My former student James O’Brien recently moved out to the left coast, and posted some photos earlier this week of a hike he took at Mount Diablo State Park in the mountains east of the San Francisco Bay area of California.
There are some classic-looking Franciscan cherts exposed there, as these folded examples show:
Seeing these pictures reminded me of the “GoSF” series I wrote last time I went to the AGU Fall Meeting (in 2010). I’m planning to attend the meeting again this year, and look forward to spending some time reacquainting myself with some of these rocks while in San Francisco.
Thanks for sharing the photos, James! Happy Friday, everyone.