Blog Profile / Oakland Geology


URL :http://oaklandgeology.wordpress.com/
Filed Under:Academics / Geology
Posts on Regator:318
Posts / Week:0.7
Archived Since:March 16, 2008

Blog Post Archive

Brooklyn Landing, Brooklyn Creek

The first Western inhabitants of this area, the Peralta family, were horse people rather than boat people. They did much of their business, with the mission and the town of San Jose in the South Bay, by land. When they did use boats, it was to transport hides and tallow from their ranch, using an […]

Oakland builders, what are you thinking?

Californians have always known we’re prone to earthquakes. The first Californians didn’t have our worries about it, though, because their structures were small and limber, no larger than a temescal sweathouse. Things changed when the missionaries of New Spain came into the country starting in the late 1700s. When the earthquake of 8 December 1812 […]

Adeline rise

Down at the foot of Adeline Street, past Green Valley Food, past J. K’s Brickhouse, past Magnolia Oakland at 3rd Street, the road ends at the old shoreline. Where the Amtraks roll by was once coastal marsh. The geologic map uses an old pre-earthquake topographic base, so ignore the freeway and find Adeline, running through […]

South Dunsmuir Ridge

I finally got to a sweet corner of town last week, the sunny side of Dunsmuir Ridge, this lovely hill in the Google Maps 3D view. The view is to the north-northwest, such that the Hayward fault runs straight up about a thumb’s width from the left edge. The maps below start with the 1915 […]

Geology of the Biff’s site

Because I walk through the area regularly, I’ve kept an envious eye on the excavation at the southeast corner of 27th Street and Broadway. Since the building slated for the site doesn’t have a name yet, I’ll call it the Biff’s site after the much-loved but long-departed Biff’s Coffee Shop that once sat there. It’s […]

The Dimond Canyon water gap

In a city full of geologic features, Dimond Canyon stands out as a classic example of a water gap. But it can be hard to see, even from the prime viewpoint of Leimert Bridge. Let’s abstract ourselves by studying the overhead views shown in maps. Google Maps, with the terrain view turned on, is where […]

Stonehurst Creek

Stonehurst Creek isn’t really a creek, just a stormwater channel. But there it is on the watershed map, with a name and everything. Of the 13 named tributaries that feed San Leandro Creek, it’s the last one before the Bay. And it’s got potential. I only discovered Stonehurst Creek because one day last June I […]

Mountain View Cemetery: The Bay area’s best landscape

Although I’m tempted just to let the photos in this post stand on their own, let me make a case that Mountain View Cemetery offers the best landscape in the Bay area. First there’s the cemetery itself. The managers have been putting a lot of effort into improving the ground — see the excellent new […]

What I marched for

Saturday was Earth Day, an occasion that usually leaves me lukewarm at best. But this year it was also the day of the worldwide March for Science. A few news stories have quoted environmentalists who resented that the march happened on “their” day. But from my viewpoint, that’s the best day of the year for […]

The Hayward fault at Warm Springs

Every extension of BART opens up a new region accessible to geologizers using public transit. So the other week I paid a visit to the far end of the Hayward fault, less than a mile from the new Warm Springs station in south Fremont. The station has nice views of the San Mateo Peninsula mountains […]

Shepherd Canyon landslides

Last week I went to visit a landslide that had been in the news. As it happened, I saw three. Shepherd Canyon always gets a lot of landslides, like its neighboring canyons in the high hills. The main reason is that Shephard Creek has a lot of cutting power, thanks to its relatively large watershed […]

East Bay diatomite

The geologic map I rely on for this blog — U.S. Geological Survey map MF-2342 — extends north to Pinole, where it shows this little pod of rocks labeled “Tsa” and “Tdi” between Pinole, El Sobrante and Richmond. Both units are of early Miocene age: Tsa stands for sandstone and Tdi stands for diatomite. The […]

Origins of Oakland ocher

Before Europeans came into this country, the locals treasured the ocher deposits in the East Oakland hills. Ocher is the name for a variety of clay-like, iron-rich minerals with a color range from yellow to red to brown. For tens of thousands of years, we’ve used ocher as pigments and preservative coatings. Some cultures would […]

The marine terrace of Clinton, lengthwise

A few years back I showed you a view across the flat marine terrace where the old town of Clinton once sat, back in the 1850s. To really get a sense of it, walk the length of the terrace some time. Here it is on the geologic map, marked “Qmt.” The photos below (1000 pixels) […]

Rubbing rocks

Rocks interact with animals of all kinds. Obviously, lizards and voles and snakes and woodchucks live on rocks and/or dig under them. Humans paint on rocks and move them around and blow them up. Today, however, I’m going to talk about animals that scratch themselves against rocks — rather, rocks that animals have rubbed for […]

Old fill and made land

Between the 1840s and roughly 1960, the Bay area made colossal amounts of dry land through “reclamation,” a euphemism for filling in marshland with whatever was handy. Oakland was no exception. Here’s a portion of the geologic map centered on Jack London Square, Oakland’s original harbor. Reclaimed land, or artificial fill, is shown in pink. […]

Artifacts from the history of geology

I had the good fortune last week to join a gathering of the Explorers’ Club at the great David Rumsey Map Center, a famous collection housed since 2016 in the Green Library at Stanford University. Laid out for our enjoyment were precious original maps from the 18th century West Coast exploring voyages of Vancouver, La […]

Two bits of gabbro

I’ve noted that while the San Leandro Gabbro has a presence in easternmost Oakland, it’s hard to find. The geologic map shows what seems like a lot of it, marked “Jgb” for Jurassic gabbro. But if you poke around on the ground, nearly all of those sites are inaccessible due to steep woods, roads or […]

The Idaho connection

I’ve been getting into the weeds as I work on my book manuscript about Oakland’s geology (tentative title, Deeper Oakland). Where did Oakland’s rocks come from? Specifically, how did they get from where they formed to where they are? This problem is particularly vexing for the older rocks with Mesozoic ages. The western edge of […]

A march for science

On Earth Day this year, April 22, an unknown but large number of scientists will be gathering together, in Washington and other cities, in a March for Science. I’ll be joining them somewhere in or near Oakland. Not only is science central to my being, it’s also central to our civilization. As the March for […]

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