Pinole Tuff Formation

The Pinole Tuff Formation is a geologic formation of the East Bay region of the San Francisco Bay Area in California.

It is found near Pinole and Rodeo area at San Pablo Bay and the Briones Hills of western Contra Costa County.

It preserves fossils, including Oncorhynchus rastrosus and fragments of a proto-hipparion prehistoric horse, dating back to the Neogene period.
 * Fossils