qfaults web comp As of January 12, 2017, the USGS maintains a limited number of metadata fields that characterize the Quaternary faults and folds of the United States. For the most up-to-date information, please refer to the interactive fault map.

Monterey Bay- Tularcitos fault zone, Seaside-Monterey section (Class A) No. 62b

Last Review Date: 2001-06-08

citation for this record: Bryant, W.A., compiler, 2001, Fault number 62b, Monterey Bay- Tularcitos fault zone, Seaside-Monterey section, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, https://earthquakes.usgs.gov/hazards/qfaults, accessed 08/23/2019 09:36 PM.

Synopsis General: Monterey Bay-Tularcitos fault zone is a complex, generally northwest-striking zone up to 15 km wide of dextral, dextral-reverse, and thrust faults (Greene and others, 1973 #1323; Dibblee, 1974 #4829; Clark and others, 1974 #6136; Rosenberg, 1993 #6158; Rosenberg and Clark, 1994 #6144). Detailed reconnaissance level mapping is by Greene and others (1973 #1323), Dibblee (1974 #4829), Clark and others (1974 #6136), McCulloch and Greene (1990 #5406), Rosenberg (1993 #6158), Rosenberg and Clark (1994 #6144), and Clark and others (1997 #6137). Rosenberg and Clark (1994 #6144) documented evidence of Holocene displacement along the Hatton Canyon, Sylvan Thrust, and Tularcitos faults. McCulloch and Greene (1990 #5406) mapped Holocene alluvium as offset along offshore traces of the of the Monterey Bay fault zone. Monterey Bay-Tularcitos fault zone lacks detailed studies and evidence of late Pleistocene and Holocene slip rates is poorly constrained. Dextral slip rates are not known. Rosenberg and Clark (1994 #6144) reported vertical slip rates that ranged from 0.02 mm/yr for the Navy fault (late Pleistocene vertical rate), to 0.4 mm/yr for the Sylvan Thrust fault (Holocene vertical rate). Post-Middle Miocene dextral slip rate of 0.3-1.5 mm/yr can be inferred for Tularcitos fault zone based on postulated dextral displacement by Graham (1976 #6155). However, timing of total dextral displacement is poorly constrained.

Sections: This fault has 3 sections.
Name comments General:

Section: Section name is proposed in this compilation. Seaside-Monterey section includes the Navy, Berwick Canyon, Hatton Canyon, and Sylvan faults comprising a zone as much as 5 km wide. Section extends from the postulated on-shore extension of the Monterey Bay fault zone at the southern side of Monterey Bay southeast to about 1 km north of Snivleys Ridge where the Navy, Berwick Canyon, and Hatton Canyon faults branch from the Tularcitos fault.

Fault ID: Refers to numbers 229 (Monterey Bay fault zone), 232 (Navy fault), and 236 (Tularcitos fault) of Jennings (1994 #2878) and number LO4 (Monterey Bay-Tularcitos fault zone) of Working Group on Northern California Earthquake Potential (1996 #1216).
County(s) and State(s) MONTEREY COUNTY, CALIFORNIA
Physiographic province(s) PACIFIC BORDER
Reliability of location Good
Compiled at 1:100,000 scale.

Comments: Locations based on digital revisions to Jennings (1994 #2878)) using original mapping by Dibblee (1974 #4829) at 1:62,500; original mapping by Clark and others (1974 #6136), Bryant (1985 #6135), Rosenberg (1993 #6158), Rosenberg and Clark (1994 #6144), and Clark and others (1997 #6137) at 1:24,000.

Geologic setting Generally northwest-striking zone of discontinuous faults located in the complexly deformed Salinian block bounded by the San Andreas [1] fault zone to the northeast and the San Gregorio [60] fault zone to the southwest. Monterey Bay-Tularcitos fault zone extends for about 84 km from about 6 km southwest of Santa Cruz, near the San Gregorio [60] fault, across Monterey Bay southeast to the Monterey Peninsula to near the crest of the Sierra de Salinas. Cumulative dextral and vertical displacement are not known. Graham (1976 #6155) postulated between 3.2 km and 16 km of dextral strike-slip displacement may have occurred along the Tularcitos fault zone, based on apparent dextral separation of distinctive beds in the Miocene Monterey Formation. Fiedler (1944 #6140) reported 380 m of post-Miocene up-to-north vertical displacement along the Tularcitos fault zone.

