San Diego Formation
San Diego Formation | |
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Geologic formation | |
Lithology | |
Primary | Conglomerate |
Other | Sandstone |
Location | |
Region | San Diego County, California, Baja California |
Country | United States, Mexico |
Type section | |
Named for | San Diego, California |
The San Diego Formation is a
Geology
It is a coastal transitional
This formation is found from the south side of
San Diego Formation deposits were formed in a large, open, crescent-shaped bay similar in size to Monterey Bay that existed on the coast in Pliocene times.[1][2]
Aquifer
The formation contains the San Diego Formation Basin, a large aquifer under Imperial Beach, Chula Vista, National City, and southern portions of the city of San Diego.
The San Diego Formation Basin is a confined shallow aquifer. It has a basin ground surface area of 79,724 acres (32,263 ha) and an estimated groundwater storage capacity of 960,000 AF. The depth to groundwater is about 100 feet (30 m).
Fossil content
Besides those of clams and other
Fauna
Cetaceans
Mysticetes
Mysticetes reported from the San Diego Formation
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Genus | Species | Stratigraphic position | Notes | Images |
B. davidsonii[10] |
An extinct rorqual belonging to Balaenoptera. |
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"Balaenoptera" |
"B." portisi |
Formerly assigned to Balaenoptera, probably a member of Cetotheriophanes. |
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H. morrowi |
A cetotheriid .
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N. miocaena |
A stem-balaenopteroid, previously considered to be a relative of humpback whale. |
Odontocetes
Odontocetes reported from the San Diego Formation
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Genus | Species | Stratigraphic position | Notes | Images |
P. sternbergi[11] |
A close relative of the baiji. | |||
S. ceruttii |
A porpoise with a lower jaw extended few inches beyond the upper jaw (similar to a halfbeak).[12] |
Pinnipeds
Pinnipeds reported from the San Diego Formation | ||||
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Genus | Species | Stratigraphic position | Notes | Images |
C. gilmorei[13] |
A relative of the northern fur seal. |
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D. seftoni[14] |
A walrus. |
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V. chulavistensis[14] |
A walrus. |
Sirenians
Sirenians reported from the San Diego Formation
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Genus | Species | Stratigraphic position | Notes | Images |
H. cuestae |
A close relative of the Steller's sea cow. |
See also
References
- ^ California Geological Survey, Regional Geologic Map No. 3, 1:100,000 scale Compiled by: Michael P. Kennedy and Siang S. Tan, 2008.
- ^ Scott Rugh, Clams of Champions: The San Diego Formation, from sdnhm.org, the San Diego Natural History Museum website accessed November 26, 2013.
- ^ a b c "Groundwater Assessment Study" (PDF). Metropolitan Water District of Southern California. 2007.
- ^ "Seawater Desalination".
- ^ City of San Diego.gov: San Diego Formation Basin, with map.
- ^ Common loon (G. immer) and yellow-billed loon (G. adamsii)
- Arctic loon(G. arctica)
- JSTOR 1364769.
- ^ Brodkorb, Pierce (1963). "Catalogue of fossil birds. Part 1 (Archaeopterygiformes through Ardeiformes)". Bulletin of the Florida State Museum, Biological Sciences. 7 (4): 179–293 (224). Archived from the original on 2007-03-11. Retrieved 2009-07-29.
- ^ T. Demere. 1986. The fossil whale, Balaenoptera davidsonii (Cope 1872), with a review of other Neogene species of Balaenoptera (Cetacea: Mysticeti). Marine Mammal Science 2(4):277–298
- ^ W. K. Gregory and R. Kellogg. 1927. A fossil porpoise from California. American Museum Novitates 269:1–7
- ^ Rachel A. Racicot, Thomas A. Deméré, Brian L. Beatty, Robert W. Boessenecker. Unique Feeding Morphology in a New Prognathous Extinct Porpoise from the Pliocene of California. Current Biology, 13 March 2014 DOI: 10.1016/j.cub.2014.02.031
- ^ A. Berta and T. A. Demere. 1986. Callorhinus gilmorei n. sp., (Carnivora: Otariidae) from the San Diego Formation (Blancan) and its impliations for otariid phylogeny. Transactions of the San Diego Society of Natural History 21(7):111–126
- ^ a b T. A. Demere. 1994. Two new species of fossil walruses (Pinnipedia: Odobenidae) from the Upper Pliocene San Diego Formation, California. Proceedings of the San Diego Society of Natural History 29:77–98
Further reading
- Ellis, Arthur Jackson; Lee, Charles H. (1919). Geology and ground waters of the western part of San Diego County, California. Department of the Interior, United States Geological Survey.
- Kennedy, Michael P. (1975). Geology of the San Diego metropolitan area, California. California Division of Mines and Geology.
- "General Plan Final Program EIR: 3.11 Paleontological Resources" (PDF). City of San Diego.