Archived report (descriptions no longer maintained)
San Gregorio fault zone, San Gregorio section (Class A) No. 60a
Last Review Date: 1999-01-16
Compiled in cooperation with the California Geological Survey
| County(s) and State(s) |
SANTA CRUZ COUNTY, CALIFORNIA SAN MATEO COUNTY, CALIFORNIA |
| Physiographic province(s) |
PACIFIC BORDER |
| Reliability of location |
Poor Compiled at 1:250,000 scale. |
| Length (km) | This section is 131 km of a total fault length of 241 km. |
| Average strike | N23°W (for section) |
| Sense of movement | Right lateral |
| Dip | 70°E–90° |
| Historic earthquake | |
| Most recent prehistoric deformation | latest Quaternary (<15 ka) |
| Slip-rate category | Greater than 5.0 mm/yr |
| References |
Bedrossian, T.R., 1979, Seal Cove and related faults: California Division of Mines and Geology Fault Evaluation Report FER-93, microfiche copy in California Division of Mines and Geology Open-File Report 90-11, 9 p., scale 1:24,000. Branner, J.C., Newsom, J.F., and Arnold, R., 1909, Description of the Santa Cruz quadrangle, California: U.S. Geological Survey, Geologic Atlas, Folio 163, 11 p. Clark, J.C., 1998, Neotectonics of the San Gregorio fault zone: Age dating controls on offset history and slip rates [abs.]: American Association of Petroleum Geologists Bulletin, v. 82, p. 844-845. Clark, J.C., and Rosenberg, L.I., 1999, Southern San Gregorio fault displacement—Stepover segmentation vs. through-going tectonics: U.S. Geological Survey NEHRP Final Technical Report, Grant Number 1434-HQ-98-GR-00007, 50 p., scale 1:24,000. Clark, J.C., Brabb, E.E., Greene, H.G., and Ross, D.C., 1984, Geology of the Point Reyes Peninsula and implications for San Gregorio fault history, in Crouch, J.K., and Bachman, S.B., eds., Tectonics and sedimentation along the California margin: Society of Economic Paleontologists and Mineralogists, Pacific Section, Book 38, p. 67-86. Dickinson, W.R., 1996, Kinematics of transrotational tectonism in the California Transverse Ranges and its contribution to cumulative slip along the San Andreas transform fault system: Geological Society of America Special Paper 305, p. 46. Graham, S.A., and Dickinson, W.R., 1978, Apparent offsets of on-land geologic features across the San Gregorio-Hosgri fault zone, in Silver, E.A., and Normark, W.R., eds., San Gregorio-Hosgri fault zone, California: California Division of Mines and Geology Special Report 137, p. 13-23. Greene, H.G., Lee, W.H.K., McCulloch, D.S., and Brabb, E.E., 1973, Faults and earthquakes in the Monterey Bay region, California: U.S. Geological Survey Miscellaneous Field Studies Map MF-518 (U.S. Department of the Interior and U.S. Department of Housing and Urban Development Basic Data Contribution 58), 14 p. pamphlet, 4 sheets. Jennings, C.W., 1994, Fault activity map of California and adjacent areas, with locations of recent volcanic eruptions: California Division of Mines and Geology Geologic Data Map 6, 92 p., 2 pls., scale 1:750,000. Kelson, K.I., Lettis, W.R., and Lisowski, M., 1992, Distribution of geologic slip and creep along faults in the San Francisco Bay region, in Borchardt, G., Hirschfeld, S.E., Lienkaemper, J.J., McClellan, P., Williams, P.L., and Wong, I.G., eds., Proceedings of the Second Conference on earthquake hazards in the eastern San Francisco Bay area: California Division of Mines and Geology Special Publication 113, p. 31-38. Kennedy, G.L., Lajoie, K.R., Blunt, D.J., and Mathieson, S.A., 1981, Half Moon Bay terrace, California, and the age of its Pleistocene invertebrate faunas: Western Society of Malacologists Annual Report, v. 14, p. 2. Lawson, A.C., chairman, 1908, The California earthquake of April 18, 1906—Report of the State Earthquake Investigation Commission: Washington, D.C., Carnegie Institution of Washington Publication 87. Lewis, S.D., 1994, Seismic reflection profiles of folds and thrust faults, offshore San Francisco region [abs.]: EOS, Transactions, American Geophysical Union, vol.75, no.44, supplement, p.681. McCulloch, D.S., and Greene, H.G., 1990, Geologic map of the central California continental margin, Map No. 5A (Geology), in Green, H.G., and Kennedy, M.P., eds., Geology of the central California continental margin: California Division of Mines and Geology California Continental Margin Geologic Map Series, Area 5 of 7, scale 1:250,000. McNally, K.C., and Stakes, D.S., 1998, Implications of the San Gregorio fault zone seismicity for Monterey Bay Coastal hazard assessment [abs.]: EOS, Transactions, American Geophysical Union, v. 79, no. 45, p. F589. Noller, J.S., Simpson, G.D., Thompson, S.C., and Lettis, W.R., 1995, Geoarchaeologic and paleoseismic investigations of the San Gregorio fault, Seal Cove, CA: USGS Open-File Report OFR 95-210, 600-601 p. Pampeyan, E.H., 1994, Geologic map of the Montara Mountain and San Mateo quadrangles, San Mateo County, California: U.S. Geological Survey Miscellaneous Investigations Map I-2390, scale 1:24,000. Petersen, M.D., Bryant, W.A., Cramer, C.H., Cao, T., Reichle, M.S., Frankel, A.D., Lienkaemper, J.J., McCrory, P.A., and Schwartz, D.P., 1996, Probabilistic seismic hazard assessment for the State of California: California Department of Conservation, Division of Mines and Geology Open-File Report 96-08 (also U.S. Geological Open-File Report 96-706), 33 p. Ross, S.L., Ryan., H.F., and Stevenson, A.J., 1998, San Gregorio fault zone studies offshore Half Moon Bay and Monterey Bay, CA [abs.]: EOS, Transactions, American Geophysical Union, v. 79, no. 45, p. F613. Sedlock, R.L., 1999, San Gregorio fault zone: late Cenozoic and modern dextral slip and slip rate, and southward linkage with the Sur San Simeon, and Hosgri faults [abs.]: Geological Society of America Abstracts with Programs, Cordilleran Section, v. 31, no. 6, p. A94. Weber, G.E., 1980, Recurrence intervals and recency of faulting along the San Gregorio fault zone, San Mateo County, California: Santa Cruz, University of California, unpublished Ph.D. dissertation, 204 p. Weber, G.E., 1994, Late Pleistocene slip rates on the San Gregorio fault zone at Point Año Nuevo, San Mateo Co., CA, in Lettis, W.R., ed., Quaternary transpressional pl. deformation in the greater San Francisco Bay area: Friends of Pleistocene Pacific Cell 1996 Field Trip, p. 193-203. |