Mesozoic volcanic rocks, unit 1 (Coast Ranges)

Undivided Mesozoic volcanic and metavolcanic rocks. Andesite and rhyolite flow rocks, greenstone, volcanic breccia and other pyroclastic rocks; in part strongly metamorphosed. Includes volcanic rocks of Franciscan Complex: basaltic pillow lava, diabase, greenstone, and minor pyroclastic rocks.
State California
Name Mesozoic volcanic rocks, unit 1 (Coast Ranges)
Geologic age Jurassic to Cretaceous
Lithologic constituents
Major
Metamorphic > Metaigneous > GreenstoneAltered basalts derived from flows, pillow lavas, tuffs, tuff breccias, and minor intrusions; gradational with relatively unaltered basalt
Minor
Igneous > Volcanic > Mafic-volcanic > BasaltGradational with greenstone
Metamorphic > Schist (Blueschist)Mafic schists (metabasalts) containing greenschist- to blueschist-facies metamorphic minerals
Incidental
Igneous > Volcanic > Felsic-volcanic (Pyroclastic-tuff)Siliceous tuff and quartz keratophyre associated with Coast Range ophiolite
Igneous > Plutonic > Dioritic > Diorite (Dike or sill)
Sedimentary > Chemical > Chert (Bed)Radiolarian chert and metachert
Comments Coast Ranges. Jurassic to Cretaceous volcanic rocks of Franciscan Complex: basaltic pillow lava, diabase, greenstone, and minor pyroclastic rocks. Includes blueschist-grade metabasalt schist. Also includes small areas of volcanic rocks associated with Coast Range ophiolite
Stratigraphic units Cuesta Diabase, Del Puerto Keratophyre Member of Franciscan Complex, Franciscan Complex (volcanic rocks), Lotta Creek Tuff Member, Osos Basalt
References

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.

Jennings, C.W., 1985, An explanatory text to accompany the 1:750,000 scale fault and geologic maps of California: California Division of Mines and Geology, Bulletin 201, 197 p.

Jennings, C.W., 1962, Geologic map of California, Olaf P. Jenkins edition, Long Beach sheet, scale 1:250,000.

Jennings, C.W., and Strand, R.G., 1969, Geologic map of California, Olaf P. Jenkins edition, Los Angeles sheet, scale 1:250,000.

Strand, R.G., 1962, Geologic map of California, Olaf P. Jenkins edition, Redding sheet, scale 1:250,000.

Jennings, C.W., and Burnett, J.L., 1961, Geologic map of California, Olaf P. Jenkins edition, San Francisco sheet, scale 1:250,000.

Rogers, T.H., 1966, Geologic map of California, Olaf P. Jenkins edition, San Jose sheet, scale 1:250,000.

Jennings, C.W., 1959, Geologic map of California, Olaf P. Jenkins edition, San Luis Obispo sheet, scale 1:250,000.

Jennings, C.W., and Strand, R.G., 1959, Geologic map of California, Olaf P. Jenkins edition, Santa Cruz sheet, scale 1:250,000.

Jennings, C.W., 1959, Geologic map of California, Olaf P. Jenkins edition, Santa Maria sheet, scale 1:250,000.

Koenig, J.B., 1963, Geologic map of California, Olaf P. Jenkins edition, Santa Rosa sheet, scale 1:250,000.

Jennings, C.W., and Strand, R.G., 1960, Geologic map of California, Olaf P. Jenkins edition, Ukiah sheet, scale 1:250,000.

Strand, R.G., 1964, Geologic map of California, Olaf P. Jenkins edition, Weed sheet, scale 1:250,000.

Wagner, D.L., Bortugno, E.J., and McJunkin, R.D., 1990, Geologic map of the San Francisco-San Jose quadrangle, California: California Division of Mines and Geology, Regional Geologic Map Series, Map 5A, scale 1:250,000.

Wagner, D.L., and Bortugno, E.J., 1982, Geologic map of the Santa Rosa quadrangle, California: California Division of Mines and Geology, Regional Geologic Map Series, Map 2A, scale 1:250,000.

