Skip to main content

Tertiary pyroclastic and volcanic mudflow deposits, unit 9 (Cascade Range)

Tertiary pyroclastic and volcanic mudflow deposits.
State California
Name Tertiary pyroclastic and volcanic mudflow deposits, unit 9 (Cascade Range)
Geologic age Tertiary (2-24 Ma)
Primary rock type andesite
Secondary rock type rhyolite
Other rock types basalt; tuff; ash-flow tuff; ignimbrite
Lithologic constituents
Major
Igneous > Volcanic > Mafic-volcanic > Andesite (Volcaniclastic, lahar)
Minor
Igneous > Volcanic > Mafic-volcanic > Andesite (Pyroclastic)
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic)
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, ash-flow)
Incidental
Igneous > Volcanic > Mafic-volcanic > Basalt (Volcaniclastic, lahar)
Igneous > Volcanic > Mafic-volcanic > Basalt (Pyroclastic)
Igneous > Volcanic > Mafic-volcanic > Basaltic-andesite (Volcaniclastic, lahar)
Igneous > Volcanic > Mafic-volcanic > Basaltic-andesite (Pyroclastic)
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
Luedke, R.G., and Smith, R.L., 1981, Map showing distribution, composition, and age of late Cenozoic volcanic centers in California and Nevada: U.S. Geological Survey Miscellaneous Investigations Series Map I-1091-C, scale 1:1,000,000.
Luedke, R.G., Smith, R.L., and Russell-Robinson, S.L., 1983, Map showing distribution, composition, and age of late Cenozoic volcanoes and volcanic rocks of the Cascade Range and vicinity, northwestern United States: U.S. Geological Survey Miscellaneous Investigations Series Map I-1507, scale 1:500,000.
Grose, T.L.T., 2000, Volcanoes in the Susanville region, Lassen, Modoc, Plumas Counties, northeastern California: California Geology, v. 53, p. 4-23.
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 Alpine - Amador - Butte - Calaveras - El Dorado - Glenn - Lassen - Mariposa - Modoc - Mono - Nevada - Placer - Plumas - Shasta - Sierra - Siskiyou - Tehama - Tuolumne - Yolo - Yuba