Oakland Geology

Huckleberry Botanic Regional Preserve is a little-visited piece of wildland just over the Oakland Hills crest south of Sibley Volcanic Regional Preserve. It owes its existence to this rock, the Claremont Chert. The brochure lavishes attention, and rightly so, on the plants of the botanic preserve, but it’s also a good place to see the chert in many settings. Cliffy here or buried there, shaly or rugged, the chert asserts itself amid the soils and growth like the bass player in a jazz combo.

Owing to its history, the Claremont Chert is high in silica and low in nutrients. It drains quickly and breaks down slowly, and for the purposes of today’s vegetation it slows down the natural process of faunal succession—the series of plants that goes from pioneer species to climax forest. Thus where much of the hills is a uniform oak/madrone woodland, the Huckleberry Preserve is a variegated assemblage of everything from gravelly manzanita balds to soft seeps populated with irises, plus huckleberry thickets of course. Hike the nature trail and meet some of the natives. The self-guiding brochure carefully states the role of fire in maintaining the hill ecosystems, mainly to show how the Huckleberry is an exception. But these days, everywhere you look in the hills is a fire long overdue. Some day we will have to catch up with the Ohlone tribes, who managed these lands with regular burnings.

The trail provides several fine views eastward. You can pretend that white settlement never happened and imagine Mount Diablo pristine, as it was when Cabrillo forced his men through this land 250 years ago. (click for larger version) And you can enjoy Round Top’s symmetry from the rare southern vantage:

This entry was posted on 11 June 2008 at 1:56 pm and is filed under Oakland chert, Oakland geology views. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.