Blake, M.C., Jr., Helley, E.J., Jayko, A.S., Jones, D.L., and Ohlin, H.N., 1992, Geologic map of the Willows 1:100,000 quadrangle, California: U.S. Geological Survey Open-File Report 92-271, 42 p., scale 1:100,000.

https://pubs.er.usgs.gov/publication/ofr92271

Blake, M.C., Jr., Graymer, R.W., and Stamski, R.E., 2002, Geologic map and map database of western Sonoma, northernmost Marin, and southernmost Mendocino Counties, California: U.S. Geological Survey Miscellaneous Field Studies Map MF-2402, 43 p., scale 1:100,000.

https://pubs.er.usgs.gov/publication/mf2402

Jayko, A.S., Blake, M.C., Jr., McLaughlin, R.J., Ohlin, H.N., Ellen, S.D., and Kelsey, Harvey, 1989, Reconnaissance geologic map of the Covelo 30- by 60-minute quadrangle, northern California: U.S. Geological Survey Miscellaneous Field Studies Map MF-2001, scale 1:100,000.

https://pubs.er.usgs.gov/publication/mf2001

Brabb, E.E., Graymer, R.W., and Jones, D.L., 2000, Geologic map and map database of the Palo Alto 30' x 60' quadrangle, California: U.S. Geological Survey Miscellaneous Field Studies Map MF-2332, 30 p., scale 1:100,000.

https://pubs.er.usgs.gov/publication/mf2332

Blake, M.C., Jr., Graymer, R.W., and Jones, D.L., 2000, Geologic map and map database of parts of Marin, San Francisco, Alameda, Contra Costa, and Sonoma Counties, California: U.S. Geological Survey Miscellaneous Field Studies Map MF 2337, 29 p., scale 1:75,000.

https://pubs.er.usgs.gov/publication/mf2337

McLaughlin, R.J., Ellen, S.D., Blake, M.C., Jr., Jayko, A.S., Irwin, W.P., Aalto, K.R., Carver, G.A., and Clarke, S.H., Jr., 2000, Geology of the Cape Mendocino, Eureka, Garberville, and southwestern part of the Hayfork 30 x 60 minute quadrangles and adjacent offshore area, northern California: U.S. Geological Survey Miscellaneous Field Studies Map MF-2336, 30 p., scale 1:100,000.

https://pubs.er.usgs.gov/publication/mf2336

Silberling, N.J., Jones, D.L., Blake, M.C., Jr., and Howell, D.G., 1987, Lithotectonic terrane map of the western conterminous United States: U.S. Geological Survey Miscellaneous Field Studies Map MF-1874-C, scale 1:2,500,000.

https://pubs.er.usgs.gov/publication/mf1874C

Graymer, R.W., 2000, Geologic map and map database of the Oakland metropolitan area, Alameda, Contra Costa, and San Francisco Counties, California: U.S. Geological Survey Miscellaneous Field Studies Map MF-2342, 29 p., scale 1:50,000.

https://pubs.er.usgs.gov/publication/mf2342

Cotton, W.R., 1972, Preliminary geologic map of the Franciscan rocks in the central part of the Diablo Range, Santa Clara and Alameda Counties, California: U.S. Geological Survey Miscellaneous Field Studies Map MF-343, scale 1:62,500.

https://pubs.er.usgs.gov/publication/mf343

Blake, M.C., Jr., and Jones, D.L., 1981, The Franciscan Assemblage and related rocks in northern California: a reinterpretation, in Ernst, W.G., ed., The geotectonic development of California (Rubey Volume 1): Englewood Cliffs, N.J., Prentice-Hall, p. 307-328.

Blake, M.C., Jr., Jayko, A.S., McLaughlin, R.J., and Underwood, M.B., 1988, Metamorphic and tectonic evolution of the Franciscan Complex, northern California, in Ernst, W.G., ed., Metamorphism and crustal evolution of the western United States (Rubey Volume 7): Englewood Cliffs, N.J., Prentice-Hall, p. 1035-1060.

NGMDB product
Counties Alameda - Colusa - Contra Costa - Fresno - Glenn - Humboldt - Lake - Los Angeles - Marin - Mendocino - Merced - Monterey - Napa - San Benito - San Francisco - San Luis Obispo - San Mateo - Santa Barbara - Santa Clara - Sonoma - Stanislaus - Tehama - Trinity