Archive for May, 2008

The top knocker of Mountain View Cemetery

17 May 2008


Up at the very top of the public part of Mountain View Cemetery is this knocker. I think it has a mixture of rock types in it, but I haven’t lain down on it with my magnifier to tease them out. For now let’s call it greenstone, which is how the area is mapped. The stone is a bit dirty, unlike every other knocker in the yard. The groundskeepers ought to give it a good scrubbing with a water jet.

Across the road from here the other week, I passed a pile of rock and soil from a grave excavation and fingered a few of the stones—looked like a gray basalt. Greenstone is a mildly metamorphosed basalt; it often has wiggly veins of carbonate. See three examples starting here. It is somewhere between about 160 and 70 million years old, that is, Jurassic to Cretaceous.

The view of the bay and the city from up here is fantastic. The view of the hills has potential. The cemetery is slowly getting rid of the eucalyptus along the east side, and more and more of the lush hills and neighborhoods is visible every year.

Oakland Earth Art

14 May 2008

stone flower

In front of a building on Jean Street near Grand Avenue is an installation of stone-based artworks by Richard Botto. In my essay on Earth art over on my site, I distinguish several varieties. This kind ranks low on the scale of sublimity or artistic rigor, but it is a lot of fun to look at and quite a commitment to beautification of the public space. And, of course, it gets people to see rocks.

Dracena Park, Piedmont

9 May 2008

dracena park

Dracena Park is a repurposed quarry pit in lower Piedmont. The quarry was started in 1852 by Walter Blair, at the head of Pleasant Valley Creek (now culverted under east Grand Avenue), and supplied stone for Oakland’s first streets. After it was closed, the City of Piedmont used it as a maintenance yard, then converted it to a splendid park with an enchanting lawn surrounded by a walkway. At the entrance is a sturdy, attractive new play complex; to the north is a narrow ravine where the headwaters of the creek once flowed.

dracena park

The stone appears to be a faulted mix of sandstone and basalt of the Novato Quarry Terrane of the Franciscan complex, like the rest of Piedmont and its surroundings. Here the two rock types are juxtaposed. I’m eager to come back and poke around these rocks some more — with my hammer left at home, of course.