Dracena Park, Piedmont

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.

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.

Protect our City from waste

I’m not trying to single out one person — you can tell because this flyer is from an earlier election — but it illustrates something I think about often. Until civilization came along, there was no such thing as waste. Browsers leave stubble and turds, predators leave bones, and the bacteria handle it all. Monkeys are omnivores and drop lots of stuff, all biodegradable, from their nimble fingers. We are monkeys too, but our fingers and brains are too good at their jobs. We’ve invented stuff the bacteria can’t deal with yet. We drop it all over the place. The human age will be known to future paleontologists as the Age of Hominid Litter.

Watch someone drop litter in the street some time. That casual, automatic act might look like default behavior, what monkeys do as they roam the woods. But the style with which people do it, from their stance to their glance, is learned behavior, a product of culture. They release their trash with panache. You just know that if you called them out, they would be offended. So today Oakland is a shabby city. Too many of its inhabitants don’t see it as a home to care for, just a setting for doin’ shit.

To do otherwise — putting wrappers in pockets or waste receptacles, automatically — can be learned too and done gracefully. I learned it and I simply don’t litter. But can a whole civilization become sustainable, acting with, as Whitman called it, the prudence suitable for immortality?

The Old Tunnel (one of them)

The former car tunnel through the Oakland hills had its entrance (or its exit, whichever you prefer) here at the top of Tunnel Road. The road is very popular with bicyclists now, and in the five years since I took these photos new houses have been built and things cleaned up in general.

At the little space in the intersection where the fare gates must have been is this pedestal and plaque. Would love to hear some of the history of this.

And, of course, the rocks. Here we have the Claremont Chert so typical of the northern Oakland hills. I need to visit here again soon, although it’s probably less accessible now.

The other old tunnel is at the top of Shepherd Canyon, where the train used to go.

North knocker, Mountain View Cemetery

Continuing my inventory of the knockers of Mountain View, this is on the far north end of the cemetery, along the lowest of the three roads back there. It appears to be the coarse, tough sandstone—technically a metagraywacke—that makes up the majority of the Piedmont block. I can’t always tell what a rock is at the cemetery because I can’t whack it with my hammer. Don’t you try that either.

Managing the lake

Lake Merritt needs a lot of care and attention to perform at its top level. This view of the pergola at its east end shows one of at least three aeration fountains in the lake. Without the oxygenation provided by these fountains, the organic matter brought in by the tides and streams, and deposited by the abundant bird population, would periodically overwhelm the natural oxygen dissolved in the water and turn the lake into a stinking anaerobic pond.

Without upkeep, this site would quickly revert to the tidal marshland that it once was. That would be nice in its way, but city-dwellers would probably complain about it. Click the photo for a postcard-type view of this end of the lake taken last weekend.

A fault runs through it: Montclair

The Hayward fault runs through the heart of Montclair, in the Oakland hills behind Piedmont. Montclair Park’s duck pond was constructed where the fault left a natural sag in the ground.

Only in seismologists’ equations, and perhaps deep down in the crust, are faults smooth, flat planes. In the world, on the surface, faults are as ragged and variable as any other geological feature. The Hayward fault is more of a zone, from a few to a hundred meters in width, with several fractures running through it. Where two strands overlap, a block of ground between them may slump in tension or rise in compression, depending on how the strands are oriented. At Montclair Park, two strands are mapped on either side of the sag basin. Lake Temescal is another example of a sag basin repurposed as a water feature. So, apparently, is Lake Aliso, the pond on the grounds of Mills College.

The first “great San Francisco earthquake” occurred 21 October 1868 on the Hayward fault. The epicenter appears to have been in southern San Leandro, and surface rupture extended from there all the way down to Fremont. In Montclair, the other direction along the fault, there was plenty of shaking of course, but no rupture of the ground from what we can tell. A trenching study, conducted along the third-base line of the little ballfield in Montclair Park, found no sign of recent movement along the fault there. But slow, silent motion does affect the fault in Montclair. The old fire station on Moraga Avenue has been rendered useless by aseismic creep, and some of the houses along the fault appear to show foundation disruption. But generally creep is invisible unless there is some structure that it affects, like the south curb of Medau Place, below. South of here, the fault crosses Route 13, reaching the other side at the head of Dimond Canyon.