Black geology matters

8 June 2020

Since my last post two weeks ago, the dreams of black Americans, deferred so often and so long, have once again exploded. I’m at risk for the Covid virus and not the type to join a march; still I have support to offer from this peculiar pulpit.

Geology is the whitest science in America. The geoscience community knows this, doesn’t like it, and keeps trying different ways to remedy it. I know this, I don’t like it, and I keep trying here in what I hope is a neutral way to expose you, whoever you are, to the geological wonders of this most excellent place. My hope is that adults will catch a spark of insight from me and pass it around, or nurture it within themselves, and bring this special side of our landscape into Oakland’s public affairs and popular culture for everyone’s benefit.

The special sauce of science is its neutral, trans-human point of view, in which new knowledge is born from the encounter between nature and the pure intellect. This viewpoint feels natural to folks like me, born in suburban white America to educated parents with good intentions. It’s an ideal that fosters a freedom to follow our curiosity wherever we wish.

My life since childhood has been one of dawning, then growing awareness that I grew up within a historical and political system with deep taproots in racism. Our inner lives are affected by how white people treat us. Duty calls upon white people in general to see this clearly and act accordingly. This post aims mainly at people like me.

That neutrality so tempting in science can be treacherous by masking us from ourselves. Inevitably, what we are affects what we see. To illustrate this point, I bring you the life of the notable geologist Joseph Le Conte. Well, a few years ago in this space I brought you the shallow, all-lives-matter version of his life. Since then I’ve looked more deeply and have more to say.

Joseph Le Conte was born on a Georgia plantation in 1823 and spent a cloistered, pampered childhood there. From the earliest days his mind sought the purity of nature and the comfort of social order. He passed the Civil War as a loyal Southerner in all respects. Le Conte first visited the Sierra Nevada in 1870, chaperoning a slapdash horseback expedition of Cal’s first undergraduates. In 1875 he published an edited version of his notes as “A Journal of Ramblings through the High Sierras of California.” (The Sierra Club reprinted it in 1900.) In the entry for 25 July, their fifth day on the road, comes this jarring passage:

Soon after leaving the plains, we stopped for water at a neat hut, where dwelt a real “old mammy,” surrounded by little darkies. On inquiry I found she was from Jackson County, Georgia, and formerly owned by a Mr. Strickland. She had come to California since the war. I was really glad to see the familiar old face, and hear the familiar low-country negro brogue; and she equally glad to see me. She evidently did not like California, and seemed to pine after the “auld country.”

That Le Conte saw fit to publish this vignette, deliberately and after reflection, says much about his and California’s deeply ingrained racism, but I want to note that it reveals the depth of his self-deception. This is the reminiscence of someone raised in “free plantation life” on the throne of white boyhood, but who never had to wield a whip on a human being or sign a human being’s bill of sale with his own hands (his share of the family’s property had an overseer).

By excusing the life he was born to on the basis of racialized Darwinism, he could wash his hands in pure intellectual water. It was only pure scientific truth and plain fact, he long argued, not a matter of malice or evil, that blacks were low and whites were high. And the lofty white intellects he prized most were in polite agreement (or mild, polite disagreement) with him. The key was that the men were articulate, mutually respectful and never raised their voices.

This man had a prominent role at UC Berkeley for thirty years, where he taught geology. He was named to the National Academy of Science in 1875. (“I might have been elected sooner,” he wrote in an autobiography, “but for the iron-clad oath of uninterrupted loyalty to the United States, which of course I could not take.”) He wrote textbooks and taught classes and all the while gave high-minded cover to the vicious forces of discrimination. Today UC Berkeley’s geoscience department is first-rate — I have no aspersions at all to cast on it — but it has a history embodied in its campus home, named Le Conte Hall.

We didn’t raise a statue to Le Conte, but we have erected monuments with his name on them: a Sierran peak, a college building, a city street, a children’s school and so forth. Those things are fair game for discussion and action. We are not to blame for our history, but we are responsible for it.

To get back to the moral, the neutrality of science is only the promise, not the guarantee, of a benign worldview or a neutral career. It’s not fair of me to suggest otherwise. What do white geologists owe this moment? I say we need to offer more effective help to those who don’t enjoy our privileges, people who are minoritized. They have reasons not to see the world as a reasonable place. They have reason to suspect our science as part of white hegemony.

