Archive for June, 2010

Twin peaks (Grizzly and Vollmer)

29 June 2010

There’s a wedge of land between the southern end of Grizzly Peak Boulevard and Skyline Boulevard that belongs to the Sibley Preserve. (It’s the little knob on the left edge of this blog’s banner image.) It has good views all around, like this one looking north-northwest. Click the photo for a larger version.

twin peaks

The peak on the left is Grizzly Peak, 1754 feet high. The peak on the right is Vollmer Peak, 1905 feet high. Both consist of basalt. Grizzly Peak’s rock is basalt of the Moraga Formation, the same stuff exposed in upper Claremont Canyon and in Sibley itself. Vollmer Peak is held up by a slightly younger unit, the Bald Peak Basalt. The bulge between is Chaparral Peak; it and Grizzly are part of Frowning Ridge, which ends in the green ridge below Vollmer Peak in this photo.

Grizzly Peak appears to be unambiguously part of Oakland, nestled in a sliver of territory between the UC campus and the county line. It isn’t Oakland’s most northerly bit of land, though. Another bit lies north of Grizzly Peak Boulevard and Golf Course Drive. I’d like to visit both spots.


The human overlay

22 June 2010

Oakland’s landscape has changed a lot over the years. The first settlers saw none of this but the sky and the hills; the foreground was grasslands teeming with grazers, wolves and grizzly bears. Even the grasses were different. The hills didn’t have the big quarry scar, and there were no palms. The view is much prettier from directly above this spot, in a BART car heading south out of Fruitvale station.

human overlay

Click the photo for an 800×633 version.

Oakland geography

8 June 2010

I don’t always poke around Oakland’s innards, its rocks and landforms and geologic history. Most of the time, I actually just enjoy the place.

lake merritt

Geography is what geology, climate, history and culture all add up to. Round Top and the ancient volcano it embodies, the hills and the sea air riding up their flanks are merely the stage for Oakland’s beautiful humanity. It is a magnificent arena, where you can see people from every part of the world in one place.

I seem to have caught up with my long backlog of photos and topics. It’s time to get outside again. What questions about Oakland’s geology are on your minds?