| Moraga Formation (Moraga Volcanics) | |
|---|---|
| Stratigraphic range: Pliocene epoch | |
 Moraga Volcanics in Robert Sibley Volcanic Regional Preserve, Berkeley Hills | |
| Type | Geologic formation |
| Underlies | Siesta Formation |
| Overlies | Orinda Formation |
| Thickness | 1,200 feet (370 m) |
| Lithology | |
| Primary | Basaltic lava, with andesite, basalt, rhyolite tuff |
| Other | Clay, conglomerate, limestone |
| Location | |
| Region | Berkeley Hills, Alameda County and Contra Costa County, California |
| Country | United States |
| Type section | |
| Named for | Moraga Valley |
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]
Contents
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. [4]
It preserves freshwater fossils dating back to the Pliocene epoch of the Neogene period. [5]
