Moraga Formation

The Moraga Formation, also known as the Moraga Volcanics, is a geological formation that dates back to the Pliocene epoch. It is located in Berkeley Hills, East Bay Region, San Francisco Bay Area, California.
The basaltic lava flow formation is found within Alameda County and Contra Costa County. It can be seen in the Robert Sibley Volcanic Regional Preserve and Caldecott Tunnel area of the Berkeley Hills. It is named for an exposed occurrence in the Moraga Valley.
It overlies the Orinda Formation, and underlies the Siesta Formation.
It preserves freshwater fossils dating back to the Pliocene epoch of the Neogene period.