, but here looking down into Lassen County above Janesville on HWY 395. It’s astonishing to stand there and realize this basalt flowed all the way to Vacaville. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1624934128432-ETPI2IRK4P7VEXA3PZ1H/DixieMtn+copyCROP3+copy.jpg Geology - Dixie Mountain According to Dave Wagner, Dixie Mountain in eastern Plumas County, here seen looking east from Clover Valley very late in the day, is a remnant of a Shasta-sized volcano, about 10 million years old. Clearly the Sierran protoCascades had some volcanoes as large as the largest in the Cascades today (Shasta is the largest, even larger than Rainier). https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1659471831194-0F7JVC8ADWNWUU52D053/Dixie+viewSr2a.jpg Geology - Dixie Peak, Plumas County, summit view south from the summit of Dixie Peak in late July 2022, showing a thick sequence of coarse andesitic breccias, flows, and some tuffs. In the distance is the eastern part of Sierra Valley, hazy from smoke from the Oak Fire far to the south in Mariposa County. The dead forest on Dixie Peak (and all around it) is a result of the 2021 Dixie Fire, which seems to have incinerated, when combined with fires near Quincy a few years before, most of the forests of Plumas County. Owing to severe drought, replacement is barely noticeable. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1693168558927-QIWF5A83PPUUJNTDOCUX/Siegfried+quarry+%26+HX-R2.jpg Geology - prehistoric basalt quarry north of Dixie Valley David Wagner says the ridge forming the north border of Dixie Valley is an andesite flow that came from Dixie Peak. I climbed to the top of that ridge near its west end, and found what I’m calling basalt. This was obviously a prehistoric quarry used during the middle archaic (pre bow and arrow, thus pre 500 AD). Long ago I had found broken bifaces of that character, and Greg White at Chico State had his classes below this on the edge of the valley, and they found many “Martis” (thus middle archaic) bifaces and dart points. I first went to the north flank of this ridge from Siegfried Canyon about 30 years ago with Cathy Sprowl, Mohawk District USFS archaeologist, when working on the Kalambo Falls project for Desmond Clark. We collected a lot of large flakes from a basalt flow downsection from the quarry. I found this basalt particularly cantankerous, so I couldn’t do much with it. I had a couple of succeses with that material though. On the right is a moderately refined Acheulean handaxe I made from a large flake struck from a block there. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669931749349-AT6SLJQUX9I0FQFEP2TW/CLplugR3A.jpg Geology - volcanics at Layman Camp Road, N of Blairsden Cordell Durrell called this edifice a basalt plug, with a light-colored vent tuff breccia at top center, but the geology is more complex than that. It is along the Feather River just south of the Layman Camp Road bridge, and easily viewed from HWY 70. However, trees have grown up to block the great photo Cordell was able to get. I had to take mine from an angle, late in the day, and with the light really bad. Oh well. The light material at lower left is dacite, the dark gray material to the right of the vent breccia is at least in part diabase. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669931773764-NCZ0YGXW21JPTBUI0YFF/CampLaymanRd3R+copy.jpg Geology - Dacite at the "plug" The”plug” is not all basalt. The lower left part is occupied by a dacite, a siliceous volcanic rock. I have not been able to figure out the structural relations yet, but, as the next picture shows, this white rock may be an ash-flow tuff, broadly speaking what Durrell would have called Delleker Formation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669931797890-8KBKLZVS1X0UA78JIENF/LaymanCdaciteR2A.jpg Geology - thin section of Layman Camp dacite Here’s a view in PPL of the Layman Camp dacite (lava or tuff). The long crystals are plagioclase, but many of the shorter rectangular ones are sanidine. Right in the middle of the picture there are some chunks of glass. The one lower left of center with an apparent vesicle at the bottom end is completely isotropic, confirming that it’s glass. The other pieces are not isotropic, hence probably devitriifed, at least incipiently. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1669931822002-GU9MNNKD5PDH5OJ8R75F/Layman+diabaseR.jpg Geology - diabase of Layman Camp Road Here’s a view in XPL of the diabase that forms part or all of the dark gray mass to the right of the colorful vent tuff-breccia. It is holocrystalline. The mafic crystals are all clinopyroxene. The jet black entities, like the one in the middle of the picture, are opaque oxides, probably magnetite. Diabase would be consistent with a basaltic plug, but the dacite is not. A mystery! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1695797807954-RBIAKZ71MZ306IC8373T/DSC_6429+copyPSR+copy.jpg Geology - Miocene volcanics west of Plumas-Eureka SP This marvellous but very steep exposure is made of white tuff (with pink and ochreous zones above), capped with a dark andesite flow on the top of the ridge. It’s basically an andesitic tuff, hydrothermally altered. It is to be found a bit north of the A Tree junction, near the crest of the Sierra, high above and west of Plumas-Eureka SP. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1695797839494-ITVE3FEX8WAAK6N2WQP9/A+Tree3R2.jpg Geology - the white tuff in thin section This is a view of that white tuff in PPL with the 10X objective. The tuff is andesitic in the IUGS classification, because the crystals are codominant plagioclase and hornblende. There is also a matrix of partially devitrified but still isotropic (black with crossed polars) glass. This glass must be more silceous than the early-formed plag and HB—in which case this tuff might be normative dacite. One would have to do a chemical analysis to find that out. What interests me most in this slide though are the well-formed crystals that grew in the voids, secondarily. They are certainly a zeolite, and very likely analcime. This zeolite commonly grows in voids in mafic to rhyolitic lavas and tuffs, often through hydrothermal action. These zeolites are white in thin section, consistent with analcime, but for some reason my camera colors them pale pink. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719705261301-2RIBUEJLA9OYD5YGKWTS/Bonta+FmR2.jpg Geology - Mehrten Formation debris flows ...along Road A15 between the Mohawk Valley and Portola. The clasts range up to 3 or 4 meters in long dimension, and include Delleker Fm. ash-flow tuff, granitic rocks, and previous andesitic debris flows. This is one of the most impressive displays of Mehrten debris flows I've seen. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1736921080275-H2VI1TFHR8V1H9ZGJGCQ/Mohawk+Cliffs+strighterR+copy.jpg Geology - Mohawk Cliff on a placid reach of the Feather River These famous Pleistocene lakebeds are near Blairsden. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609106588036-GPZQIPBS7NZR2S8AC01W/MC1.jpg Geology - Mohawk Cliff This exposure of organic-rich lake beds along the Feather River near the Blairsden bridge records includes many different tephras studied in detail by Andrei Sarna-Wojcicki, while the history of Lake Mohawk, which filled Mohawk Valley during the Pleistocene, was worked out by Joanna Redwine. Both the Summer Lake ash, which erupted from the Medicine Lake volcano around 200 ky, and the Rockland ash, which erupted near Mt. Lassen around 600 ky, are here. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609191791569-FYL4XTN9ICSISG8QZ8BA/MohalkLakeopal2ps2.jpg Geology - Mohawk Cliff mystery In the upper part of the Mohawk Cliff there is a thin layer that looks like a partially opalized pumiceous tephra. All parts of this rock are optically isotropic. However, nobody is sure about the lithology. Opalization might have been caused by the abundance of diatoms in the lake that must have been contributing their tests to make accumulating sediments siliceous. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609191821471-ZLM5D0NF7YYUPT79LI9B/Mohawk1.jpg Geology - Mohawk Cliff mystery The gas vesicles may be original pumice vesicles, or perhaps they were caused by gases given off by what appear to be organisms confined inside the bubbles. They may have been emitting gases while the opal was gradually solidifying from a gel. Note the small black bodies have processes that communicate to the outsides of the bubbles. These may be fungal spores. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609191849594-6PX2RMHREDOE8WYJ7GJN/Mohawk2ps.jpg Geology - Mohawk Cliff mystery Here’s a magnified view of one of the larger bodies in the vesicles. Hotsprings expert Diego Guido has suggested to me that these may be interlocking fungal hyphae. I have shown these things to multiple experts, and everyone remains puzzled. We are all merely guessing. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609106622028-EIGH7SW5MDLORW451FW8/Cliocliff1.jpg Geology - Mohawk Lake beds near Clio This magnificent roadcut of fluvial-deltaic sands and pebble beds, with a white diatomaceous silt near the top, records the margin of Lake Mohawk when it was probably much deeper than what deposited the Mohawk Cliff near Blairsden. The exposure is along road A40 near Clio. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609106644264-VT09I8YF5RVMX5X2ELDM/SLash.jpg Geology - Summer Lake Tephra LL This is one named bed of the Summer Lake tephra, which erupted from the Medicine Lake volcanic center around 200 ky. It is in the roadcut to the left of the prior photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596672096763-FMDYXSH4GHH4USRXJFV2/DSC_5157+copyinterm.jpg Geology - Red Ant Schist It crops out along highway 49 on the north Yuba River, east of the Feather river ultramafic belt. Blueschist minerals and lawsonite in particular indicate a probably early Jurassic pre-Francisan subduction zone. The blue color in this outcrop is from glaucophane and/or crossite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596672127797-X2IW4KANYT7G6O9ARFLM/RedAntPPLX40interm.jpg Geology - Red Ant Schist 2 Irregular micro-folding of the blueschist layers indicates a dominant shear stress at a low angle to original bedding. The white zones are highly recrystallized quartz. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596672167151-2SZCF9N0266PWGSJ4AHP/RedAntblueschist+needlesinterm.jpg Geology - Asbestiform Blueschist The Red Ant Schist blueschist minerals, examined at higher magnification, show a widespread asbestiform structure, consisting of fine blades and needles. When optic sign can be determined, it is length slow. This rules out riebeckite, and both crossite and glaucophane have been identified by others. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596672201951-DCRLQWCX6MTQ0EVMGQE9/RedAntStilp%26epidoteinterm.jpg Geology - Stilpnomelane and epidote Some parts of the greenschist (which is more abundant than blueschist in the Red Ant Schist) are dominated by epidote (the high-birefringence crystals in the lower part of this thin section), and stilpnomelane, the golden-brown radiating clusters of blades in the upper part, set in quartz. Under these metamorphic conditions, calcium has largely segregated to the epidote (and to lawsonite in associated blueschist paragenesis), and iron has segregated mostly to the stilpnomelane. Sodium went to crosstie/glaucophane. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596672269824-36BW8V0UCQ2OVJF3R4Y3/disharmonicfolding.jpg Geology - Red Ant Schist disharmoic folding in quartz bands and schist, probably representing chert and shale in the deep-sea protolith https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1693863327442-RKNIBUWY94P87Y7H5HDC/DSC_5334+copyR.jpg Geology - amphibolite blocks west of Downieville These blocks have been analyzed in depth by John Wakabayashi and his student Nobuaki Masutsubo. The large one at right and the small one low near the center are amphibolite blocks in a blueschist-facies melange matrix, part of the Red Ant Schist. More details with the next two pictures. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1693863355479-FWTXFVN03YNFBFHEJIIV/larger+block+PS1R2.jpg Geology - thin section from the larger block This is a view in XPL with the 4X objective. The large colorful crystals are hornblende. The finer layers have quartz, lawsonite, and chlorite-and much more. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1693863379676-7Y99LMLZ49QD6DKSSG11/apatite%3Fcropped2R.jpg Geology - abundant lawsonite This amphibolite block was originally HP-HT. But as it rose to the surface it lingered long enough at HP-LT to receive a strong blueschist-facies overprint, and it was flooded with lawsonite. Amphibolite blocks nearby also contain glaucophane. The surrounding melange matrix also has abundant lawsonite, according to John W. The is a view in PPL with the 4X objective. The small white rectangular crystals in the lighter area near the top are lawsonite. John describes a dizzying geologic history for these blocks, in GSA Field Guide 65. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719297167429-KQ747PFC04O6O7KR1DG5/Alleghany%3Famphibolite%3F6.jpg Geology - Alleghany, Sierra County, metamorphic sole Nobuaki Masutsubo mapped this area in detail. "Capping" the spur in the distance is serpentinite of the Feather River Ultramafic Belt (actually dipping almost vertically), structurally underlain by a metamorphic sole. According to Nobuaki, the brown rocks closer to the viewer here (part of the metamorphic sole) contain much amphibolite....along with other liths. The sole is isoclinally folded, repeating the section. I took seven samples there, and only two showed highly sheared hornblende. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1752008215817-DUKTU1JPHCF6ZR3KVWX1/sheared+HB+from+AlleghanyRsharper.jpg Geology - sheared hornblende …from the Alleghany metamorphic sole… Shot in PPL with the 10X objective. The darker green areas within the sheared xtal are probably hornblende. The lighter green areas surrounding them are probably actionolitic amphibole. The brown needle clusters may be stilpnonmelane. I thank John Wakabayashi for helping me with this thin section. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1719297199155-EG0RHTLCB6PNAPREVF8R/Alleghany%3Famphibolite%3F3.jpg Geology - migmatitic felsic leucosomes? This is part of an outcrop along the road ca. 200' west of the left part of the landscape shown in the prior photo. I speculate amphibolite can be seen on the right under the sunglasses, foliated to the left of the sunglasses. The light areas I further speculate are migmatitic felsic leucosomes, produced by partial melting of amphibolite in a very hot metamorphic environment, perhaps owing to heating along faults. Nobuaki Masutsubo described such things in this section. I’ve had a lot of trouble finding amphibolite where he mapped it…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737596630710-TA81QMAX3NMY9W7STPR1/Alleghay+boulder+cgR2.jpg Geology - megaboulder conglomerate This boulder conglomerate of Miocene age has boulders over a meter in long dimension. It’s near the top of a ridge next to a very deep canyon close to Alleghany. Clearly there were some powerful rivers in the Miocene Sierra. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1749844993323-PNND3Z8UAPFROY0AELH6/BEST+amphibolite5%3F+copy+2R.jpg Geology - amphibolite outcrop …north of American Flat, which is N of Alleghany. We found this outcrop using the geologic map of Nobuaki Masutsubo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1749844960834-50OL8TCT7KJ8KUTR11QF/Best%3F+amphibolite+copy+2-R.jpg Geology - closeup of amphibolite …in the outcrop in the previous picture…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1749930588632-RD5Y0J4HWUPW8STMTEEG/BEST%3FRsharper.jpg Geology - amphibolite …from a more northerly outcrop. We found the outcrop using Nobu’s map. Face of a foliation, below; foliations seen in cross section, above. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1751871798650-HJW70LISY26XP2Y685O8/N+amphiboliteR.jpg Geology - amphibibolite outcrop north of American Flat …which is west of Forest City, a remote place in Sierra County…This area is famous for amphibolites. This is the more northerly outcrop from which the sample in the previous photo was derived. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1751871836808-DKBC0YLK4MVUM0V9LP1G/best+amphibolite+PPL-R2.jpg Geology - olive green hornblende ….indicating HP-HT metamorphism. There is very little plag in this sample, which was taken from the outcrop in the preceding photo. Shot in PPL with the 4X objective… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1751937083188-OM3RF2UEK6S6OT46014O/best+amphibolite+XPLsharper-R2.jpg Geology - American Flat amphibolite There is only amphibole in this photo. One can see the characteristic crossing amphibole cleavage. Shot in XPL with the 4X objective. And sampled from the same outcrop as the. previous slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1718865394470-EKU601TUYHD3DMBFG035/Au+gravels.jpg Geology - Auriferous Gravels at Malakoff Diggins This is a view from the Diggins Trail. The Auiferous Gravels is a formation name. It is of early middle Eocene age, laterally equivalent to the Ione and Domengine formations, probably close to 48 Ma. See two following pictures. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1718865420578-Z17T71YLCRCOHVRD14C2/m+gravelsR.jpg Geology - Auriferous Gravels at Malakoff, closer view On the Diggins Trail one can get close to current cross-bedded sandstone and conglomerate, much like what can be seen at Gold Run along HWY 80, but without the danger of getting run over by people in a hurry to get to Tahoe. The light color is from dominance of quartz clasts. The ochreous color is from iron oxide, a result of weathering in a subtropical or paratropical climate. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1749844672852-5UJWTG2BWDTBE6Z0GVKG/Malakoff+BEST-R.jpg Geology - beautiful landscape near Malakoff Ain’t it WONDERFUL? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1600238476853-R3AAEPTNAH6Y2JP8VKGS/dikes1.jpg Geology - Smartville Complex dikes These lovely basalt dikes crossing tonalite are along the Yuba River near the Colgate powerhouse. The tonalite had to be crystallized enough to be rigid for it to fracture with clean breaks so the contact between basalt and tonalite is sharp. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1600238505746-T944X41EKO72EKWF7RNE/dikes2.jpg Geology - Smartville Complex basalt and tonalite Again near Colgate powerhouse on the Yuba River. Here basalt has probably invaded the top of a partially emptied tonalite magma chamber and flowed out over the tonalite. The weight of the heavy basalt pressed down on the tonalite, which was substantially crystallized but still had interstitial liquid. The liquid rose buoyantly up into the basalt. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1600238554894-MM3YCMHUN0ERC3CMW2N8/tonalitelith2.jpg Geology - Smartville Complex tonalite A closeup of a fresh surface of tonalite, with mafic inclusions that are mostly biotite. The tonalite here is about 160 million years old based on dating of zircons. Tonalite is a plutonic rock dominated by plagioclase and quartz. The scattered mafic crystals are nearly all biotite, though there are rare hornblendes. Clearly this magma included a lot of water. I was on a field trip led by Chip Lesher of UC Davis for his igneous petrology class. He taught us these things. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1600238576594-PWUMY11BCIFZI88ZC7EB/tonaliteps3.jpg Geology - Smartville Complex tonalite A thin section in XPL of the specimen in the previous photo. Most of the scene is occupied by plagioclase. There is a bunch of quartz in the upper left quadrant. The colorful crystals are all or nearly all biotite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597006338669-ECYJ15JDRTRKHHRO806X/125+copypsinterm.jpg Geology - Castle Peak north of Donner Pass The northeast-facing side is far different from what one sees from HWY 80 and far more dramatic. Here hundreds of feet of gray late Miocene tuff and tuff breccia are overlain just at the top of the peak by a brown basalt flow. This is all part of the Mehrten Formation, the Miocene volcanics of vast extent that are preserved on the tops of interfluves between major river canyons today, but which thus obviously covered a much vaster area before the present gigantic canyons were cut. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1704440688747-RK3YQ3FBEGAS8Z25ZN1B/Castle+enclaves+comboR2.jpg Geology - mafic enclaves in granodiorite …south flank of Castle Peak, Tahoe NF. On left is a spectacular glacially polished block with numerous mafic enclaves, probably the result of basalt injected into the magma chamber and, via turbulence, breaking apart and freezing into blobs. The right photo shows a closer view of a mafic enclave, cut by an aplite dike. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1704440713745-ZB0J1HDU09L7UAKTT6S2/Castle+ck+TS+comboR.jpg Geology - two views of a thin section of a mafic enclave …south of Castle Peak…There are some large plag xtls, not well shown here; there is abundant cpx (lots of twin planes), and abundant biotite. Hornblende, as seen in the reddish-brown xtl at left, is scattered. Both views are in XPL, the left with the 4X objective, the right with the 10X. Biotite is a mafic mineral containing potassium but with about four times as much magnesium plus iron. It crystallizes at relatively low temperatures, and clearly came in last. It overlaps both cpx and plagioclase. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1724631389988-HDF6ULYFTVR47PZS6MQZ/Skylandia+mostR.jpg Geology - Skylandia At Skylandia Beach on the north shore of Lake Tahoe, there is what has been called a tuff ring by Cousens et al. 2011. It has been dated at 2.2 Ma. It is composed mostly of basaltic andesite lapilli and ash, with numerous clasts large enough to qualify as bombs (>64mm). This unit is too young to be part of the Miocene ancestral Cascades Arc, and is part of the north Tahoe-Truckee volcanic field, which the authors consider to be slab-window volcanics. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1724631415745-MWVEMSJKUE9OTLTJBW74/Skylandia+layeringR.jpg Geology - Skylandia beds ...a closer view.... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1760138626214-X1XHOESO3G7EQ6J8ZK5M/sunset+%40+Cave+Rock.jpg Geology - sunset at Cave Rock …on the E shore of Lake Tahoe. Photo by Katie Colbert. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1760138017754-JEG80ZIOI22N6QUECFK1/Cave++RK+lith2R.jpg Geology - dike rock I shot ….VERY CLOSE to Cave Rock….dacitic porphyry….I have to assume from the close proximity to the volcanic plug of Cave Rock the latter is dacitic. It’s said to be 3-5 Ma….AI states that Cave Rock plug is “mostly andesitic.” That leaves room for dacite porhyry dikes…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1760140525134-V1VHEPH0ZRRY4THW5ETM/biotite%2C+HB+%26+microclineR2sharperAAA.jpg Geology - dike in thin section It has a lot of microcline w. tartan twinning, a lot of quartz, hornblende, and biotite—with it’s single layering, it dominates this view…Shot in XPL with the 4X objective…clearly AT LEAST dacitic poryphry, and obviously hypabyssal… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597039517913-ZGQ79GJV0NY8MWXKUW9T/HWY40a.jpg Geology - Nine Hill Tuff along old HWY 40 This tuff exploded from a caldera near present-day Virginia City in the Oligocene. As a raging hot ash flow, it followed river valleys from Nevada across the ancestral Sierra Nevada and thence west. Here you see a bake zone on the margin of a channel cut into weathered granodiorite in the Eocene. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597039547780-SJVDXSOSC26INXV0T0HZ/HWY40B.jpg Geology - Nine Hill Tuff A thin section view in plane-polarized light shows the dominance of glass shards but also crystals of quartz and sanidine. It’s a vitric-crystal tuff. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596927971625-70XS35Y32YK36WZGQF4G/grano.jpg Geology - Granophyre, Donner Pass thin section showing granophyric intergrowth of quartz and feldspar in a siliceous volcanic pebble picked up by the Nine Hill Tuff, an ash-flow unit outcropping at Donner Pass along old HWY 40. Accessory plate inserted to dramatize colors. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597039604980-MBX92RYMIF4M8Y5PSZPI/CedarsRda.jpg Geology - Oligocene ash-flow tuff near Serene Lakes The Oligocene tuffs originating in Nevada filled substantial pre-existing river channels and reached great thickness, of which only a fraction is exposed here along the road from Soda Springs to the Cedars. This entire section is ash-flow tuff with varying amounts of welding. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597039635977-KE5BGB62J1P2CYNNKVE8/CedarsRdB.jpg Geology - Ash-flow tuff handaxe Some of the white Oligocene tuff is flakeable, here resulting in an Acheulean handaxe. This material is brittle and weak and would not have been used by native Americans. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597039662582-QH8J42ILFF1T8NV9KEMA/CedarsRdc.jpg Geology - Road to Cedars thin section Here is a PPL view of a thin section of the ash-flow tuff out of which the white handaxe was made. It shows considerable flow-alignment of glass shards, and even a book of biotite (brown) has assumed the same orientation before the tuff came to rest. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1626850519792-3AB9STQ79FNAOUIIGDB6/DMtn.jpg Geology - Devil Peak, Placer County This peak, a prominent landmark near Serene Lakes, nearly 8,000 feet high, consists of columnar basalt which appears to be sitting stratigraphically above Mehrten debris flows. But can we be sure? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1626850545622-QV7350373TTX8K032I2O/devilsresize+copy.jpg Geology - Devil Peak, well up Here we have climbed up into a narrow ravine embraced by columnar basalt. The columns here are dipping close to 45 degrees. I am suspicious that the peak may be the remnant of a basalt plug that pierces the Mehrten rather than resting on it. I would love to be able to get a date on the basalt, but basalt lava dates are normally whole-rock Ar/Ar, which typically has wide error margins. Speculating, this may be the core of a rather young basaltic volcano. The latest dated eruption at the Lassen-sized Silver Peak volcano at Ebbetts Pass is only 4.8 my old. Volcanism in the Sierra should generally terminate from south to north, so, whether Devil Peak is flow or plug, it could be younger than 4.8 my. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1696785218058-6O4YUF0SMRNANDTGBUXX/Cisco1R.jpg Geology - Cisco Butte, Placer County Cisco Butte, at 6646’, is at the NE corner of Odette Ogle’s proposed Emigrant Gap mafic-ultramafic ring complex. The peak is composed mostly of gabbro and diorite, so when it’s not lit up by alpenglow as it is here, it’s quite dark. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1696785244817-EW59PGPNAPUFWPEZQ0PC/pegmatite1R.jpg Geology - pegmatitic diorite at Cisco Butte We found this block at the bottom of the talus slope on the NW side of Cisco Butte. You can see from the mm scale that these crystals are quite large. Since the exposure of the mafic crystals is generally flattish, it’s hard to see termini. I think they are mostly hornblende with scattered pyroxene, so I’m tentatively calling this a pegmatitic diorite. Only thin sections would confirm this, but I could not bear to break up this beautiful block. I’m guessing somewhere high on the peak, or buried deep beneath talus, there’s a vein of pegmatite. The white is mostly or even entirely plagioclase. Again, only a series of thin sections would confirm this. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596923443114-AFHM431RNAAQ8XL6KQC6/dunite2interm.jpg Geology - Placer County dunite This is the rock that produced the thin section in the next photo. Dunite is chemically an extreme environment, supporting only thin growth of conifers, but the resulting open ground proves refuge for some rare and lovely plants that would not survive in a forest, for example the pink-headed buckwheat in the botany section. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596923466001-YTHHMD7JNBVKK93PE68X/duniteinterm.jpg Geology - Placer County dunite thin section from the same ultramafic terrain as that which included the pyroxenite in the last two photos. The rock consists of interlocking olivine crystals that, in handlens view of fresh surfaces, give the appearance of Hawaiian greensand. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596923506669-A2DVU9MBLY458TQS969D/pxiteinterm.jpg Geology - Placer County pyroxenite with HB 1 This is the drab-looking rock, pedestrian to the uninitiated, the exterior of which conceals the glory revealed in the succeeding thin section. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596923547649-8XN63ZT9P84C767CMFNX/Mon3interm.jpg Geology - Placer County pyroxenite with HB 2 Large hornblende crystals at right represent the large crystals seen in hand specimen, while a logjam of smaller pyroxene crystals crowds in on the left. Presumably the large HB xtls reflect pockets of residual melt remaining after most px had crystallized. Such very mafic rocks make some of the most gorgeous thin sections as mafic crystals have high interference colors. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1596923574181-UD1C3L67JB88N9EX672S/orbicule.jpg Geology - Placer County dunite orbicule This olivine blob, with some pyroxene in its core, probably represents magma mixing, where some highly ultramafic magma came into contact in small quantity with a larger volume of pyroxentie-peridotite magma. The blob was shaped into an orb by rolling as it chilled in the less mafic magma. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609206780152-4WL0XSRW0HUX1ZYW6T6I/LL2a.jpg Geology - interaction Close to the Loch Levin trail, near Big Bend, a breccia of the Jurassic Tuttle Lake Formation, below, is being raggedly incorporated into viscous granodiorite, above. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609206797806-UZ5BKYJMFCWP976KNZOU/LL3.jpg Geology - interaction 2 Here a large block of Tuttle Lake Formation, with a lot of epidote in it, is right of center. Most of the other inclusions appear to be granitic rocks, as is the lighter matrix, but some or most of the dark gray material may be modified clasts from the Tuttle Lake. Look how they seem to swirl around the big block and make it appear as if the latter has been tumbling. Even viscous siliceous magma chambers are very dynamic places. The motion may not be swift, but it is inexorable. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609206819544-RKY6U45026GFAYYJODY7/LL4.jpg Geology - interaction 3 Here a large block that was determined by orthogonal jointing has peeled away from an earlier, more mafic granitic wall-rock and “plunged” into the melt. The latter being highly viscous, the plunge would have been in slow motion. The sharp borders must have been retained because this is a higher-temperature rock than the magma it fell into, it’s big, and probably it fell in pretty late in the cooling process. Just speculating. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609206841828-S9HNHGJMODKJVGO0U6PV/LL5.jpg Geology - diorite porphyry This was a large block lying on the surface near the contact between the pluton and the Tuttle Lake outcrops. It may have been a remnant of a dike that fell into the chamber, or it may have come here glacially from far away. But it was really a striking rock—even moreso in thin section. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609206866409-NRL7HPSZIOGEPHWRLNTS/LL6.jpg Geology - diorite porphyry thin section Clearly the white phenocrysts are plagioclase. In between is colorful hornblende. Those are the components of this rock. What seems unusual is the incredible abundance of fluid inclusions in many of the hornblendes. This suggests to me that the melt was a wet one, with plenty of volatiles. Hornblende is itself a hydrous mineral. Without volatiles you would get pyroxenes rather than hornblende. So, a wet melt. One can proble fluid inclusions like these to get an assay of what the melt chemistry was like at the time of HB crystallization. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597126404111-ASJP82G109TSU4K7S1K2/258+copyred.jpg Geology - Casa Loma Road SE of Alta This huge serpentine barren drops precipitously to the North Fork of the American River far below. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597126430146-QFX0GCKFNIRJT9FMLUUU/260+copyred.jpg Geology - top of the Casa Loma serpentine barren This is a dike, or possibly a knocker, of plagiogranite in the serpentinite (which can be seen on both sides of it). Plagiogranite is an oceanic crustal rock and affords evidence that the serpentinite is part of an ophiolite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597126456811-S2ITAUGYY9TFFPAGMFSK/262+copyred.jpg Geology - Casa Loma plagiogranite closeup The phenocrysts are plagioclase, and the rock is largely plag and quartz and accessory minerals, with no potassium feldspar. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597126485693-2KE3KSIHHLH1FLYHK77T/262aAltaPlag%26qtz+copy+2red.jpg Geology - Casa Loma plagiogranite thin section Here, in a crossed-polars view, can be seen a large plagioclase phenocryst, highly altered, at the top. The groundmass is mostly smaller crystals of quartz, interlocking with sutured margins indicating the pressure of metamorphism at great depth, and opaque oxides. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597126510233-ONERTQIBIPBCX8UA4ALJ/262bAltaZircons+copyred.jpg Geology - Casa Loma plagiogranite zircons A few football-shaped zircons can be seen, especially imbedded in quartz in top center. Zircons are basically unaffected by metamorphism, and were inherited from the protolith of this rock. So the quartz grew around them. Zircon tends to have an unusually high concentration of uranium, so it is an important target for uranium-lead dating. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597126536318-CRM9E6F6MWDVOUID8LVH/262cAltaPPL+needles1+copyred.jpg Geology - Casa Loma plagiogranite Here at high magnification in PPL one can see needles of actinolite. The rock had metamorphosed at least to the beginning of the greenschist facies. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1641002508694-V0BUG052LA796OLC0MOW/Alta+tremoliteR2.jpg Geology - Alta plagiogranite tremolite I sampled the plagiogranite where it contacts the serpentinite. Unlike the center of the plagiogranite, which is full of actinolite, the margin seems to lack actinolite and instead contain tremolite blades. I only have two thin sections, so this is speculative. Tremolite is the magnesium end member of the Mg-Fe solid solution series with ferroactinolite being the Fe end member, and actinolite between them. Tremolite has more than 90% magnesium. I am tempted to suggest that the plagiogranite reacted with solutions coming from the serpentinite, thereby picking up excess magnesium. However, if this is true, we still don’t know if it was a result of intrusion, or, alternatively, metasomatism. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597126562387-0MQEAADIBZCR0QHMWAH5/262d+copyred1.jpg Geology - Casa Loma Road graphitic slate near the end of the road is the most beautiful slate I have ever seen. This is part of a Permo-Triassic metasedimentary body enclosed within Feather River ophiolite. Harwood (1992) places this complex unit in his Nothern Sierra Terrane, which consists of a series of accreted island arcs. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597126585240-GRFZP27DLSD4MIBEC0I6/262e+copyred.jpg Geology - Casa Loma Road graphitic slate The slate has a slight conchoidal fracture so I couldn’t resist trying to make an Acheulean handaxe out of it. I won’t try that again. The conchoidal fracture is only incipient. Also, this is a graphitic slate, reflecting organic content in the original sediments, and the graphite comes off as an ultra fine black powder that soils your hands. No less beautiful though! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1656917831214-W55JPJYWRD9C83JW9I6S/AltaGCoutcropsR.jpg Geology - Casa Loma metaconglomerate Interbedded within the foregoing slate (and shale) sequence, all standing nearly vertical, is this cement-hard conglomerate. These prominent dark conglomerate outcrops are seen closer up in the next picture. This is all very close to the Eucher Bar trailhead. The unit involved is mapped by Harwood (1992) as a small body of Permian and Triassic metasediments enclosed within Feather River ophiolite. This Permo-Triassic sedimentary unit becomes extensive and continuous in the Feather River country. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1656917850613-R4BOKD9P6I91LM8UD78L/AltaoutcropCloseR.jpg Geology - Casa Loma metaconglomerate It is a mostly clast-supported pebble conglomerate in which the clasts range from sharply angular to subrounded. I think some of the long, aligned white items near the bottom started their lives as clay rip-up clasts. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1656917869553-IJ9S7APKH2UOJJUBB59I/AltaCGR2A.jpg Geology - Casa Loma metaconglomerate This thin section, in XPL with the 2X objective, shows mostly quartz grains; there are are some showy muscovites too. The big grain occupying the lower center of the picture is quartz, showing a range of recovery from deformation. Stress can distort and bend crystal lattices, introducing strain, mostly large numbers of dislocations of the lattices. Recovery is partly the process of moving these dislocations around so that a lower-energy state can be achieved. One can see subgrains, new grains, suturing, and bulging. The subgrains and new grains are separated by dislocation walls (dislocation logjams), and the bulging always protrudes grains with fewer dislocations into those with more, thus decreasing the overall internal energy. Dynamic recrystalliztion may be followed by static recrystallization after deformation ceases but with temperatures stiil elevated. This would make new large crystals free of dislocations, but we’re far from that stage here. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1668755411000-JUS27ETL6JVF8HFSOZK9/262m2+copyPS2RED.jpg Geology - Limestone quarry near Auburn This abandoned limestone quarry, upstream on the middle fork of the American River from its junction with the north fork, is famous because it contains Hawver Cave, which produced a diverse assemblage of Rancholabrean mammals. The limestone is part of the Permian-Triassic rocks of the Calaveras Complex, which runs SW of the Shoofly thrust and Northern Sierra terrane. The Calaveras is an accreted subduction complex, perhaps accreted in the Jurassic, and, as such, consists of a chaotic, olistostromal mixture of blocks, some of them gigantic (a whole seamount near the Stanislaus River)…The limestone here is a block in melange. The melange matrix is usually argillite and chert. Snow and Scherer correlated the Calaveras Complex, which comes north only to the Placerville-Auburn area, with the Red Ant Schist near Downieville on the north Yuba, because both lie SW of the Shoofly sequence, and both are subduction complexes. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1607647059491-UNP6LFA2TBMQHV48Z7CH/damsite.jpg Geology - Auburn Dam site The serpentinite with dikes is along the river just upstream from the rapids. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1607646332194-0SS9GOJ7Y6O1YSIO0RDM/2dikes.jpg Geology - dikes at Auburn dam site In this fabulous serpentine outcrop at the Auburn dam site, basalt dikes appear to have intruded during conversion of peridotite to serpentinite. The peridotite had to lose calcium to make serpentinite, and this caused what seems to be a calcium-rich rodingite reaction rim on the basalt. I needed help from Howard Day to get this far. There are three dikes in view. The main one is recumbently folded. Another is inside that fold, and another, in which a termination can be seen, is below the big folded one. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1607646369426-28MFCHZ5L7OZFOJPEU87/combo.jpg Geology - dikes at Auburn dam Left, the reaction rims on the largest basalt dike. (The protolith was basalt, but that has been replaced by a metamorphic assemblage, though the core still looks superficially like basalt.) Right, the lower, smaller dike, seeming to twist like an earthworm against resistance, trying to make one more thrust, then frozen in time. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1651350201662-40ICUY22CJWUDQGL9RIR/mylonitizedDiorite1R.jpg Geology - mylonitized metadiorite Leslie Moclock did a superb MS thesis at UC Davis (2013) on the Bear Mountains Fault zone along the American River at Auburn. She found metadiorite bodies that she interpreted as synkinematic intrusions with the formation of melange within this wide fault zone. Much of the metadiorite has been mylonitized, as shown in this specimen, photographed on-site. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1651350237049-Y9WINRX5GNXVVA9GP14M/Wolf+Bar.jpg Geology - amphibolite of Wolf Bar Further upstream from the preceding serpentinite and metadiorite, Moclock mapped the amphibolite of Wolf Bar. The American River is in the background. This is a high-grade exotic metamorphic block, that in its grade is much higher than rocks surrounding it in the BMFZ, and it must have a different source. It yielded an Ar/Ar age of 196 my, which I think is good evidence of a suture zone predating the CRO and Franciscan subduction. The suture zone may not coincide with the BMFZ, but this exotic block ended up residing there. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1651350257855-RZFC4TON9NW35I0M2HQC/Wolfamphib1A.jpg Geology - Wolf Bar amphibolite The rock ranges from 50-90% hornblende. The rest is mostly plagioclase, which is more resistant and stands out on this weathered surface (photographed on-site). Titanite is a common accessory mineral, and it sometimes includes rutile, which indicates high-pressure metamorphism. I thank Leslie Moclock for all her hard work on mapping and petrography. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1600408919836-SBAFSV4C28TC0TKZC1K6/WRandJF.jpg Geology - Wayne and Jenny My old boss Wayne Roderick and Jenny Fleming, renowned California native plant horticulturists, at the type locality of Ceanothus roderickii, ca. 1980. The substrate soils of the area are based on weathered gabbro and peridotite. This is where I got the chunk of gabbro for the thin section seen in following slides. I had to know what Wayne was growing on! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1604803828945-GL06P4C5O9Q7924OZZM0/CFinterm.jpg Geology - gabbro of Shingle Springs Here are weathered and fresh surfaces on the gabbros that underlies the Ceanothus roderickii type site. The obvious abundance of hematite suggests some of the opaque material in the thin section is this iron oxide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1598424498124-21DC0I42AKK5BGO8A8D2/ShingleSprings1a.jpg Geology - Shingle Springs gabbro Interlocked plagioclase and clinopyroxene define gabbros, but the black material that invades embayments in the pyroxene is an opaque oxide that must have come in late. I do not know what it is. This is part of the Eldorado County mafic/ultramafic terrain including the gabbros of nearby Pine Hill. The Shingle Springs site where I collected this sample is the type locality of Ceanothus roderickii. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1598424528558-KFOBH4GTDTYQQLBJBN1V/ShingleSprings2a.jpg Geology - Shingle Springs gabbro, closer Note how the two clinopyroxene crystals in the center have many small inclusions, mostly plagioclase crystals. This is called poikilitic texture and these must be calcic plagioclase that crystallized early, before the cpx. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1700363355027-46YC0TJKAEHJLDDLWK0F/Freel+dike+%26+enclavesR.jpg Geology - aplite dike and mafic enclaves On the trail up Freel Peak, 9/23. The mafic enclaves were particularly abundant and dramatic. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1700363381538-WH81I10IZ32K5P7HKC45/apliote+dike+biotite+fansRS.jpg Geology - Thin section of the aplite dike Same dike as in the previous picture. As expected, the dike is just a fine-grained rock of granitic composition. Mostly quartz and Kspar, with abundant small biotites (not seen in this view), and scattered plagioclase. I found this one agglomeration of larger, brillianty colored phyllosilicates. John Wakabayashi and Howard Day helped me understand them. My first guess was biotite partially altered to chlorite, then I took a wrong turn. Howard and John brought me back; my original surmise was correct. The small biotites that are brown in PPL would have more TiO2 and a higher T. These larger green ones (in PPL) formed later, at a lower T with less TiO2. Then they were partially replaced by chlorite, perhaps through hydrothermal action associated with intrusion of the dike. The fan-like shapes of the crystals is wonderful, but a mystery to me. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601445619842-RBPT41PA0VCFMMYLF7OM/Carson+juniper.jpg Geology - Juniper on Carson Pass granodiorite The opening of joints is assisted by organisms, especially tenacious ones with large deep roots and a long lifespan. Carson Pass is famous for its gnarly and extraordinarily photogenic Juniperus occidentalis. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601445596312-FJBOPNE66QO3NCJWBUIJ/Carsonorthojoints.jpg Geology - Carson Pass granodiorite This orthogonal/blocky jointing is much more commonplace in granitic rocks than the exfoliation jointing seen on Yosemite’s domes. It starts with shrinkage during cooling, then the joints can expand with removal of overburden….. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601445689106-ISCXX4VRNYXBEXAJHVST/granomacro.jpg Geology - Carson Pass granodiorite Run-of-the-mill granodiorite is be far the most abundant granitic rock in the Sierra. It is the plutonic equivalent of dacite, with significantly less silica than granite, the volcanic equivalent of which is rhyolite. One needs to picture the time of rising of these Sierran plutons as one with numerous large dacitic volcanoes, as well as andesitic ones from plutons even less siliceous. The hand specimen demonstrates that this is a hornblende-biotite granodiorite. Under a hand lens the biotite could be seen to be abundant. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601501172271-NZ547FMEF286UB1AN34U/CarsonPgrano2A.jpg Geology - Carson Pass granodiorite Run of the mill it may be, but fascinating and lovely in thin section. The large orange and brown moth-eaten crystals are hornblende. The thinly layered bronze-colored ones are biotite. The light gray thinly layered crystal at bottom center is plagioclase. Much of the rest is quartz though some may be Kspar. Hornblende is the highest temperature mineral here and it may have begun to break down with slow cooling. It has been oxidized and partly replaced with iron oxides, which are black in this XPL view. There is slight alignment of elongate crystals which probably occurred very late, after crystallization of the biotite. The layers in biotite are weakly bonded, so any rotation could cause them to fray at their ends. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601445719386-CC72JRDYPYT2913Z0BFK/RoundTopps2.jpg Geology - Round Top at Carson Pass Here is the plug of an andesitic volcano on the very crest of the Sierra. Dated at 13-14 Ma. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601502682075-5EFQXJRPP33BJ7CVET6G/RoundTopBETTER.jpg Geology - hornblende andesite of Round Top This is a porphyry. The groundmass is sufficiently coarse that one can ID all the crystals there as plagioclase. This happens with dike rock or lava that cooled deep inside the plug so it was well insulated and could cool slowly, after formation of the large phenocrysts in the magma chamber at depth. Hornblende phenocrysts are more abundant than plagioclase ones in this rock. Some of the plag is occupied by brightly colored saussurite, which is epidote-dominated, and the product of hydrothermal alteration, as is the dark rind of oxides on the hornblendes. Andesites tend to be more crystalline than basalts, since the former are more viscous owing to their higher silica content, so earlier crystals settle out more slowly. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1720057699186-0Z9X9AMV4FZUF6GAB35R/Mehrten+debis+flows.jpg Geology - Mehrten Formation debris flows at Kit Carson Pass ...a wonderfully thick and repetitive sequence of Mehrten Formation Miocene volcanic debris flows... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1724633740705-CF7J371N4QZYAWL17PAC/Thundr+Mtn+2.jpg Geology - Thunder Mountain ...is east of Sliver Lake and south of HWY 88. It is composed mostly of Miocene volcanic debris flows. Note the wonderful reflection of the mountain in this pond just below Granite Lake. Rana sierrae has been periodically observed in both. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1604803877924-8ZYUCCJFISLTOCZ29WUU/Pickett%26Hawkinsinterm.jpg Geology - Hawkins and Pickett Peaks These two volcanoes southeast of Luther Pass, Hawkins left, Pickett right, produced a large volume of debris flows and are capped by 10.77 Ma two-pyroxene andesite intrusives. They have had all that time for the original volcanic center, which must have been huge, to erode away. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1604803852938-COC6UF9L3LHS1XPWDSPF/MarkleevillePeak+interm.jpg Geology - Markleeville Peak This was another large volcano, its eroded remnant residing on the east side of Charity Valley, which is south of Hope Valley. Its dacite and andesite flows and intrusives are a little more than six million years old. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1728091372014-HYTABB9EFX66EWVHXDHM/Mark+Pk1.jpg Geology - Markleeville Peak in full sun "Magic light," as in the preceding photo, has an overblown reputation. It obscures the natural colors of rocks, so geologists have to wonder what they are. In this photo the rocks have truer color-- gray trending to green. The green may be hydrothermal alteration. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1643175108900-NTXWPIJDWQ65ITT3D9D6/MarkleevillePkflowR2.jpg Geology - dacite flow in Markleeville Peak complex This thin section shot in XPL with the 4X objective matches well what Hagan et al. 2009 call dacite intrusives of the Markeeville Peak complex, but this is not an intrusive, and its outcrop is decisively part of a flow. This view shows multiple highly altered hornblendes in the upper half, biotites left of center, and some plag crystals, and, at lower right, a likely kspar beside an orthopyroxene. I saw no quartz in the section, but that’s not unusual for dacites. The matrix will be more siliceous than the phenocryst assemblage. Presence of the opx suggests, but does not demonstrate,magma mixing. Overall the matrix is too aphanitic for an intrusive—in most cases! The geologic map is compatible with this flow originating from Markleeville Peak itself, and, in outcrop, flow- direction indicators also seem consistent with this idea. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601101262230-C8IVD6HPES6PYCK4YZ6N/Hiramoverlake1.jpg Geology - Hiram Peak is at Highland Lakes SW of Ebbetts Pass. This peak looks like a simple cone from the north, but it is actually a double peak if viewed from the east. It is the very eroded neck or plug of a relatively young volcano. Cathy Busby et al. described the Ebbetts Pass Volcanic Center in 2013. It ranges down to only 4.6 Ma. It is on the crest of the Sierra farther east, and includes multiple vents, most notably a composite cone greater than 18 km in diameter. Hiram Peak is a little older, and is considered to be a source vent for the Disaster Peak Formation, other sources of which nearby have been dated at 6.5 and 7 Ma. These are all very young dates for Sierra volcanoes, many of which were in the crestal region rather than to the east. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601502568713-GJXO70PLDR07RV2UVILM/HiramBEST.jpg Geology - Hiram Peak hornblende andesite This thin section of hornblende andesite from near the summit of Hiram Peak is typical of vent rock from andesitic volcanoes in the Sierra. The phenocrysts are abundant and closely spaced, and the groundmass is noticeably grainy, in contrast to lavas that did not have a chance to cool more slowly by virtue of the insulation provided inside a vent. Plagioclase dominates, but hornblende is very abundant. The colorful phenocrysts here have a black/opaque coating of iron oxides, probably titanium-bearing. This occurs with oxidation as a magma cools while approaching the surface and is still interacting with the small amount of residual melt. The rims are not very thick, which suggests that the extrusion was not very slow. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605383541258-LG6S5Q0TX0NWVZ2J1GZ6/caldera%26Ebbetts.jpg Geology - Ebbetts Peak and stratovolcano The dark knob at right is Ebbetts Peak, an andesitic intrusive. The gray peaks in the background are Silver Peak, left, and Highland Peak, right. These are two sides of a giant stratovolcano on the crest of the Sierra, with latest eruptions dated at a mere 4.8 Ma. This has been the subject of long research and multiple great papers by Cathy Busby and others. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1721678876933-J4R4PXRDTNMS2X5Q2RFR/Busby+Lassen-sized+stratovolcano.jpg Geology - stratovolcano south of Ebbetts Pass ...a more complete view of the preceding, taken from Ebbetts Peak. Unfortunately a dark shadow cast by a cloud at far right conceals obvious westerly dips of most or all of the units, complimenting east dips on the east side of this great volcano. Cathy Busby was the first to notice this. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605383569922-CV136YCEEVPAZ6MRUZGD/rimsCF.jpg Geology - clast from talus of Ebbetts Peak In the sea of andesite, one small clast was very different. It was glassy and lustrous, and had sizable quartz crystals. The piece at left has a sawn surface, so it doesn’t show the luster. Note the colorful rims around the quartz crystals. The picture at right shows part of a thin section of this specimen. The quartz crystals are deeply embayed to the point of fracturing, so that melt invaded the fractures. The rim, like jewelry, is either pyroxene or amphibole (more likely the former) arrayed in palisade fashion. It is a reaction rim where the quartz was reacting with the more mafic melt. The quartz crystals are xenocrysts introduced during magma mixing, probably from the granite the intrusion pierces. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605383593238-HL0XW1VQ9E57N4DS1XX3/dumbellCF.jpg Geology - glassy clast from Ebbetts Peak talus Two views of the same thin section, here in PPL and focusing on the glass matrix. The comical little barbells are plagioclase-cored, with football-shaped reaction fronts at the ends of the plag crystals. This is occurring after solidification of the rock. The plag crystals are chemically interacting with the solid glass. Perhaps the earlier quartz interaction with the melt put these plag crystals out of chemical equilibrium. I have never seen this kind of structure anywhere else. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1678587402700-QBRG8PUWBT19ZF4YKY8U/DSC_3578.JPG Geology - Gopher Ridge Volcanics This unit usually offers the westernmost metamorphic outcrops in the Central Sierra. It is Jurassic in age. This landscape is NW of Copperopolis. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1678587425165-0EAXW8KXWP6OSC9CRB0J/DSC_3492R2.jpg Geology - Gopher Ridge Volcanics pillows Part of the landscape in the previous photo. These are likely pillow basalt, but could be pillow andesite. The Gopher Ridge Volcanics includes both mafic and silicic units. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1678587446860-65R2VDXF3VXFUVYGG0IF/DSC_3599R2.jpg Geology - "Farmington Chert" This exposure is in a roadcut through the landscape shown in the previous two pictures. Where a fresh surface is exposed, you can see that the rock is blue-green. It has generally been called chert, but I suspect it may actually be a silicified tuff. It was favored throughout the prehistory of California for making flaked-stone tools. In my last photo block showing lithics, you can see two Acheulean handaxes I made in this material, but not collected here. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708122353778-9UMU1FYTAQTSEJUX3TQJ/Calaver+LS.jpg Geology - Calaveras Complex limestone, sensu lato This scene is at New Melones Reservoir, observed by permission at a quarry off Parrot’s Ferry Road. The arm of the reservoir that comes in on the left is the drowned Stanislaus River. The Calaveras Complex is mostly a subduction-zone melange, the subduction occurring in the early Mesozoic, and also possibly in the Permian. Large masses like this limestone are olistoliths that landslided in marine waters into the subuduction trench. As I understand this site (or not) the limestone (some or most of which must be marble) is a shallow-water deposit covering a giganitic seamount. The whole mass would have slumped into the trench. Scanned from a miserable old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597005406487-1LFVYL79CH4X46H7P6VP/09eps2.jpg Geology - Red Hills March 2009 The north-facing flank of this spur in the western part of the Red Hills was solid Coreopsis stillmanii. The gray shrubs are the gray form of Ceanothus cuneatus, which is nearly endemic to the Red Hills of Tuolumne County. Clint Eastwood filmed a gunfight in his movie “Unforgiven” here, pretending this was Wyoming and these were Artemisia tridentata; but anyone with the slightest education could tell this is California. The gray pines do not grow in Wyoming, and the buckbrush is obviously not sagebrush. For shame! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597005386442-ESG69KFN5WR2ZBDLPX6I/Lewisiaridgedunite1ps1.jpg Geology - dunite in the Red Hills This is a thin section made from the rock that supported the fabulous 2009 displays in the prior two photos. This is dunite, mantle rock that has come up along the foothills fault zones. The colored parts are shattered olivine crystals. The light gray is serpentine. The latter originates via alteration of the olivine and incorporates water in the process. This causes an expansion which helps explain the shattering of the parent olivine. Both crystals lack calcium, which is why this part of the Red Hills has few weeds but vast amounts of native flowers. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597903789868-L59FOO8BOT5HP2DAEQOE/RedHillsSerpred.jpg Geology - Red Hills serpentinite Here is a specimen that shows advanced conversion of dunite to serpentinite. The gray blade-like forms are probably antigorite, the highest-temperature serpentine polymorph. The brightly colored crystals are small remnants of olivine. Antigorite is typically formed through prograde metamorphism (heating) of other serpentine polymorphs. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597903822575-IHJWY6KT7HE8724OZ8KV/DSC_1986+copyps2red.jpg Geology - serpentine outcrop north of Coulterville This outcrop off Black Creek Road drew me irresistibly with its flashing crystals. See following two photos to see what’s involved. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597903842304-USGINIS4IE64TC3ASV4C/DSC_1913+copyps1red.jpg Geology - Serpentinite north of Coulterville Here’s a closeup of a fragment of the outcrop in the prior photo. I was puzzled. were the big crystals remnant pyroxenes, as in hobnail peridotite, or were they big plates of a serpentine mineral? See next photo to find out. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597903865825-2BWE5YD63EFTQ73OC1KC/Black+Creek+Road+serpps1.jpg Geology - Black Creek road serpentinite thin section Here’s a view of a thin section of a naturally detached chunk of the outcrop. The dark mesh at upper left is classic lizardite. However, according to John Wakabayashi, even the huge, smooth plates at bottom and right are probably lizardite, which commonly pseudomorphs pre-existing crystals, in this case pyroxenes. What a magnificent rock! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1618554322120-TB28NTSF0YQ4JRVLR4HL/wehrliteRHR.jpg Geology - Red Hills wehrlite This unit near the east end of Red Hills Road has been mapped as wehrlite, an ultramafic rock composed mostly of olivine and clinopyroxene. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597092275873-O4D376H6TU6GDINMLSN6/DSC_0250ps1red.jpg Geology - Wehrlite, Red Hills Road View of a thin section in XPL from a block of what is mapped as wehrlite near the east end of Red Hills Road. The large crystals are all clinopyroxene. There is some serpentinized olivine near top center. I would have called this a clinopyroxenite, https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597092322373-C31X7W7ES1BLVXACJL50/DSC_0257ps2red.jpg Geology - wehrlite 2 Same thin section as prior, but in this case showing a vein cutting through on the left side. It too is made mostly of cpx, though there are opaque oxides concentrated in it, too. I marvel at how embayed (moth eaten) the clinopyroxenes are. I think the magma must have mixed with a hotter, more ultramafic one, causing resorption in the cpxs. Even in the big crystals that dominate the rock outside the vein, their embayments are concentrated along the vein. Alternatively, hydrothermal action may have been involved. A fascinating rock. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597092360324-D02SZ8BDXTQTK0X3QZM6/DSC_0264ps1red.jpg Geology - wehrlite 3 Here’s a closeup of the vein, same thin section from the east end of Red Hills Road. Again, I marvel at the degree of resorption of the clinopyroxenes. They are practically skeletonize in some cases! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1618554708734-IWTQ22FL6U3JJM5Q936I/RHRgarnetamphibR2.jpg Geology - garnet amphibolite along the Bear Mts Fault Zone There are blocks and slivers of garnet amphibolite like this along and east of the Bear Mountains Fault Zone. These high-grade occurrences have led Dave Shimabukuro and John Wakabayashi to infer a west-dipping subduction zone here around 200 my ago. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1620597969929-4PJ0GK17D0ALGFBP8SH2/RHRgarnet+amphib2Ared.jpg Geology - amphibolite thin section, Tuolumne County This is a PPL view of a thin section of the amphibolite in the preceding photo. Such rocks have been studied by Dave Shimabukuro and his student Jo Black along the Bear Mountains Fault Zone from Don Pedro Reservoir north to Colfax. The blue and green are hornblende, which has these colors in the epidote-amphibolite metamorphic facies. The blue is actually bluer than my camera indicates, and paler. Hornblende was used for K/Ar and Ar/Ar dating, which indicated 200 my. Zircons were found and U-Pb dated to 216 my. The former is taken to be the age of metamorphic appearance of the HB; the latter, time of formation of the basalt photolith. There is also much epidote in the specimen. The two large fractured white crystals are garnet. Dave found rutile overgrown with titanite in these rocks, and inferred high-pressure, high-temperature metamorphism at depth, followed by decreasing metamorphic grade as the rock was disgorged. So the initial metamorphism appears to have been in a subduction zone at ca. 33 km depth, when the zone was still hot, in its early stages. All this courtesy of Dave Shimabukuro. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1618554738530-CC8NMAHYB4HJKXM1QXTX/RHRgreenR.jpg Geology - metamorphosed serpentinite This odd rock, sitting east of and adjacent to the amphibolite in the prior photo, started as serpentinite, but was later metamorphosed to greenschist facies, as the next photo shows. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1618554767798-OLD050A0D2QQAINZP24N/4thorder%2BR.jpg Geology - metamorphosed serpentinite This thin section in XPL shows bladed or needle-like mostly grayish crystals of antigorite serpentine. The large light brown crystal is a carbonate, as can be seen in its rhomboidal cleavage and high interference color as demonstrated by the bright part at the right edge of the left half, which shows 4 red lines. The mineral is thus at least 4th order in color. Having grown in serpentinite, it is likely dolomitic, meaning it contains both calcium and magnesium, the latter likely derived from the serpentine. The brightly colorful mineral scattered throughout is tremolite, which John Wakabayashi identified for me. This too contains both calcium and magnesium, so I infer that calcium-bearing solutions were introduced during metamorphism to greenschist facies. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597890778736-U5LEHP0R38YGX7F8Z00V/epidote.jpg Geology - Diorite of Chinese Camp This quartz-epidote vein in the diorite of Chinese Camp has unfortunately been bashed with sledges. In thin section, following, it is spectacular. Such veins are the work of hydrothermal solutions finding their way along fractures and filling them. The diorite has been U-Pb dated at 190 and 200 my, and it cuts the oceanic island arc rocks of the Penon Blanco Formation, which are thus older, and pre Nevadan. There is a very large composite volcano in the PB Volcanics between the Tuolumne and Merced Rivers. Since no clastic sediments are associated with it, it was probably always below sea level. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597890802683-LRHFMVE0193VUVGN1E3Q/dioriteofChinaCampps1red.jpg Geology - diorite of China Camp Here’s a bit of that vein in thin section. The high-interference-color epidote has a palisade form, as it grew inward from the walls of a fracture. At left there is quartz, including some that is very sheared, perhaps reflecting the forces that opened the fracture in the first place. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1704267392832-DJHDJCDF99KNU3T4PCG5/Jack+Rd+melangeR.jpg Geology - Melones Fault Zone melange This landslide in siliclastic-matrix melange is near the south end of Jacksonville Road, adjacent to Don Pedro Reservoir in Tuolumne County. The melange was apparently squeezed up from considerable depth in the FZ, as it contains scattered blocks of blueschist, as seen in the next picture. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1704267418706-47ORP1U31MSFPAFLH30Q/DSC_5566psR2.jpg Geology - blueschist in the Melones FZ melange The red dots are pyrite altered to hematite. This rock is very schistose, with a salient foliation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1704267445822-29R5CB6A47LZH0NCBY6T/Jack+Rd+comboR.jpg Geology - views of thin sections of the blueschist in the Melones FZ The left view was shot in PPL with the 4X objective, the right in PPL with the 10X objective. I think this is all or mostly riebeckite. In the left view the black item was pyrite before conversion to hematite. I think growth of pyrite was contemporaneous with the last stage of deformation of this schist, as the pyrite is nearly surrounded by quartz, which apparently grew in strain shadows. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1618621984274-ISBHC2NXB5NO5W7XEZ14/marbleps3R.jpg Geology - mylonitic marble south of Jamestown This isolated block is across the road from the Jacksonville Rd-Melones FZ melange. The side of the road where the melange is includes this lithology in place. There are at least two stages of deformation here. The first created the mylonitic banding, which happens in the brittle-ductile transition. The second produced the beautiful folds, and this must have been within the ductile zone, after deeper burial. This view of the block is about five feet across. