Moraga Formation (Moraga Volcanics) | |
---|---|
Stratigraphic range: Pliocene epoch | |
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]
It preserves freshwater fossils dating back to the Pliocene epoch of the Neogene period. [5]
The Berkeley Hills are a part of the East Bay Hills, a range of the Pacific Coast Ranges, and overlook the northeast side of the valley that encompasses San Francisco Bay. They were previously called the "Contra Costa Range/Hills", but with the establishment of Berkeley and the University of California, the current usage was applied by geographers and gazetteers. The Berkeley Hills are included as part of the Diablo Range in the United States Geological Survey (USGS) Geographic Names Information System list of GPS coordinates for the latter.
Robert Sibley Volcanic Regional Preserve is located in the Oakland Hills of the East Bay region of the San Francisco Bay Area, California. The park is part of the East Bay Regional Parks District (EBRPD), covers 928 acres (3.76 km2), and lies east of Oakland, partly in Alameda County and partly in Contra Costa County. It can be entered from Oakland via Skyline Boulevard, or from Contra Costa County via Old Tunnel Road.
The Antelope Shale is a geologic formation in the San Joaquin Valley of central California.
The Claremont Shale is a Miocene epoch geologic formation in the Berkeley Hills of the East Bay region of the San Francisco Bay Area, California.
The Mulholland Formation is a Pliocene epoch geologic formation in the Berkeley Hills and San Leandro Hills of the East Bay region of the San Francisco Bay Area, California. It is found within Alameda County and Contra Costa County.
The Orinda Formation is a Miocene epoch geologic formation in the Berkeley Hills of the East Bay region of the San Francisco Bay Area, California.
The Pinole Tuff Formation is a geologic formation of the East Bay region of the San Francisco Bay Area in California.
The Pismo Formation is a geologic formation in California. It preserves fossils dating back to the Pliocene epoch of the Neogene period.
The Etchegoin Formation is a Pliocene epoch geologic formation in the lower half of the San Joaquin Valley in central California.
The Crowder Formation is a geologic formation in the Central and Western Mojave Desert, in northern Los Angeles County and eastern San Bernardino County, in Southern California.
The Tulare Formation is a Pliocene to Holocene epoch geologic formation in the central and southern San Joaquin Valley of central California.
The Topanga Canyon Formation is a Miocene epoch geologic formation in the Santa Monica Mountains, Simi Hills, Santa Ana Mountains and San Joaquin Hills, in Los Angeles County, Ventura County, and Orange County, southern California. It is primarily composed of hard sandstone with some inter-bedded siltstone.
The San Joaquin Formation is a Pliocene epoch geologic formation in the lower half of the San Joaquin Valley in central California.
The San Francisquito Formation is a geologic formation located in northern Los Angeles County, California.
The Harold Formation is a geologic formation in the Central Mojave Desert, west of Victorville and north of the San Gabriel Mountains, in eastern San Bernardino County, Southern California.
The Palm Spring Formation is a Pleistocene Epoch geologic formation in the eastern Colorado Desert of Imperial County and San Diego County County, Southern California.
The Ocotillo Formation is a Pliocene fluvial-alluvial fan geologic formation in the Colorado Desert of Southern California.
The Imperial Formation is the name of two distinct and unrelated geologic formations in North America, of different geologic Eras.
Rocky Ridge is a 2,020 ft (620 m) ridge in the Inner Coast Ranges in western Contra Costa County, California, in the San Francisco Bay Area. Being the second-highest mountain in the county, it is visible from much of the surrounding area. The ridge is a very prominent feature in the geography of the towns of Lafayette, Moraga and Orinda, California.
Kaiser Creek is an approximately 3 mile long perennial creek in western Contra Costa and Alameda Counties, California, in the San Francisco Bay Area. It is a tributary of the Upper San Leandro Reservoir, part of the larger San Leandro Creek system.