Archive for September, 2010

Big Rock at Lake Temescal

27 September 2010

I was at Temescal Regional Recreation Area yesterday—you probably call it Lake Temescal—and was happy to spot one of my favorite places.

big rock

This big hunk of Franciscan something-or-other sits near the head of the lake, displaying the ugly attractiveness that the French call jolie laide. Not a hundred feet away runs the Hayward fault, and there’s a free-running stream here too. Some classic oak trees shade picnic tables, and you can even swim where fish can nibble your toes.

Big Rock is the place I used to illustrate my post “Leave the Stone Alone.” Because for some reason, people seem to respect Big Rock.



22 September 2010

A few places in Oakland feature these sandstone blocks. Two I can think of immediately are on Lakeshore Avenue, including this one.

sandstone blocks

I always wonder whether the stones were salvaged from somewhere else, like Andy Goldsworthy’s wonderful “Stone River” on the Stanford campus. They have tool marks on them, and I don’t know much about stonecarving tools, but I’ll bet they haven’t changed in centuries. These stones echo the most ancient practices of civilization, in which building stones were recycled again and again without regard to the structures they previously gave life to. The stones were precious in bulk rather than as individuals, the way that gold bullion is precious.

These stones always remind me, every time I see them, of one of William Randolph Hearst’s greatest follies. He purchased an ancient chapter house, built in Spain by Cistercian monks in 1190, and shipped it to California as disassembled stones. He never got around to putting them back together again, and as I recall the story, they sat in a pile somewhere in Golden Gate Park. (That’s probably an exaggeration, but who knows?) Now those stones were precious in the way that old gold coinage is precious—they embody history. These days we are a sentimental people, and the Spanish stones have a bit of holiness in them, as if the monks’ prayers had saturated them. Scattering them on the ground in a strange land is an affront to their previous owners.

That’s why I loved today’s Tribune column by beer writer Jay Brooks. A California branch of the Cistercians, the Abbey of New Clairvaux north of Chico, has acquired the stones and plans to reassemble the chapter house using the profits from a series of Trappist-style beers to be made by Sierra Nevada Brewing next year. The Trappists are the order of monks that include the Cistercians, and they’re famous for brewing Belgium’s greatest beers. That’s worth a toast.

Basalt at Joaquin Miller Park

13 September 2010

Oakland has a long narrow strip of basalt mapped along the Hayward fault between Park Boulevard and Seminary Avenue, but it’s hard to find outcrops of it. I remember searching for it in the valley south of the Mormon temple and coming up empty. There’s supposed to be a bit of it in the hill at 98th Avenue that deflects Arroyo Viejo, though that’s so shattered that it’s hard to tell what you’re looking at. But in Joaquin Miller Park there’s a second tendril of the basalt running from under Joaquin Miller High School up the creek bed. There’s a nice exposure along the road next to the Browning monument, where this chunk sits.

joaquin miller basalt

The bluish color is correct; like the serpentinite around it, this rock is of Jurassic age and is part of the Coast Range Ophiolite, and a long history of burial, compression, upheaval and tectonic motions has left it rather altered from its original looks. But once it was a thick flow of oceanic lava. In fact, I may be fooling myself in seeing the vague remains of lava pillows in this roadcut:

joaquin miller basalt

I didn’t have the time (or the magnifier) to examine this closely—just another question to follow up on some time.

At some point in the next few days, I’ll be finalizing the contents of a new interpretive sign that will be installed at the park. Along with the usual subjects of plants and animals and human history, the rocks will get their due.