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1746982524763-YLPLY63HB7T1SQBBEYFM/Two+Mile+BarR.jpg Geology - stratigraphy at Two Mile Bar, Tuolumne County Here is a wonderful section showing Mehrten debris flows abnd conglomerates capped by Table Mountain Latite. The latter clearly flowed over an irregular surface. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1661209462752-RDWGIA6ZFGH5CM5VOEHA/TMLJamestown2.jpg Geology - Tuolumne Table Mountain near Jamestown. This latite flow in most places is columnar-jointed, as it is here. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597704166336-M5PHJMKARFPVHVGTLOKA/DSC_5265+ps1red.jpg Geology - Tuolumne Table Mountain The latite flow followed the valley of the ancestral Stanislaus River, sometimes called the Cataract Paleochannel, from the Little Walker Caldera east of the present crest, all the way to the San Joaquin Valley, a bit more than 10.3 million years ago. In the distance you can see a meander in the flow, reflecting a meander in the original river channel. The sides of the river valley have been eroded away, leaving the more resistant latite standing—this is called “reverse topography.” Do you see the Lupinus bridgesii? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711214672750-J7D8TQ63EMLFUVO9I2WK/image1.jpeg Geology - goldfields on Tuolumne Table Mtn. Shot by Valerie Edwards in March 2024. The goldfields (Lasthenia californica ssp. californica) are followed in April by vast sweeps of Lupinus nanus with abundant Lupinus stiversii. One may speculate that the reasons for this abundance are the table-like top of the latite flow, with depressions containing vernal pools, hence water retention in early spring. But I think the soil dries out fast, because it’s very thin up there, and the water drains through the latite, between the columns especially, and these conditions limit competition from exotic annual grasses. I’m just guessing though… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597704199720-CLKDE0TYGDY1DFDOPFXI/DSC_7391red.jpg Geology - Table Man latite close up This is a plagioclase-augite-olivine porphyritic latite lava, with more alkali than can be found in a typical basalt or andesite, though it is very like a porphyritic basalt. Typically clear to white rectanglular plag crystals dominate, as here, and usually they are flow-aligned, though you can’t see that in this view. The black crystals are augite. In this specimen about 50% of what you see is black glassy groundmass. The crystals formed in a magma chamber and flowed far from the source vent until the glass chilled. This magma was basalt-like in the sense that the matrix was not viscous like that of a dacite. However, there is probably some settling of crystals manifested in this specimen, as crystals when they become so densely packed make the lava viscous themselves, and would slow it to a stop. So these probably settled once the lava stopped flowing. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597704231559-2ZXNVMO92UMJG2C5UHMG/LatiteBest3red.jpg Geology - Table Man latite thin section The green rectangular crystal is augite, and so are the four banded ones to its lower left, even though one has an amphibole shape. In PPL it is clear with a subtle pink blush just like all the other augites. The banded light rectangular xtal at the bottom is a plag. The two yellow crystals are olivine, but they are decaying to iddingsite, which is red. All the phenocrysts are embayed and worm-holed. I’m still working on what may have caused this. The iddingsite is probably post-cooling. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1597704270355-D9B95RWPLAGS7R0WY3MT/DSC_0060ps3red.jpg Geology - Table Man latite This cluster of augites has numerous pockets in which original melt was trapped and later quenched to glass, which is black and isotropic. Look close and you will see that there are also tiny crystals of various kinds trapped in these glass pockets. By sampling the glass, petrologists can study their isotopic content and infer aspects of the evolution of the magma. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708222739860-APSOBTU6BQ8KXK8IWQ5V/Wilms+Rd+tuffR2.jpg Geology - tuff of Wilms Road The chemistry of this unnamed tuff within the Mehrten Formation has, to my knowledge, never been studied. So we can’t know at this point if it correlates with any known tuff. I could not see it among the ledges in the hills shown in the preceding picture, and it looks like the tuff of Wilms Road is downsection from those ledges. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708222774903-PHWED6HAZR48ZRG6FDR2/mafic+bandsR2A.jpg Geology - tuff of Wilms Road, closer The dark bands are composed ot mafic crystals too small to resolve with my 14X hand lens, but seem to be mostly biotite and hornblende. The evenness of the dark bands suggests that the tuff at this site fell into quiet water. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1684959818664-WQN6KCBOZMHO2APZTE7A/PBvols.jpg Geology - Penon Blanco Volcanics This is a landscape SW of Moccasin in the central Sierra foothills. The rocks are part of the Triassic-Jurassic Penon Blanco Volcanics, which are mostly island-arc andesites. Next picture shows a closer view. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1684960121600-VHSE4ZA38LLGJV78O4OU/PB+volcs+brecciaR.jpg Geology - Penon Blanco Volcanics breccia, closer Here’s a closer view of Penon Blanco Volcanics breccia along Marshes Flat Road in the hills SW of Moccasin. One can see that the clasts range from subangular to angular, but it’s not always easy to tell clast from matrix. Both are porphyritic with mafic phenocrysts. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1678754120410-SR0JRK8A6129BHDWUI1A/Mocc+block+comboR.jpg Geology - metaultramafic block along Melones FZ We encountered this anomalous block along the Melones Fault Zone, which apparently disgorged it from great depth, south of Moccasin and east of HWY 49. John Wakabayshi helped us interpret it, which can be seen with the next picture. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1678754143191-FRLHGT4P10CJYTD9P28V/MoccasinXPL1R.jpg Geology - Thin section of the metaultramafic block What look like pyroxenes crowded together and studding the block are not. John thought the block originated as a a pyroxenite though. But then it was probably subjected to high-temperature metamorphism that converted the cpx to hornblende (the characteristic amphibole cleavage is obvious). Subsequent lowering of temperature allowed conversion of parts of the hornblende crystals to tremolite (the blades surrounding the bright orange HB remnant), and generated a matrix of antigorite (light to dark gray and black)+ a small amount of chlorite. The variety and uniqueness of lithologies everywhere I go never cease to amaze me. One has to be a detective all the time. I’m not a very good one yet. I stumble along the best I can and need to ask for help a lot! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1714716872168-DEQQUPACO0Q3W9NJIZMQ/Cold+sprns1R.jpg Geology - intervolcanic gravels This is an impressive wall, left by quarrying, at Cold Springs along HWY 108. There is a lahar at the top, and fluvial gravels and sands beneath. This is a vivid reminder that much of the block-and-ash-fall tuff produced by Miocene volcanoes on or near the crest of the Sierra went into stream channels, making lahars. But also much of the volcanic debris spread widely over the landscape, and exists now mostly just capping interfluves, as the present canyons were cut later. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1759733696870-91FQINN2U54SVMA8C428/stratovolcano%3F+south+of+Sonora+Pass+copy+2.jpg Geology - looks like a stratovolcano S of HWY 108 …But do not be deceived. It’s Miocene Stanislaus Group lava flows and debris flows—south of the steep grade on the upper west side of 108…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1645688700694-BGE0GZ532KZXUUTDSERK/sonorapass11-1+025R.jpg Geology - Little Walker Caldera Here, at the east base of Sonora Pass, massive deposits of the Little Walker Caldera, exposed by glaciation and by downcutting of the West Walker River, compose the two ridges. That river more or less coincides with the west margin of the caldera. This caldera was the source of the Table Mountain Latite. The far ridge includes Mt. Emma, near the center of the caldera. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1722108198326-HKVCJ47UN1E3LY5UN64J/LWC2A2.jpg Geology - heart of the Little Walker Caldera ...from a different perspective...Shot from above the summit of Sonora Pass, and emphasizing sky in soft, magic light. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1660977901520-N53QW40Y8MFT4SJBEA30/TML%26EurekaVtuff+copy.jpg Geology - Just north of the Little Walker caldera Just east of HWY 395 and east of the Walker River, just north of the confluence of the West and Little forks, the Table Mountian Latite is overlain by one of the members of the Eureka Valley Tuff. The latite is about 10.4 million years old, and the various members of the Eureka Valley Tuff range from 9.8-9.4. So eruptions were in two major pulses, the second forming the caldera (Pluhar et al. 2009). Here the latite seems to be making its way toward the Cataract Paleochannel, down which it flowed at least as far as Knights Ferry in the low Sierra foothills. We found, here and in the caldera, coarsely porphyritic latite similar to the hand specimen shown a few pictures back, but within the caldera we also found reddened, autobrecciated latite (probably the base or top of a flow), as well as aphanitic black. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1695588611801-WR43BKM3HRG6ZDSYUM8L/Emma+Lake+%2B+Mt.+Emma2R%2C+9-23.jpg Geology - Mt. Emma and Emma Lake In the heart of the Little Walker Caldera. The rock composing Mt. Emma is much altered hydrothermally, owing to its position in/as the heart of the caldera. Almost all of the eruptive products of the caldera are potassic or highly potassic. So I’m guessing Mt. Emma began as (mostly intrusive) trachyandesite. Ryan Fay obtained samples from Mt. Emma. I studied some of them and the rocks are indeed intensely altered. Feldspars were mostly replaced by epidote. This is consistent with hydrothermal action. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725048799936-TC2CE2BTOSG1UJABK6JP/Emma+combo.jpg Geology - Mt. Emma thin section We got up there again in 2024, and obtained samples from the outcrops on Mt. Emma. This sample was porphyritic, and shot with the 2X objective, PPL at left and XPL at right. The brightly colored xtals in XPL are epiditote, and these appear greenish in PPL at left. The groundmass is stuffed with mini plag xtals having a marked flow fabric. And, although they cannot be seen in this view of the slide, there are lots of small xtals that I interpret as Kspar, consistent with trachyandesite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601359103727-0EKJXS2YDV8XQ2P8TYOI/SonoraPassmanganese.jpg Geology - Sonora Pass manganese oxide seeps These long-term seeps channeled by joints in the granite are depositing manganese oxide. To give a sense of scale, some of the junipers are sizable trees. High on the Sonora Pass Road, HWY 108. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1703987292685-ZAR9IEGAB0OHMO19E507/UCD+layered+gabbroR.jpg Geology - layered gabbro from Tulare County This block of layered gabbro is in the magnificent garden of rocks on three sides of the Earth and Planetary Sciences builing at UC Davis. It came from the western part of the Sierra foothills at Fountain Springs, Tulare County. Layered plutonic rocks are uncommon but always fascinating and mysterious. Current thinking suggests the layering was produced by oscillatory crystallization in a relatively stagnant magma chamber with little current or convection. Each layer depletes the two adjacent layers of either mafic minerals or plagioclase, and a sequence stacks up chemically rather than stratigraphically. Marvellous rock! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763013971199-O29AP76MM2DYBQQBDXIN/Dogtooth+Peak+skarnR+copysharper+copy+2.jpg Geology - Thin section of Dogtooth Peak skarn …shot in XPL with the 4X objective…This the famous skarn of Dogtooth Peak, in the Kaiser Wilderness. the cross-twinned xtals are certainly cacite or dolomite; the coloful xtals are epidote, which includes cacium. I may have to look again at the thin section to see it shows garnet. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738028833045-1B6CKXF6QEMYQ6QC8EZ8/Torrey+Pines+badland+copy.jpg Geology - Bay Point Formation These are the youngest terrace deposits at Torrey Pines State Reserve. They are beach sediments and alluvium, sculpted dramatically by rain and wind. Scanned from a slide I shot in the 1980s. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1700982794446-777BJ12Q1CHEW669KOHA/soft+sed+deformation+at+ScrippsPS2A.jpg Geology - Ardath Shale, Scripps La Jolla THIS BLOCK OF PHOTOS PROCEEDS LOOSELY FROM SOUTH TO NORTH. Some spectacular soft-sediment deformation in the early Eocene Ardath Shale, on Scripps Beach at La Jolla in San Diego County. The overlying sandstone visible in this photo is the base of the early middle Eocene Scripps Formation. Evidently the thick sands, deposited rapidly, weighed down on the mud beneath, dewatering and dramatically deforming it. All of this happened in a deep marine environment. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1735333450987-QE5VSC9O4J9MXCJYTWYD/Anza+Borrego+Granitic.jpg Geology - granitic rocks in Anza Borrego SP These rocks show pervasive spheroidal weathering. Mechanical weathering dominates over chemical in deserts, so there is very little production of soil that could hide the speroidal weathering. Also, I think carbonic acid in the little rain that falls here must generate salts that pry apart the coarse crystals--which would contribute to the spheroidal shapes. Scanned from a slide shot in the 1980s. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435701873982-I5LZOT97QPXO5B6J84H6/panaint.jpg Geology - north Panamints Paleozoic strata on the west face of the northern Panamint Mts seen from Lake Hill in Panamint Valley. Capping the range here is a black Plio-Pleistocene basalt, a young, very fine-grained, glassy unit that was used by prehistoric inhabitants to make beautiful flaked-stone tools. This basalt flow gives a maximum age for time of separation of the top of the Paleozoics in the range and the top of the same Paleozoic formations in the valley floor or in the Coso and Argus ranges to the west. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1598226869616-9UEWOHDHPNDZB2MU1CZI/best1ps1.jpg Geology - Badwater turtleback Part of the Badwater turtleback in the north part of the Black Hills in Death Valley. Here the Miocene volcanics and sediments at left are sliding down the gently domed surface of the turtleback. The latter is composed of various Proterozoic elements, but especially mylonitic gneiss. In thin section that rock is dominated by Kspar, broken in brittle fashion, and plastically deformed quartz circulating around the larger feldspar crystals. These alternate with schistose layers that have muscovite, a little chlorite, and smaller minerals not resolvable with a petrographic microscope. Mylonites form in the brittle-ductile transition, at 10-20 km depth. This is a classic metamorphic core complex, in which basin and range extension has caused exhumation of metamorphosed Proterozoic rocks, partly through isostatic rebound. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1598226892196-3F2VUY1VY3OWIUVGH1AM/BWT1ps1.jpg Geology - Badwater turtleback a closer view of the weathered fault surface of the turtleback dome https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1598226925819-PDT2VLJQRZ8IU027IVLN/Mylogneiss1ps1.jpg Geology - mylonitic gneiss There are pieces of what’s inside the dome lying around in the gravel of washes. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1598252714635-3AWLOH5NLYP47JODO21T/mylonite2ared.jpg Geology - mylonitic gneiss Here is a view of a thin section of mylonitic gneiss from another area, but like what can be seen in the Badwater turtleback. The large crystals in the lower part, near extinction, are potassium feldspar (one is microcline with characteristic tartan twinning). They have broken in brittle fashion, but swimming around them are quartz that has been elongated and curved around the feldspars by plastic deformation. The colorful crystals are mostly white mica, probably muscovite, and they show similar deformation. The mottled gray and white crystal above the large feldspars is quartz dividing into subgrains to redistribute itself to accommodate stress. The smaller quartz grains are sutured (seen at higher magnification), another indicator of high pressure. Fine-grained layers are present between coarse ones, and that’s one reason this is a gneiss. This is called compositional banding, as darker layers have more mafic minerals. Gneiss is of higher grade than schist, and usually lacks the foliation of a schist. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1726961877683-ALYH4OVJYAXYVZUCJO0J/Pogonip+BESToved.jpg Geology - Ordovician Pogonip Group Scanned from a slide taken in 1980 or 1981 of the Funeral Mts., SW of Pyramid Peak. Various members of the Pogonip Group can be seen in the background, all or mostly carbonates. I think at far left in this cliff there are members of the Cambrian Nopah Formation. Echinocactus polycepahlus in foreground https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1673054877334-J9Y8QF28AWUNAWC375H8/Nopahs-Al-R2Asharper+copy.jpg Geology This is a scan of a very old slide, the photo taken by Al Seneres. It shows Proterozoic and Cambrian strata on the west side and crest of the Nopah Range, which is well to the SE of Death Valley, and very close to Nevada. In about 2002 I climbed up to the thick dark gray zone, which I believe is Neoproterozoic Noonday Dolomite. The next photo shows what I found there. The base of the sequence here is Mesoproterozoic Kingston Peak Formation, while the top is middle Cambrian Bonanza King Formation. The whole succession thus spans at least 500 million years. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1673054903624-3B38L43EYVJEUY19KO0E/Nopahs+eborispinasharper3R2+copy.jpg Geology Agave utahensis eborispina (Ivory-spined Agave) is widespread in Nevada, but creeps over the border into California in just two ranges: the Nopahs, here, and the Resting Spring Range, which is the next range to the north. The clumps grow out of cracks in the dolomite, which is so hard, and so sharply scalopped, it can tear apart vibram soles. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707359295300-3TLX9QOAO1E47MT398YU/marble+canyonR.jpg Geology - Pennsylvanian Bird Spring Limestone …near the entrance to Marble Canyon in the Cottowood Mountains…Scanned from a slide….Look at the next photo! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707359318912-6LRRXCM1U0FYR5UV5AE9/si+nodules+marble+caR.jpg Geology - black chert nodules in that limestone …analagous to flint nodules in Cretaceous chalk in the Cliffs of Dover….Scanned from a slide…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1755584957481-JKLXEFPI7RSK7PPNDDHV/Titus+Canyon5R-psR.jpg Geology - Titus Canyon Formation at Bloody Pass …on the road to Leadfield….The redbeds in the foreground are the Lower Redbeds of Stock and Bode (1935}, the fossil-bearing unit in the lower Titus Canyon Forma†ion, Bruce Lander tells me. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738110821611-8JKOXXK17RF6C0SHYE9T/Artist%27s+PalletteR.jpg Geology - Artists' Pallette You're looking at hydrothermally altered volcanics, both flows and tuffs, of the Miocene Artist Drive Formation. Marli Miller explains that the earthy colors (presumably including the purply pink) are from iron oxides, while the "seafoam green" is probably from celadonite (see photos and legends in the Berkeley Hills block of photos). Scanned from a slide I shot LONG ago.... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1723847915682-3JBF3RK9W49ZEFL9U425/basalt+E+ZabriskiR.jpg Geology - view SE from Zabriskie Point ...shows in foreground Miopliocene Furnace Creek Formation lake beds, which contain a dark basalt flow, and on the distant ridge Artist's Drive Formation, which is older than the Furnace Creek Fm. The Artist's Drive Fm includes here dark basalt, tuffs, and sediments. The strata are dipping toward us, which is why the Artist's Drive seems higher topograpically than the younger Furnace Creek. The latter unit produced much of the borate minerals--mostly ulexite and colemenite--which the famous 20 mule teams hauled. The borate minerals were mostly produced by hydrothermal springs in the lake. There was plenty of silicic and mafic volcanism going on. Snow can be seen on the higher Panamint peaks at upper right. Scanned from a slide I shot in the late 1970s... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707349063937-O8IJJRYFT4CIQZO6D2BG/Barstow+syncline.jpg Geology - Barstow Syncline This in-your-face fold is in the Barstow Formation, NE of the city of Barstow. The formation typifies the Barstovian Provincial North American land-mammal age, and ranges from about 19 to 13.4 Ma. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1607217887408-07WTN5WUBCSUYIW2R1TA/MtsPS.jpg Geology - El Paso Mountains standing close to the trace of the Garlock Fault, with lovely Cassia armata blooming in the foreground, and the El Paso Mountains in the distance. The range is composed of Precambrian and Paleozoic metasedimentary and metavolcanic rocks, plus various intrusives. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1607217924514-PUPEL65BIB8MKWLBNU7W/MesquiteClasts.jpg Geology - Mesquite Schist This “spotted schist” is in place in Mesquite Canyon, underlying the Permian Garlock Series, and possibly of Precambrian age. The spots have been characterized as pseudomorphs after andalusite (and some cordierite) porphyroblasts, with replacement mostly by quartz and chlorite. The matrix, resplendently silver when weathered, consists largely of sericite and quartz. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1607217964973-8YBZWOBJOE7F5Q6RY8V8/MesquiteSchistXPL.jpg Geology - Mesquite Schist thin section This view in XPL shows sericite and quartz in the matrix flowing around pseudomorphed porphyroblasts that have been flattened perpendicular to the maximum compressive stress and elongated in the direction of maximum extension. My equipment is not sophisticated enough to tell me what the replacement minerals in the pseudomorphs are, but Dibblee stated that they are chlorite and quartz. Traces of remnant cordierite have been detected in the pseudomorphs, and its presence may reflect interaction with the nearby pluton in Weiss Mountain to the west. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610522928870-8M4BYZ3PDDS4B4ELVKDR/myloMesquiteCnRED.jpg Geology - mylonitic gneiss of Weiss Mountain Another conspicuous clast type in the wash through Mesquite Canyon is this mylonitic gneiss. Left looks down on a foliation surface with lots of hornblende. Right transects the foliations. The protolith is hornblende-quartz monzodiorite to granodiorite of Weiss Mtn, just west of Mesquite Canyon. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610523105299-FQGFQS4HJ3OR5M9F5MVT/HBfoliationRED2.jpg Geology - Mesquite Canyon mylonite in thin section This XPL view shows clear wavy foliations with hornblende concentrated in some layers and quartz in others. The quartz was elongated by plastic deformation and developed subgrains in the process of recovery from strain, as well as new grains during dynamic recrystallization. There is much epidote and sericite, I think, in the fine material. Plagioclase crystals are abundant. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610523129685-YX2RGXL2M0A17Z0BIDWL/sphene+comboRED2.jpg Geology - sphene in the Mesquite CN mylonite There is quite a bit of sphene (=titanite) in the mylonite. This is the principle titanium-bearing mineral in acid igneous rocks and in gneisses derived from them. Three sphenes can be seen in the PPL view at left. The bipointed form is classic. The right view in XPL shows much epidote and sericite, I think, and, curiously, some of what seems to be epidote is included in the sphene crystal. This may indicate late growth of sphene, which included a bit of epidote but pushed most aside. Or the epidote may have grown at a late stage within the sphene. I would be guessing. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708136421179-YNT9NAYFC0HYF8QJJ11G/Cajon+PassR+copyimproved2R.jpg Geology - Mormon Rocks in Cajon Pass …scanned from a slide taken ca. 1990. These Miocene sedimentary rocks include mostly sandstone, with more conglomerates near the base and more siltstone near the top. They are now called Cajon Valley Formation, and range from ca. 18-12.7 Ma. They have provided diverse mammalian faunas of Hemigfordian and Barstovian age, most notably for me including several genera of horses, plus chalicotheres. That’s Jimmy Vale’s car. Clarity of this picture was affected by smog from the LA Basin. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707342715262-FYJ4BWB7UOITMUH8RS6I/gneiss+2R.jpg Geology - Precambrian gneiss in upper plate This is in the upper plate that thrusted Precambrian rocks over the Mesozoic Pelona Schist. I found this outcrop and much more along a dirt road heading SE from the summit of San Francisquito Canyon Road, which would place this area in the Sierra Pelona above Bouquet Canyon. See next photo for a closer view. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707342755157-HOAW52G7U0UJQLQHE56V/gneiss1R2.jpg Geology - closer view of Precambrian gneiss in the Sierra Pelona Classic gneiss, but very weathered as befits its age. It seemed to me it graded laterally into a granitic lithology. If so, I would call this a granitic gneiss. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609711447620-2QJG8MGQ1OS9TXCA0DNF/SandCn1.jpg Geology - Kinnick Formation The Hemingfordian Miocene Kinnick Formation north of Tehachapi and Monolith in Tehachapi Pass includes this conspicuous aquamarine blue tuff. See next photo for closeup. According to Chapman et al. 2017, zircons in the Kinnick have been dated at about 18 my. The Hemingfordian age is based on mammalian fossils. These authors infer the eruptive center for the Kinnick to have been north of Tehachapi. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609711467313-9NGJSPR5A2PF9OL02IN0/SandCanyonmacro4red.jpg Geology - Kinnick tuff closeup The formation is well exposed in Sand Canyon, where this piece was photographed. The white clasts are rhyolite, the reddish-brown clasts are, in my opinion, more rhyolite. The latter weather out of the matrix, some in pieces up to 6 or 8 inches across. They are very chert-like, and local Indians flaked them. Most are flow-banded. See next photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609711492640-MXZ7XH1QQEDYT4W8HZRJ/flowbanding2red.jpg Geology - Kinnick blue tuff clast The reddish-brown clasts are very chert-like and are mostly flow-banded. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609711517211-LDFW3T1U4U0X870ZXU1O/SandCncomboRED.jpg Geology - Kinnick thin section These are two views, in PPL with the 4X objective, of a thin section of the blue-green hand sample. Clasts of flow-banded rhyolite grade into pumice. The phenocrysts are largely plagioclase with fewer quartz. There are also sizable pieces of perlite, of which an example can be seen at upper right. There are lots of fine glass shards in the matrix. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609711543853-2RZBF9HILNR43LTOTFQ0/JawboneKinnickAAA.jpg Geology - Kinnick Formation in Jawbone Canyon The Kinnick occurs disjunctly in lower Jawbone Canyon, where Blue Point is the most striking display. This photo faces south near but away from Blue Point. The aquamarine blue is simply gorgeous. I can’t explain the color, but an arm-wave might suggest hydrothermal alteration. The tuff here contains reddish-brown rhyolite clasts in abundance, matching those in Tehachapi Pass. In Jawbone we are at much lower elevation, and the Kinnick here has been dropped into the Mohave by normal faults that are broadly part of the Sierra range-front fault system(s). https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609711566129-JIW8JUGG1P4HLJOU73LQ/BluePtcomboRED.jpg Geology - Blue Point Kinnick thin section Here are two views of a thin section from a hand sample of Blue Point in lower Jawbone Canyon. These are in PPL with the 4X objective. Here the petrography differs from that in Sand Canyon. Vesicular glass chunks are much more conspicuous. Other clasts are less crowded. Many are siliceous lithics that are more crystalline than clasts in my Sand Canyon sample. The loose phenocrysts are Kspar and quartz; there is no plagioclase. Some of the lithics are flow-banded. So the petrographic differences are striking, but this is clearly the Kinnick Formation despite the differences. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609711598961-OUWKBVZQEMY5087TZUUK/Cudahy2a.jpg Geology - view NE from Cudahy Mine The western Mohave is clearly under-appreciated by those who make a bee-line for the ranges of the eastern Mohave. Here I am standing at the abandoned Cudahy dutch cleanser mine, overlooking Last Chance Canyon. Black Mountain on the skyline is mostly basalt of the Miocene Cudahy Camp Formation. In front of that backdrop, fluviolacustrine beds of the Clarendonian Miocene Dove Spring Formation, including pink tuff, are interbedded with additional mafic volcanics, although the dark brown flow unit to the right may be part of the Cudahy Camp Formation. I’m standing on tuff of the Dove Spring, which was mined for dutch cleanser. But the beauty is the thing. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609711622280-RTJOATGIE3DHGBFIYAPM/niches.jpg Geology - Dove Spring Formation niches This outcrop of Dove Spring Formation shows resistant sandstone interbedded with more easily eroded mudstone. Whenever I look at this I think of a limerick Ted Kipping told us one day long ago along the Carson River: “There was a young lady from Chichester, who made the very saints in their niches stir. Each morning at matins, her breast in white satins, made the bishop of Chichester’s briches stir.” https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667246741581-1LWPFQWEGMT3NQB3DEPX/SimicomboR.jpg Geology - late Eocene Sespe Formation, Ventura County This panorama shows in the foreground part of the late middle Eocene (Duchesnean land mammal age) part of the nonmarine Sespe Formation north of Simi Valley. I was there in 1981, meeting up with Mark Mason, a UCMP grad student who was working on his dissertation on this area. I helped with collecting for a day, and Mark proclaimed that the little partial dentary I found was a new species of Miacid (the earliest carnivores). I do love badlands! Scan of a slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1712644909850-ZAN3A4WJZLGPDOX6SFH6/Sespe+cliff3R+copy.jpg Geology - Sespe Fm. in Santa Monica Mts. Bruce Lander, one of the leading experts on this area, tells me that this is the unnamed lower member of the Sespe locally. It is below Saddle Peak and Piuma Road, and though it is undated, it is overlain by the Piuma Member, which contains an Arikareean mammalian fauna, which might make the lower member here Oligocene. Note how these bold resistant sandstones contrast strikingly with the lower member beds north of Simi Valley, which are Eocene badlands in mostly mudstone. SMOG made photography very challenging. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1598077573252-G8EA8KXYIJIJRAQURTOH/VGlimestone1.jpg Geology - Vaughan Gulch Limestone The Vaughan Gulch Limestone of Silurian age crops out here near the mouth of Mazourka Canyon in Inyo County. Like a thick book standing on its spine, its thin individual layers are differentiated by varying contents of clay and silt in the limestone. Fossils are abundant in the purer limestones, especially corals. I was standing on a coral reef in the western Mohave Desert when I shot this. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1668999364684-FM966WDYSKGJDSEEU38F/granitetafoniRED2.jpg Geology - granitic tafoni This is at the top of Short Canyon near the trail to Owens Peak, in Kern County. Formation of such cavities in sandstone is well understood, but formation in granitic rocks is stil murky. However, in a 2022 paper in Geomorphology, Roque and others present compelling evidence that a lot of tafoni in granitc rocks is formed under the water table while the rocks are still buried. Water works its way down joints and causes many places to weather to such a degree that they become mushy. When the rocks are uplifted, the softs parts are the first to erode. Thus, one can picture the tafoni in Short Canyon forming in a moister climate when the rocks were still below the surface. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1758093217303-HH1J5PNZ1CTFTNKGXV8D/BEST+SEVAHAH+FOLDsharper2R.jpg Geology - Sevahah cliffs, Inyo County This is part of the Mt. Morrison roof pendant. It displays a lovely syncline…. The cliffs are composed of Paleozoic marine sedimentary rocks, surounded by granitics. