Roadside Outcrop Near Malibu, California

May 03, 2019


Photographer: Jon Marcus 
Summary Authors: Jon Marcus; Jim Foster

Shown above is a wall of shale with some thin sandstone layers that I passed by while driving on a windy road in the hills above Malibu, California. Part of the Miocene conglomerate Topanga Formation, these rocks, initially thought to be chert, were deposited in a marine basin with sand coming from distant river deltas. The diverse rocks in this area contain a variety of fossils including foraminifera and cetacean.