Skip to main content

Tertiary intrusive rocks (hypabyssal), unit 3 (Pinnacles Volcanic Field)

Tertiary intrusive rocks; mostly shallow (hypabyssal) plugs and dikes. Includes some Mesozoic rocks.
State California
Name Tertiary intrusive rocks (hypabyssal), unit 3 (Pinnacles Volcanic Field)
Geologic age Tertiary
Primary rock type rhyolite
Secondary rock type
Other rock types
Lithologic constituents
Major
Igneous > Hypabyssal > Felsic-hypabyssal > Hypabyssal-rhyolite (Dike or sill)
Incidental
Igneous > Hypabyssal > Felsic-hypabyssal > Hypabyssal-dacite (Dike or sill)
Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-andesite (Dike or sill)
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
Ludington, Steve, and Gray, Karen, 1987, Petrochemical studies of the Pinnacles Wilderness contiguous wilderness study area, Monterey and San Benito Counties, California. U.S. Geological Survey Open-file report 87-135, 9 p.
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 Monterey - San Benito