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1758152749139-PLEH1PSZ2HUTMH7STGKH/Iceland+SparR.jpg Geology - Ship's Prow …folded limestone in a spire or spar up Convict Creek in Inyo County, is the north end of Mt. Baldwin, down cataract from Mildred Lake….mostly hornfels closer….Everything here is Paleozoic… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707156620870-7TJ5JIH28H13EERFD4RS/vent+in+CososSless+saturated.jpg Geology - dome in Coso Range, Inyo County The Coso Range is pock-marked, viewed from the air, with tidy rhyolite domes like this. I climbed to the brim of this one, and found obsidian scattered about…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1736403922055-MZAXQDF6BODZVXESXFML/inyos3+229R.jpg Geology - view ENE from the crest of the Inyo Mts. …SE of Big Pine…I was entranced by this landscape. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1721678317641-05IRRMMFKR7RLZ0W0HBJ/Beauty+Peak+best.jpg Geology - Beauty Peak, Bodie Hills ...is well-named. I'm always entranced when I gaze upon this scene. According to John et al. 2015, Beauty Peak is 2.9 Ma post-subduction shield volcano originating in an extensional regime, and composed of basaltic trachyandesite and trachyandesite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725321120863-MZYO1UE3T7OQB4SV0KMA/rotten+basement.jpg Geology - rotten basement rocks ...cliff above lower Masonic. It doesn't look like granitic rock, but thin sections tend to tell a different story. See next photo, which combines two thin sections. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725321090156-KU2SIECQCM4B9WWRWT90/cliffs+above+lower+Masonic+comboR.jpg Geology - views of two thin sections ...from the cliff in the preceding photo. Both shot in XPL with a 4X objective. Left, looks like sericitic alteration in a plagioclase crystal. This slide also had large interlocking quartz xtals. Right, apparent coarse sericite surround by quartz xtals, which dominated this slide. Sericite is formed by hydrothermal or deuteric alteration of feldspars. That's why I call the cliff from which I took these samples "rotten basement." https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725341658920-TQNAPVJSO3GETD6B7Z98/Masonic+upper+mine+dumpR.jpg Geology - mine dump above lower Masonic It really was that yellow. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725341692840-FM88RHOFCL38HCGMDLCN/silified+blockR.jpg Geology - silicified block in mine dump above lower Masonic In parts the replacement by silica was obvious (left), in places the porphyritic texture persisted (right). Each of these shots show an area ca. seven inches wide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725341718728-VLFRLKR6KQBZ4HDRDGRP/silicified+block+combR.jpg Geology - alunite The bright yellow crystals are alunite. Alunite is usually produced in intermediate volcanics by the action of sulfur-bearing fluids. The wholesale silicification of this large block (ca. 7 feet long) is evidence that the fluids were hydrothermal. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725341744271-YDYQD3PYMCFF775R8DIZ/alunite+%2B+%3FproustiteR2.jpg Geology - alunite and probably proustite in the silicified block The brownish-yellow bands are alunite; the bright intense red may be proustite, a compound of silver, arsenic, and sulfur. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1645687667670-V4B5TOT77NE0M4002E9R/bodieplus+115R.jpg Geology - down Bodie Creek Phil Olrich and I encountered this scene in a June long ago, on our way down Bodie Creek east of Bodie. David John, who mapped the area, explained to me that the yellowish unit at left is a columnar-jointed flow that is part of a rhyolite dome, called the Rhyolite of Bodie Creek, 10.2 my old. Above it at right is a dark lava flow, the Trachyandesite of Beauty Peak, 2.9 my old. Above that is another part of the rhyolite dome. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1721680502240-RTHR1TG7KV7V04IT4HL8/rhyolite+of+Bodie+Creek2.jpg Geology - rhyolite of Bodie Creek David John originally loaned me a copy of a photo he took of this spectacular columnar jointing crossed by flow banding. I went down there with an FX camera and got a more lucid shot, July 2024. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725049473138-BEURK1M8ULSPC57SEUAI/DSC_0365+copyPS-R2.jpg Geology - rhyolite of Bodie Creek thin section This is in PPL with the 4X objective. A large quartz phenocryst at left has engulfed a biotite xtal that grew earlier. At right is a Kspar xtal. The many voids have small quartz xtals growing into them. Kspar xtals are common in this rock, but usually small compared to the quartz xtals. My scope cannot adequately resolve the groundmass, but I think I see glass shards. So this might be an ignimbrite rather than a lava flow. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1667246762846-C7JUTLYHBG00X6UK5XKC/CalienteR2.jpg Geology - Caliente Formation The Caliente Formation, which has a large outcrop area south of the Carrizo Plain, produces lovely badlands. The unit is mostly Clarendonian in age, thus between 9 and 12.5 my. It has produced an extensive mammalian fauna, and I studied some of those fossils in my graduate years and again recently. The Caliente is considered, on the bassis of distinctive and traceable volcanic clasts in conglomerates, to have been separated from the Mint Canyon (east of Castaic, in Ridge Basin near Saugus), by right-lateral motion on the San Gabriel Fault, and, to a lesser extent, the San Andreas. Scan of an old slide taken in the late 1980s. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738028797775-U5RT09G6LPJG9JV5GGB1/Caliente+badlandsR+copy.jpg Geology - Caliente Formation …more scenic Clarendonian badlands… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1745389403048-Y1HURDCJGQWEOS8AW23H/SLOvolcNecksRcleanSHARPER++copy.jpg Geology - volcanic necks at San Luis Obispo These Miocene volcanic necks, three of 23, are mostly dacitic, arrayed from WNW to ESE, and thought to represent an extinct transform fault. Their arrangement cutting across the grain of the coast ranges is highly anomalous and distinctive. They begin at the west end with Morro Rock. View SW from Cuesta Ridge, through a mist of remnant coastal fog. Scanned from a slde I shot in the mid 1980s. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707260200152-JUDPXEXMFQRCN3XKEIZN/Pinnacles%2522%2522.jpg Geology - Pinnacles NM Another view of the rhyolitic breccias. Volcanic breccias are commonly eroded into pinnacles. I think it was scenes like this that gave rise to the name for this area. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1661900609052-Y9YACNV99CN9L4VX3C9I/NeenachhandR2.jpg Geology - Neenach flow-banding Here’s a hand sample, photographed in the field, of flow-banding in Neenach Volcanics rhyolite lava. Rhyolite is about as viscous as toothpaste, or even jello, generally making domes. So wherever a rhyolite outcrop is found, it’s a good bet the center of the vent/dome was close by. Scan of an old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1711436259634-4LW1O7WJ5CXBEIUL5XSD/Parkfield+Grade+best2.+jpg.jpg Geology - Parkfield Grade melange This site is south of Coalinga. It is a truly classic Franciscan melange landscape, with hard blocks floating in more soupy matrix. Many of the blocks here are blueschist. Scanned from an old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654547004900-EX8ZVYQMBH4LMRDSXAVZ/FrePK2+copy.jpg Geology - Fremont Peak, Monterey County South of San Juan Bautista and inland from Monterey Bay, Fremont Peak (formerly Gavilan Peak) consists at its summit, shown here, of marble—with both dolomitic and limestone protoliths. It is a roof pendant sitting on Salinian granitic basement, far traveled by motion on the San Andreas, from somewhere south of the south end of the Sierra. As Doris Sloan pointed out in her excellent article in Bay Nature on this peak, Salinian metamorphic roof pendants in the Bay Area are generally small, not abundant, and not accessible. They’re on Inverness Ridge, but very hard to get to. Much more can be seen in the Santa Lucia Range,for example at Cone Peak. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1650925006398-ACU37RTET4LSUZFEPJ3E/QSabe2AR.jpg Geology - Southern Quien Sabe Range A view SW to the southern part of the Quien Sabe Range from high on Basalt Hill south of San Luis Reservoir in western Merced County. The pointiness of so many peaks and the rugged character of the Quien Sabes results from the fact that the range is a complex of resistant Miocene felsic intrusives, from >9 my to >11 my. These vents were predecessors to the volcanics of the Berkeley Hills, which, when erupted, were closer to the Quien Sabes than to their present location. The tawny hills in middle distance beside the reservoir are underlain by Great Valley Sequence sandstones and shales. We were there too late in the day to get a great photograph, but I put it up for sentimental reasons. How I long to get into that range! Unfortunately, private property and my age make this imposssible. I can still dream though. Acc. to John Wakabayshi, the Ortigalita Fault has somewhere around 6-20 km of late Cenozoic dextral slip. San Luis reservoir fills a pull-apart basin along that fault. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1639981637737-IHTN9A22CP1OY6761DAS/SLRESscene1R.jpg Geology - Panoche conglomerate at San Luis Reservoir This is looking south from the very coarse Cretaceous Panoche Formation conglomerate to Basalt hill, which includes andesitic tuff K/Ar dated at 8.3 Ma, and basalt above, K/Ar dated at 7.4. These young volcanics come very close to I-5, and may have originated from the Quien Sabe Volcanic field, or from sources which have been discovered close to the west end of the reservoir. I regard these as Quien Sabe outliers. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1650178187043-EGOODRQ5CPZM5JEEIZOD/PanochecgLagR.jpg Geology - Panoche conglomerate This is the same conglomerate, showing lag clasts sitting on bedrock. Staff is about five feet long. View south, with southern Quien Sabe Range at right. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1639981662576-KKTCEVC0RGBOLQPRZZ93/SLRfelsictuff2R1.jpg Geology - clasts in the Panoche conglomerate This one is a very nice, young-looking rhyolite tuff, with lots of quartz phenocrysts and some biotite. The only obvious alteration is that the glassy matrix is thoroughly devitrified. The three clasts, all volcanic or hypabyssal, reflect volcanoes that were going off atop magma chambers in the Sierra around this time. The volcanoes were almost all eroded away, and what’s left is the granitic plutons. But some plutons were already exposed in the late Cretaceous, as the Panoche conglomerate here includes lots of granitic cobbles and boulders. I envision low sea-level stands when rivers could bring big clasts pretty close to this area, and submarine slides would do the rest. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1639981689173-JQLBE7GUD00BFNUWAB8L/rhyolitetuffR.jpg Geology - the rhyolite tuff clast in Panoche conglomerate quartz and biotite in devitrified glass. PPL view with the 4X objective. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1639981714143-AX665RLLK1P7P0SLYQ83/SLRfelsicR1a.jpg Geology - hypabyssal rhyolite This clast in the San Luis Res Panoche conglomerate is almost certainly dike rock from the Cretaceous Sierran volcanoes. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1639981732751-6XQE6Z7OPDH0Y46T8UQU/mottledclast2R.jpg Geology - hypabyssal rhyolite Here’s that dike rock, shot in XPL with the 4X objective. Very large quartz crystals, two shown here, join abundant highly altered Kspar crystals on the same scale, these all set in a more or less equigranular matrix of much smaller, intricately interlocking quartz and feldspar. The quartz phenocrysts are erose on their margins from resorption, which made them fluid enough there to imbibe some of the smaller crystals from the matrix. They are also subhedral to euhedral, reflecting their likely origin as high temperature or Beta quartz, even though they subsquently switched to Alpha or low temperature quartz at ca. 573 degrees C. The Alpha quartz has trigonal crystal symmetry, the Beta hexagonal, but they occupy the same space and shape established by Beta growth, because at 573 degrees the shape has already been locked in by surrounding crystals. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1639981761672-OJNIE8PAJA5QJDC1C1K9/darkclastPSRed.jpg Geology - darker clast in the Panoche conglomerate This clast has no mafic minerals. It is dominated by large plagioclase crystals, which may give a misleading impression of overall chemistry if they crystallized early and were swept up by turbulence in the magma chamber. That looks to be the case, as the matrix shows possible evidence of three different melts that were mixed together. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1639981807626-G1RYSR6MFPF78TVWZG3W/darkerclastmoreR.jpg Geology - darker clast in the Panoche conglomerate Here is one of the abundant melt types in this clast from the Panoche conglomerate. The gray crystals around the margin are highly altered plagioclase. The vesicles in the middle are filled with zeolites with a radiating-needle habit. I don’t know if the zeolite was formed at the eruption site, or later by zeolite-facies metamorphism with deep burial in the Great Valley Group. The latter usually shows ittle or no metamorphism. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1650178220327-GBTO750YRDU3INLIAJSA/SLRgranite2R.jpg Geology - granite boulder in situ in Panoche conglomerate This is an example of the many granitic clasts in the Panoche megaclast conglomerate at San Luis Reservoir. This one has no mafics other than biotite. At upper right is a cobble that could be greenstone or keratophyre. This is an example of the scant possible representation of the CRO as a western source. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1650427118438-W3U6KU6F181XMMWGITT8/AFgranite2.jpg Geology - Panoche conglomerate granite In this clast, plagioclase (highly altered) and Kspar+quartz are present in subequal quantities, with almost no mafics, what there are being mostly very small crystals of biotite. So beautiful! Another gift of the Cretaceous Sierra. Kspar can be pink, so that may be part of the cause of this gorgeous color. In feldspars some +3 aluminum substitutes for +4 silicon in many of the silica tetrahedra. It's not unusual for ferric (+3) iron to substitute for some of the aluminum. It may have also to do with the style of alteration of the plag, which in thin section is brown, hence possibly including hematitie….Quien sabe? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435728791080-WU5FZBMMDW81UVNCXTC5/Panoch1inter.jpg Geology - Corcoran Clay in Tulare Formation This scene along the road to Mercey Hot Springs is arresting owing to the blue color of the fine-grained sediments, probably imparted by reduction of iron oxides in reducing conditions of the Pleistocene lake mud. The Corcoran includes a bed of the 774 ky Bishop Tuff, and that bed ought to be somewhere near the base of this exposure. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435728834630-IGLAK436F142XOE32KB8/panoch2inter.jpg Geology - Corcoran Clay A closer view of the beautiful blue-clay badlands of Pleistocene age along the road to Mercey Hot Springs. These are lakebeds. They were originally flat-lying on the floor of the San Joaquin Valley, and tell a story of timing and degree of uplift of the Panoche Range. The uplift was pretty rapid. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1680670164214-52VP0NAKBXAEAN1DUG3M/G+Ridge+4-2-23R.jpg Geology - Glaucophane Ridge, San Benito County Glaucophane Ridge is well-named for its abundance of blueschist blocks. The matrix ranges from serpentinite to siliciclastic, sometimes closely intermingled in excellent melange fashion. This is the structural top of the local Franciscan Complex. It is structurally overlain the Coast Range Ophiolite, which here inlcudes much keratophyre, resembling the so-called Leona Rhyolite along the Hayward Fault in the East Bay—but the latter unit is actually keratophyre of the CRO.. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1680889749673-RB0S18M8TEK6DXN9RK6R/DSC_0387+copyR2A.jpg Geology The melange has countless blocks of blueschist, and occasional eclogite. The lith shown here looks to me as if it might have begun its life as a chert-shale sequence, which then went far down the Franciscan subduction zone, where it was converted metasomatically mostly to glaucophane, and intensely folded in a ductile environment. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435711103295-PW6Q38R2WEKU15GYU7J0/Glaucophane+RidgePSsmall_edited-1+copy.jpg Geology - blueschist metachert This thin section is from a pebble in Franciscan-derived alluvium along the road to Mercy Hot Springs. This crossed-polars view shows glaucophane wrapping around a garnet (the latter black), and quartz grains with sutured margins. It is often thought that basalt is the main precursor of blueschist, but here the rock is too quartz-rich to have begun as a basalt, and the parent rock was probably chert. Sutured margins and undulose extinction suggest the quartz was subjected to great pressure. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435711121217-IE7JH07J83UWREW594V9/GlaucophaneRidgePPLpssmall_edited-1+copy.jpg Geology - blueschist metachert This plane-polarized image of the same view as the preceding (the pebble from the road to Mercy Hot Springs) shows the characterisitc violet-blue color of glaucophane in PPL. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707261159411-40USLEXH6K41HFE5JNHT/Cantu.jpg Geology - Cantua Oaks The late Eocene Kreyenhegan Shale crosses Cantua Creek near where the real Joaquin Murietta had his headquarters. We are looking to the east, and the creek is a bit to the south. The siliceous shale of the Kreyenhegan contains a lot of pyrite, which oxidizes to make sulfuric acid. This soil is thus nearly as acid as that of the pygmy forests in Mendocino County. This acidity dramatically reduces the ability of annual grasses to grow here. Consequently protected from fire, the oaks (and a few junipers) thrive. The oak is Quercus X alvordiana, a hybrid between Q. johntuckeri and Q. douglasii. The association is completely anomalous as there are no other trees anywhere else in the landscape. The sulfur in the pyrite gets replaced by selenium, making iron selenite. The Kreyenhegan is one of the main sources for the agriculturally concentrated selenium that poisened Kesterson Reservoir. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707260168165-8T70VO4NBODXEHCT88YY/viewNfrom+Big+Blue--bestR2.jpg Geology - view north from the Big Blue Hills View looking north, scan from an old slide. We are standing atop the middle Big Blue Hills in western Fresno County. This is a classic sequence of Tertiary rocks. At far left are cliffs of Domengine Sandstone. In the middle the nearly white strata are siliceous Kreyenhegan Shale. Next to the right is a thin band of Temblor Formation, and overlying that at far right is the Big Blue Formation, a chaotic mixture of bedded serpentine sandstone with blocks of serpentine breccia and Temblor sandstone, the result of megalandslides (olistostromes) coming off the San Benito Mountain highlands in Miocene time. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1710914322330-TQIEAIW3RSHBVZ9GPK54/Amsickia+verni+view+southR.jpg Geology - Tumey Hills, western Fresno County Clothed in March 2019 in the loveliest of fiddlenecks, Amsinckia vernicosa. I will show a very interesting outcrop in the ridge in the distance. View south. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1710914351325-P5YUTE26HX5IR7F4GFND/ssdike%26sill+in+Tumey+ShaleR.jpg Geology - Tumey Formation injectite The mostly Oligocene marine Tumey Formation has a lower sandstone member and an upper of mudstone and shale. Here sandstone has intruded the shale as both dike and sill in one. These sedimentary intrusions formed the plumbing for seafloor coldseeps with distinctive communities of organisms. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1699409403960-PD27OME8L7LB7Q7IX2JL/Povert+Flat+ss+at+type+localityR.jpg Geology - Poverty Flat Sandstone of Bartow et al. 1985 Here south of Orestimba Creek, this mid-upper Eocene unit is at its type locality, Poverty Flat. The unit here is very gently dipping, usually 10 degrees or less. It is underlain by the much more steeply dipping middle Eocene Kreyenhegen Formation. The Sidney Flat Shale at Black Diamond Mines has been referred to the Kreyenhegen by Dibblee. The upper Markley which overlies the SFS there is thus probably correlative with the Poverty Flat SS. Fossils suggest they are the same age. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1699584349722-INED3CAGD0UTBNWXIQ70/Pov+%3FkaoliniteR2.jpg Geology - Poverty Flat SS thin section This was taken in PPL with the 4X objective. The thin section has no plagioclase or any mafic minerals. It seems to be largely composed of quartz grains—unusually sharp ones. There may be some Kspar there, but my rig can’t get interference figues on grains this small. The brown crystal complex with only one cleavage is a clay mineral, probably kaolinite or a related highly aluminous clay. All of this suggests long weathering in a subtropical or paratropical environment. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1699584437794-7IDFO8RSGN46MDOWUGVC/Pov+Flat+glass+shardsR.jpg Geology - Poverty Flat SS glass shards This was taken in PPL with the 10X objective. One can see several glass shards near the center of the image. In XPL these are completely isotropic. These may have come from erosion of one of the ash-flows tuffs erupting in NE Nevada at the time, or from an ash fall. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1621213034177-O708T4A2IKC4XO68TCMU/OrestimbaVSR.jpg Geology - Orestimba Creek "Valley Springs" Here in the low hills flanking Interstate 5, Bartow and Lettis mapped a tuffaceous unit they referred to the Oligocene Valley Springs Formation, which in the Sierra is an ash-flow tuff that stormed down paleocanyons from an eruptive center on the Nevadaplano. This was part of the mid-Cenozoic “ignimbrite flareup” that produced many giant Yellowstone-like calderas in Nevada, as the suducting slab at depth withdrew westward from its shallow position during the Laramide orogeny, thus steepening, and leaving in its wake an extensional regime that allowed magma to rise. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1621213058151-6UKMFMS9XWZT4GGPBN7R/OrestimbaValleySpringsR.jpg Geology - Orestimba Valley Springs vitric tuff This combines two views in PPL with the 4X objective. Seeing this was like walking into a hyaena den—nothing but bones! All you see are glass shards and glass chunks with vesicles in them, and fine matrix between them that my scope can’t resolve. Note the chunks with vesicles have conchoidal fractures around those holes. Chris Henry told me a tuff he collected there that may be this one was dated at 30.36 my, which is the same age as the intracaldera tuff of Deep Canyon in the Clan Alpine Mts of west-central Nevada. That caldera is probably the source of this tuff. How did it get across the marine basin filling the San Joaquin Valley? Andrei Sarna-Wojcicki has speculated that the nearby Stockton arch may have been above sea level at that time, giving paleo river valleys closer access to this site. The rest would depend on currents. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1621213078286-T8O718QXLDSC34L5PW0E/Tesla%2BValley+Springs2R+copy.jpg Geology - Del Puerto Canyon Valley Springs Bartow and Lettis also mapped their Valley Springs Formation low in the sequence of strata making up the face of this ridge, seen looking north from Del Puerto Canyon Road. Downsection is the early Eocene marine and non marine Tesla Formation. Up section from the Valley Springs, and composing most of the section in the cliff face, is late Miocene conglomerate, sandstone, and siltstone that does not have a formational name on their map, but would correlate with strata a little northward, from Ingram Creek north to Corral Hollow, that are medial to late Clarendonian in age, so-called owing to their fossil mammals of that age. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1612423822283-JXXT2ZA1BJ7GRS4NR7XH/plag+dike.jpg Geology - Del Puerto plagiogranite This very siliceous intrusive rock is an uncommon element in the Coast Range Ophiolite. The ophiolite is best observed in Del Puerto Canyon. Plagiogranites usually form in oceanic settings where there is partial melting from a basaltic magma, combined with major hydrothermal action. The rocks typically have abundant plagioclase and quartz, but no potassium feldspar. The dike is cutting through keratophyre and gabbro, https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1612423875287-JSNSL62WDFSLEJ8FFKZR/plagio.jpg Geology - Del Puerto plagiogranite, closer https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1547964272036-W2Y634X3PMFSA4B1CU4B/dpc2.jpg Geology - Del Puerto plagiogranite 2 This thin section is shown at low magnification in XPL, with the accessory plate inserted. The last bit is the important one here. It means I’ve enhanced the colors to make some elements more visible. The big blue thing at left is a quartz phenocryst. The rest is a coarse groundmass (typical of dikes), which in this case is a granophyric mix of quartz and plagioclase that crystallized simultaneously and ended up all entangled, because there was not time to sort themselves out. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1547964337400-J8WJEDVYBM8R66RCF5D4/pl-grdpc1.jpg Geology - Del Puerto plagiogranite 3 Here’s that granophyric groundmass more magnified . Maybe the inventor of tie-dyes had taken a course in optical mineralogy. The outcrop of the rock along Del Puerto Canyon Road does not arrest passers-by with its beauty or magnificence. If only they knew what wonders are hidden within! And what infinitely deeper wonders beyond! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1612424552141-XTTL778U1TTTOUC4CEZG/cols1.jpg Geology - Del Puerto keratophyre part of the Coast Range Ophiolite. Keratophyre is an albitized intermediate rock erupted on the seafloor. The bluegreen is probably from a combination of chlorite, epidote, and reduced iron oxides. This felsic rock is analogous to spilite, which is alblitzed seafloor basalt. In each case the calcium of plagioclase has moved into epidote and been replaced by sodium from sea water. Note the upper flow is columnar-jointed. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1612424579065-Q9A3JTJZG641PTLTYL3D/cols2.jpg Geology - Del Puerto keratophyre a closer view of the columnar jointing https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1612424603206-94E1351F8Q99A2IKYE9P/kerato.jpg Geology - Del Puerto keratophyre The bluest parts look like this. Most of the rock is grayer. Weathered parts are ochreous. This rock resembles the “Leona Rhyolite” of the East Bay, which is, again, a keratophyre and part of the Coast Range Ophiolite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1615935661242-AEW1RQE2Q9VJCAPP760N/keratcomboR.jpg Geology - Del Puerto quartz keratophyre Upstream a bit from the bluish keratophyre outcrops, there is quartz keratophyre. This is the seafloor volcanic equivalent of plagiogranite. This combines two views of one thin section in XPL with the 4X objective. At left are two quartz crystals, in the middle is calcite with extreme interference colors and twin lamellae, and at right is chlorite with its characteristic beautiful anomalous blue interference color. The groundmass seems to be mostly plagioclase but it is beyond the resolution of my scope. Albite twinning is not evident, probably because it tends to be absent in metamorphic rocks, and because these crystals are highly altered. What you see are the classic minerals of quartz keratophyre. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707790722100-X9CVSXPH27EO7KXCQ2W5/San+Pedro+Pt--Ryan3.jpg Geology - Paleocene marine San Pedro Fm. at Devil's Slide These strata consist mostly of deep-water turbidites. This formation unconformably overlies granitic rock of Montara Mtn., and is considered part of the Salinian block. A wonderful photo on the “beach” below Devil’s Slide, shot by my colleague Ryan Fay. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707790749617-SQ9KI1NC2J2EX8J129GC/soft-sed+def--Ryan.jpg Geology - classic soft-sediment deformation in the San Pedro Formation …again, below Devil’s slide, and found and photographed by Ryan Fay. The wildly deformed part looks like sandstone (gray) with thin beds of limestone (white). Classically, sand is more porous than the muddy sediments deposited on top of it. The weight of the muddy sequence squeezes water out of the sand, in the process deforming it. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738302362579-CSDYDGQTF6SJ1WEOG6OO/Rocland+Ash%2CMerced+Fm.+Fort+FunstonR.jpg Geology - Rockland Ash in type section of Merced Formation This tuff was erupted ca. 570ky from near Lassen Peak, acc. to Doris Sloan. Below it, at ca. 620ky, there is a transition between locally derived Franciscan grains below, and Sierran grains above—-marking the making way of the “California River” from the Sierra to the Bay Area. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611459025782-7DAA10NMWY4FMUIKOE0F/TenesseePoint%2Bintermps2B.jpg Geology - Tennessee Point pillow lava Perhaps the most breathtaking place anywhere to observe pillow lava, in the most spectacular form. Don’t the pillows look like a herd of walruses climbing up out of the surf? Stratigraphic up is to upper right in this view, based on the convexity of pillow tops. Paleomagnetic studies show that these Franciscan seafloor rocks traveled here from somewhere near the equator. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737943552098-ZLDYYSPLX177ANFD8W05/TennseeP+t+pillow+copy.jpg Geology - cross section of a pillow …showing radial jointing. This was at Tennessee Point. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1670889671960-9BSEM71PEIKBVKAXSRIB/DrakesW4R2.jpg Geology - basal Purisima Formation, Drake's Bay Alan Galloway mapped this as the basal member of his Drake’s Bay Formation, which since his time has come to be recognized as Purisima. The basal member here is glauconitic, hence the striking greenish color. The basal unit here is bouldery with granodiorite blocks, denoting that uplift of the Chimney Rock-lighthouse granodiorite spine was underway by Pliocene time, shedding blocks into shallow marine waters. The dip of the Purisima is quite steep, here on the south flank of the Mendoza Syncline, suggesting ongoing uplift by the Pt. Reyes Fault, a large thrust fault offshore west of the lighthouse. The very west end of Drake’s Beach, shown here in a scan of an old slide, is generally not accessible now, as it has elephant seals in occupancy most if not all of the year. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725744494969-KYBCUS7D53ILIHD5LCLW/Laird%2Bgranodioriteat+KehoecroppedR.jpg Geology - Laird Sandstone + at Kehoe Beach This panorama shows early Miocene marine Laird Formation sandstone faulted over a horst of Cretaceous granodiorite right center; the cliffs become all granodiorite ( and some schist) at far leff. Out of the picture to the right the Laird overlies Monterey Formation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1725744521801-8Y6EFWQ75IP30VDOJGKT/Laird+SS+c%3Bleaner.jpg Geology - Laird Sandstone in fog This closeup of Laird Sandstone shows many differentially cemented layers. I find the Laird very beautiful. The fog in the scene adds some sense of haunting, and there's a bit of magic light, too. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1752361385110-1YNQ2VDPH6QAC3ECL8RK/Laird+fold+in+magic+lightR.jpg Geology - fold in the Laird sandstone, closer view …in magic light, too!… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1752361435906-MAC9P8Y4GC22RGB2HV7T/looking+NW+from+N+end+of+KehoeR.jpg Geology - looking NW toward McClures from N end of Kehoe The sky turned blue before dark. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1634866188196-624YSTDOU94ISO1SQWRA/kehoe2R.jpg Geology - dikes at Pt. Reyes A closer view of the abundant aplite and rare pegmatite dikes, just south of the previous view. This spectacular complex is in the northern granitic headland of Pt. Reyes peninsula. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1652666421423-GFDBNIGZGLV7DLFXAVQQ/McClures1R.jpg Geology - Quaternary beach deposits at Pt. Reyes These furruginized sands are uplifted Quaternary beach deposits. They are not cross-bedded, therefore not dunes. At left is granodiorite basement upon which the old beach sands rest. The sands have plenty of red chert grains, but also granitoid grains, so it appears they were in a position to receive sand from two sources. That is puzzling. The Pleistocene stream that came down to the ocean where Tomales Bay is now, received sediment from Salinian on Inverness Ridge to its SW, and Franciscan from the ranges to its NE, as demonstrated in conglomerate at Millerton head. This may have been part of the conveyor belt. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1745174676042-961E0PVZZMLAGUQI6CHN/si-ca+rx+on+Blue+Rock+Spring+Riudge.jpg Geology - silica-carbonate rock NE of Vallejo Strangely, Graymer, Jones and Brabb 2002 mapped this whole ridge as serpentinite. But the side facing Vallejo and the crest is all silica-carbonate rock. There’s a little serpentinte on the NE side of the ridge, and a lot more Si-Ca rock. This is part of the Coast Range Ophiolite, basement to the Great Valley Sequence. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1682372265411-4LQ5QT82QL79BTQ0M7ML/Syat+betterRsharper.jpg Geology - Syar Quarry near Vallejo This gradually disappearing wall is mostly pillow basalt. It is part of the Coast Range Ophiolite and it is associated with serpentinite and slica-carbonate rock. The light “veins” mark fracture zones, highly altered, probably the result of hydrothermal solutions following the fractures and degrading the basalt. This may be the largest exposure of pillow basalt in North America. