Archive for the ‘other’ Category

North point

23 August 2011

north point

This is Oakland’s northernmost point, a little wedge of land between Summit Road and Tilden Park. It’s mainly occupied by a large EBMUD water tank and is supposedly underlain by Moraga Formation basalt, though I didn’t see any.

Oakland’s southernmost point is a runway at the airport, a place I expect never to visit, although I’ve certainly flown over it enough times. But that’s artificial fill. The southernmost bit of real land seems to be just north of the San Leandro water treatment plant between the end of Eden Road and Davis Street.

Joseph Le Conte’s grave

17 July 2011

Joseph Le Conte (1823–1901) is probably the most eminent geologist in Mountain View Cemetery. Born in Georgia to a wealthy family, he graduated from the University of Georgia in 1841 and earned an M.D. in New York in 1845. Five years later he gave up his practice in Macon to study geology and zoology at Harvard under Louis Agassiz, earning a B.S. in 1851. He then taught geology at three different universities, then endured the Civil War on the losing side, before riding the transcontinental railroad to Oakland in 1869, where he became the first professor of geology at UC Berkeley and his brother John the acting president, later a professor of physics. He spent the rest of his life here. The Cal paleo museum has a page about his role during this time. A much longer memoir, by Cal botanist Eugene Hilgard, was published by the National Academy of Sciences in 1907 and is fascinating reading.

In 1870 he first visited the Sierra Nevada, a six-week excursion on horseback, and traveled the West extensively thereafter. He moved with his family to Berkeley in 1874; “He always greatly admired and enjoyed the site of the university and town,” Hilgard says. The next year he was elected to the National Academy of Sciences. Le Conte’s textbook Elements of Geology was published in 1878 and went through four editions before his death. He was a dedicated and brilliant teacher who once said, “We never know any subject perfectly until we teach it.” As a writer, I can relate to that.

He died of heart failure in his beloved Yosemite Valley, which he was showing to his eldest daughter, on 6 July 1901. The funeral was a week later. “Many came from long distances to pay this last tribute of respect to Joseph Le Conte; the regents, faculties, and students of the university, where all activities had been suspended for the day, and a long line of carriages formed an imposing procession, accompanying the body to Mountain View Cemetery, near Oakland, where it was interred alongside of his brother John. A few months later the grave was marked with a large granite boulder procured by the Sierra Club from the vicinity of the camp where he died, in the Yosemite Valley.” So the “Yosemite” engraved on the stone must refer to the place where he died. Among his achievements, Le Conte was a founder of the Sierra Club.

Hilgard wrote of him, “It was Le Conte who through whom the University of California first became known to the outside world as a school and center of science on the western border of the continent; and for a number of years he almost alone kept it in view of the world of science. His presence and connection with the University was largely instrumental in attracting to it other men who otherwise would have hesitated to emigrate from their eastern homes to what was then the outskirts of civilization; and his ceaseless scientific activity acted as a strong stimulus both to his colleagues and to the students coming under his instruction, whose affection and esteem remained with him through life. . . . His modesty and simplicity survived, unscathed, the applause and laudations bestowed upon him, and his strong will and cheerful disposition carried him up to a mature age in undiminished mental vigor, despite an apparently frail body.”

Suiseki 2011

19 June 2011

This weekend was the 16th annual show by the California Suiseki Society, held at the Lakeside Garden Center. This is what it looked like.

suiseki

In my amateur opinion, it was a strong show with a lot of variety in its 35–40 stones. Nearly all the entries were from California with a heavy emphasis on the northern Coast Range. The photos below are a few of the stones that impressed me—but there were many more that were too hard to photograph well. Unlike last year, the exhibitors picked a background paper with a color that seemed a little too intrusive to me. But you’ll see how my camera did. I’m not going to comment on the styles of the suiseki because I’d surely botch them. But the rocks themselves are generally familiar stuff, like this dark slate.

suiseki

I’m always taken with the serpentinite conglomerate of which there are several excellent examples each year.

serpentinite

This blue-green Klamath serpentinite is by Tony Saraceno. I have a nice streamworn boulder of it at About.com. That’s not a suiseki, just a specimen.

peridotite

This one is by Tom Colby. Not everyone filled out their cards, but I like to acknowledge the collectors when I can.

suiseki

Felix Rivera collected this nice serpentinite. He’s the founder of the society; see his site at felixrivera-suiseki.com where the society’s home page lives.

suiseki

And Bob & Polly Gould exhibited this exquisitely weathered marble from Southern California. At least, I think it’s marble. Doesn’t matter.

suiseki

Look for the next show in mid-June 2012, right here in Oakland.

Caldecott Tunnel and the Orinda Formation [updated]

17 May 2011

caldecott tunnel

Those of us in the geology community have been eager to hear more from the Caldecott Tunnel’s fourth bore project. The bore is cutting through the Berkeley Hills in a perfect transect, allowing geologists to sample every meter of the rocks along the way. This weekend, I heard some news in a presentation at the CalPaleo 2011 meeting.

