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.USGS.gov: "Upper Cretaceous and Lower Tertiary Rocks Berkeley and San Leandro Hills, California", by J. E. Case, GEOLOGICAL SURVEY BULLETIN 1251-J, 1968.
The basaltic lava flow formation is found within Alameda County and Contra Costa County.Oakland Geology Blog: "Grizzly Peak and Moraga basalt" It can be seen in the Robert Sibley Volcanic Regional Preserve and Caldecott Tunnel area of the Berkeley Hills.Geology.about.com: "California Transect - Stop 30, Orinda Formation and Moraga Volcanics" It is named for an exposed occurrence in the Moraga Valley.
It overlies the Orinda Formation, and underlies the Siesta Formation.Lawrence Berkeley Lab.gov: "Berkeley Lab Geologist Studies the Ground Beneath His Feet"
It preserves freshwater fossils dating back to the Pliocene epoch of the Neogene period.
See also
Mulholland Formation — occurs to the south, in the Berkeley and San Leandro Hills.
List of fossiliferous stratigraphic units in California Paleontology in California
References
External links East Bay Regional Parks.org: official Robert Sibley Volcanic Regional Preserve website EBparks.org: Volcanism at Sibley Volcanic Preserve