6 July 2018

Friday fold: twisted turbidites at Usal Beach

Posted by Callan Bentley

Last week, I spent two perfect days camping with family at Usal Beach, in Mendocino County, California. Along the beachside cliffs there, I spotted plenty of lovely turbidites: graywacke and shale and a little bit of conglomerate that had been scraped off the subducted Farrallon Plate to help contribute to the bulk of the Franciscan complex. That accretionary process imparted some stresses on these deep-sea deposits, and in many places they show significant deformation. Here are a dozen images to highlight some of the folds I saw: