GoSF1: Introduction and overview
The first in a multi-part series on the geology of San Francisco and the surrounding area.
california
AGU, day 4
My final day at AGU was Thursday, and I spent a lot of it working on school stuff, but I did zip down to the Moscone Center for a session on communicating science to the public in an age of increased public scrutiny. Michael Mann of Penn State was the big draw here, discussing his … Read more
AGU, day 3
I took a break yesterday morning from nonstop AGU meeting stuff, and got out into the city a bit. A former student of mine, Alan P., lives in San Francisco these days, and works at a local bike shop. So Alan scored us a couple of bicycles and we went for a ride from North … Read more
AGU, Day 2
Man, this meeting is intense. There’s so much going on all the time that for every session or talk you commit to, you’re missing literally dozens of others. This is kind of like going to the library and picking out a book, knowing that there are many other books you’re not reading — but with … Read more
AGU; Days -1, 0, and 1
San Francisco is great. I got out here Friday night and spent a lovely day Saturday hiking over the Golden Gate Bridge and through the Marin Headlands with my fiancee. That evening, for my 36th birthday, we went out to the Tadich Grill, source of the best cioppino (Italian seafood soup) in the city. Sunday, … Read more
Faultcano
Visit the “faultcano” in the Owens Valley of eastern California: a cinder cone which has been cut and offset along a normal fault associated with Basin & Range extension.
Three joints
Long-time readers (and students) know that I have a special corner of my heart reserved for plumose structure and hackle fringes, that finely-filigreed anatomy of a fracture surface. Fractures are everywhere in rocks, and often they show neat little “topographic” details that show fracture propagation direction and stress fields. Here are three that I haven’t … Read more
S-C fabric in meta-ignimbrite
Here’s a sample from my 2004 geology M.S. thesis work in the Sierra Crest Shear Zone of eastern California. The rock is a sheared ignimbrite (ashflow tuff) tuff bearing a porphyritic texture and a nicely-developed “S-C” fabric. With annotations, showing the S- and C-surfaces, and my kinematic interpretation: S-C fabrics develop in transpressional shear zones: … Read more
Hol(e)y basalt, Batman!
Today, our theme is vesicles. Here are some images of vesicles in basaltic lava flows in the Owens Valley of California, the same spot where we saw the baked fanglomerate that I showcased a few days back. In this photo (and the zoomed-in detail shot below), you can see a couple of things. One is … Read more
Easter egg
Searching through my photo archives this morning for something suitably “Eastery”… something in pastel colors, perhaps? … a petrified lagomorph? … how about an egg, or something egg-shaped? This is as close as I got: This is in the Owens Valley of eastern California, showing a boulder of the Mesozoic Sierra Nevada Batholith bearing a … Read more