Tertiary intrusive rocks (hypabyssal), unit 4 (Tranquillon-Obispo)

Tertiary intrusive rocks; mostly shallow (hypabyssal) plugs and dikes. Includes some Mesozoic rocks.
State California
Name Tertiary intrusive rocks (hypabyssal), unit 4 (Tranquillon-Obispo)
Geologic age Tertiary
Lithologic constituents
Igneous > Hypabyssal > Felsic-hypabyssal > Hypabyssal-rhyolite (Pluton, Dike or sill)
Igneous > Hypabyssal > Felsic-hypabyssal > Hypabyssal-dacite (Pluton)
Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-andesite (Pluton)
Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-basalt (Pluton)
Comments includes Morro Rock intrusions

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., 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