Earth:Moraga Formation
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Short description: Pliocene geological formation in California
Moraga Formation (Moraga Volcanics) Stratigraphic range: Pliocene epoch | |
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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 .[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]
- Fossils
It preserves freshwater fossils dating back to the Pliocene epoch of the Neogene period.[5]
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
- ↑ 1.0 1.1 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". http://www.fossilworks.org/cgi-bin/bridge.pl?action=home.
External links
- East Bay Regional Parks.org: official Robert Sibley Volcanic Regional Preserve website
- EBparks.org: Volcanism at Sibley Volcanic Preserve
Original source: https://en.wikipedia.org/wiki/Moraga Formation.
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