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1665430712243-REG2KSH5QL802SFKFS2L/SYARpillowWallR.jpg Geology - closer view of the grand pillow wall at Syar Quarry between Vallejo and Benicia. The largest display of on-land pillow basalt on earth? Scan of an old slide…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608499068075-MDSXP0ALGKKXBQC8I0DY/syar%2B036ps%2Bcopy%2B2.jpg Geology - Syar Quarry pillows A very small part of the massive agglomeration of pillows in the Syar Quarry wall https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1665430739670-MXQLG5H1GRD0WRZDFS4C/SyarALT+zonesR1.jpg Geology - closer view of the alteration zones The quarry manager kindly drove me there and collected samples for me while I watched. It was very suprising to discover that the light-colored, crumbly and more erodeable dike-like zones are merely basalt that has been intensely hydrothermally altered. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608441338295-Q34UB86LSDAA1FT8V8T8/DSC_0447psRED.jpg Geology - spherulitic smectite A thin section of the hydrothermally altered units in the Syar Quarry preserves abundant plagioclases of the original basalt, so they are not vein fillings but alteration zones. Included are many of these orb-like bodies, which are probably vesicle fillings. Details with next photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1608441361897-TQ6SY5HWG3L0BHILVHKV/DSC_0411ps2RED.jpg Geology - spherulitic smectite Here is a magnified part of one of the orbs, in XPL. The orb consists of many smaller spheres packed together, though these have fan-like sides. R. Zierenberg at UC Davis convinced me that these are made of a clay mineral in the smectite group, which commonly fills vesicles in metabasalt. Since these infillings seem to be very well preserved, I’m guessing the last hydrothermal event replaced any former vesicle fillings with the smectite. What lovely entities can be found in hydrothermal settings! The fracture alteration zones were a crumbly, soft, white to light gray clay-like material. I was surprised to find it dominated by residual plagioclase from the basalt that was so dramatically altered by hydrothermal solutions. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1727036287261-J1T9X1H73R8FO6CBUOUS/Ring+MTN+eclogite+%2B.jpg Geology - most beautiful rocks in the world This shows garnet glaucophane schist wrapped around eclogite. At a location I won't disclose in Marin County. There are too many morons ready to hammer this lovely rock to as many small pieces and they can get and sell. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1683252048846-EPCPPHW6LAULS6VIWV1Y/Ring+MTN+garnetite+5-14R.jpg Geology - Ring Mtn garnetite layers I could not resist the sheer beauty of this rock. The colors are real, not photoshopped. I wish the resolution was better, but I was not carrying the proper camera for macro resolution. No matter; one can still worship the beauty of creation (and the Creator) through this rock. Glaucophane schist is not infrequently as deep blue as what you see here. The layers of concentrated small garnets can be called garnetite. I will not divulvge the location of this block. There has been geologic vandalism even in affluent Marin County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706399193659-P959P85DCL1VXIBYRHND/Goodyear+Q+X+680R.jpg Geology - Goodyear Road quarry, Benicia This abandoned quarry, seen looking north across HWY 680, has wonderful, but generally overlooked, geology. The base of the 4.86 Ma Lawlor Tuff is close to the freeway, and I’m standing near the top of that tuff to take this photo. There are at least two more siliceous tuffs downsection from the Lawlor at the quarry, so far undated with no chemistry yet studied. They are separated from the Lawlor by basalitc breccia and much more. One may speculate the the great thickness of Lawlor here may have been increased by a splay from the Concord-Green Valley Fault running more or less along the freeway—about which more later! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706399223061-XX83Q5CSMDWSVJ714PAD/subjacent+Tuff+copy.jpg Geology - top of the Lawlor on Lopes Road, Benicia This is what I was standing on to take the previous picture. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706399246519-QE1TJO5XUQ3P6K7H3K3Y/fiamme+copy.jpg Geology - fiamme at top of Lawlor on Lopes Rd., Benicia This is at the very top of the Lawlor south across HWY 680 from the abandoned Goodyear Road quarry. There is a basalt flow overlying the top of the Lawlor here, just a few feet above this picture. The basalt baked and compressed the underlying tuff, transforming pumice clasts into elongate lozenges of black glass. Andrei Sarna-Wojcicki saw these decades ago. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706399285966-U2L2HZ4ARYBT3ZKLKJSX/Lopesvs+Bailey+flow+bandingR.jpg Geology - flow banding in two "basalts" On left is the “basalt” of Lopes Road, directly overlying the Lawlor Tuff. On the right is the “basalt” along Bailey Road near Clayton in Contra Costa Co. These are the only two mafic lavas in which I’ve seen this striking oxidized flow banding. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706399309687-2B21NTOCZY9SFKEF1YYC/basalts+cfR2.jpg Geology - two "basalt" thin sectons On left is “basalt” of Stoneman Park at Pittsburg in eastern Contra Costa Co., which is the same unit as that along Bailey Road. On right is the “basalt” of Lopes Road, Benicia. The photo of left was shot in XPL with the 4X objective. Right photo was shot in XPL with the 10X objective. These two mafic lavas are very similar petrographically. The Stoneman Park flow appears to be stratigraphically directly above the Lawlor. I suspect that a splay from the Concord-Green Valley fault may have delivered the “basalt” of Lopes Road to its northerly station. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1594365675037-KG69AV454FB56AW0OU85/riebeckiterhyolite1ps3cropped2.jpg Geology - the famous riebeckite rhyolite of Sonoma County This lovely stream-worn rock in Adobe Canyon is a rhyolite that is clearly flow-banded. Additionally, the matrix between clasts, which were flattened while hot and plastic, flows around the clasts on a micro scale. The beautiful color is from a combination of blue riebeckite, a sodium-rich amphibole, and green aegerine, the sodium-rich end member of the augite series. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748237837704-F0A2KCX0E4R47XNX0VQE/riebeckite+rhyolite+breccia.jpg Geology - riebeckite rhyolite breccia …in Adobe Canyon, close to the preceding… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1748390012166-1L6OL3GYEPLLSXD083WY/Adobe+Cn.++BEST-R.jpg Geology - Adobe Canyon riebeckite rhyolite …heavily oxidized, hence BEAUTIFUL.. The matrix shows a HOST of tiny bue xtals of riebeckite, and green xtals of aegerine. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1612047937905-0JYXLAPHZTQNVKVM5TDH/Lovejoyfloat2.jpg Geology - Lovejoy Basalt These huge blocks tumbled or slid out of place on the east side of Drake’s Point, east of Pleasants Valley in Vacaville. They are composed of columnar basalt that erupted about 15.4 my ago from a fissure on Thompson Peak in the Diamond Mountains NE of Sierra Valley, and flowed more than 240 km to get here. At ca. 150 cubic kilometers, this is the largest known eruptive event in California’s geologic history. To flow this far, the basalt must have been roofed over with an insulating layer of chilled lava. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1613703594619-T4BXACIJ8NQKMFKR9MQP/Drakescolumns1.jpg Geology On the the summit ridge around Drake’s Point the basalt is in place. The columns are small in diameter but this old quarry face suggests a flow about 80’ high. Of the many flows that came out of the fissure at Thompson Peak, only two made it to Vacaville, but at least one still had considerable thickness. The Lovejoy also caps South Table Mountain at Oroville. Many years ago I had an XRF study done on the basalt at Putnam Peak, a bit north of Drake’s Point, and the basalt at Oroville. They XRF said they had a single source. The basalt here and at Putnam Peak, a bit to the north, are overlain by Neroly Formation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1612058095002-364GY5W82Z6L68ZGN88K/table2a2RED.jpg Geology - Oroville Table Mountain This is Lovejoy Basalt on Table Mtn near Oroville. The Lovejoy physically and chemically resembles flood basalts of the Columbia Plateau, and is the same age, suggesting a connection to the mantle plume that initiated the Yellowstone hotspot track. Here on Table Mtn the landscape is dominated by ridges of exposed basalt talus alternating with vegetated swales—an amazing sight to see with Google Earth. The wave-like appearance has been explained by slowing of flow as the basalt emerged from paleocanyons onto the more level Sacramento Valley surface. Its cooling upper surface was compressed and lifted by inflation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1617519255556-47HHVWS4CTPJ3AN85HAH/DSC_7605+copy2R.jpg Geology - Putah Creek block Here is one huge block of Lovejoy basalt that tumbled all the way from the ridge top far to the north, into the bed of Putah Creek. We are looking at the ends of columns. The blocks tend to roll like giant logs, as clusters of columns, so the columns tend to end up on their sides. Isn’t it BEAUTIFUL? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1677035792559-VDPHVDLJ9F7M741BZYJD/Lovejoy+striation+cfR+copy.jpg Geology - striations on Lovejoy Basalt columns left 2, from near Vacaville, the southern terminus of the flows; right 2, from the type locality of the Lovejoy along Red Clover Creek, far to the north in Plumas County. These are small fragments of columns, displaying “striations” that are common at both localities. Basalt columns cool from their tops down, but episodically, not continously. The episodic parting of the columns forms these fascinating ridges. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1618552721831-NTJRLLAWQXZ834Y8CEV4/HWY128.jpg Geology - Putah Tuff along HWY 128, Solano County The Putah Tuff forms this entire cliff along HWY 128 east of Lake Berryessa. It erupted 3.36 my ago from the caldera, some remains of the infill of which form Mt. St. Helena today. This eruption is thought to have been one of the main caldera-forming events. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1618552743387-AC88XFZYP1XBTWYOUKKB/Putahcombo3.jpg Geology - Putah Tuff in two varieties The Putah Tuff is contained within the lower part of the fluvial Tehama Formation and is sometimes reworked, sometimes clean airfall. At left is Putah tuff in the form of a mudflow from along HWY 128. At right is arifall from along nearby Pleasants Valley Road. The tuff covered a wide area of the western U.S., and has been located in Death Valley as well as in Fish Lake Valley, west-central Nevada. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766192365384-8YHQ2ZYZD9627RM7SCLG/Venado-ss.jpg Geology - Venado Sandstone at Monticello Dam This sandstone is Upper Cretaceous age. It can be traced hundreds of km. eastward where it finally rests on Sierran basement. It’s mostly deep-water turbidites. The GVS is homocline; what looks like the east side of anticline at left is deceiving—it is just the effect of gravity, which can move MASSES of rock down slope. West of the dam there’s a megabreccia that John Wakabayshi (2025) interprets as an olistostrome… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766269032211-H4XVKSQAL0MVHUIZR615/GVS+w.+of+MonticelloR2.jpg Geology - GVS west of Monticello Dam The evident dip to the east strongly suggests there is no anticline in the previous photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1682127590476-19ONJDV9PITO3D6JRPBU/Napa+tuff+comboR.jpg Geology - Tuff of Napa, plus? This is a view looking northerly from the western part of Monticello Road, where it makes its descent to Napa. The exposure shows the gentle westerly dip that descends from the escarpment in the previous picture. To the right is an outcrop of the informally named Tuff of Napa, Ar/Ar dated between 4.70 and 4.71 Ma. This outcrop overlies the exposure at left. The latter may be Tuff of Napa also, or it could be the older Huichica or Lawlor. In any case it is apparently reworked. It’s risky going down there as there is a shooting range there. The right hand picture showing the Tuff of Napa demonstrates that the caldera that produced this tuff (plus the Lawlor) was very close by. In fact it is just west of the west base of Mt. George. These large clasts make the lithology look like a breccia, but every piece floats in water. Although they don’t look like classic pumice, that’s essentially what they are, only the pores are too small to see with the naked eye. This is an airfall deposit very close to its source. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1622613698374-QUJYPC4ZKXG2IDY0KZMH/PCRquarry1AcopyR.jpg Geology - Pope Creek Breccia , Napa County This dramatic breccia apparently consists largely of mafic clasts with their edges rounded, but angular clasts predominate in places. There is very little mud matrix. Instead there are tightly packed smaller clasts between the larger ones. This is near the base of the Great Valley sequence west of Lake Berryessa. I imagine a seafloor with much topographic relief owing to proximity of a ridge to the west, uplifted by underplating, and exposing ophiolite. Rocks in the high ground broke and tumbled down in submarine landslides to create this unsorted mixture of clast sizes and shapes. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1622613718999-M123ULXDSX2Z0MYOSBHO/brecciacombo1R.jpg Geology - Pope Canyon Road quarry Here are a couple of views of the breccia shown in landscape view in the previous photo. I made a thin section of one clast that looked superficially like sandstone. It turned out to be a metabasalt of greenschist facies, dominated by rotted plagioclase, and also by mafic crystals, the latter probably beginning as pyroxenes but almost entirely altered to chlorite and actinolite. There were also plenty of opaque oxides. So it was a mafic clast, not sandstone, but a peculiar desert-varnish-like layer coats the clasts and conceals their identities in superficial view. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1681444505152-Z79AMX582X5766TMH0T3/Pope+Ck+Breccia+blockR.jpg Geology - Pope Creek Breccia block At first blush it looks like cemented talus. And, although the clasts look like sandstone, they are actually mafic volcanics. The most acceptable hypothesis for the formation of this unit is from basalt cliffs in an extensional setting above a subduction zone. Alternatively, strike-slip motions could have been involved, but also above a subduction zone—or coinciding with it… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1645344739762-TKZZWDTHLZ9SOZKFLZCK/dikes4R+copy.jpg Geology - Pope Creek Bridge sheeted dikes These sheeted dikes are overlain by the Pope Creek Breccia. They are part of the Coast Range Ophiolite, exposed dramatically here just upstream from the historic Pope Creek Bridge, which is on an abandoned side road just downstream from the quarry. Sheeted dikes are rarely exposed in California, which is surprising as the outcrop of CRO in total covers a vast area. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1710541160330-G54AB6I1Z74VJTUKZ8K4/Pope+CK+pillowsR.jpg Geology - pillow basalt along Pope Canyon Road …in Napa County. These occur in large blocks surrounded by Franciscan melange. The ultimate origin of these large blocks could have been Franciscan or CRO. Geologic relationships are complicated here, and all the land is posted. Left, a picturesque outcrop above the road. Right, a place where individual pillows have escaped their bedrock and are sliding into Pope Creek. Both sites are between the mouth of the creek and the Pope Creek Bridge with its sheeted dikes. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1626763626181-N9745YQLJMAMCAQT47UK/MystV.jpg Geology - Mysterious Valley Formation This is a sedimentary melange with mostly serpentine matrix, at the mouth of Pope Creek where it enters Lake Berryessa. Three large knockers are in view, one of them across the lagoon. The one at left is metachert. The mass at right is becciated amphibolite, a high-grade metamorphic rock. Across the water is a giant block of argillite. The origin of this unit is debateable, but I think a giant serpentine mud volcano, tapping the top of the Franciscan subduction zone via faults through the overlying mantle wedge, may provide the best explanation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1626763646754-OD5I2DTL0IZYUPWXJ3W4/feldspathicamphibollite.jpg Geology - amphibolite block There are numerous smaller blocks of this material, which looks superficially like metagabbro, lying about the landscape in the previous photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1626763667388-48Q99QUSIJEH0VS1WTO0/pope+creek+amphiboliteR.jpg Geology - amphibolite thin section This view in XPL with the 4X objective shows part of a thin section of one of the blocks like that in the preceding photo. These are not pyroxenes, so this is not gabbro. There are thicker layers of hornblende, as seen here, and thinner layers of highly altered and comminuted plagioclase. That makes this a feldspathic amphibolite. It is a fairly high-grade metamorphic rock, probably plucked into rising serpentinite from crustal depths ca. 25 km. I have read that there are rare blocks of blueschist in the formation. I think one should visualize a very large serpentine mud volcano on the floor of the forearc basin, very early in the basin’s depositional history. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1647055216228-GZABFFZ4HH7L2QPXT7ZF/titanite2R3+copy.jpg Geology - titanite with rutile cores John Wakabayashi studied the amphibolite in the preceding photos. He found titanite cored with rutile. In mafic rocks, rutile is a good indicator of very high pressures. This supports the idea that a serpentine mud volcano scavenged directly from the Franciscan subduction zone. The lozenge-shaped crystals in this PPL view with the 10X objective are titanite. I think some of the inclusions here are rutile. The surrounding larger crystals are hornblende. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1645427547108-HB5S4RJH2CBDGXX4Q5KU/amphibolite2+copy.jpg Geology - Pope Creek amphibolite breccia Much of the amphibolite in the knockers at the mouth of Pope creek is brecciated like this piece. I’m guessing the matrix, which is harder than concrete, is comminuted amphibolite. The brecciation, according to John Wakabayashi, is tectonic. John has found that the amphibolite is rutile-bearing, and high pressure, equivalent in grade to Franciscan high-grade blocks; but here it is in olistostromal or serpentine mud volcano deposits in the forearc. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706494481053-IA5A75POH276IQ0XHL0N/metagabbro2.jpg Geology - metagabbro block in Mysterious Valley Formation This block is in the woods across the channel south of the amphibolite and chert blocks. It’s greenschist facies metagabbro. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1706494509128-RIXD17CXIRYXZPDEPTQB/Pope+CK+metagabbro+blockR2.jpg Geology - Thin section view of the metagabbro block The bright blue and green blocky xtals are cpx. The long grayish rectangles are highly altered plagioclase. The orange and blue starburst of needles at bottom center is actinolite, with some of the needles ovegrown over anamalously dark brown chlorite. This might have been a blueschist facies rock before it became greenschist facies, but I can find no remnant of the former facies—so maybe not. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1657585343260-FN2O54DY3MIYLMQEB2XC/SnellVrimrockR+copy+2.jpg Geology - Snell Valley, NE Napa County This famed valley for wildflowers is flanked to its north by this crudely columar-jointed dacite lava far-traveled from its source in the Mayacmas Range to the west. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1681444542273-RWG1DQ22MLAMGXDN8ERE/Snell+dacite+cliff.jpg Geology - Snell Valley dacite flow showing crude columnar jointing… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1681444576166-3K7E97SNV2U3T0SFUP2C/Snell+dacite+combo1R.jpg Geology - Snell Valley dacite flow macros There are many hematite- plus calcite-filled lithophysae. The right hand photo shows a quartz crystal near the middle. This flow has been mistakenly referred to as basalt, even olivine basalt. It is not. There is no olivine, but there is lots of quartz. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1657585366843-IP996NB54L2HWL7QBA0Q/SnellTSbest.jpg Geology - Snell Valley dacite thin section This view, in XPL with the 4X objective, shows a quartz crystal at lower right. There are plenty of quartz pheoncrysts in the section overall. There are also sanidines. The reddish amber mushroom-like entities seem to be goethite, grown secondarily with the adjacent calcite, from the same low-temperature fluids. Many of these oft-repeated associations are filling vesicles. Robert Zierenberg at U.C. Davis figured all this out, after I and all my other experts were stumped. The gray rectangular crystal with super high relief, mostly embedded in the calcite, is an unknown for me. There are a lot of these crystals, often embedded in calcite and associated with the goethite. I was unable to get interference figures, and extinction angles were ambivalent. It could just possibly be titanite, which has extreme relief and is often in felsic igneous rocks. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1707770906893-0R6GFHR8878F7W0MQZA3/Mt.+St.+Helena+from+west-sharper.jpg Geology - Mt. St. Helena, Napa County …viewed from the west, north of Calistoga… Donald Sweetkind and others have demonstrated the mountain to be an erosional remnant of the infilling of a silicic caldera, composed of numerous tuffs but also collapse breccias from the walls. Andrei Sarna-Wojcicki believes that eruption of the 3.27 Ma Putah Tuff was probably the caldera-forming event. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1653289964777-GQW1T4KTAVPQ8J8MMDEY/Hunting+screeR.jpg Geology - Hunting Creek scree, Napa County ultramafic scree slopes near Knoxville in Napa County, habitat for Eriogonum nervulsoum, Asclepias solanoana, and Streptanthus morrisonii, plants that thrive only in the absence of competition. These unstable, calcium-deficient screes eliminate competition. May 2016 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1647157653487-AXO3UDZB6JTX5WVPAAFJ/BVrdsharperR.jpg Geology - view north from Cowboy Camp, Colusa Co. This is a view north from the high peak at the north end of Cowboy Camp in Colusa County, looking out over Bear Valley Road and beyond. HWY 20 is out of view just south of Bear Valley Road. The triangular gray cliff in the center is composed of sedimentary serpentine melange. This is interbedded with siliciclastic sediments of the lower part of the Great Valley Sequence, some of which can be seen as shales and mudstones to the upper right of the gray triangle, and can be examined at the junction of BV Road and HWY 20. Locally the sedimentary serpentinite contains blocks of amphibolite as well as brachiopod-bearing limestone, and forams have even been found in the serpentine matrix. So in this area, and some others, sedimentary serpentinite is actually part of the Great Valley Sequence. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1538198188342-48SSR6GTUOCHIV4759FF/serpsnakesCowboyCampinterm.jpg Geology - Cowboy Camp serpentine snakes Cowboy Camp in Colusa County is notable for a serpentine area that includes blocks of massive serpentinite shot through with veins of chrysotile that really do look like snakes. Is this how serpentine got its name? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654986320927-48RGYM7NVQV2LCJCLCLE/marble+canyonR.jpg Geology - Cowboy Camp, Colusa County Looking west from the BLM overlook off HWY 16 near its junction with HWY 20. The ridge here is all or almost all sedimentary serpentinite within the basal Great Valley Sequence. The massive volume of this deposit is amazing. But the ravine in the center is of special interest. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654986347713-8OQQ7J4OUO3J7RBA7ICL/Cowboy+white+blocksR2.jpg Geology - Cowboy Camp ravine This is a closer view of the ravine in the preceding picture. Lots of blocks! The white ones caught our fancy. They looked superficially like marble—but wait! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654986379245-ZKSX55KX1UXI26JNVUX1/Cowboy+white+block+macroR2.jpg Geology - Cowboy Camp macro of white block On closer examination, it still looks like marble—but wait! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654986403941-MZETL3ZQ26NJCC2APZZH/Cowboy+Camp+white+blockR3.jpg Geology - Cowboy Camp white block thin section This view in XPL with the 4X objective shows what the white blocks really are: essentially gabbro, but leaning toward anorthosite. But wait! Shouldn’t the colorful pyroxenes seen here (among plagioclase, which dominates the rock) appear as dark crystals in hand sample? Not if they are iron-poor diopside, which I think they are. NOT ALL MAFIC ROCKS ARE DARK!! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654986432695-G5T3LGH0RN9HF94XWZEO/405amphiboliteR3+copy.jpg Geology - Cowboy Camp amphibolite or diorite There are rare high-pressure blocks in that ravine. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1654986459007-ENUMNO2RDX9W56J1VLJL/CowboyamphibXPL2.jpg Geology - Cowboy Camp amphibolite or diorite This may be a feldspathic ampibolite, with just a few pyroxenes scattered about. Shot in XPL with the 4X objective. While the gabbro likely originated in the Coast Range Ophiolite, the amphibolite would have from deep in the subduction zone, which was at much greater depth. Both got plucked off into serpentine diapirs or were carried by serpentinite through fractures, either way probably feeding serpentine mud volcanos on the forearc seafloor. Lack of a clear metamorphic fabric argues in favor of this block being diorite, which would have come from the CRO. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610922082793-0LDA9RTPXNRT3ZIPGSJT/Cedars2RED.jpg Geology - The Cedars, Sonoma County The Cedars, north of Cazadero in Sonoma County, is California’s ultramafic Grand Canyon. It’s towering ridges consist of peridotite, dunite, and wehrlite. Roger Raiche discovered several exciting new plant taxa here as well as southernmost range extensions. Then he convinced the BLM to protect the property as an ACEC—all in all, one of the greatest contributions ever by an individual to conservation in California. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610922111648-CMIKIR9ZDAWRGXFZYJO4/CedarsDunite3RED.jpg Geology - wehrlite This thin section was from a sample somewhere high on the ridge in the last photo. The rock looked like dunite, but it contains scattered clinopyroxene, which makes it technically wehrlite. The colorful crystals in this XPL view are olivine. There is a sinuous fracture filled with opaque oxides (black) cutting across it. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1610922139320-V8C1VXMP3JGTA6RLDF2W/Cedarsnorth.jpg Geology - The Cedars, Sonoma County The majesty of the place can be appreciated, but not comprehended, in many views like this, in all directions. Sheer, Martian-landscape scree slopes like this support my favorite of Roger Raiche’s discoveries, Eriogonum cedrorum. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1716446938194-Z3L61I5FV32HCRHGZD6X/cedars+travertineR.jpg Geology - Cedars travertine apron This is a spring that flows with calcium-rich water, hence the travertine apron. This demonstrates that calcium-bearing parent rocks, e.g. lherzolite or gabbro, are still being metamorphosed to serpentinite, which contains no calcium, sometimes at very shallow depths and nearly ambient temperatures. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763332053226-VWZLJELJWN5XF6WNS0ZG/Sutter+Buttes+from+westSHARPER+copy+3.jpg Geology - andesitic domes of Sutter Buttes The peaks are andesitic domes. The strata surrounding the peaks are sedimentary— ” the moat”— ranging from Cretaceous to 1.6 Ma. Part of the rampart beds of andesitic flows & breccias is on the extreme far right. Sutter Buttes is NOT part of the Cascades; but closely related to the Clear Lake volcanics…Sutter Buttes erupted 1.8 to 1.6 Ma….Scanned from a slide… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1763335396544-L5Z83LV3JUV5P2XYPOMU/geol+map+of+Sutter+Buttes-SHARPER.jpg Geology - new geologic map of Sutter Buttes …showing all the features described in the text of the previous image…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1636859283727-07HDEGP4QFY2Q4T2O9ZY/bigstack2.jpg Geology - Huge seastack on Sonoma coast This enormous monolith is on terrace one along the Sonoma coast north of Shell Beach. About 100,000 years ago, it was on a wave-cut platform down in the water, but since then the land has lifted. It is made of high-grade metamorphic rock, in this case ampibolite, that was created in our subduction zone during the Mesozoic. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1636859314449-BGU3EYWVDAU7K4E725BQ/lichen2.jpg Geology - Sonoma seastack up close A closer view of the seastack in the prior photo. The layering is foliation, and the blue is probably glaucophane created by retrograde metamorphism as the block rose from the depths. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1636859345268-OJCM9O8NQ4HQLJ4F6B40/schist+copyR2.jpg Geology - Sonoma coast lawsonite This is a schist, with foliated matrix both bluish (probably glaucophane) and greenish (probably chlorite from retrograde metamorphism of the glaucophane). The porphyroblasts are lawsonite, one of the classic signature minerals of blueschist metamorphism in subduction zones. Lawsonite is calcium-bearing. It can be generated from various calcium-bearing minerals, for example prehnite or the zeolite laumontite. with increasing pressure. Lawsonite is also hydrated, and must lose its water as it breaks down with increasing heat at deeper levels in the subduction zone, producing, for example, anorthite plus quartz. However in certain circumstances it can persist even in the highest (pressure) grade rock, eclogite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1683330943686-AL136L37RY5EWHWQP072/phengite%2BamphiboleR2.jpg Geology - amphibole needles in phengite, Ring Mtn. Here is a a part of another block on Ring Mountain. The needles look to John Wakabayshi to be a sodic amphibole (glaucophane/riebeckite. They are set in a groundmass of white mica, in this case phengite, a version of muscovite with more silica (and less aluminum) than is usual for this species. Owing to the reduction in aluminum content, which is in octahedral coordination, iron and magnesium can be introduced in octahedral coordination to maintain charge balance. So phengite has more silica as well as more cations in addition to aluminum. Phengite is the common form of muscovite in blueschist facies rocks. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1685581930558-74A9PGHPASNSYZRJ38A2/RingMtnHoward5-10-14R2.jpg Geology - lawsonite eclogite on Ring Mtn In a place on Ring Mountain, Marin County that I will not name. The green with red garnets is eclogite, a very high-pressure and also a rather high-temperature rock. The light tan crystals are lawsonite, which is a characterstic blueschist-facies rock, which is a high-pressure but lower- temperature facies than that which produced the eclogite. I surmised that the lawsonite came in with retrograde metamorphism as the eclogite rose to the surface or cooled in place. John Wakabayashi thought my surmise probably correct, as the lawsonite looks like it overgrew the original eclogite fabric. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1744784974387-4IFPJZUAT5OXQ3NA4SLW/Pt+arena+strata+copy.jpg Geology - Pt. Arena Formation …consists of laminated cherts and siliceous sandy shales 14-16 my old…The San Andreas Fault isolates the Gualala Block, of which Pt. Arena is a part. The Gualala Block started in the Mesozoic off Southern California. The SAF dives into the ocean just north of Pt. Arena. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1744785008529-IQKB3QJQQ7DKXNF8RSVU/Pt.+Arena+terrace+1cleanerR+copy.jpg Geology - wave-cut bedrock bench ….south of Pt. Arena lighthouse…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701898800892-MB4IY3B1VPQYK6YCETXY/Laytonville+quaary+overview.jpg Geology - Laytonville Quarry, Mendocino County Shown here is a large block in a landslide in Franciscan melange. The protolith was mostly seafloor sediments that were subjected to blueschist facies metamorphism between 158 and 168 Ma. This is the type locality for some extremely rare minerals, namely Deerite, Howieite, and Zussmanite, after the three illustrious authors of the best manual for optical mineraolgy. Quarrying removed half the block, and untold geological wonders-an act of criminal ignorance. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701898830607-W3VBZ8LZTPP7GB3QB9JJ/Laytonville2.jpg Geology - block at the Laytonville Quarry Shows glaucophane (blue) interleaved with bands of black and white—the former, stilpnomelane and phengite, the latter, mostly quartz. Its beauty speaks for itself. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701898853539-PKVNA3N9S6467CI22GUY/Laytonville3.jpg Geology - another block at the Laytonville Quarry …showing tight folds in glaucophane-quartz-stilpnomelane-phengite… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701898879118-QHW4V9Z78MR3L0KMQ5I6/Laytonville6R1.jpg Geology - another block in the Laytonville Quarry …showing stilpnomelane (black) and white mica encased in quartz (pink)…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701898904691-TXGE5MX5X224ZC41Q00L/Laytonville7R1.jpg Geology - another block in the Laytonville Quarry …showing very colorful metaironstone. The seafloor sediments were Fe-enriched on the seafloor before being subducted. