Geology

The San Francisco Bay Area’s crazy quilt-pattern of rock formations — shaped by earthquakes — are the key to understanding the region’s landscapes. From ice-age dune sand in San Francisco to recently subsided land in the Santa Clara Valley or the veritable maze of earthquake faults in the East Bay, the geology is a fascinating blueprint of the region’s natural history.

Latest from Geology

Giacomini Wetland Restoration Project

October 01, 2007 by Aleta George

Forty miles northwest of San Francisco, the San Andreas Fault slips into the Pacific Ocean, creating Tomales Bay, the outlet

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The Checkerspot Comes Home

October 01, 2007 by Carolyn J. Strange

Contrary to common notions of autumn as a season of dying back, our fall rains often herald new beginnings. That’s

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Speak of the Devil

July 01, 2007 by David Rains Wallace

Mount Diablo is such a towering icon of our landscape that it is sometimes easy to forget how much complexity lies within its familiar outline. Indeed, the mountain holds many stories: from the drama of its birth under the ocean, to its (mis)naming by early American settlers, to last year’s rediscovery of the rare Mount Diablo buckwheat. Today the story continues, with the mountain and its surrounding ridges and canyons anchoring a bold vision for a broad swath of protected open space and wildlife corridors stretching from Concord to Livermore.

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At Home off the Range

July 01, 2007 by Richard Mahler

Once home to California’s largest landowner, Mount Madonna near Gilroy showcases an impressive range of habitats, from redwood forests to open oak woodlands, serpentine barrens, and chaparral.

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Ring Mountain Rocks!

April 01, 2007 by Horst Rademacher

Perched 600 feet above San Francisco Bay, Ring Mountain has spectacular views of the surrounding ridgelines, Bay, and urban areas. But you can also find much deeper views into the earth preserved in the remarkable rocks strewn about this wild and open landscape.

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The Rock in the Redwoods

January 01, 2007 by Carolyn Strange

Take a hike to a scene of otherworldly geology, hidden away in this Peninsula preserve’s forests of tanoak, Douglas-fir, and second-growth redwood.

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Tafoni Around the Bay

January 01, 2007 by Matthew Bettelheim

The tafoni weathering formation featured at El Corte de Madera Creek Preserve is a particularly accessible example of an uncommon

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Book Review: Geology of the San Francisco Bay Region

October 01, 2006 by Sue Rosenthal

Geology of the San Francisco Bay Region, by Doris Sloan, UC Press, 2006, 360 pages, $17.95
www.ucpress.edu
“The world-famous Bay

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When was the last volcanic eruption in the Bay Area? Where was it?

October 01, 2006 by Michael Ellis

You can easily visit the 10-million-year-old Sibley Volcano (see Voice of the Volcano, April-June 2005) in the hills above Oakland.

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Carquinez Breakthrough

September 30, 2006 by Kathleen Wong

The open hills along the Carquinez Strait are home to working ranches and open space preserves that are meeting places for native species from both the coast and the Central Valley. Today’s quiet pastoral landscape makes it hard to envision the violent formative flood that may have cut this critical waterway between the Bay and the Central Valley some half a million years ago.

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