Local Rock Garden
Geologic Tour of Oakland, California
(c) 2003 Andrew Alden, licensed to About.com, Inc.
This unassuming Rockridge cottage on James Street has a collection of stones that stopped me in my tracks: Each of the picturesque boulders, framed by neutral gray gravel, is a common Oakland rock type.
The serpentinite in the front and blueschist in the back are common in local exposures of the Coast Range Ophiolite in the high hills. The fine checkered boulder in the middle is chert like that in the Franciscan rocks (Novato Quarry terrane) around Piedmont and the Mountain View Cemetery slopes. And the long light-colored rock behind it, to all appearances, is vesiculated tuff from the Tertiary volcanics east of the Oakland Hills crest.
You can't buy these local stones at nurseries, so the homeowners must have gathered them from the wild. With a little more work, they could have a real Zen rock garden here. It isn't often that you see such a keen appreciation for the local bedrock.
See a few of these rocks close up in the Oakland Rock Gallery.
