My friend Sarah Penniston-Dorland, of the University of Maryland, supplied this week’s Friday fold. it comes from Catalina Island, California, where Sarah just wrapped up some field work with two of her students. All three of them have given me permission to post the images here:
The Catalina Schist is a suite of subduction-related metamorphic rocks. These rocks are amphibolite facies gneisses, but part of the Catalina Schist. The metamorphic ages of the high grade rocks are ~115 Ma. There are a lot of migmatitic rocks in the amphibolite facies of the Catalina Schist.
I think there is a refolded fold in the main part of the main face of this scene:
Pretty cool. Sarah also documented some other folds on Catalina Island, and I hope to share some of those in the weeks to come.