The final episode of the 10-part “Geology of San Francisco” series concludes with a visit to the spot where the San Andreas Fault runs off the edge of California and down into the sea. Mussel Rock, site of the opening vignette of John McPhee’s “Assembling California” is located there.
When I was out in California in October 2009, about the same time that Garry Hayes passed me on the highway heading up to Yosemite while I was headed down towards the Modesto Airport, I pulled over to check out some rock exposures on the side of the road. This was near the Don Pedro … Read more
The penultimate episode of Callan’s more-than-a-week-long series on the geology of the San Francisco region: today we briefly visit the sand dunes that covered San Francisco Peninsula during the Pleistocene.
The 8th edition of the ongoing “Geology of San Francisco” series examines brittle fractures and the chemistry they host along their planar surfaces.
Merry Christmas! Along with the red cherts of last Tuesday, enjoy today’s green rocks — serpentinite and serpentinite mélange of Marshall Beach, west of the Golden Gate Bridge in San Francisco.
The geological tour of San Francisco continues with an examination of the graywacke deposits of the
“GoSF” = Geology of San Francisco As I am sure you are aware, I’m taking this week to write up the three field trips I took last week to examine the geology of San Francisco and neighboring areas. My plan is to cover: Introduction and overview Seafloor basalt Deep sea chert Kirby Cove, Marin Headlands … Read more
Part 4 of the ongoing series examining the geology of the San Francisco area. In today’s post, Callan visits Kirby Cove in the Marin Headlands, where intensely deformed chert can be found on one end of the cove, pillow basalts on the other, and an “artificial dune” in the middle.
Episode three in the multi-part series on the geology of San Francisco. This post focuses on the chert layers of the Marin Headlands
Second in the on-going series about the geology of San Francisco: this post explores the pillow basalts of the Marin Headlands Terrane.