A petition for geoscientists (which I’ve signed) puts this part of the problem well: “Geoscience is intimately tied to fossil fuels, mining, environmental contamination, atmospheric pollution, water quality, natural hazards, parks and tourism, and climate change. Black, Indigenous, and Latinx People and other minoritized groups are disproportionately impacted by limited access to these resources, and the negative impacts of each of these.”

We also need to admit that the minoritized have real reasons to beware being out in the wild, poking at rocks and acting unusual. I’ve encountered people who challenged my presence, and I know it’s easier being white. The minoritized need our full support in visiting the outdoors freely, without fear.

Of course black folks are doing their own work, through organizations like Outdoor Afro (founded right here in Oakland), the National Association of Black Geoscientists, the American Association of Blacks in Energy and others. For its part, the Geological Society of America presents a prize each year, the Bromery Award, to worthy scientists from minoritized communities. Nearly every awardee mentions the special problems that nonwhite geologists experience.

But white folks need to open up, open up more, and do their part. For my part, I recognize that each of Oakland’s communities has its own idea of what the hills mean, what earthquakes mean, what the land around them means, who got the benefit of our natural resources and who did not. I’ve visited every bit of this town, including places some folks fear to go, and everywhere I’ve learned something about the variety of human and natural experiences Oakland contains. I want to listen harder, study deeper, avoid unintentional offense, spread knowledge and cheer, and help in whatever ways I can to set things right.

In search of lime

25 May 2020

I like to brag that Oakland contains more rock types within its boundaries than any other city in America. But alas, it’s missing one of America’s most widespread rock types: limestone. Yes, there are pods of dolomite limestone in the Claremont Shale, but that’s a far cry from what Oakland’s first outside settlers hankered for, which was real calcite limestone.

Limestone is essential for civilization because it’s the default industrial source of lime (calcium oxide or hydroxide), without which you can’t manufacture any kind of decent mortar, or plaster, or cement. Lime has been made for thousands of years by simply roasting limestone, which consists of the mineral calcite (calcium carbonate). This was traditionally done in a lime kiln, a stone furnace that was loaded with rock and firewood.

The Bay area does have bodies of limestone, and these were staked out early. But the nearby firewood supplies (i.e. forests) were soon depleted, and the industry was fitful and limited until reliable supplies of coal and, still later, oil became available.

One alternative to limestone in Oakland was oyster shells, which we once had in abundance. Unfortunately, many of the old Native shellmounds had oyster shells in abundance too, and this led to the end of them.

A few years ago I had the chance to visit the remains of an old-fashioned lime kiln in the Santa Cruz Mountains.

Another old site was on the coast near Rockaway Beach, south of Pacifica. I wrote a piece about it for KQED a while back that explains where most of our local limestone comes from, tectonically speaking.

This kind of industry lasted only a few decades. Around the turn of the last century, big manufacturers started to mine massive bodies of limestone. One was on the Santa Cruz County coast at Davenport; it supported a company town out there for a whole century. Another was in the South Bay near Cupertino, based in a quarry on Permanente Creek. One of Henry J. Kaiser’s early companies operated it, and when Kaiser eventually became head of an industrial giant, during World War II he took the name Permanente for the name of his innovative company health-care plan. The quarry is still digging, almost 80 years later.

By Steve Jurvetson from Menlo Park, USA – – image description page, CC BY 2.0, from Wikipedia commons

Another big limestone quarry was in American Canyon, in Napa County. But the one that fascinates me most is the former Cowell lime quarry, which sits between Walnut Creek and Concord, on Lime Ridge. For about 40 years, starting in 1908, this quarry exploited a thick deposit of travertine — hot-spring limestone. It supported a company town too. Now some of the workings are in Lime Ridge Open Space, where you can scrutinize these unusual deposits. They aren’t like anything else around.

This post was inspired by my maniac brother Steve, who explores the woods around his Lyme, New Hampshire home to locate old cellar holes. Now he’s branched into old lime kilns.

In other news, I’m happy to report that the latest Covid-19 guidelines now allow the use of public transit for outdoor recreation. This means that all of my geology walks and rambles can be undertaken again, and I’m looking forward to getting out there, taking due care of course.

Decorative blueschist

11 May 2020

Since the shutdown I’ve been scrupulous about going out only on essential business. Yes, my idea of essential is wandering around with one eye on the ground, the other on the landscape and my mind in the clouds, but it’s not really essential. Basic, baseline exercise is essential, and I can get that in with a walk of a mile or two.