Length (km) This section is 25 km of a total fault length of 84 km.
Average strike N48°W (for section) versus N44°W (for whole fault)
Sense of movement Right lateral

Comments: Navy fault is primarily dextral strike-slip fault, based on geomorphic expression (Rosenberg, 1994 #6144) and first-motion studies (Cockerham and others, 1990 #6152). Berwick Canyon fault is considered to be a dextral reverse fault. Younse (1980 #6162) considered the Berwick Canyon fault to be predominantly normal (down-to-north), but his cross-section C-C' suggests thickness changes of Tertiary sedimentary rocks across the fault which would indicate a strike-slip component. Both Hatton Canyon and Sylvan Thrust faults are predominantly up-to-north reverse faults. Road-cut exposure of Sylvan Thrust indicates fault is thrust fault (Rosenberg and Clark, 1994 #6144).

Dip Direction S; SW

Comments: Navy, Berwick Canyon, and Hatton Canyon faults identified as steeply dipping. Exposures of Sylvan Thrust show fault planes dipping 38? to 47? SW (Rosenberg and Clark, 1994 #6144).

Paleoseismology studies

Geomorphic expression Navy fault is delineated by geomorphic features indicating late Pleistocene and possible Holocene dextral strike-slip displacement such as aligned linear drainages, aligned benches and saddles, springs, and southwest-facing bedrock scarps (Clark and others, 1974 #6136; Rosenberg and Clark, 1994 #6144). Well-defined scarps, closed depressions, and dextrally offset drainages were not observed by Bryant (1985 #6135). Berwick Canyon fault delineated by aligned linear drainages and poorly defined benches and saddles (Rosenberg and Clark, 1994 #6144).

Age of faulted surficial deposits Fault strands in this section offset Mesozoic crystalline basement rocks, Tertiary sedimentary rocks, Quaternary to late Pleistocene marine and fluvial terrace deposits, and, locally, Holocene colluvium (Clark and others, 1974 #6136; Dupre, 1990 #6153; Vaughn and others, 1991 #6147; Rosenberg and Clark, 1994 #6144).
Historic earthquake
Most recent prehistoric deformation latest Quaternary (<15 ka)

Comments: Timing of the most recent paleoevent is not well constrained. Traces of the Sylvan Thrust fault offset colluvium that has 14C age of 4,890?90 yr B.P. and traces of the Hatton Canyon fault offset colluvium that has 14C age of 2,080?40 yr B.P. (Rosenberg and Clark, 1994 #6144). Most recent displacement on Navy fault has not been established, but Clark and others (1974 #6136) considered fault as possibly active, based on geomorphic expression and association with offshore faults that offset seafloor (McCulloch and Greene, 1990 #5406). Rosenberg and Clark (1994 #6144) mapped folded late Pleistocene terrace deposits adjacent to the Navy fault which suggest post-late Pleistocene displacement.

Recurrence interval
Slip-rate category Between 0.2 and 1.0 mm/yr

Comments: There are no data for total slip along the Seaside-Monterey section. Rosenberg and Clark (1994 #6144) reported late Quaternary and Holocene vertical slip-rates for the faults of the Seaside-Monterey section. Late Quaternary vertical slip rate for Navy fault is 0.02 mm/yr, based on 10 m vertical offset of 600 ka fluvial terrace (Wright and others, 1990 #6161). Rosenberg (1993 #6158) reported a Quaternary vertical slip-rate of 0.03 mm/yr for the Hatton Canyon fault, based on 30 m vertical offset of 1.1 Ma fluvial terrace. Rosenberg and Clark (1994 #6144) calculated a Holocene vertical slip-rate of 0.07-0.14 mm/yr for the Hatton Canyon fault, based on 0.15-0.3 m vertical offset of 2.08 ka colluvium (14C age). Late Pleistocene vertical slip-rate of 0.04-0.05 mm/yr for Sylvan Thrust reported by Rosenberg and Clark (1994 #6144), based on 15-20 m vertical offset of 415 ka coastal terrace. Holocene vertical slip-rate of 0.2-0.4 mm/yr was calculated for the Sylvan Thrust fault by Rosenberg and Clark (1994 #6144), based on 1-2 m vertical offset of 4.89 ka colluvium (14C age). Poorly constrained slip rate assigned to the entire fault by Petersen and others (1996 #4860) for probabilistic seismic hazard assessment for the State of California was 0.5 mm/yr (with minimum and maximum assigned slip rates of 0.1 mm/yr and 0.9 mm/yr, respectively.
Date and Compiler(s) 2001
William A. Bryant, California Geological Survey
References #6151 Beal, C.H., 1915, The geology of the Monterey quadrangle, California: Stanford, California, Stanford University, unpublished M.S. thesis, 88 p., scale 1;62,500.