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701655230526-OZVVBCH2B6LSMSWRR859/Scotia+bluffs.jpg Geology - Scotia Bluff, Humboldt County This is part of the shallow marine Pliocene Scotia Formation along the Eel River. It’s an upper member of the Wildcat Group. The whole group strikes NNW and dips NNE, but 70 degrees in the lowest strata, and only 35 degrees here in the Scotia Formation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701655252451-XPEFUL13KPFZRQV36010/Scotia+bluffs2.jpg Geology - Scotia Formation This grand exposure is a bit south of the prior one and dips more steeply. Cape Mendocino is nearby, and one of the most tectonically active regions on the continent. No wonder then that a dip this steep was acquired since the mid to late Pliocene. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1742879127845-Y78Q3SOPZQGGMJ2KWDK0/Pecten+from+Rio+Dell.jpg Geology - Pectin Pectins of various subgenera occur through the entire section of the Wildcat Group at Scotia. This extraordinarily well-preserved one was collected from that section https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701655291960-DLI31QAR73Q1YGIJ4QL3/Agate+Beach+bluffs1R.jpg Geology - Agate Beach, Humboldt County. I’ve always liked this wonderful exposure of uplifted Quaternary terrace deposits, most beach or lagoonal. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701655314030-CU1VFBUK8K4DSU70HAS0/Agate+Beach+bluffs2.jpg Geology - Agate beach terrace deposits A closer view. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701655346118-Z7Q36Y8RBP7X2MYCZBSH/Gold+Beach+bluffs1R.jpg Geology - Gold Beach Bluffs, Humboldt County This bluff is right next to Gold Beach in Prairie Creek SP. It’s entirely fluvial here, though there are some shallow marine sediments farther south. The clast you see in the conglomerate here were sourced in the Klamath Mts., not from Franciscan rocks, which reach only a little bit north of Big Lagoon—well to the south. James Trexler concluded from the source of the clasts and great volume of fluvial sediments here that this represents an earlier course of the Klamath River, from .6-2 MA. The control, he surmised, was tectonic (down-warping). https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701655365928-557RDCP3ZY1QHUZ2JNJZ/Gold+Beach+bluffs2R.jpg Geology - Gold Beach Bluffs, closer view Check out the wonderful crossbedding! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701763614357-W52IDZ0QURP7ZWZMH0M9/diatreme+comboR.jpg Geology - Coyote Peak diatreme, Humboldt County This breccia pipe intruded from great depth through Franciscan complex, mostly graywacke, with four K/Ar dates, all 21 Ma. It’s famous for its mineralogy. Metasomatism flooded clasts of graywacke with K and Ti. Meanwhile the Na from albite in the wacke went to rare sodic amphiboles and acmitic aegirine. K made microcline. You can see zonation in the graywacke clasts in the photo, the largest of which, at left, is ca. 4” in maximum dimension. Orickite and coyoteite have been found only in this diatreme, in very small pseudo-pegamatitic clots thought to have formed late in the cooling of the magma. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701763635433-1QLHO6AW08B1W4B98XAX/Bald+Hills.jpg Geology - Bald Hills, Humboldt County …near the Coyote Peak diatreme…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701895138170-IU202E4F0YQ52PSFYXG8/Black+Lassick+2.jpg Geology - Black Lassick These Mars-like barrens in eastern Humboldt County hold delicious surprises. It is often in the most barren places that one finds the rarest and most beautiful plants. The peak seems to me to be a huge knocker of steeply easterly dipping Franciscan sediment (mostly shale but with much sandstone too) floating in serpentinite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701895691899-AQYGAPIELJLPZMCBJCC6/Red+Lassick.jpg Geology - Red Lassick This red peak is composed of metavolcanic rocks that probably began their life as deep seafloor basalt. I’m guessing it’s another giant block floating in serpentinite. As there are no geologic maps for the Lassicks, this is only my tentative suggestion. See next two pictures. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701895854636-DYSOY7LUA8BHQA76KAMT/Red+Lass+talus.jpg Geology - talus of Red Lassick You can see that the rock is oxidized and veined. I would call these aggravated metavolcanics! See thin section view in the next image. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1701895467734-LWNM9VF3VTPDB4SV29JC/Red+Laas+tsec1R.jpg Geology - thin section of rocks in Red Lassick Here’s a view in XPL with the 4X objective. The brightly colored crystals are largely epidote. The dark areas have a lot of decomposed plagioclase, but the dark areas are also crammed with opaque oxides. There is also scattered chlorite visible in PPL. You can see a serpentine vein cutting near vertically through the middle of the section. Epidote and serpentine together suggest hydrothermal alteration. The rock is extremely altered, so I call it “aggravated.” https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1675579664631-VKOEPSUUU9Y59859VQ37/cinderconeView.jpg Geology - Painted Dunes at Cinder Cone, Lassen Here is a view from the top of Cinder Cone in the NE corner of Lassen Volcanic NP. At the top edge of the picture, one can see block lava with steep sides. This is because it is not pure basalt as in Hawaii, but andesitc basalt to basaltic andesite, which is much more viscous. The painted dunes, which are so colorful, are apparently a mixture of red scoria, black scoria, and light tan ash. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1743059729530-Q7BTKICW3Q7ZWRHJ0TCL/basalt+flow+from+Cinder+ConeR.jpg Geology - basalt flow out of Cinder Cone Lassen NP When the vent was occluded by cinder, a basalt flow emerged from the base of the peak. It’s a steep-sided blocky basalt flow, the steepness probably owing to the flow cooling. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1743059758991-6HB7FK0FU5X9SCRCD7YM/basalt+flow+from+Cinder+Cone%2C+closer.jpg Geology - closeup of the block lava One can see the chondoidal fractures where giant flakes have spalled off, suitable for making large Acheulean handaxes and cleavers! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1737937590194-YZJBBUDM843OSFOCCJ1N/Iron+Mtn.+MineR2+copy.jpg Geology - Iron Mountain Mine near Redding Industrial mining began here in 1888. They were mining for copper, zinc, gold, silver, and pyrite. Now it’s a supefund site reputed to have the most acid mine drainage in the world. I heard that the pH is into the negative range. Photo by Al Seneres. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1738520944382-ZB7XBXJPWH9U61GLU2WT/Jim+MallioryR+copyR2.jpg Geology - Jim Mallory and a younger and stronger me JIm Mallory. at the type locality of Arctostaphylos malloryi. Walter Knight named this manzanita after Jim Mallory, who discovered it. The preceding photo of Iron Mtn. Mine was shot from here. Photo by Al Seneres. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1742620258944-GFB88TGS8LZHRZNGV1JU/Black+Marble+MtncleanerR2.jpg Geology - Black Marble Mtn. crest What you see from this vantage point is mafic metavolcanics of Paleozoic to Triassic age, that overlie white marble. Photo by John Game that he took in the 1990s, and kindy loaned to me for a lecture. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1742621257242-KBYRIXKQC4NYES82Y8EJ/White+Marbleof+Black+Marble+MtnR.jpg Geology - white marble of Black Marble Mtn. This white marble is overlain by the mafic volcanics shown in the previous photo, I believe. Photo shot by John Game in the 1990s and kindly loaned to me for a lecture. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1609833102417-GB9BVBHKI1IZP9277LAD/Eddy2RED.jpg Geology - Mt. Eddy, Siskiyou County This magnificent mountain of peridotite and serpentinite is the highest peak in the entire Klamath Mts province. Taken at Upper Deadfall Lake. The subalpine forest you see is a mix of foxtail pine and western white pine. Scattered dwarfed whitebark pines are near the top of the peak. Minimization of competition by near lack of calcium, combined with steep rocky slopes, make room for numerous rare endemic perennials. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435872159533-SNA02FV8ZJYI7WD6JZC8/Eddyfreshinterm-1.jpg Geology - peridotite, Mt. Eddy Characteristically boldly and irregularly fractured olivine crystals, with serpentine growing in the cracks. At upper middle the yellow is a crystal of clinopyroxene. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1743228371075-D4DACXYJROFJD7QE84QZ/Mt+Eddy+DEadfalllks+%26glacial+features+copy.jpg Geology - looking west from the summit of Mt. Eddy The three Deadfall Lakes reside in a glacial U-shaped valley; and fire in the distant Trinities… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1705110530332-S3CSMIVJE3DK67PRBBJS/cement+bluff+comboR.jpg Geology - Cement Bluff This is a ca. 100 meter thick till sequence, east of the summit of Parks Creek Road in Siskiyou County. The lower grayer part has mostly clasts of serpentinite, while the upper browner part has mostly clasts of peridotite. I learned from Dr. Earl Alexander that the white coating is nesquehonite, a magnesium carbonate mineral—which makes sense, as the clasts are all rich in magnesium. The different clast compostions in the two units may suggest glaciers coming from two directions. Alternatively, one glacier could have locally removed serpentinite, thus exposing peridotite. The name Cement Bluff is ironic. The matrix is indeed as hard as concrete, but the cement is silica! Earl has stated in his book on serpentine geoecology in western North America that silica cementation in strembeds is common in ultramafic areas of the Klamath Mts., from weathering of mafic minerals, especially olivine. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1705110499408-N02RKZ5OW9KLBKQC7GG8/pxiteParks+Ceek+road+cliffR.jpg Geology - pegmatitic pyroxenite cliff …along Parks Creek Road, Siskiyou County. See next image…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1704577034545-K2OHQ4I8NFPXRS9CF072/enstite+pegmatiteR.jpg Geology - enstatite pegmatite near Mt. Eddy This wonderful rock is exposed along Parks Creek grade on the way up to Mt. Eddy. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1678774019838-D128AOQGLCHXR9TRD3Y8/glassmtncomboR.jpg Geology - Glass Mountain in Medicine Lake massif Julie Donally-Nolan at the USGS produced a fine geologic map of the Medicine Lake volcanic massif, which is huge. The latest eruption was shown by C14 to have been ca. 1133 AD, and it came from Glass Mountain, pictured here. Glass Mtn is actually a collection of multiple vents. It consists of rhyolite lava and obsidian, plus 10% pumice, which has long been mined. This place has long been a focus of raw material procurement by First Peoples on Northern California ans Southern Oregon, and obsidian from this source was traded all the way down to the Yurok at the mouth of the Klamath River. The Klamath and Trinity Rivers tribes made the largest flaked-stone bifaces ever known, some of them about a meter long and about 10” wide, and very elegantly flaked. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1628920357687-RUVGMVO9IE3GWX97K1FF/PineCreektuffR.jpg Geology - Pine Creek Basin, Warner Mts, NE CA The north side of Pine Creek Basin below Warren Peak presents nearly vertical cliffs of basalt, overlying a sequence of volcaniclastic sediments (gray) with a conspicuous blocky white tuff near their base. Below this there is more basalt, here concealed. The basalts range from 14-16 Ma, bracketing the tuff to near 15 Ma. Big blocks of this tuff fall out and tumble into the odd forest below, composed of white fir and whitebark pine. The tuff may have been erupted from a caldera not far away in Nevada. The basalts appear to have erupted from shield volcanoes still within the Warners today, like Emerson Peak to the south. They are the same age as Columbia River Basalt, but of different chemistry and more closely related to the volcanics of the western Cascades, which were active at the same time. So the Warners are part of a very wide arc, rather than part of the Miocene flood-basalt province to the north. I thank Chris Henry for helping me figure this out, with papers he supplied and his own insight. Scan of an old slide. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708894351823-HYEEWD2Y5BIJ0TY74ZI0/top+of+S+WarnersR2.jpg Geology - summit saddle of Pine Creek Basin This is looking south. The landscape shows the general structure of the Warner Mts., with dips always to the west, owing to uplift along the Surprise Valley Fault at the base of the escarpment to the east. One can see a bake zone near the top of the section here. This is a stack of mafic to intermediate flows, breccias, and tuffs. The scree in the saddle was cushion-plant heaven… http://californiageology.net/conservation daily 0.75 2025-12-09 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435700465170-L9JBAMBS7GREE91KETT6/bv3innt.jpg Conservation - Adobe Lily, Bear Valley photo by Wayne Roderick, late March, 1980s https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1708394724698-MHF5GRJ3QJMC7KRFJWL4/Frit+plur+BV+bestR2.jpg Conservation - Adobe Lily in Bear Valley These frits in Bear Valley dwarf their brethren on Wayne’s Knoll high on Walker Ridge, which are pygmies by comparison. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1743744469039-KS8PIEI0PGUJKGQNLQK2/Bear+V.+1987sharper2A-R.jpg Conservation - tidy tips of two kinds …a small part of the display in Bear Valley, the first week of May, 1988… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1436140017396-74R42KZRNHSS9HWNA6JE/barninterm.jpg Conservation - Bear Valley 1995 A field thick with tidy tips in heavily grazed pasture in the north part of Bear Valley in April 1995 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1658214609991-Z32U4CJ2G7A9Q7Q84XXJ/BV4.jpg Conservation - Bear Valley, Colusa County, 1995 Lupinus nanus, cream cups, and comps in April 1995. How would you feel about a line of 400 foot tall wind towers whirling atop Walker Ridge in the background? https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1578533800634-OXSLWZKMTA7V60LH5ZFC/plate8ainterm1.jpg Conservation - more Bear Valley 1995 It was fields like this that convinced the American Land Conservancy to save Bear Valley from development. George Clark and I started the ball rolling and kept it going, with help from Ralph Benson at TPL, Phyllis Faber, Janet Cobb, and Harriet Burgess at ALC. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1578533772677-86VJBLIHTQ603KBGTCBD/plate7interm1.jpg Conservation - more Bear Valley 1995 Miles of flower fields, varying dramatically in composition from place to place. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1578535067595-3U9HDR3IYWBVU28IFJ85/plate11interm2.jpg Conservation - Bear Valley 2005 It was a respectable year. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605909895969-4DE150AJCCG9OZZ6ZT9V/Bartlet.jpg Conservation - Barrel Springs Walker Ridge has many serpentine moist meadows. Each is completely unique. This one at Barrel Springs is stuffed with rare and unusual plants. The cover here is a Plectritis. Snow Mountain in the far background. The meadow has been butchered in recent years by motorized morons who use winches to pull out BLM bollards so they can rut and trash the meadow to prove their manhood. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1761682397624-839ICYQYM34IY30GP69L/breccia+block+at+Barrel+SprngsR.jpg Conservation - breccia block at Barrel Springs This block of ?cataclastite was brought in by BLM to join other blocks to keep jeeps and 4WD trucks off the meadow. It looks like cataclastite to me. I’ll have to ask BLM where they got it—-probably locally on Walker Ridge. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605994362541-0QWYIO92L1GITURKZ3PZ/ulig.jpg Conservation - serpentine larkspur Delphinium uliginosum is a rare serpentine endemic of the southern inner north coast ranges, confined to wet meadows, seeps, and steam sides. It is abundant at Bartlett Springs and in other wet meadows on Walker Ridge. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1436140264548-OMU2GCW5UL9F67IXS5O0/plate72interm.jpg Conservation - Cold Spring, Walker Ridge Walker Ridge in its present state without windfarm is hauntingly beautiful. It has many moist serpentine meadows scattered about its summit regions, and these are all full of interesting plants. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605983827682-3PMEHSB3YX4VK4W3VO33/stenanth3.jpg Conservation - Serpentine Paintbrush Castilleja stenantha is restricted to wet serpentine, usually along streams. It is abundant at Cold Spring. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1436140451909-45C1V4KTG0ARXUGUTCQO/plate60ps.jpg Conservation - Walker Ridge This is a dry meadow with a small ephemeral streamlet on one edge. The diversity and profusion of rare and beautiful plants in this meadow near the junction of Walker Ridge Road and Bartlett Sprigs Road are extraordinary. This particular scene is dominated by Clarkia gracilis tracyi. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605909935370-HFNZ1UARG97ER3KCLZ4S/Ctracyi3.jpg Conservation - Tracy's Clarkia Clarkia gracilis is widespread, but this spectacular subspecies (Squarespace keeps automatically turning the name to Tracy, after the town) is limited to serpentinite in the inner north coast ranges. It makes some of the most stunning displays on Walker Ridge as well as along Bear Valley Road. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605987561597-CDTIKY5KWRTOA19I76WM/tracyi.jpg Conservation - Clarkia gracilis tracyi Clarkia gracilis tracyi with its characteristic nodding bud, not to mention its exquisite beauty https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605910112021-CDP57RQKJ2TFKYKI6J48/Nemamon.jpg Conservation - Nemacladus Nemacladus montanus is a tiny annual in the Campanulaceae that botanists love to find, because it is rare, and because it is SO pleasing to gaze upon! This one was found among rocks lining the summer-dry stream bed shown in preceding photos with clarkias and botanists. It is west of the junction of Walker Ridge Road and Bartlett Springs Road. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606030855599-ZAYM64P2ZFA7UWZJ4B5F/broseabette3rPS2interm.jpg Conservation - Brodiaea rosea This endangered species is locally abundant west of the Walker Ridge Road-Bartlett Springs (Brim Grade) road junction. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606030904629-VCJQX6EFU4XYUKZSELHD/lciliolatum.jpg Conservation - Lomatium ciliolatum hooveri This is a very rare serpentine endemic. I have seen it most between Brim Grade and Barrel Springs. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606030885097-4JODEG938EEUXG44DNDP/Lcilinfl.jpg Conservation - Lomatium ciliolatum hooveri Low-res closer view of the inflorescence. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605983774814-HVPIFRXI6RZJRXQVQSYX/hairgrass.jpg Conservation - Mountain Hairgrass Deschampsia caespitosa in subirrigated serpentine gravel of Stanton Creek https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605983684477-3MDVEO9XVS7FY8BWXUIM/cleve2.jpg Conservation - Napa Butterweed Senecio clevelandii is an extremely rare serpentine endemic restricted to moist substrates in a limited part of the inner north coast ranges. These were shot along Stanton Creek but the species also occurs sparingly high on the ridge along streams and in wet meadows. I have seen it many times in Napa and Colusa counties but in every instance it has occurred in very small numbers. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605994860522-Z6MO1SL8JL5VHR0HQGUL/tripodum.jpg Conservation - Eriogonum tripodum This exceedingly rare mounding woody buckwheat grows in serpentine alluvial gravels near Stanton Creek. It is disjunct to comparable settings in the Red Hills of Tuolumne County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605910224746-0ZP2IROAEWACSGWRRVHA/WilburE.jpg Conservation - view toward Wilbur Springs Note all the white flowers in this view in the summer following the 2008 fire. These are all prickly poppies, which appear here only after fires. These are some of the grandest wildflowers in California. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601849308235-TFCWZK4RLFEPQ9GLKQLQ/argem09.jpg Conservation - prickly poppy on Walker Ridge Argemone munita ssp. rotunda appeared in abundance on Walker Ridge in Lake and Colusa counties for two years after a huge fire in 2008. These stunning plants, with their six-inch-diameter flowers, are seldom seen in the coast ranges except after fires. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611042988352-58D0MN45SKRABYNDD3TV/amwhite.jpg Conservation - Prickly Poppy in the Walker Ridge burn. Photo by Bob Case. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611041396182-9JWS2GDU0BVS7ZWVTFBA/erio.jpg Conservation - Oregon Sunshine and onions A field of Eriophyllum lanatum and Allium amplectens in the burn area. Photo by Bob Case. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611041640112-ZP7XE0A10BMTOEXPLI9X/WRHesperos2.jpg Conservation - two dwarf flaxes Hesperolinon disjunctum, left, and H. californium, right, near the preceding meadow. Note the striking difference in structure of the plants, the latter being much more congested, and its petals narrower. H. disjunctum in particular is very rare. Photos by Bob Case. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606033397746-RMCSVV24YQA9KOQETGK0/dicentra2.jpg Conservation - Golden Eardrops It has a strange name, until you look close at the flower. The Latin name was unfortunately changed from Dicentra chrysantha to Ehrendorferia c., but we all know Latin names are less stable than colloquial ones. These beautiful tall annuals came up in masses all over the southern parts of Walker Ridge after the 2008 burn. By 2010 they were less abundant and in subsequent years they were gone. But their seeds are waiting in the soil under chaparral for the next fire. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1600411188992-JMG2OWR4FGIB7NVTMPI5/WRidge2.jpg Conservation - Walker Ridge scene post-fire Triteleia laxa, Dichelostema volubile, Eriophyllum lanatum. A shining path through charred chaparral. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605910466507-M20VRW79HNBUB7PHF3ZV/laxa.jpg Conservation - Ithuriel's Spear Triteleia laxa after the burn https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605909959045-2EY4ZJHMZA1PEE4MCR95/drymar.jpg Conservation - Dymaria-like Dwarf Flax Hesperolinon drymarioides is very rare. It is a serpentine endemic of the inner north coast ranges, and I think one of the loveliest species in the genus. This picture was taken in the 2008 burn high on Walker Ridge. I have seen a few plants along Stanton Creek, but the burn produced a large number in one place. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601848808645-NG6RL7G44G65O9NHGSGO/Walkernorth4.jpg Conservation - Walker Ridge and Snow Mountain view north from Walker Ridge, foreground, with its enriched chaparral and fabulous scree areas, to Snow Mountain with its red firs on the left skyline, and St. John Mountain with its sugar pines to right. It is all one, and all must be cherished. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1600412286183-LJIVJAP0P4PTI7F2ESBD/SutterButtesB.jpg Conservation - Sutter Buttes from Walker Ridge Viewed from a high point on Walker Ridge in a vast pool of the day’s last light, as Bear Valley and the Great Valley sequence ridges beyond are darkened by the shadow of Walker Ridge. Scan of a very old slide. The Sutter Buttes are not the southernmost Cascade Range volcano, but are probably more closely related to the Clear Lake volcanic field. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605983800148-GD46ZH1Q0IKP7XWKNVPG/ivResdusk.jpg Conservation - View at dusk over Indian Valley Reservoir looking w-sw…Mt. Konockti on skyline, a 400,000 year old dacitic volcano in the Clear Lake volcanic field. Shot taken at the top of the Panorama Scree. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605936280518-C8PJSD9DMCJJQ082AZZD/latisectus.jpg Conservation - Leptosiphon latisectus on the Panorama Scree https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601763570049-REIKIIZVH7VLYG2LQNRL/onionpatchps.jpg Conservation - Allium cratericola This is the best patch of this onion I’ve ever seen. It’s at the Panorama Scree, a site extremely threatened by the wind power boondoggle. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601763588182-8SAATQF8D8SSKD4QIKJI/plate42bps.jpg Conservation - Allium cratericola up close at the Panorama Scree https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605983715597-FQPXKKA6L8TR3FNT5L8C/crater.jpg Conservation - Allium cratericola on the Panorama Scree https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605909852162-HWC0IP6IL0A90CLQ7KJI/Asolano.jpg Conservation - Otherworldy milkweed Asclepias solanoana is extremely rare, and lives only on the barrenest unstable serpentine screes. It occurs at the Panorama Scree. I know three other sites for it on the ridge. Usually it occurs as only a handful of individuals. Like two or three. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605936423606-FZJ2MCEQ565LZTHZWSKC/rediviv2.jpg Conservation - Bitterroot Lewisia rediviva on the Panorama Scree. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611041419706-QDATIS8QRF786RCGDCFD/cgreen.jpg Conservation - Serpentine Collinsia Collinsia greenei on the Panorama Scree, the only place I’ve found it on Walker Ridge. Its deep blue-purple flowers make it the darling of wildflower macrophotographers. It is a very rare plant, that can grow off serpentinite if it finds a scree barren enough to suppress competition. Photo by Bob Case. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1611041491374-5FNZ7DF5BTS5CZX8U6ZP/strep.jpg Conservation - Brewer's Jewel flower Streptanthus breweri is a serpentine endemic which, like Hesperolinon disjunctum, makes the jump from inner north to inner south coast ranges. The jewel flower is a chameleon species, taking on many aspects depending on soil, exposure, moisture availability, and probably genetics. Photo by Bob Case. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605942457161-ME541GH62YH9SLBMHGG2/affinis.jpg Conservation - Fritillaria affinis This immensely variable species occurs in this delicious delicate form at the Panorama Scree. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605910014743-6PA6G7EQ8HA17JV8MXCD/Fpurd.jpg Conservation - Purdy's Fritillary Fritillaria purdyi is very rare. I have seen it in only two places on Walker Ridge, in each case with only a few individuals, which is typical for the species. In this case it is near a road bank and could easily disappear with road widening. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605910136128-E871JAQ5XZX0RT5R5NP7/Sgreen.jpg Conservation - Greene's Senecio Senecio greenei is a serpentine endemic that is common but nowhere abundant. It is always something exciting to find. There are few burnt-orange flowers in the California flora (can you think of others?). Horticulturists would love to grow this, but nobody has ever succeeded—ever, never. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601936451668-PLA2MCGQJ3JLQ7OHNUA6/SnowMtn2.jpg Conservation - view north from Walker Ridge from left to right, Goat Mountain, Snow Mountain, and St. John Mountain, looking north from near the top of Brim Grade on Walker Ridge. Snow Mountain has red firs, St. John sugar pines and disjunct curl-leaf mountain mahogany. This is one of the glories of Walker Ridge: so many wonderful vistas! Photo by Sue Rosenthal, April 2011. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1578555477272-H6F9BQS7KLS0XEIX2S9P/nervulosum.jpg Conservation - Snow Mountain Buckwheat Eriogonum nervulosum from Napa to Colusa counties grows only un unstable, sliding serpentine scree, conditions so harsh as to be nearly devoid of competition. Here is it on the Kilpepper barren on Walker Ridge. The species is closely related to Eriogonum ursinum of the northern Sierra. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605909879413-BI1XD2K92YL4KRNDZNKS/Balsam.jpg Conservation - Endangered balsam root Balsamorhiza macrolepis is extremely rare. I know of one colony on Walker Ridge, where road widening could impact it. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605910038906-232FONMPZLRLT783OEHX/harmonhall3.jpg Conservation - Harmonia Harmonia hallii is a very rare tar plant that occurs abundantly in good years near Brim Grade and between there and Barrel Springs. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1601763615051-RTGUK3QMTXMV6628XT5M/plate69ps2.jpg Conservation - Allium falcifolium on the Brim Grade One of the best patches of this species I’ve ever seen. If the road is widened here for the wind tower boondoggle, this patch will probably be wiped out. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605909981286-RUB3TBRJOGOCLSL798Z3/DSC_0296+copy+2.JPG Conservation - Splendid Mariposa Calochortus splendens occurs abundantly on serpentine near the top of Brim Grade, and at Barrel Springs, as well as near the south end of the ridge, as is the case with this and the next photo. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605909998562-BDPZO9VU76XTBQ9ZQLCE/splendens2.jpg Conservation - Splendid Mariposa near the south end of Walker Ridge (north of HWY 20) https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606031031220-FUMZAST10O1A9E8P2N0K/watsonii.jpg Conservation - Marah watsonii This Marah with its distinctive deeply cut and folded leaves grows in the ranges around the margins of the Sacramento Valley. I have seen it in three places on Walker Ridge: on a barren chert scree, on a serpentine barren, and on non-ultramafic soil in chaparral on the southern part of the ridge, as in this case. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605910068731-6K1PHDR0GZKHD4XDMQTP/lut.jpg Conservation - Yellow Mariposa Calochortus luteus in a dense patch right along Walker Ridge Road. Threatened by vehicles. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606032662042-MDV414EV1SZN0VU988G2/hespcalo3.jpg Conservation - Hesperolinon and Calochortus luteus This display is right along Walker Ridge Road, where it could easily be destroyed by parked vehicles or construction equipment staging. I found it enchanting. The dwarf flax looks like Hesperolinon disjunctum to me. Apologies for the very low resolution, but the scene is artistically inspiring anyway. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605910194513-0PEY9C6B1TUSVK0402XL/warrior.jpg Conservation - Indian Warrior Pedicularis densiflora is a hemiparasite like its relatives (paintbrush, owl’s clover, etc.). It has chlorophyll and produces its own food, but its roots also derive food from other plants to which they attach. Photographed on Wayne’s Knoll near the south end of Walker Ridge. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605942481129-9HDWWEAI6U58SHEZN40D/plur2.jpg Conservation - Adobe Lily Fritillaria pluriflora can be abundant in Bear Valley, but it is limited on Walker Ridge. Here it is near the south end on Wayne’s Knoll. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605983743155-GO4KX38G59M8FDXDV8PE/euryceph3.jpg Conservation - Senecio eurycephalus So far I have only seen this one Wayne’s Knoll. It is rare throughout its range. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605994322376-TAPM2Q524ZXBVQUNFAPC/eury.jpg Conservation - Senecio eurycephalus another individual of this delightful rare plant at Wayne’s Knoll https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606031064029-F7ZVU55YORZLUJMOBL6U/WRknoll.JPG Conservation - Hesperolinon disjunctum I found this along the Brim Grade in 1999, and Chris Thayer and I found it later at Wayne’s Knoll, where this mediocre photo was shot. The name disjunctum derives from the disjunction of this species between the inner north coast range and the inner south coast range. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605987526256-5ZPRARRPLR5U3SDHP1ZF/navjeps2.jpg Conservation - serpentine Navarretia Navarettia jepsonii is a rare serpentine endemic we have observed on Walker Ridge at Wayne’s Knoll. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605909912549-FFKAQFLOPKN7BITWELNW/Calosuperb.jpg Conservation - Superb Mariposa Calochortus superbus has two color forms that grow together in abundance on the southern part of Walker Ridge. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605983659466-YGKEU6230DR3EKPXO09Y/Astragjeps.JPG Conservation - Jepson's Locoweed I learned this as Astragalus rattanii var. jepsonianus. I’m too old to unlearn that. Whatever you call it, this rare member of the pea family grows along the road at Wayne’s Knoll and could be eliminated by road widening. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605909834390-BWYUI0HXDTL8ZEKSE2JB/apurd2.jpg Conservation - lovely Purdy's Onion The rare Allium fimbriatum purdyi probably has its best stands on Walker Ridge. Some of these would be wiped out by road widening. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605983626929-BWDWOVF9SNV9B6NL6ZBH/Amelanch.jpg Conservation - Sierra Plum Prunus subcordata is very rare on the ridge. This is the only site I’ve seen, and it’s right on the road where widening will wipe it out. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606030933803-U7JJBZQ08TJ7ILBQIS9N/styraxPSinterm.jpg Conservation - Snowdrop Bush The east flank of Walker Ridge supports a very enriched scrub association. Styrax is the star of the show. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1606030977894-QQGFAUJGH8QNS96OS9PF/tricanthBrim.jpg Conservation - Centaurium trichanthemum This gentian relative has the most ornate (and photogenic) anthers in its genus. It is right along the road along the Brim Grade, and likely to be eliminated by any roadwork there. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1605910166896-ZVU37XD2NMPQLRB01L8Z/viewNE3.jpg Conservation - View northeast looking northeast over the north end of Bear Valley from Walker Ridge, over the Bear Valley Buttes at left, a hogback of Great Valley Sequence sandstone. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1436136519520-5F6XZ11K99QHI3POVV1M/a+view+of+part+of+the+Tesla+townsite Conservation a view of part of the Tesla townsite, tucked away at the head of Corral Hollow https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1436136700498-KLIXVX0CC6TFGLFAM8YW/DSC_0025_edited-1.jpg Conservation the beautiful buckeyes of Tesla https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1438803326557-0X1MVPCYZ82M31S71RRZ/early+Eocene+Tesla+Formation Conservation quartz-rich sandstones and associated mudstones of the early Eocene Tesla Formation produced coal and fossil plants. View north from above the Tesla town site. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1438803519472-UBI7PQP8DTK0JN7V7PYK/Jimtown Conservation Site of Jimtown at Tesla, left side of photo. Dark depressions are vestiges of root cellars, one of which probably was used by my great grandparents. Diagonal road ruts above date back to the late 1840s when the main route to the southern Sierra mines passed through here. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1438803788684-VCRFH91FTKMDABSHQBEK/Tesla+flowers Conservation Paintbrush, Senecio breweri, and lomatiums in April near the Tesla townsite. William Henry Brewer, after whom the senecio is named, visited Tesla in the early 1860s. He was not hopeful for the future of coal production, but he was mistaken. After Black Diamond Mines in Contra Costa County shut down its coal operation, Tesla became the most productive coal-mining site in California and a thriving community. The residents were able to enjoy lots of wildflowers. A frequent early visitor was Grizzly Adams, who trapped (and fought) grizzly bears very close to where this photo was taken in Mitchell Ravine. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1438804714778-HUWVRUMCF4YIEHEJI3L2/creek+at+Tesla Conservation Corral Hollow Creek, Tesla town site https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1438804784506-Y36PM98ZJHKOVRQ2TTIW/Tesla%2C+creek Conservation Corral Hollow Creek near its headwaters, well above the Tesla town site http://californiageology.net/sciences daily 0.75 2021-02-11 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435632339516-DXUN001AYWGLHD3LMI4M/image-asset.jpeg Geology, Botany and Conservation Geology https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435632926167-R6313GZCEE9FDJWSFC55/image-asset.jpeg Geology, Botany and Conservation Botany https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1435632717069-FERJ5OSTJZAK1KAYQLI6/%2Fphotos Geology, Botany and Conservation Conservation http://californiageology.net/geology-east-bay-more daily 0.75 2026-01-03 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767233315466-PQ30RU2RXGZ6UCF7JMHI/blue+Neroly+copy+2.jpg Geology - East Bay (more) - blue Neroly …in Corral Hollow…The light-colored clasts might have started as pumice and weathered to clay. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767233737057-J0IFYG30BE7NHCXB9EYN/pebble+sub+.jpg Geology - East Bay (more) - porphyry pebble at Stoneman Park …in Pittsburg, CC Co. It’s andesite, showing derivation from the Sierra. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767927557554-IOYPI8JKN5GC5X9029K0/pebelles+in+Liv+Gravels.jpg Geology - East Bay (more) - pebbles in Livermore Gravels https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767380448920-76P3E65JO9E0WBJQNCRD/DSC_5782.JPG Geology - East Bay (more) - Franciscan shale/slate …in the Arroyo Bayo….The next 2 images show the same exposure… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767380491731-M6I38L30AVI6X8BAEVO3/DSC_5786.JPG Geology - East Bay (more) https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767380516813-U20KSZWY2U5L0P9XF1XR/DSC_5793.JPG Geology - East Bay (more) https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770603012104-57IW2BDHBG0E8JTUKQL9/blue+serpenite+on+Long+Ridge.jpg Geology - East Bay (more) - blue serpentinite …on Long Ridge, Mt. Diablo… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768793683722-5RKGCKF5NPZC7XGSNPGD/DSC_2940.JPG Geology - East Bay (more) - pillow basalt along the Mary Bowerman Trail According to John Wakabaybashi (2025), these metabasalts are in the albite-lawsonite facies. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768891482526-V5M3I9USY6VY3E7XRF53/pillow+basalt+on+MB+Tr.jpg Geology - East Bay (more) - another view of pillow basalt on the MB Trail …of the albite-lawsonite f.acies… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768892216489-AQKR9I59J3FXLWFVSUE0/greenstone+metabasalt+on+Devil%27s+Pulpit+Tr.jpg Geology - East Bay (more) - greenstone metabasalt on Devil's Pulpit Trail …looks like there is some brecciation on the left side… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768892965370-V7ZK8YK39WETTA8NBRK0/slicken-sided+metabasalt+on+DP+Tr.jpg Geology - East Bay (more) - slicken-sided metabasalt on Devil's Pulpit Trail Just goes to show there is ongoing movement in the rocks. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768693712250-GBOFHGHI5R2QL9YYU1D4/Diablo+eclogite+1.jpg Geology - East Bay (more) - eclogite on Mt. Diablo …’nuff said…Read the caption. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768695228573-RE1Y51XKBZ47I6H2I7L3/Diablo+eclogite+1+copy+6sharper2A.jpg Geology - East Bay (more) - eclogite on Mt. Diablo …’nuff said…Read the caption. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768693743653-XT2H4QEQI0XJ3BQ3MIVT/Diablo+eclogite+2.jpg Geology - East Bay (more) - eclogite on Mt. Diablo …’nuff said…Read the caption. http://californiageology.net/berkeley-hills-more daily 0.75 2025-12-13 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766021407020-2K7U56OHS19MFTHTHM7W/dike+at+Sibley.jpg Geology - Berkeley Hills (more) - basalt dike This resistant basalt dike resists weathering. It’s near the EBMUD water tank high on Round Top in Sibley Regional Volcanic Preserve. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766022301008-67EZ5GGBUODU3NHL6O0F/cacticlastic+basaltR.jpg Geology - Berkeley Hills (more) - cataclastic basalt on Round Top This high up on Round Top. Garniss Curtis thought it formed by collapsing into a void created by an eruption. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769888393836-3U4H402LB6695HTMJGQK/Ross+Wagner+%26+Ryan+Fay.jpg Geology - Berkeley Hills (more) - Ross Wagner & Ryan Fay ….sudying debris flows on the northwest-facing side of Siesta Valley, where there is thought to be a vent… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769888700474-QFKOVV3J92RIBQLQT0C9/debris+flow+combo.jpg Geology - Berkeley Hills (more) - debris flows …that Ross & Ryan were studying… http://californiageology.net/geology-general-more daily 0.75 2025-12-22 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766522874812-VW532EXR6Q7EWYU3XMMQ/JKf+chert+in+headlandsR.jpg Geology - General (more) - Franciscan chert …in the Marin Headlands….The most spectacular exposures of chert are inter-layered with pillow basalt. Clyde Warhaftig made the most detailed and elegant map ever made in history here—which has seen the the light of day only in reduced and abstract form. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767732518979-QMMP6EJ3MHM8EKZ3Q106/Oursan+Trail+concretion.jpg Geology - General (more) - Oursan Trail concretion Oursan Trail concretion was deformed (folded) and then covered with sandstone BEFORE it became a concretion. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768010199487-I4YHNXK5925WT1N6JZSA/Anderson+Dam2A.jpg Geology - General (more) - Anderson Dam # 1 Santa Clara Co. Read the legend. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768010227265-SI7CA6HMTZTGO4BP723L/Anderson+Dam.jpg Geology - General (more) - Anderson Dam # 2 Santa Clara Co. Read the legend. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767593513377-G0MDEZERQBEX443G70YO/Venado.jpg Geology - General (more) - Venado Sandstone …as seen across Putah Creek and across Monticello Dam…The Venado is low in the Great Valley Group. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766381487330-FEGUJED8EX1550JR4CC6/GVS+overlying+Venado+SS+showing++homocline.jpg Geology - General (more) - Great Valley sequence overlying Venando ss. This really shows the GVS homocline welll https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766791218381-EQH6831AZV7G8FUCDC4D/GVS+w.+of+MonticelloR2.jpg Geology - General (more) - Great Valley Sequence southwest of Monticello Dam …dipping steeply to the east, basically condardant with Venado Fm. N of the dam… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766973583250-SHI30ZXAPRO50P2FNZKR/olistostromeR.jpg Geology - General (more) - olistostrome …..west of the last photo….Photo by Katie Colbert https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767147457672-PZWHNF3SUGF0OPB0JV35/KT+inspecting-sharper.jpg Geology - General (more) - Katie Colbert …examing the olistostome, for scale…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766974222316-I2TWRC3M8QAYAP7S03VS/fold.jpg Geology - General (more) - fold …in prior photo…Photo by Katie Colbert. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767043662097-EO79CZXALBOQ2ZU81ORQ/paleomag+holes.jpg Geology - General (more) - palomag holes Notice that the clasts are all from the GVS. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767057063333-5SUENJ58FZ50XCHRJS63/GVS+clasts.jpg Geology - General (more) - GVS clasts …in the olistostrome…Note the fabric. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767057560766-JCRHI0K9Z224VM4QAWLU/argillite.jpg Geology - General (more) - argillite …in the olistostrome… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774051781674-B25RM493A4F68DWDTT9G/Katie.+Colbert.jpg Geology - General (more) - Katie Colbert …studying sedimentology at Salmon Creek SP—on the southern Sonoma coast… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774051807285-H0MF6DHJU2ADL0ICR7SE/antidunes+in+process.jpg Geology - General (more) - antidunes in process of formation Antidunes form when there is glut of sediment & where there is a powerful current. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773613747141-6DTSYBTLATL2Q7XO06BP/mammoth+rubbing+rock.jpg Geology - General (more) - mammoth rubbing rock Breck Parkman discovered this just south of Goat Rock. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773613956277-R9UOE4BRFT4RGR041WR9/polished+glaucophane.jpg Geology - General (more) - Mammoth rubbing rock …consists of glaucophane schist… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773614004041-84BKRLP6E20UK4U8OFSB/Screenshot+2026-03-14+at+7.09.30+PM.jpg Geology - General (more) - the polish is up to 14' high …’nuff said…! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774135670332-HLQQPYYXZIVSJF1SP3WG/Katie+Collbert+with+Mammoth+.jpg Geology - General (more) - Katie Colbert with Mammoth Rocks …in distance….She is also near the red algae. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774135698027-2JFT5L0ZSNTYIQ6JXL5G/DSC_3043+copy.E.jpg Geology - General (more) - red algae south of Goat Rock This alga is rare in shaded-wet places on the coast. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774135728120-N7V7Z4P59MRWD248URHZ/DSC_3050FR.jpg Geology - General (more) - red algae …a closer view… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767836436181-3F0ZDWG2R6YHQJ8AT0QB/Red+Lassick.jpg Geology - General (more) - Red Lassick https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767838021499-PV4B44NX0PB5X20SAYAL/Red+Lassick+rxR.jpg Geology - General (more) - Red Lassick altered metabasalt This rock is highly altered—with a lot of hematite, probably from hydrothermal alteration, as the next photo suggests. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767836467995-JYG8FFQU9QRK46H1482N/Red+Lassick+T+secR2.jpg Geology - General (more) - Red Lassick thin section …in XPL with the 10X objective….Shows a serpentine right up the middle; and plenty of epidote—probably resulting from hydrothermal alteration. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767468136372-9HXB0HRJ9F5258GJ79EE/Bald+Hills.jpg Geology - General (more) - Bald Hills, Humboldt County …above Orick… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767564313213-JWPGMAHJNX5TAYF2RBS8/Coyote+pk.jpg Geology - General (more) - Coyote Peak …in the Bald Hills… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768433273955-KJZXMQ26FJKWPYM84JHF/horsefly.jpg Geology - General (more) - blood-sucking horsefly They were swarming us on Coyote Peak. We had to take refuge in our vehicles. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767468167405-D6NR5LN0UDI5XCABRTXA/diatreme+comboR.jpg Geology - General (more) - diatreme This a photo of the famous diatreme in the Bald Hills…two pictures, side by side. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767563219489-12E2LQ213XRQ7O5G5VCL/aegreine+in+PPL.jpg Geology - General (more) - Aegirine in PPL Aegirine is normally a product of crystalization of alkaline or K-magmas…Shot in PPL with a 10X objective. This from the Coyote Peak diatreme, with research-permission. This is generated in the light sandstone inclusions. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766530423726-INFWUGQEFFWZ0O9FY8VE/Polystichum+lemmonii+growing+dunte.jpg Geology - General (more) - Polystichum lemmonii …growing on dunite, at Mt. Eddy, Siskiyou County…. http://californiageology.net/geology-sierra-more daily 0.75 2026-01-03 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771015053555-PC7MTKHEVH4V283P6CKI/DSC_3126+copy.JPG Geology - Sierra (more) - serpentinite …North of Coulterville along HWY 49…Katie Colbert is stuying this faulted mess in the Melones Fault Zone …beautiful!…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771015106572-SPP8PD8H3TQCOEXBW8HF/DSC_3086.JPG Geology - Sierra (more) - serpentinite …same site as prior photo… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771015140536-WHFVX5E3IUFQZ9ANA779/DSC_3109.JPG Geology - Sierra (more) - serpentinite …same site as prior photo…Ain’t it beautiful!… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766459449616-B3Z97UUD50RA2966BQ94/glacial+POLISH+in+Carson+PassR.jpg Geology - Sierra (more) - glacial polish …dazziiing in Carson Pass…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767398140048-A72GXJNYR83Y2AUC5AWN/Table+Mt.+Latite.jpg Geology - Sierra (more) - Table Mt. Latite Sorry about the wires! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767398263538-6806GZJTQ5WOZSCELFKL/drill+hole+in+TTM+latite.jpg Geology - Sierra (more) - driil hole …in Table Mt. Latite for paleomag…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765738193671-WUJH0ZGKCZ0EYGDGG0PV/Donner+lithicsR+copy.jpg Geology - Sierra (more) - giant basalt flakes …for handaxes. I left them at the columnar basalt on Lyons Peak in Eldorado County because they were too heavy to carrry. I wish I took just one! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765763874532-3AFT8MCONEAE88J1L7XS/biface+in+ignimbrite.jpg Geology - Sierra (more) - knife I made... …in ignimbrite I found near French Meadows Reservoir…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771353982686-ZML0CQ1GU1JPL8BID71W/202.jpg Geology - Sierra (more) - broken quartzite …at the start of Eagle Lakes Road…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771353926759-0UMDDIT2AHIRE8TVSMP7/breccia+at+start+of+Eagle+Lakes+Rd.jpg Geology - Sierra (more) - breccia composed of quartzite & schist ….at the start of Eagle Lakes Road…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769753125035-X4TMUOK8HK2ZKJ1F247W/228.jpg Geology - Sierra (more) - Emerald Pool …Nevada County…’nuff said!…According to R. A. Schweickert, this is Jordan Creek. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769753187973-SP72PP466JUSAON3TCTT/234a.JPG Geology - Sierra (more) - marble and iron-stained quartzite …at Emerald Pool…This the lowest structural unit in the in the Shoo Fly. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769753224678-Y5HQ1VJ6M5JUPQPV5DKX/241.jpg Geology - Sierra (more) - foliated quartzite in marble ….at Emeraled Pool…In the brittle-ductile, or below it, rocks get plastic. All the rocks here have been tranposed into parallelism with a major ductile shear zone. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769753312483-NW2E5PAC1QAG58A0XQJ7/sense+of+motion+to+the+rightR.jpg Geology - Sierra (more) - porphyroclast …sense of motion to the right…at Emerald Pool… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769753350817-EADC48C51P7PEWDZ3UNI/boudinage+at+Emerald+Pool.jpg Geology - Sierra (more) - boudinage in quartzite …at Emerald Pool… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772245024001-9RIGAE3W89FBQMHOSVX2/glacial+erratic.jpg Geology - Sierra (more) - glacial erratic …along Bowman Lake Road… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772245049190-S5QLC6ZZNT9AJEMURTFJ/glacial+striea.jpg Geology - Sierra (more) - glacial striations …along Bowman Lake Road…Notice the striatiations are at a sharp angle to bedding. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772320501142-VORZA939G3XUI622LA68/glacial+striations+on+dome+at+Big+Bend.jpg Geology - Sierra (more) - glacial striations …on a dome at Big Bend—named for a tight bend in the North Yuba River… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772320747346-3LLYTD0D792Q54A1WEVE/chatter+marks+on+a+dome+at+Big+Bendjpg.jpg Geology - Sierra (more) - chatter marks …on a dome at Big Bend… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772316117791-42CRYP0Z7JRVBX3TU30W/250+copy.jpg Geology - Sierra (more) - classic Valley Springs Formation …along the RR tracks at Alta… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772316348212-QDJFDR2R1U6FHOJ3K2ZW/246tif+copy+2.jpg Geology - Sierra (more) - Auriferous Gravels …at Gold Run… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772316469148-M3OK9EEEDSA7XT625T15/251+copy.jpg Geology - Sierra (more) - hydraulic mine …near Gold Run, south of HWY 80… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772316640372-OYB7AT33859GLPEWJUKG/248A+copy.jpg Geology - Sierra (more) - hydraulic mining …vic. of Gold Run…This produced the exposures we see along HWY 80 across from the rest area. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765739738299-E3JKZVD3CC3HE79UKXVW/DSC_6704+copy+3R.jpg Geology - Sierra (more) - metavolcanics at Auburn Dam site …with sense of motion indicators… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765739795056-0CXTDXNLG4H7TTPRUZHJ/DSC_6773+copy+2.JPG Geology - Sierra (more) - sense of motion indacitor This sigmoid feature indicates motion from left to right. It was about 4 inches long. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765762975967-Q1S9KEYO1CGTKQ4Z8G8T/sense+of+motion+inds.jpg Geology - Sierra (more) - more sense of motion indicators …in the metavolcanic outcrop at Auburn Dam site… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1765763002600-YFO0AXKBC8312WK6V3F6/sense+of+motion%3Amylonite.jpg Geology - Sierra (more) - sense of motion indicators ….in a mylontic fabric in the same metavolcanic outcrop at the Auburn Dam site.… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767996005285-K2TPK0JKWBT6971X3HR7/serpentine+%40+Auburn+Dam.jpg Geology - Sierra (more) - chrysotile at Auburn Dam site https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767996030240-UAGHOLNNYMQPW96V4L1Y/chrysotile+w.+carbonate+%40+Auburn+Dam.jpg Geology - Sierra (more) - chysotile with overlying carbonate At Auburn Dam site; the carbonate is probably calcite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771207683855-B03B3AJ51BA52AADWWF1/soapstone+%40+Auburn+Dam.jpg Geology - Sierra (more) - soapstone at Auburn Dam site I think, in addition to serpentinite, these rocks were part of the reason the dam was abandoned. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768519083459-MJ7ZFVRW8605SVVER1XR/red+cut+along+Italian+Bar+Rd.jpg Geology - Sierra (more) - classic Sierran red soil We found this along Italian Bar Road, which extrudes from Columbia, Calaveras County. The red soil is sometimes taken to indicate Eocene deep weathering under subtropical conditions. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1700982794446-777BJ12Q1CHEW669KOHA/soft+sed+deformation+at+ScrippsPS2A.jpg Geology - Sierra (more) - Ardath Shale, Scripps La Jolla (Copy) (Copy) (Copy) (Copy) THIS BLOCK OF PHOTOS PROCEEDS LOOSELY FROM SOUTH TO NORTH. Some spectacular soft-sediment deformation in the early Eocene Ardath Shale, on Scripps Beach at La Jolla in San Diego County. The overlying sandstone visible in this photo is the base of the early middle Eocene Scripps Formation. Evidently the thick sands, deposited rapidly, weighed down on the mud beneath, dewatering and dramatically deforming it. All of this happened in a deep marine environment. http://californiageology.net/other-photos-more daily 0.75 2026-03-31 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767309698918-KGS1QXIXYHG6L23NMCBU/twilight+from+Marin+HeadlandsR.jpg Lithics, Landscapes, and Critters (more) - twilight ...look south to San Francisco… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767318454805-XNO6W5XV7P6C6G3PHXCC/surf+at+Tennssee+PtR.jpg Lithics, Landscapes, and Critters (more) - surf at Tennessee Point …in the Marin Headlands north of Rodeo Beach… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768863865027-QI88QOA1JY46YYDT8PSN/ripples+in+sand+%40+Abbotts.jpg Lithics, Landscapes, and Critters (more) - megaripples in dunes at Abbott's Lagoon …’nuff said!… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771893032720-53DG44ZWXQ5E28C0HR9I/Bodega+Head1.jpg Lithics, Landscapes, and Critters (more) - Bodega Head …composed of Salinian granondiorite… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771893061944-40E0TWEB7X026L1MVGLQ/Bodega+Head2.jpg Lithics, Landscapes, and Critters (more) - Bodega Head # 2 …same site as prior image; and composed of same lith…coarsely crystalline granodiorite… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771896640925-2VYRDPGPFZB6UR09PQ5Z/beach+deposits+overlyling+granodiorite.jpg Lithics, Landscapes, and Critters (more) - Bodega Head # 4 …terrace (probably ferruginized beach sand) deposits overlying granodiorite… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771895372994-4ONDR8O3SXWKVADJ90V0/coarsely+chrystalline+granodirorite.jpg Lithics, Landscapes, and Critters (more) - coarsely chrystalline granodiorite …same site as prior image… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771896500097-N2F8D3PPJOQVWKDNJZCX/coarsely+chrystalline+granodiorte.jpg+.jpg Lithics, Landscapes, and Critters (more) - granodiorite …same site as prior image… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771904525347-GPMKUQPPA0Y837X0QZGY/aplite+dike+in+granodiorite.jpg Lithics, Landscapes, and Critters (more) - Bodega Head # 5 aplite? dike in coarse-grained granodiorte… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771893097770-KCD6ZGCO5TSYO6QRNYI7/Bodega+Head3.jpg Lithics, Landscapes, and Critters (more) - Bodega Head # 3 …same site as prior image; and composed of the same lith… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771981520878-JVMS2QS8SVM2F8YST295/Bodega+Head+porpoise.jpg Lithics, Landscapes, and Critters (more) - Bodega Head # 6 KT and I saw a porpoise out there--clearly playing and jumping! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766022848083-GURJAKT0YSU1NRZTL3AC/A+myriostigma.jpg Lithics, Landscapes, and Critters (more) - Astrophytum myriostigma …in the fabulous glass houses at U.C. Davis… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766023772717-8Z31CSZ6AC3SRMZ2XYI4/Poot%27s+Astrophytums.R.jpg Lithics, Landscapes, and Critters (more) - Poot's Astrophytum collection Poot’s Cactus is near Escalon, in the San Joaquin Valley. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766428541651-39M50DOXCJTR43WZY867/Poot%27s+MelocactusR.jpg Lithics, Landscapes, and Critters (more) - Poots's collection of Melocactus ‘nuff said! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774296450959-JXAY7OR3JYJ8Z65ON66Y/Pt+San+PedroA.jpg Lithics, Landscapes, and Critters (more) - Point San Pedro Consists of Paleocene turbidites & a little beccia. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774226627715-TKMLN6U72N2NSX072E4Z/ice+on+Lake+near+Devil%27s+Garde.jpg Lithics, Landscapes, and Critters (more) - ice on lake …near Devil’s Garden—Lassen NP… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774227357176-6FRSCATIFJ0VDLFYGRVM/Chaos+Crags+Lassen.jpg Lithics, Landscapes, and Critters (more) - Chaos Crags …north side of Lassen Peak… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767480786669-KN75WFFNDNP6WUS1I9IS/wave+splash+Trinidad+BayR.jpg Lithics, Landscapes, and Critters (more) - Trinidad Bay, Humboldt County The wave splash is beautiful! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767575827273-I7P0YM0HB7K3FV67X66V/Oregos.jpg Lithics, Landscapes, and Critters (more) - Oregos Mouth of Klamath River with Oregos, who brought the salmon to the Yurok… It’s the complex rock to the right. I asked a Yurok elder if the god was in the rock or WAS the rock: her reply “both.” https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768242610760-BWG4D1XKPFUYTMNA4898/fern+canyon.jpg Lithics, Landscapes, and Critters (more) - Fern Canyon--in Prairie Creek SP Katie Colbert caught my younger self in magic light… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768243197983-82O1I8VPRV8BQAG0F1IP/maple+in+P+C+SP.jpg Lithics, Landscapes, and Critters (more) - maple in Prairie Creek SP …covered with moss… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768245837171-ZYDJTKF0MVW76194VY3A/alder+backlit+%40+Jacoby+Creek.jpg Lithics, Landscapes, and Critters (more) - alder leaf backlit …at Jackoby Creek, south of Eureka… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768432617380-LYSZ75D92CLTRQHE2AYO/Rana+boylei.jpg Lithics, Landscapes, and Critters (more) - yellow-legged frog I saw this along Jacoby Creek, south of Eureka, in Humboldt County, CA. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768354110709-W4463KAQ9O9MK4ES951N/Hydrodamalis.jpg Lithics, Landscapes, and Critters (more) - vertebra of Hydrodamalis …from the Pliocene Falor Formation, in the Blue Lakes Museum… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768354649446-XFH3OBC9QKBQFRE56Y25/39g+copy.jpeg Lithics, Landscapes, and Critters (more) - painting of Russian hunters …hunting Hydrodamlis…They put an end to some 30 million years of sea cow evolution in the Pacific Ocean. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767725761542-XMIYUJ9ZQRKUX35ORMOP/late+K+ammonite+from+Rumsey+Hills.jpg Lithics, Landscapes, and Critters (more) - late Cretceous ammonite From the Rumsey Hills; the sutures got more complex in the late K… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771285423030-0X7M21Y8SOOVSUAQ9AVM/253.jpg Lithics, Landscapes, and Critters (more) - UC Berkeley paleobotany students and profs …left to right—Howard Schorn, Dr. Wayne Fry, Richard Lis, SWE, Dr. Harry MacGinitie, Dr. Jack Wolfe, Herb Meyer…Regetably excluded—Patrick Fields…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767568295619-F4UMX3P2RB1SIVOIVVK2/spider+caught+a+bumbel+bee+.jpg Lithics, Landscapes, and Critters (more) - crab spider with bumble bee on Coyote Peak, Humboldt County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767306327131-7PJ0JDVYNNFLLWEZ40AT/tailings+piles+along+the+North+Yuba+Trail.jpg Lithics, Landscapes, and Critters (more) - piles of tailings …along the North Yuba Trail… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766363017626-QVCF7AECMR45MIX7YGV8/red+firs+on+RLT+10-18jpgR.jpg Lithics, Landscapes, and Critters (more) - red firs on Round Lake Trail ….in October 2018….I never get over lichens all at one level owing to snow pack. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766864217293-S8TRRMBVL9KR9VG9RTEZ/red++firs+on+RLT.jpg Lithics, Landscapes, and Critters (more) - red firs on Round Lake Trail 2 …in a severe drought year…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770700582544-F43RUVBA17IYSXEK3MQN/Sierrra+Buttes+viewed+from+Bassetts.jpg Lithics, Landscapes, and Critters (more) - Sierra Buttes …viewed from Bassetts… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767210163090-9QN8R68FBD027R6MGZ4I/ripples+in+xtal+Lakesharpend+%26+cropped.jpg Lithics, Landscapes, and Critters (more) - ripples ….in Crystal Lake, summit of Mt. Hough, Plumas Co…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768157602012-5TFEV969LII15Y5JRBB0/ship+going+thru+deltaR.jpg Lithics, Landscapes, and Critters (more) - ship going through the delta near Pittsburg ….concealed by vegetation…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767486908525-I299COFMZOKAI03MHHBV/Desolation+from+BiBreak--best.jpg Lithics, Landscapes, and Critters (more) - Desolation Wilderness …as viewed from Big Break…Pyramid Peak at right…I saw pikas at the summit of Pyramid. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767486938472-7YOCDZ0NI22ZLV40TJXQ/DesolationthruWillowPassps.jpg Lithics, Landscapes, and Critters (more) - Desolation Wilderness …viewed from Briones RP thru Willow Pass. Pyramid Peak at far right…Pyramid is the highest peak in Desolation—shot with Nikon D750 then cropped. I saw pikas on Pyramid. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768101756957-9FCERRRR8WVIS3J0GLYK/DesolationWilderness+from+Peavine+Ridge.jpg Lithics, Landscapes, and Critters (more) - Desolation Wilderness …viewed from Peavine Ridge, Eldorado County—Pyramid Peak at right… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767479710898-SAJCTKYZJBI1AYBHEXC9/Smith+River-R.jpg Lithics, Landscapes, and Critters (more) - Smith River at Stony Creek …near Gasqet in Del Norte County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767480394961-MQE0LN576KQ8W2J9DTQS/V+chrysatha+R%26E.jpg Lithics, Landscapes, and Critters (more) - Vancouveria chrysantha This species is endangered. We found it at Stony Creek near Gasquet in Del Norte County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769046666741-232BR9CFDB183TI7PAMT/buckeyes+%40+Briones.jpg Lithics, Landscapes, and Critters (more) - buckeyes at Briones …along the Alhambra Creek Trail, 1/21/26… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769903368472-O1MHBLVXNMIQS36CA2V2/RTop%26Siesta2-10-19+copy.jpg Lithics, Landscapes, and Critters (more) - Round Top & Siesta Valley Siesta Valley is a syncline, in which Round Top can be found in the SW flank. Upper Muholland Member of the Siesta Formation is the foreground. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769903397527-NAWH8NCGJQPWUBTHBGZU/RockyRidge2-10-19.jpg Lithics, Landscapes, and Critters (more) - Rocky Ridge Cierbo Formation is at the crest. Lower Muholland Formation Member of the Siesta Formation in is in foreground; middle distance Orinda Formtion. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772838780093-WOGGGLSS91IN09NGG0P3/looking+south+from+Sidney+Flat--enlarged.jpg Lithics, Landscapes, and Critters (more) - look south from Sidney Flat …at Black Diamond Regional Preserve… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772838845123-W4BG7MAY8CTCBYP6H5U6/oak+on+Arata.jpg Lithics, Landscapes, and Critters (more) - Valley Oak on the Arata Ranch …at Black Diamond Regional Preserve… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768890871771-CJJTLIKMLTUT1YDQ56X0/328.JPG Lithics, Landscapes, and Critters (more) - burnt scrub oak …near John Muir picnic site on Mt. Diablo… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768893646188-8S15KR2ANUZ7XET5IL2Z/view+from+near+the+summit+of+Diablo.jpg Lithics, Landscapes, and Critters (more) - view from near the summit of Mt. Diablo …bathed in magic light… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769298105930-14096O10DTGMI3DDVSUK/view+of+N.+Bay+from+DiabloR.jpg Lithics, Landscapes, and Critters (more) - view of Bay …from Mt. Diablo… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769298134485-I63B31GDD04IIQSOQH32/another+view+of+N.+Bay+with+micorwavejpg.jpg Lithics, Landscapes, and Critters (more) - another view of north bay …from Mt. Diablo…this time with a microwave tower… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774747728450-Y50WER6GBBHJ7LQYQE8A/Katie+Colbert.jpg Lithics, Landscapes, and Critters (more) - Katie Colbert with screech owl …this a baby…note the downy feathers… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766613999340-8UWFVU1QTCTBODFLUCT7/Mimulus+guttatus.jpg Lithics, Landscapes, and Critters (more) - Monkey Flowers …Mimulus guttatus & Triteleia hycacinthina in the Red Hills in May…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766613543745-GBIB69EJ2FTFPW8L31J1/Clarkia+biloba.jpg Lithics, Landscapes, and Critters (more) - Clarkia biloba …in the NW part of the Red Hills in May… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768504501917-HSRT00WAXPDOGYMUXXYL/scene+in+the+north+part+of+the+Red+Hills.jpg Lithics, Landscapes, and Critters (more) - scene of the north end of the Red Hills …with the gray form of Ceanothus cuneatus…The gray form of this Ceanothus appeared in the movie “Unforgiven” which was supposed to take place in Wyoming. I recognized the Red Hills of Tuolumne County CA instantly. The Red Hills are the only place where the gray form grows. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767379649284-KWX4WZ2E8W6H938L30QC/Clarkia+dudleyana+along+HWY+49+near+Jamestown.jpg Lithics, Landscapes, and Critters (more) - Clarkia dudleyana ….along HWY 49 near the south end of Don Pedro Reservoir…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767653292168-25DHCVA4WNOQHO9Q0Z0F/Clarkia+dudleyana.jpg Lithics, Landscapes, and Critters (more) - Clarkia dudleyana …closer… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772489352290-F8YQL66SHW6GC9JVZZMV/DSC_6061+copyR.jpg Lithics, Landscapes, and Critters (more) - Gilia tricolor & Eschscholzia caespitosa …in the southern Red Hills… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766366030918-KYZI9T0F79O744WTAHGS/awkard+buildings+%40+Copperopolis+copper+Mine.jpg Lithics, Landscapes, and Critters (more) - awkward and decrepit buildings …..at Copperopolis Copper Mine.…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766366079762-ME6E1IDFHLF02ZYQBVUS/copper+mine+dump+%40+CopperopolisR2.jpg Lithics, Landscapes, and Critters (more) - copper dump @ Copperopolis https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1766366123374-T73A1HQ2RTYHZRK0KJNC/R.jpg Lithics, Landscapes, and Critters (more) - my old friend Chris Thayer ….examining genetically altered Mimulus guttatus by copper in the mine dump… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773530365206-70JXDCNHSEL7P0NHK7J5/Graniteville.jpg Lithics, Landscapes, and Critters (more) - Chris Thayer with King Bolete …found in Graniteville…Nevada County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773702669362-UT1215PR3FAEZ8SOXG05/Katie+Colbert+studying.+breccia+inside+Little+Walker+Caldera.jpg Lithics, Landscapes, and Critters (more) - Katie Colbert …studying breccia inside Little Walker Caldera…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771025751636-ZVWU15I6DYJ0C4OJWFJP/DarwinFalls3.A.jpg Lithics, Landscapes, and Critters (more) - Darwin Falls …cut through Paleozoic carbonates… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771025787754-DEU17A6EJ0PUZIHUUREI/DarwinFalls1.A+jpg.jpg Lithics, Landscapes, and Critters (more) - Darwin Falls …a different view; maybe a different waterfall…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767733991460-A02ZGXLUMX8ZGCE7XAAQ/White+Mtn.+Peak+in+magic+light.jpg Lithics, Landscapes, and Critters (more) - White Mountain Peak …in magic light… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769727169251-7WK6PX2SCAP2ICI260LI/habitat+of+L+serrata.jpg Lithics, Landscapes, and Critters (more) - habitat of Lewisa serrata along Mosquito Ridge Road …on metavolcanics… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767126851623-043T2FGHE204W5MXVRVR/biface+in+ignimbrite+copy.jpg Lithics, Landscapes, and Critters (more) - knife/biface I found the block of igminbrite from which I made this knife near French Meadows Reservoir, in Placer County. It was wonderful toolstone. When I went to find more in the last few years, I could not find the location. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774744176870-0EO7OPOKI26U4Y0UG6NE/JDC+cleaverR.jpg Lithics, Landscapes, and Critters (more) - cleaver …made in Grizzly Peak dacite (actually chemically basalt)…Desmond Clark wanted thi displayed on his tombstone; I took a lot of pride in that. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774744208738-IFO0OJ5Q0UUA2T5F5C9G/Glass+Mtn.+HXR.jpg Lithics, Landscapes, and Critters (more) - obsidian handaxe made in Glass Mountian obsidian …and finished in the RPBG… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774911702141-JL6VFFBSI0AN26APL901/Shonchin+Buttt.jpg Lithics, Landscapes, and Critters (more) - Schonchin Butte--Lava Beds NM A fluted obsidian spearpoint was found here. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774911976285-L1WF59RBSGDVPX7NL2OL/fluted+obsidian+pt.+from+Schonchin+Butte.jpg Lithics, Landscapes, and Critters (more) - the fluted obsidian spearpoint …from Schonchin Butte…nuff’ said!… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774919232354-GGJ6391YI6ILRNWXQ4TH/Mummut+americanum+in+Carson+City+Museum.jpg Lithics, Landscapes, and Critters (more) - Mammut americanum in Carson City Museum … I suppose was produced by a salvage dig in the state of Washington… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774925527965-1OYGCKD3P8ROGJI7ZAPJ/Actodus+primus+%26+Equus+occidentalis+LACM.jpg Lithics, Landscapes, and Critters (more) - Arctodus primus & Equus occidentalis …at the LACM…Equus occidentalis was smaller than horses today. The short-faced would have smacked it down. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772336594546-U6ERC3CSAN2X5OILC4YZ/168b.jpg Lithics, Landscapes, and Critters (more) - historic photograph …of snow sheds in Donner Pass…. Central Pacific constrution in 1868… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772418048705-2XSQ88OX0WSLP639KKRS/Central+Pacific+RR+at+Cisco-enlarged.jpg Lithics, Landscapes, and Critters (more) - Central Pacific RR at Cisco …in the late 1860s or early 70s… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772417600128-L17ZG8MPZWKGBUJTM13J/Ross+%40+Wabena.jpg Lithics, Landscapes, and Critters (more) - my dear friend Ross Wagner …at Wabena Point, Eldorado County,.., https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772417802436-8F9UDPW7LCEEJOYD81GL/lake+from+Black+Mtn.jpg Lithics, Landscapes, and Critters (more) - lake scene and mountains …viewed from Black Mountain Eldorado County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767210122363-PJKVKISEUJM4P4XRES76/sunset+%40+Tamsen+Donner+camp.jpg Lithics, Landscapes, and Critters (more) - sunset at George & Tamsen Donner Camp…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772243452716-GKGM4077FOEMTSKLZ6HT/N.+Fk.+American.jpg Lithics, Landscapes, and Critters (more) - American River north fork …seen from Forest Hill bridge… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772243632501-SNEH4WEXQX12HAH6OYDC/high+bridge.jpg Lithics, Landscapes, and Critters (more) - the Forest Hill bridge …at 730 feet high, it’s the highest bridge in California… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771286364195-JVANGVJ8OEOPLQX6P7U6/Bourne+Mansion%40Empire+Mine+SP.jpg Lithics, Landscapes, and Critters (more) - Bourne Mansion …at Empire Mine SP, one of the best state parks in California… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773789910739-78BHCFPRJNO447WJPIE1/Green+granodiorite+Bourne+Mansion.jpg Lithics, Landscapes, and Critters (more) - green granodiorite Bourne Mansion was built of this lovely rock.. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773795822531-UOORP3O6MD5MI6GODDWO/Pelton+water+wheelA.jpg Lithics, Landscapes, and Critters (more) - Pelton water wheel …in Empire mine SP…One can see the water wheel was. driven by powerul blast of water from a monitor. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773796442570-45JJRQSDQDFVZDZZ31WW/Pelton+water+wheel.jpg Lithics, Landscapes, and Critters (more) - Pelton water wheel …a closer view…You can see here the cups into which the monitor shot a powerful blast of water. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774667569857-YT0JXEOBLETI9I1LWVDM/morels+in+our+yard+4-14-24R.jpg Lithics, Landscapes, and Critters (more) - native morels in our yard …April 2024… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774747558050-OQW976LMBC6ST2JBONEY/enlarged.jpg Lithics, Landscapes, and Critters (more) - Jim Roof …with his roadrunner VW van in in Death Valley 4/61… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774912781804-S1B7D3NRW4T5XFQUREIM/Dodge+Ram+at+Vasey%27s.jpg Lithics, Landscapes, and Critters (more) - 2007 Dodge Ram at Bassetts This truck was stolen from my driveway. I was frantic—as I LOVED this truck…It was spotted in the north East Bay within the time it would not be towed. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1775012554394-J1T4FGUFURMEQXPC2IFV/San+Pedro+Point.jpg Lithics, Landscapes, and Critters (more) - Paleocene turbidites at San Pedro Point https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1775012596104-7108ICFRKAOJ18F5HYR6/Paleocene+turbidites+at+Devil%27s+Slide.jpg Lithics, Landscapes, and Critters (more) - a closer view of Paleocene Turbidites …at Devil’s Slide…These strata are along strike with strata at San Pedro Point. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771394873358-DXR96WV4SRAPC5Y8YO2G/F150+4X4R.jpg Lithics, Landscapes, and Critters (more) - F150 4X4 …my truck… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771552133623-UDONEF2EB40V5WVVBSD4/steam-powered.+tractor+Willits+Museum.jpg Lithics, Landscapes, and Critters (more) - steam-powered tractor …in Mendocino County Museum, Willits…My F150 is more powerful. This seems to have been built in the predessor of the Caterpillar Tractor Factory in San Leanadro. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772906566456-ALT5WT58RHE04X0SQDZ1/SWE+with+rock+glacier.jpg Lithics, Landscapes, and Critters (more) - me with rock glacier …on Mount Rainier…This was when I was still young and joyful! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772907408466-L383BM22CG9SMLVACCJZ/subalpine+fir+%26+Pacific+Silver+Fir.jpg Lithics, Landscapes, and Critters (more) - subalpine fir & Pacific silver fir …on Mount Rainier…Abies lasiocarpa & Abies amabilis are both at isolated sites in the Klamath Mts. and threatend by global warming. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774318634940-VYUNCV0AO99DQR68HBLQ/Jack+Edwards.jpg Lithics, Landscapes, and Critters (more) - Jack Edwards He was 4F and working at Kaiser Richmond Shipyard; he was my Dad. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772923157468-PSHC75XDTDNQ7EI7JB4N/botanist.jpg Lithics, Landscapes, and Critters (more) - botanist going home ‘nuff said… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1775013034623-92IQL8TR4BJCPZZROWJK/San+Pedro+Point.jpg Lithics, Landscapes, and Critters (more) - San Pedro Point turbidites https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1775013069381-OZ9TSL6WA38MJBNYYIOH/Paleocene+turbidites+at+Devil%27s+Slide.jpg Lithics, Landscapes, and Critters (more) - Paleocene turbidites @ Devil's Slide These strata are along strike with those @ San Pedro Point. http://californiageology.net/botany-more daily 0.75 2026-03-28 https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774222041497-BZ0VVLPW72O12IFVPSJS/Marah+macrocarpa+St.+Monica+Mts.r+4-14KT+copy.jpg Botany (more) - Marah macrocarpa …in the Santa Monica Mountains….Shot by Katie Colbert. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769296906403-CBZXVT5CR5WJWCD5RE6A/Campanula+exigua+on+MB+Tr.jpg Botany (more) - Campanula exigua …on Mary Bowernan Trail…dainty thing!…also rare… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768941653705-FBJ0OZ5YWW1YX7VDIKS6/K.+corymbosa.jpg Botany (more) - Keckiella coymbosa on Devil's Pulpit Trail …the whole plant… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768941867849-SDQKLR9BR7HZZZL0LYPJ/K+coyrmbosa+2.jpg Botany (more) - closer https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768941932284-FN7YIW7PY888VR2C34K3/Diablo7-11+197.JPG Botany (more) - even closer https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770602204120-MFKDPJXJX5OAMJ27DG8X/Mimulus+andrsaceous+MB+TR.jpg Botany (more) - Mimulus androsaceous …along the Mary Bowerman Trail…At least both used be called that! https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773118814445-YL8Z84SZWNTT9YQWN57S/viscidaMartinez+005R+-+enlarged.jpg Botany (more) - Arctoshtyphlos viscida berries …anomalously growning in Martinez… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773118850021-DKBL52H4MEV5HNA5MJE8/viscidaMartinez+012RR.jpg Botany (more) - Arctosthaphylos viscida nascent inflorescene …anomaously growing in Martinez… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771028507369-1R94QYU7W9WS8S8ZG8Y2/grass+needs+ID.jpg Botany (more) - Zizania cf. palustrus …at Yolo Bypass in wetlands…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771028743713-P3QM2WBRNM5PMEQFZXIX/plant+needs+ID.jpg Botany (more) - Ammania coccinea …in Yolo Bypass wetlands… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773785721687-6WUJXG6CSVQBCDYH6LKW/Iris+longipetela+habitat.jpg Botany (more) - American Canyon …showing Iris longipetela habitat… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773785759004-G7WUALXNPY4OAUTVJPSC/Iris+longipetela2.jpg Botany (more) - American Canyon This is the ridge north of Vallejo that is mostly silica-carbonate rock. However, the Iris longipetela is mostly growing on serpentinite. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773785787366-7TJGSCNFAI51PW09Q9JE/AA.jpg Botany (more) - Iris longipetela …a closer view… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774222649360-31NXLG9RWB2CRD57642T/Lrediviva+SnellRS+copy+2R.jpg Botany (more) - Lewisia rediviva …in Snell Valley Preserve—Napa County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770616920885-2B0OX9C45RIWLYA5F34I/Thayer+studying+D.+uliginosum+in+Butts+burn.jpg Botany (more) - Thayer studying …Delpinium uliginosum in Butts burn—Napa County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770616953813-FY8LZOP2GKI3BK9RFHJK/Delphium+uliginosum+Butts+burn.jpg Botany (more) - Delphinium uliginosum …in a wet place in the Butt’s Creek burn… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770616984502-KAICMKKV10XYWDF46DZR/Clarkia+gracilis+tracyi+++Butts+Ck.jpg Botany (more) - Clarkia gracilis tracyi …along Butts Creek—Napa County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770864187265-GEADTMG2J6HA5AZY6B2G/Nemacladus+.montanus2jpg.jpg Botany (more) - Nemacladus montanus …on serpentine scree in the Butts Canyon burn… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770864221187-08V5G9Q6I552M1LBRN0X/Nenacladus+montanus.jpg Botany (more) - Nemacladus montanus …a closer view—site as prior plant… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770617013337-RV08RQP7KZ5W1F1SGVAP/Lagopylla+minor+Butts+Ck.jpg Botany (more) - Lagophylla minor …along Butts Creek—Napa County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767396348151-11KLF3WDNTDH0LVSY48G/Sedella+pumila+--Red+Hills.jpg Botany (more) - Sedella pumila …in the Red Hills, Tuolumene County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772488537974-QUPKASL5CVFLD0GF950X/DSC_2597_edited-2+copyA.jpg Botany (more) - Clarkia williamsonii & Eschscholzia ceaspitosa …along Red Hills Road…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767396829622-CFDL8D669JUA4PB5PED3/Clarkia+williamsoniiR2.jpg Botany (more) - Clarkia williamsonii …in the Red Hills… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768189563695-CR5TC9EO8VZL78VNXVEI/S.+poygaloides+2A.jpg Botany (more) - field of Streptathus polygaloides …in the Red Hills, Tuolume County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768189595538-RCK4T814SES6BTLG45W8/S.+polygaloides+in+Red+Hills.jpg Botany (more) - Strepthanus polygaloides ….a closer view in the Red Hills…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768510041733-G2VHIVW9USNHEID7PJYX/Lomatium+webberi.jpg Botany (more) - Lomatium congdonii Rare & endagerned, this species in a serpentine endemic found only in the Red Hills—so far as I know. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768526800083-UHIXFNXP34L3TLQ91APO/DSC_2713.jpg Botany (more) - Eriogonum tripodum in the Red Hills This species also occurs sparinly in eastern Lake County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771357202569-WZL4DZXDKA9C5VV8XG1P/Allium+sanbornii+var.+congdonii+at+North+end+of+Red+Hills.jpg Botany (more) - Allium sanbornii var. congdonii …north end of Red Hills… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772407420282-K06T2LDC0BND789B8KP1/DSC_5954enlarged.jpg Botany (more) - Meconella californica …along Red Hills Road… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772407632381-J6L3HSUPII1LKC9SMQWD/Isopyrum+californicum-enlarged.jpg Botany (more) - Isopyrum californicum …along Red Hills Road… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768109993396-K4E020K9CAYIVGQSM8CZ/annusLbolanderiRedHillsR.JPG Botany (more) - Helianthus annuus, L, Helianthus bolanderi, R …in the Red Hills, Tuolumne County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768527643074-URGQ1GXVDH7ONLJLMVJY/DSC_2454.JPG Botany (more) - Collinsia heterophylla (dark form) …in Tuolumne County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768527582267-CJDY8249CV2CTQU1YH8K/Collisia+heterophlla.jpg Botany (more) - Collinsia heterophylla (dark form) …again, closer view, in Tuolumne County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767219678529-NYSYAL3360P3CG0JAAB1/R.jpg Botany (more) - Cucurbita foetidissima ….near Oakdale…The next 2 photos show the same plant. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767231234772-M0R754FHE6OMV7RG4KFW/R2.jpg Botany (more) https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767231410028-9SIYGQUPIW598YMV064B/R3.jpg Botany (more) https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767292152579-VEEDXYT4W6OXW014U1HB/Cucurbita+AM+1.jpg Botany (more) - Cucurbita foetissima We found these gourds on a levee near Tracy. The photo is blurry as I screenshotted a blurry video… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767467612077-PS1C2G69R36QA9XDN37D/Sorbus%40Frog+LakeR2.jpg Botany (more) - Sorbus at Frog Lake …near Carson Pass, Alpine County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770591771398-QZWIX5D9JRU0914W12K1/Katie+Colbert+%40+Willow+Spring.jpg Botany (more) - Katie Colbert at Willow Spring …Nevada County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770591954127-9OCOWCR8H8SOT8CDUQMK/Cobra+Lilies.jpg Botany (more) - cobra lilies …same site as prior photo… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770592110589-61JYKE9PNZTCS33M109Z/Tolfiedeas+%40+Willow+Spring.jpg Botany (more) - Tofieldia glutinosa …same site as prior 2 photos… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772320960208-ZP955EVGZ41BXZN5P2XS/226bA.jpg Botany (more) - Eriogonum lobbii …on rocks along Bowman Lake Road… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770588833552-5ABB30MDHCYROD7EQTJA/Stipa+stillmanii+N.+of+Bear+River.jpg Botany (more) - Stipa stillmanii …north of Bear River, Placer-Nevada County line… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770588865960-VF4MCADEBPATOWNI8WPO/Stipa+stillmanii+inflor.jpg Botany (more) - Stipa stillmanii inflorescence …same locality as the prior photo…This a very rare plant. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770685766480-WQ00QJ6XJHFZ506U3727/Hesperolum+pumilum+old+Hwy.jpg Botany (more) - Hesperchiron pumilus …on old HWY 40 in Donner Pass… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771122816655-GBHEYIWXNJKIGSANW4E9/hwy40b.jpg Botany (more) - Pestemon newberryi …on Donner Peak; exfoliating grandiorite behind… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771124000978-TFE1IHV4XK9D4FH2S78T/HWY40aA.jpg Botany (more) - Penstemon newberryi …same site as prior photo… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770687705546-MA14TJD9DXM1O5FVXX8S/sierraval%2Bcarman+178.JPG Botany (more) - Hesperchiron pumilus …in meadow in Carman Valley, Sierra County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773982954489-Q43RCPZL09K1Y0AQNOQ8/DSC_6080.jpg Botany (more) - Lilum humboldtii humboldii …in front of the North Bloomfield schoolhouse…. ] https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773982977779-576U8XTJMB99EQST18ZA/DSC_6055.jpg Botany (more) - the same …in closer view…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771288885816-PZT6XEF4BV8CDL5F83H4/habitat+of+Lilium+parvum.jpg Botany (more) - unnamed lake near Black Mtn. …habitat of Lilium parvum….. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771288338744-36Q6RBBJGVTNJ7N6H6ZF/Lilium+%40+Black+Mtn.jpg Botany (more) - Lilium parvum …near Black Mtn.—Eldorado County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771355532986-X1WT2X3W03U18G17SVJP/black+oaks+at+start+of+Eagle+Lakes+Rd.jpg Botany (more) - high evelation black oaks …at start of Eagle Lakes Road… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771355559995-16J0WA6KNYGAT5YDVJV4/black+oak+lvs.+at+start+of+Eagle+Lakes+Rd.jpg Botany (more) - black oak leaves …at the start of Eagle Lakes Road….They should have denser stomata, as the partial pressure of CO2 is less at high elevation. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771294007747-U8TA2CBNSB7CM270UIHA/Calytridium+umbelltum%40+across+HWY+80+from+Cisco.jpg Botany (more) - Calyptridium umbellatum …across HWY 80 from Cisco…and an annual monkeyflower of which I can’t remember the name… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770766037946-562KOU7G7FC583DQFRDP/Calydium+umbellatum+across+HWY+80+from+Cisco+Butte.jpg Botany (more) - Calyptridium umbellatum ….across HWY 80 from Cisco Butte…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770688761046-EHGUPR0WVT8DJ08OXWDX/field+of+Camassia+in+Carmen+Valley.jpg Botany (more) - field of Camassia …in Carman Valley… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770700770045-28IXVJSJBHX1I12UMYQ5/Camassia.jpg Botany (more) - Camassia …closer… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769668292799-85DXDKQS4B538BW748RY/the+canyon+which+Lewisa+seratta+grow+on+the+N.+face+of.jpg Botany (more) - The canyon on Mosquito Ridge Road Lewsia serrata grows on the-facing flank of this canyon. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769670219207-C69I1OSPQYQQNGM633R5/Lewisa+serrata+habitat.jpg Botany (more) - Lewisia serrata on Mosquito Ridge Road …on metavolcanics… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769669470803-S8ORCCWYAN9Y1BHJE4BS/Lewisa+serrata+on+metavolcanics.jpg Botany (more) - Lewisia serrata …on metavolcanics… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769668363264-VW94QLDG4GC296NAH8R9/Lewisia+seratta+in+flower.jpg Botany (more) - Lewisa serrata in flower …a shy bloomer… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773700770398-GJFE2C24TBLT7B9U9VP6/whtiebark+cones+%40+Lassen+Pk.jpg Botany (more) - whitebark pine cones …high on Lassen Peak… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1773700804281-JEGMZJ6JYT157HL73FFB/whitebark+cone+%40+Emma.jpg Botany (more) - whitebark cone …at Emma Lake…do not know what causing the resin drops. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774226137862-5IRMZCG1M3DELXPO5LBN/Gaultheria+humifumsa.jpg Botany (more) - Gautheria humifusa …just outside the Lassen NP south entrance station…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771458359653-JOJU2M8E0QKT8W3J1WU2/washigtonium--Bald+Hills+Rd.jpg Botany (more) - Lilium washingtonianum …along Bald Hills Road, Humboldt Couunty… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771458397369-JT6T4QMGSVRLE1C36QHU/washingtonium2.jpg Botany (more) - Lilium washingtonianum …same site as prior photo… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771458428211-4381491S64GRQRQTKX4J/washingtonium3.jpg Botany (more) - Lilium washingtonianum …same site as prior photo… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767838905517-5ZW131926Y2ZAQUXJIMZ/Horse++MtnR.jpg Botany (more) - Horse Mountain Preserve ….Humboldt County…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767849035279-N5M6J9VKSGKWIZREBORI/SF+Mtn.+schist.jpg Botany (more) - the famous South Fork Mtn schist See why it’s famous in the following images. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767927378787-YQKS956G3PU2Q1UDWYNT/SF+Mtn+schist+closer.jpg Botany (more) - South Fork Mtn. Schist …a closer view… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767849669572-Z17QWSUFOU59VPWJVEQR/SF+Mtn.+schist+TS.jpg Botany (more) - SF Mtn schist thin section It’s supposed to be a blueschist; but I might see phengite—with foliation; and I see blue xtals in PPL, which is probably glaucophane. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767850269790-8N2S0P2DALB3Z7S1DQXU/SF+Mtn+schist+X+sec.jpg Botany (more) - Coast Range Thrust The SF Mtn. schist lies right below the CRT. It was overthrust westerly by Paleozoic sedimentary rocks. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767468837910-8S7I35RIFPYSRN4WL5HI/Horse+Mtn.+Viola+beckwithii.jpg Botany (more) - Viola beckwithii …on Horse Mountain, Humboldt County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767577187838-TJX3BZU8TUW7HDM8TDGV/Antennaria+neglecta+howelliR.jpg Botany (more) - Antennaria neglecta ssp. howellii …on Horse Mtn. Humboldt County…I have always loved this plant, with green on the tops of the leaves, and woolly white on the bottoms. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771442415951-9SAEBAQHPMI3QG3LDT17/Luina+hypoleucaR.jpg Botany (more) - Luina hypoleuca …in Humboldt County, descending the east side of Berry Summit to Hupa Valley…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771442451537-75NFAZ0CAM2DIX2HJH2G/Luina+hypoleuca+E.+of+Berry+Summit.jpg Botany (more) - Luina hypoleuca …a closer view… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768170257216-E23O0UAGEGT93R63FG2G/DSC_3293.jpg Botany (more) - Castilleja ambigua humboldtiensis …at Elk River Dunes, south of Eureka… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767675922366-HQ8VGTIKB78VRIPU8IGH/Orobanche+californica.jpg Botany (more) - Orobanche californica …..at Big Lagoon, on the beach…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768170976125-OX27C29NROYYWXMKD20D/bog+%40+Big+Lagoon.jpg Botany (more) - where we found the sundew …in the following image: the “bog” at Big Lagoon, Humboldt County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768071953476-3JGPR1E03Z9GYJ0EYBQJ/sundew+at+Big+Lagoon+bog.jpg Botany (more) - sundew at Big Lagoon bog or fen …’nuff said!… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771371862706-KGSE7O9BHB3YIOGD3PCQ/Elk+River+dunes+w.+midden.jpg Botany (more) - Elk River dunes ….a little south of Eureka, Humboldt County, CA…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771372401824-NUWWU6DUN5P266HBSVF7/DSC_8212aAa.jpg Botany (more) - Layia carnosa …fleshy tidytips @ Elk River dunes…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771372596456-BFP1ZFLT1LNL00RC7R6X/Convolvus+soldanella+%40+Elk+River.jpg Botany (more) - Convolulus soldanella ….at Elk River dunes…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771372863153-E8YOFDT9MOSLIB1BCZ7D/Abronia+pink.jpg Botany (more) - Abronia villosa …at Elk River dunes… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1769728835201-QS5OAIJXYAFVYZAPB1VR/Ccanadensis+in+fruitR2.jpg Botany (more) - Cornus canadensis in fruit This species once could found in two places close to Fort Bragg, Mendocino County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767577779298-JJ8NS9H8P8JRXEQ6WGRI/Smith+River-R.jpg Botany (more) - Smith River …at Stony Creek, where many rare plants grow, including Vancoveria chrysantha…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767480069132-EJSSDHIVE49T04WA6W5Q/V+chrysatha+R%26E.jpg Botany (more) - Vancouveria chrysantha This species is endangered. We found it at Stony Creek near Gasquet in Del Norte County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771457147507-VFLYHZ2QJNUKQVGTWU93/27.JPG Botany (more) - Arctostaphylos nevadensis ssp. knightii …named for my good friend and mentor Walter Knight…area of Gasqet, Delnorte County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767636601530-0K8YYVI6804LIJ2RUN4A/yellow+Dicentra.jpg Botany (more) - Dicentra formosa ssp. oregana We found this yellow form far out Low Divide Road, in Del Norte County. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767481711373-IZ4UM6MVEHEJ6ZCT64V7/Empetrum+nigrum.jpg Botany (more) - Emptrum nigrum …at Elk Head, Humboldt County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768864084360-NP6GO1B6MU1X2OH7BQOJ/R.++bloomeri+%40+Abbotts.jpg Botany (more) - Ranunculus bloomeri …in the bog at Abbott’s Lagoon…This species has some of largest flowers in the genus. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768864446257-O63QK0JSEN5SRPGSZF7P/Allium+dichylamedeum+%26+Castllija+wightii+%40+Pt.+Reyes.jpg Botany (more) - Allium dichamydeum & Castillija wightii …at Pt. Reyes…Can’t recall where I saw them. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770667992722-G4DR8Q9UCSNCRUQAAUV9/Lilium+maritimum+X++pardalimum+%40+Bull+Pt.+fen.jpg Botany (more) - Lilium maritimum X pardalimum …at Bull Point fen… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770668031070-354F2XOQN4OWVTK8YSJ9/Stachys+chamissonis+%40+Abbotts+Lagoon.jpg Botany (more) - Stachys chamissonis …in the fen at Abbotts Lagoon…John Thomas Howell said in Marin Flora that this one of the most beautiful coastal plants. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772044054652-3XBTEEYHN2MQYJTX19P8/Nemophila+menziesii+atomaria.jpg Botany (more) - Nemophila menzeisii atomaria …on Bodega Head… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772044088817-O93K9LTCQSP4NKQEAKOT/Nemophila+menziesii+atomaria2.jpg Botany (more) - Nemophila menziesii atomaria …on Bodega Head; closer view… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1772044125459-1VKPWNKHXZGB7Q6TP4NY/Triphysaria+eriantha+rosea.jpg Botany (more) - Triphysaria eriantha rosea …on Bodega Head… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771983978371-NMW30ISJGBB6LUNR38II/Castillea+latifoliia.jpg Botany (more) - Castileja latifolia …somewhere I can’t recall on a north coast sebluff… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767481744014-NW51W9YZG86EJXL1QSB6/locality+ofSHARPR2.jpg Botany (more) - Elk Head Like a prow of ship, it faces NW into the slamming winds. This where Empetrum grows. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768335219883-10XXNXHDKCKV9GMOSP14/Sedum+spathulifolium+Darington.jpg Botany (more) - Sedum spathulifolium WHITE! Steven Darrington found this on a roadcut south of Orick, and named a cultivar. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768433907641-8OV20VN8I677575Y3YZF/yellow+lily.jpg Botany (more) - yellow lily hybrid We saw this on a road north of Weitchpec. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768434789831-FPXS8W1BOMAQ1T8FGU6Q/Cephalanthera+austine.jpg Botany (more) - Phantom Orchid---Cephalanthera austinae We saw this on the same road north of Weitchpec.…along Bluff Creek Road, Humboldt County. Presumably this parisitises mycorhizae, like Corraloriza does. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771549707835-GU61TSVDUTD39ZHIAOPV/Phlox+adsurgens+Bluff+Creek+Road.jpg Botany (more) - Phlox adsurgens …along Bluff Creek Road, Humboldt County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771551487083-59YLL6VWVCLKYRY1EJ9F/Linnea+borealis+combo.jpg Botany (more) - Linnea borealis …along Bluff Creek Road… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771548872179-MU2493FX3S2IXUI8W65Z/Lilium+pardilum+ssp.+vollmeri+Onion+Mtn.+pond.jpg Botany (more) - Lilium pardalinum ssp. vollmeri …in wet area near a small pond near the summit of Onion Mountain, Humboldt County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767913220808-EE8U42483NFI0QJQ9ENA/beach+at+Lake+Earle+S+P-R.jpg Botany (more) - beach at Lake Earl …Del Norte County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767919498657-YZOCK0KYJAVAJ7VV3S2U/Phacelia+argentia.jpg Botany (more) - Phacelia argentia …growing in coastal dunes very close to the beach near Lake Earl... https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771372999047-XYMSUS9WJR6G3FOX24QS/114AaA.jpg Botany (more) - doug fir, Pinus contorta, & uva-ursi …south of Lake Earle, Delnorte County… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1767238401122-NCT5HDY6UDNYL4KDQOMB/Hibiscuslarger2.jpg Botany (more) - Hibiscus californica I found this plant near Lost Cabin Island, long ago. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768071280329-KZG65ETJ2SWG2JDMX8ZV/Calochortus+argillosus+on+Oursan+TrailR.jpg Botany (more) - patch of Calochortus argillosus …on the Oursan Trail above Briones Reservoir… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768027446640-CM8QVN6OHV82YNXNSWC3/Calochortus+argillosus+on+the+Oursan+Trail-DSC_4629+copy.jpg Botany (more) - Calochortus argillosus ….on the Oursan trail above Briones Reservoir…. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1768027615498-UMHMN8HVGGB3C5DB9CBQ/-.jpg Botany (more) - GIANT blue elderberry …on Hampton Road, town of Briones… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774668464209-2UBH0M4IVMPLNE6HQSCX/Styrax+flowers+decorating+basket+grass.jpg Botany (more) - Styrax flowers decoratitng basket grass …in our garden… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770512645541-C60NX8N6XKWSZUGAY6TG/Pachypodiums.jpg Botany (more) - Pachypodium namaquanum …in our garden in Martinez… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1770512693495-S70RJPFFH850YNDOE5XM/mummies.jpg Botany (more) - mummies This how wrap them for the winter—bubble wrap, covered by frost cloth. https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774666802241-IPV1JPXBMLFPS59T20G4/DSC_0176.JPG Botany (more) - Dudleya pachyptum in my collection …nuff’ said!… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774742306262-X63S3LR7Z6PSZWHHQGAN/Aloe+polyphyllaR.jpg Botany (more) - Aloe polyphylla …usually known for its spiral leaves; This shows it has beautiful flowers too… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774766336704-KSU7S2YUG1RLKDJSYH79/PleiospilosnelliiA+copyR.jpg Botany (more) - Pleiosplios nellii …the true African “living rock” (not Lithops)….among river pebbles in a container in my succulent collection… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1774665583208-XMVSAC3T2GGM6QUIBMBB/Echinopsis+in+our+garden.jpg Botany (more) - Echinopsis in our garden …nuff’ said!… https://images.squarespace-cdn.com/content/v1/55777788e4b062d1db033a12/1771483522533-29E2S2TOBLPDDJJ6NVXE/hairy+entity+in+Pyramid+Pass.jpg Botany (more) - Actomecon merriami …near Pyramid Peak in the Funeral Mts., Death Valley…