That said, a walk of a mile or two can take you to lots of interesting places no matter where you live. The upper part of Fairmount Avenue is within that perimeter, and that’s where this stone wall caught my eye. Oakland’s houses of a certain age occasionally feature our local blueschist, and this is a particularly striking example.

Just a few feet farther, the scope of the work emerges.

The entire front of the property, plus the long stairway to the entrance including the risers, employs this stone to dignified effect.

Blueschist can be garish, but here it complements both the concrete and the Craftsman house in color and texture. I took a close look at it to compare with its appearance at various Oakland locations. The stone is unusually sound and was apparently quarried for this purpose. I don’t think rock yards carry this kind of unfashionable stone today — it’s hard to source large, consistent quantities, and artisanal stonemasons are no longer as plentiful as they were a century ago.

I don’t know any commercial sources of rock like this, although it’s conceivable the old Hutchinson quarry in El Cerrito, where the recycling center is today, used to yield some from its upper level. I suspect it came from a pit in the Crestmont/Serpentine Prairie area. This big exposure on Old Redwood Road shows the general quality of the rock up there.

Some of the rock in Crestmont is a pretty close match, but in general it’s more fractured and pocked with carbonates.

I suspect, but have no way of proving at present, that this old pit at the back edge of Serpentine Prairie was the source. Our serpentinite/blueschist isn’t useful for crushed stone, and although “a few tons” of poor-quality asbestos was once mined up here, this particular rock has no sign of containing tempting amounts of chrysotile. So that leaves decorative stone as the most likely product.

And that reminds me that I need to visit the meadow up there soon, for the exercise.

Pill Hill

27 April 2020

Pill Hill, an odd outlier of ancient alluvial gravel in North Oakland with a long history, rises almost 50 feet above its flat surroundings. Today it’s thoroughly encrusted with buildings, as seen here looking up Broadway from the YMCA gym building and down Broadway from the Kaiser hospital parking structure.

Beginning in the 1860s it was known as Academy Hill or College Hill for its private schools in gracious settings, which included St. Mary’s College, the Pacific Theological Seminary (now the Pacific School of Religion on Berkeley’s Holy Hill), the California Military Academy, the Pacific Female College, Hopkins Academy (where publisher J.R. Knowland started his first newspaper as a student), and other long-gone institutions.

Although the hill started out as bare grassland, after a few decades of landscaping the location was described in 1885 as “healthful, retired, and beautiful” and was served by horsecar lines on both Telegraph Avenue and Broadway.

Anthony Chabot built the first reservoir of his Contra Costa Water Company here in 1868, near today’s Summit Street and Hawthorne Avenue at the hill’s highest point. It held a million gallons of Temescal Creek water, and Academy Hill institutions may have been early customers supplementing their own wells. See its location on the 1878 Dingee Map:

and here’s the spot today.

The 1949 USGS topographic map shows the hill lovingly outlined in 5-foot contours. Given all the construction and digging done here since then, I think not even a modern lidar survey will ever match the fidelity of this map.

You can see that all the academies were gone by then (except for Grant Senior High, now the Zapata Street Academy), replaced by hospitals. Hence today’s name of Pill Hill. Probably the availability of large land parcels, the subsequent improvement of the water supply, the great street access, the advantages of a concentrated healthcare district (including the original Samuel Merritt College) and the attractive setting favored this change. When Pill Hill’s three big hospitals combined in 1992 to form Summit Medical Center, it was the hill they shared that inspired the name. The views from the hill, especially from the higher hospital floors, remain excellent.

Pill Hill is part of the widespread body of old Pleistocene-age gravel that I call the Fan, specifically lobe 2. Here it is on the geologic map.

Where this material extends across 27th Street, there’s a low hump in the road that the builders didn’t bother to flatten.

And at its north end, the construction of I-580 wiped out the hill, but a little bit still extends into Mosswood Park. This cut in the low rise at the park’s south edge may expose the gravel, but of course I can’t dig into it.

The rest of the hill’s periphery is an abrupt edge; this view west from Broadway down 30th Street is typical. I showed a few more views of the hill in this post from 2011.

The gravel of the Fan is considerably older and more consolidated than the alluvial plains around it. Exposures are very difficult to find, which is maybe why I’m a bit obsessed. The official description of this map unit (Qpaf, Quaternary (Pleistocene) alluvial fan) includes the tantalizing bit that they “locally contain fresh water mollusks and extinct late Pleistocene vertebrate fossils.” I did present one good (short-lived) exposure here in 2015.