San Francisco Bay Region Geology and Geologic Hazards

Stories > How Was the Geolgoic Map Made?

How Was the Geologic Map Made?

Geologic maps are made by carefully studying the location, age, and identity of geologic materials in a region, as well as the orientation and position of geologic structures. This information is compiled in a Geographic Information System (GIS) that combines a digital map and a database. This data is interpreted to "fill in" areas where the geologic materials and structures are not visible (covered by dense vegetation or thick soil, for example).

Learn more about geologic maps and how they are made.

The maps that were compiled to make the geologic map of the San Francisco Bay region are listed below:

Bezore, Stephen, and others, 2002, Geologic Map of the Cordelia and Fairfield South 7.5' Quadrangles, Solano and Napa Counties, California: California Geological Survey CD 2002-07

Bezore, Stephen, Randolph, C.E., and Witter, R.C., 2002, Geologic map of the Petaluma 7.5' quadrangle, Sonoma and Marin counties, California: a digital database: California Geological Survey Preliminary Geologic Map

Bezore, Stephen, and others, 2003, Two Rock quadrangle, California Geological Survey Preliminary Geologic Map

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 MF-2337, 31 p., 1 sheet, scale 1:75,000, 8 Arc-Info databases.

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, 1 sheet, 1:100,000 scale, 43 p.

Bonilla, M.G., 1998, Preliminary geologic map of the San Francisco South 7.5' quadrangle and part of the Hunters Point 7.5' quadrangle, San Francisco Bay area, California: a digital database: U.S. Geological Survey Open File Report OF 98-354

Brabb, E.E. (comp.), 1997, Geologic map of Santa Cruz County, California: a digital database: U.S. Geological Survey Open File Report OF 97-489

Brabb, E.E., Graymer, R.W., and Jones, D.L., 1998, Geology of the onshore part of San Mateo County, California: A digital database:; U.S. Geological Survey Open-File Report 98-137, includes plotfiles for 2 sheets, scale 1:62,500, database description pamphlet, 9 pp, geologic description and interpretation pamphlet 13 pp.

Brabb, E.E., Graymer, R.W., and Jones, D.L., 2000, Geologic map and map database of the Palo Alto 30"X60" quadrangle, California: U.S. Geological Survey Miscellaneous Field Studies MF-2332, 32 p., 2 sheets, scale 1:100,000, 10 Arc-Info databases.

Clark, J.C., and Brabb, E.E., 1997, Geology of Point Reyes National Seashore and vicinity, California: a digital database: U.S. Geological Survey Open File Report OF 97-456

Graymer, R.W., 1997, Geology of the southernmost part of Santa Clara County, California: A digital database: U.S. Geological Survey Open-File Report 97-710, includes plotfiles for 2 sheets, scale 1:100,000, database description pamphlet, 11 pp, geologic description and interpretation pamphlet, 20 pp.

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 MF-2342, 31 p., 1 sheet, scale 1:50,000, 20 Arc-Info databases.

Graymer, R.W., Jones, D.L., and Brabb, E.E., 1994, Preliminary geologic map emphasizing bedrock formations in Contra Costa County, California: A digital database: U.S. Geological Survey Open-File Report 94-622, includes plotfiles for 2 sheets, scale 1:75,000, database description pamphlet, 10 pp, geologic description and interpretation pamphlet, 20 pp.

Graymer, R.W., Jones, D.L., and Brabb, E.E., 1996, Preliminary geologic map emphasizing bedrock formations in Alameda County, California: A digital database: U.S. Geological Survey Open-File Report 96-252, includes plotfiles for 2 sheets, scale 1:75,000, database description pamphlet, 14 pp., geologic description and interpretation pamphlet, 33 pp.

Graymer, R.W., Jones, D.L., and Brabb, E.E., 2002, Geologic map and map database of northeastern San Francisco Bay region, California; most of Solano County and parts of Napa, Marin, Contra Costa, San Joaquin, Sacramento, Yolo, and Sonoma Counties: U.S Geological Survey Miscellaneous Field Studies Map MF-2403, 1 sheet, 1:100,000 scale, 28 p.

Knudsen, K.L., Sowers, J.M., Witter, R.C., Wentworth, C.M., Helley, E.J., Nicholson, R.S., Wright, H.M., and Brown, K.H., 2000, Preliminary maps of Quaternary depositis and liquefaction susceptibility, nine-county San Francisco Bay region, California: a digital database: U.S. Geological Survey Open File Report OF 00-444

McLaughlin, R.J., Clark, J.C., and Brabb, E.E., 2001, Geologic maps and structure sections of the southwestern Santa Clara Mountains, Santa Clara and Santa Cruz Counties, California: U.S. Geological Survey Miscellaneous Field Studies Map MF-2373

McLaughlin, R.J., Sarna-Wojcicki, A.M., Fleck, R.J., Wright, W.H., Levin, V.R.G., and Valin, Z.C., 2004, Geology, tephrochronology, radiometric ages, and cross sections of the Mark West Springs 7.5' quadrangle, Sonoma and Napa Counties, California: U.S. Geological Survey Scientific Investigations Map SIM-2858
Rice and others, 2002, Novato quadrangle, California Geological Survey Preliminary Geologic Map

Wagner, D.L., Greene, H.G., Saucedo, G.J., Pridmore, C.L., Watkins, S.E., Little, J.D., and Bizzarro, J.J., 2002, Geologic map of the Monterey quadrangle and Monterey Bay, California: a digital database: California Geological Survey CD 2002-04

Wentworth, C.M., Blake, M.C., Jr., McLaughlin, R.J., and Graymer, R.W., 1998, Preliminary geologic map of the San Jose 30 X 60 minute quadrangle, California: A digital map image: U.S. Geological Survey Open-File Report 98-795, includes plotfiles for 2 sheets, scale 1:100,000, database description pamphlet, 6 pp, geologic description and interpretation pamphlet, 47 pp.

Witter, R.C., Knudsen, K.L., Sowers, J.M., Wentworth, C.M., Koehler, R.D., Randolph, C.E., Brooks, S.K., and Gans, K.D., 2006, Maps of Quaternary deposits and liquefaction susceptibility in the central San Francisco Bay region, California: U.S. Geological Survey Open File Report OF 2006-1037

These maps are available through the USGS Publications Warehouse and the California Geological Survey External link - link policy applies.

 

 

Accessibility FOIA Privacy Policies and Notices

Take Pride in America home page. FirstGov button U.S. Department of the Interior | U.S. Geological Survey
URL: /sfgeo/
Page Contact Information: ask@usgs.gov
Page Last Modified: 8/18/2006