July 08, 2012 by Bay Nature Staff
With a volcano at its heart, Sibley Preserve is an unparalleled place to see Coast Range geology exposed as well …
July 01, 2012 by Ann Sieck
Every day, east of Highway 24′s Caldecott Tunnel, thousands of commuters hurtle–or crawl–past a fine swath of the East Bay’s glorious greenbelt, where just off the highway, the north trailhead of Sibley Volcanic Preserve invites exploration.
January 06, 2012 by Horst Rademacher
Workers digging the new fourth bore of the Caldecott Tunnel are getting a once-in-a-lifetime view of one of the defining features of the East Bay: the range of hills that runs from San Pablo Bay south to Fremont. By visiting just a few accessible sites aboveground, you can find clues that tell the story of how these hills rose from their humble origins as deep ocean sediments and volcanic flows to the iconic fault-riddled hillsides of today.
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. …
April 01, 2005 by Gordy Slack
We all know that the East Bay hills are ripe for an earthquake, but volcanoes? Don’t look for lava in the headlines anytime soon, but there is a place in Oakland where an ancient volcano has laid bare a tale of fiery eruptions, long-extinct ecosystems, and the massive movements of tectonic plates. Many people go to Sibley Regional Preserve for the views of Mount Diablo or the quirky labyrinths at the bottoms of old quarry pits. But look closely at the trailside rocks, and you’ll see lava flows and a volcano turned on its side!