Archive for December, 2008

View of “Mount Ararat”

31 December 2008

mount ararat oakland

One of the geologic puzzles I worked on during 2008 was the identity of “Rockridge Rock.” One candidate is a crag along Acacia Avenue once known as Cactus Rock; another candidate is an outcrop that supposedly was dynamited away in the early 1900s. I’m reluctant to accept either as the true Rockridge Rock without better evidence. In the meantime I’m intrigued by the hillock called “Mt Ararat” on an old map of the area. It’s topped with a bedrock eminence that’s almost completely hidden by homes and trees, but if you remove those (and there’s good historical reason to do that) I think what’s left is a legitimate candidate. This summer, while exploring the ground north of Mountain View Cemetery, I got a fair shot of the hill. Click the photo for a larger view.

I’ve been too busy to carry my search further lately, but I haven’t given up.


29 December 2008


I’ve kept this photo around for a long time, but I still can’t say exactly why. It reminds me of shots of Montmartre in Paris. It’s looking southeast toward the intersection of Park Boulevard and Chatham Road, which becomes a freeway onramp at this point. The road in the front is a nameless alley that branches off Excelsior Avenue, serving a tiny block of just nine houses.

I guess the shot exemplifies the hidden treasures of Oakland, hundreds of them, visible only to those who go about on foot with their eyes open. Not all of them are about geology. On top of the geologic palimpsest, the land bears another whole layer of human history: streets and lots laid out and partially erased leaving remnants and traces, not all of which can be deciphered. The people who witnessed the changes pass on, and details vanish. It is something like geology, whose story is likened to a newspaper with most of the pages torn out and the rest burned.

Presenting the Oakland geologic map

25 December 2008

geologic map

Time to share my geologic map of Oakland, adapted from USGS Miscellaneous Field Studies Map MF-2342. That map covers a much larger area, but I’ve cropped it to Oakland and faded out the neighboring cities. You’ll note the slash of the Hayward fault. Also note how much of the bay shore is fill. Click the photo to access the 2400×2400 version.

I know you’ll enjoy staring at this. Feel free to copy the file to your own machine and view it at your leisure.

Happy holidays! By the way, I have a challenging Christmas geo-quiz up on today; answers tomorrow in a separate post, so as not to spoil the experience for latecomers.


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