| Moraga Formation (Moraga Volcanics) | |
| Type: | Geologic formation |
| Age: | Pliocene epoch |
| Period: | Pliocene |
| Prilithology: | Basaltic lava, with andesite, basalt, rhyolite tuff |
| Otherlithology: | Clay, conglomerate, limestone |
| Namedfor: | Moraga Valley |
| Region: | Berkeley Hills, Alameda County and Contra Costa County, California |
| Country: | United States |
| Underlies: | Siesta Formation of Great Valley Group |
| Overlies: | Orinda Formation |
| Thickness: | 1200feet |
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.[1]
The basaltic lava flow formation is found within Alameda County and Contra Costa County.[1] [2] It can be seen in the Robert Sibley Volcanic Regional Preserve and Caldecott Tunnel area of the Berkeley Hills.[3] It is named for an exposed occurrence in the Moraga Valley.
It overlies the Orinda Formation, and underlies the Siesta Formation of Great Valley Group.[4]