#6135 Bryant, W.A., 1985, Faults in the southern Monterey Bay area, Monterey County, California: California Division of Mines and Geology Fault Evaluation Report 167 (microfiche copy in California Division of Mines and Geology Open-File Report 90-11).

#6136 Clark, J.C., Dibblee, T.W., Jr., Greene, H.G., and Bowen, O.E., Jr., 1974, Preliminary geologic map of the Monterey and Seaside 7.5-minute quadrangles, Monterey County, California, with emphasis on active faults: U.S. Geological Survey Miscellaneous Field Studies Map MF-577, scale 1:24,000.

#6137 Clark, J.C., Dupre, W.R., and Rosenberg, L.I., 1997, Geologic map of the Monterey and Seaside 7.5-minute quadrangles, Monterey County, California—A digital database: U.S. Geological Survey Open-File Report 97-30, map scale, scale 1:24,000.

#6152 Cockerham, R.S., McCulloch, D.S., and Greene, H.G., 1990, Earthquake epicenters and selected fault plane solutions of the central California continental margin, Map 5B (Selected fault plane solutions and earthquake epicenters), in Greene, 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, scale 1:250,000.

#4829 Dibblee, T.W., Jr., 1974, Geologic maps of the Monterey, Salinas, Gonzales, Point Sur, Jamesburg, Soledad, and Junipero Serra 15-minute quadrangles, Monterey County, California: U.S. Geological Survey Open-File Report 74-5021, 7 sheets, scale 1:62,500.

#6153 Dupre, W.R., 1990, Maps showing geology and liquefaction susceptibility of Quaternary deposits in the Monterey, Seaside, Spreckels, and Carmel Valley quadrangles, Monterey County, California: U.S. Geological Survey Miscellaneous Field Studies Map MF-2096, 2 sheets, scale 1:24,000.

#6140 Fiedler, W.M., 1944, Geology of the Jamesburg quadrangle, Monterey County, California: California Journal of Mines and Geology, Report XL of the State Mineralogist, v. 40, no. 2, p. 177-250, scale 1:62,500.

#6154 Galliher, E.W., 1930, A study of the Monterey Formation, California, at the type locality: Stanford, California, Stanford University, unpublished M.S. thesis, 29 p., scale 1:62,500.

#6155 Graham, S.A., 1976, Tertiary sedimentary tectonics of the central Salinian block of California: Stanford, California, Stanford University, unpublished Ph.D. dissertation, 510 p., 1 pl.

#6156 Greene, H.G., 1970, Geology of southern Monterey Bay and its relationship to the ground water basin and salt water intrusion: U.S. Geological Survey Open-File Report, 50 p.

#1323 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.

#2878 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.

#5406 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.

#4860 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.

#6158 Rosenberg, L.I., 1993, Earthquake and landslide hazards in the Carmel Valley area, Monterey County, California: San Jose, California, San Jose State University, unpublished M.S. thesis, 123 p., scale 1:24,000.

#6144 Rosenberg, L.I., and Clark, J.C., 1994, Quaternary faulting of the greater Monterey area, California: Technical report to U.S. Geological Survey, under Contract 1434-94-G-2443, 27 p., scale 1:24,000.

#6147 Vaughn, P.R., Allwardt, A.O., and Crenna, P.C., 1991, Late Quaternary activity on the Berwick Canyon fault and Chupines fault near Monterey, coastal central California: Geological Society of America Abstracts with Programs, Cordilleran Section, v. 23, no. 2, p. 105.

#1216 Working Group on Northern California Earthquake Potential (WGNCEP), 1996, Database of potential sources for earthquakes larger than magnitude 6 in northern California: U.S. Geological Survey Open-File Report 96-705, 40 p.

#6161 Wright, T.L., Greene, H.G., Hicks, K.R., and Weber, G.E., 1990, AAPG June 1990 field trip road log, coastal geology—San Francisco to Monterey, in Garrison, R.E., Greene, H.G., Hicks, K.R., Weber, G.E., and Wright, T.L., eds., Geology and tectonics of the central California coastal region, San Francisco to Monterey: Bakersfield, California, American Association of Petroleum Geologists, Pacific Section, Volume and Guidebook, p. 261-314.