| Moraga Formation (Moraga Volcanics) | |
|---|---|
| Stratigraphic range: Pliocene epoch | |
 Moraga Volcanics in Robert Sibley Volcanic Regional Preserve, Berkeley Hills | |
| Type | Geologic formation |
| Underlies | Siesta Formation of Great Valley Group |
| 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.
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 of Great Valley Group.
- Fossils
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.
- Pliocene California geology
- List of fossiliferous stratigraphic units in California
- Paleontology in California
References
- ^ USGS.gov: "Upper Cretaceous and Lower Tertiary Rocks Berkeley and San Leandro Hills, California", by J. E. Case, GEOLOGICAL SURVEY BULLETIN 1251-J, 1968.
- Oakland Geology Blog: "Grizzly Peak and Moraga basalt"
- Geology.about.com: "California Transect - Stop 30, Orinda Formation and Moraga Volcanics"
- Lawrence Berkeley Lab.gov: "Berkeley Lab Geologist Studies the Ground Beneath His Feet"
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.
External links
- East Bay Regional Parks.org: official Robert Sibley Volcanic Regional Preserve website
- EBparks.org: Volcanism at Sibley Volcanic Preserve
 | This article about a specific stratigraphic formation in California is a stub. You can help Misplaced Pages by expanding it. |
This article related to the Neogene period is a stub. You can help Misplaced Pages by expanding it. |
- Berkeley Hills
- Pliocene California
- Geologic formations of California
- Geology of Alameda County, California
- Geology of Contra Costa County, California
- Natural history of the California Coast Ranges
- Natural history of the San Francisco Bay Area
- Volcanism of California
- Pliocene Series of North America
- Pliocene volcanism
- Basalt formations
- Tuff formations
- Andesite formations
- Rhyolite formations
- California geologic formation stubs
- Neogene stubs