The east end was where the boring began. The Orinda Formation is beautifully exposed there—most of it, anyway—on both sides of Route 24.

orinda formation

Much of it is coarse conglomerate of late Miocene age, about 10 million years old, that’s thought to represent landslides into a freshwater basin in the middle of volcanic terrain.

orinda formation

That part, naturally, has no fossils because the environment was too rugged for even large bones to survive. But there’s other stuff in the Orinda, like lava flows at the top of the unit belonging to the Moraga Formation. This is a view of the underside of the lava, where it flowed onto the moist sediments one day long ago.

moraga lava

And there’s a good amount of fine-grained sedimentary rock, suitable for preserving fossils, as you move down section toward the hills. Caltrans has a contract with PaleoResource, a well-regarded firm, to monitor the work and recover fossils that turn up. In the initial digs, the scientists found and cataloged thousands of items, including lots of fish fossils, clams and crabs, birds and the first leaf fossils ever found in the Orinda. The press tends to zero in on large mammals, though, so we’ve heard about bones from wolverines, horses, rhinos, camels, pronghorns and even the obscure oreodont.

However, PaleoResource scientists have told me that Caltrans has not allowed the paleontologists into the tunnel proper, in violation of the contract and the agency’s own policies. That’s the kind of thing that makes me awaken at night and grind my teeth. Not only are we not learning about the lower Orinda Formation, we’re not studying the transition into the underlying Claremont Formation and the Sobrante Formation on the west side.

I try to take the long view. The tunnel is being dug in three passes, and conceivably the rocks can be sampled later. But PaleoResource officials have told me their contract runs out this summer, before the next phase of digging.

So I try to take a longer view. Once upon a time, nobody cared about paleontology. Heck, they didn’t care about archaeology. Today, turning up a human bone will stop a job in its tracks. Fossils aren’t that disruptive; they can be salvaged and documented in a day or two. Many agencies and jobs go well, the paleo people and the construction people interacting well and yielding good science. Other jobs are jobs from hell, but the long arc of history is curving toward respect for science.

Update: I’ve put up some photos of new fossils from the dig on KQED Quest Science Blogs.

Geological Designs

19 February 2011

Block by block, I’m exploring Oakland. In West Oakland there isn’t much geology, but it has a thriving (or at least widespread) stone district. This small fabricator is on Peralta Street.

geological designs

This steel sign above the lovely window screen shows that the company name is actually “designs,” not “design.” So does Google.

geological designs

Stone, like concrete, brick and aggregate, is among the first things a new settlement demands. Like their wares, stone dealers seem to hang in there for the long term. I find them charming, but of course even stone has fads and trends and every other challenge a business experiences. The extra challenge of a stone business, I suppose, is gravity.

Stone shops tend to cluster around heavy transport, and an old rail line runs past this address. Other stone yards occur in East Oakland near the tracks there. And another common site for very specialized stone businesses is near cemeteries. I often stop and admire the monument shop on Piedmont Avenue just down from Mountain View Cemetery.

By the way, I have a new gig with KQED Quest as one of their science bloggers. My posts go up Thursdays at www.kqed.org/quest/blog.

Fake rocks

28 January 2011

The Hillcrest School, up in upper Rockridge/Broadway Terrace, has a beautiful campus with gardens, trees and this play structure.

fake rocks

I wish it were real rocks. Of course the artificial outcrop is good for encouraging unstructured play, confidence using one’s body and all the rest. The lessons it teaches will serve the kids well as they move on to indoor climbing walls and other safe amusements. But I cherish grit, lichens, little holes with secrets inside, moss, roughness that scratches to get your attention. I favor visual texture, variegation, the presence of minerals in their cryptic typicality, the possibility of fossils. I want kids to explore wild rocks in wild places, even if it’s only a roadcut or a vacant lot. I think these kids deserve a real, local knocker, the kind their neighborhood abounds in. We have enough fake rock in our Disneylands and along our freeways.

Thank you.

Northbrae rhyolite

27 December 2010

Berkeley is full of interesting rocks, many of them preserved in pocket parks. The most prominent of these is Indian Rock.

indian rock

Click the photo for a 1000-pixel version. Some 100 years ago this tough rhyolite, a volcanic rock very high in silica, was mapped as part of the same rock body as the one in Leona Quarry and farther down along the hills. But a master’s student at Cal State Hayward gave it a good look in the 1990s and determined that the Northbrae rhyolite, as this occurrence was named, is quite a different rock. (In fact the Leona rhyolite isn’t considered a rhyolite any more, but rather a high-silica welded tuff/volcaniclastic sequence.) Whereas the first mappers thought that both rocks were Pliocene, which is quite young (about 5 million years), the Leona was later shown to be Jurassic (about 150 m.y.). The Northbrae is not that old, but neither is it as young as Pliocene. It’s just a little older than the Moraga Formation basalt and the volcanic rocks of Sibley volcano, about 11 million years, making it Miocene. It came out in that same episode of eruptions, which today sits to the north around Clear Lake and The Geysers.

And it’s still definitely rhyolite. Rhyolite is the stiff, slow-moving lava that makes up little volcanoes like the young dome inside Mount St. Helens, or the rugged knobs of the Inyo Domes, over the Sierra in the Mammoth Lakes area, or farther south in the Coso Range. It makes great rock for climbers—strong, imperishable, full of handholds and rarely giving way under a person’s weight.

The rhyolite of Berkeley is well worth a visit. Just go at a time when the climbers aren’t busy; the rock parks swarm with them in nice weather. I don’t think Oakland has any of this rock, but it might.


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