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Tertiary volcanic flow rocks, unit 14 (Tranquillon-Obispo)

Tertiary volcanic flow rocks; minor pyroclastic deposits.
State California
Name Tertiary volcanic flow rocks, unit 14 (Tranquillon-Obispo)
Geologic age Tertiary (16-18 Ma)
Primary rock type rhyolite
Secondary rock type dacite
Other rock types basalt; volcanic breccia (agglomerate)
Lithologic constituents
Major
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow)
Minor
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Volcaniclastic, volcanic breccia)
Igneous > Volcanic > Felsic-volcanic > Dacite (Flow)
Igneous > Volcanic > Mafic-volcanic > Basalt (Flow)
Igneous > Volcanic > Mafic-volcanic > Basalt (Volcaniclastic, volcanic breccia)
Incidental
Igneous > Volcanic > Felsic-volcanic > Dacite (Volcaniclastic, volcanic breccia)
Igneous > Volcanic > Mafic-volcanic > Andesite (Flow)
Map references
Jennings, C.W., Strand, R.G., and Rogers, T.H., 1977, Geologic map of California: California Division of Mines and Geology, scale 1:750,000.
Unit references
Luyendyk, B.P., Gans, P., and Kamerling, M.J., 1998, 40Ar/39Ar geochronology of Southern California Neogene volcanism. AAPG Bulleting, v. 82, p. 852 (abstract)
Stanley, R.G., Wilson, D.S., and McCrory, P.A., 2000, Locations and ages of middle Tertiary volcanic centers in coastal California: U.S. Geological Survey Open-File Report 00-154, 27 p., url http://geopubs.wr.usgs.gov/open-file/of00-154/
Jennings, C.W., Strand, R.G., and Rogers, T.H., 1977, Geologic map of California: California Division of Mines and Geology, scale 1:750,000.
Counties San Luis Obispo - Santa Barbara