| State | California |
|---|---|
| Name | Tertiary volcanic flow rocks, unit 14 (Tranquillon-Obispo) |
| Geologic age | Tertiary (16-18 Ma) |
| Lithologic constituents |
Major
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow, Volcaniclastic-volcanic breccia)
Minor
Igneous > Volcanic > Mafic-volcanic > Basalt (Flow, Volcaniclastic-volcanic breccia)
Igneous > Volcanic > Felsic-volcanic > Dacite (Flow, Volcaniclastic-volcanic breccia)
Incidental
Igneous > Volcanic > Mafic-volcanic > Andesite (Flow)
|
| Stratigraphic units | Tranquillon Volcanics |
| 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/https://pubs.er.usgs.gov/publication/ofr00154 Jennings, C.W., Strand, R.G., Rogers, T.H., Boylan, R.T., Moar, R.R., and Switzer, R.A., 1977, Geologic Map of California: California Division of Mines and Geology, Geologic Data Map 2, scale 1:750,000. |
| NGMDB product | |
| Counties | San Luis Obispo - Santa Barbara |