Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the 

U.S. Government

This map was printed on an electronic plotter directly from digital files. Dimensional calibration may vary between electronic plotters 

and between X and Y directions on the same plotter, and paper may change size due to atmospheric conditions; therefore, scale and 

proportions may not be true on plots of this map.

For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225, 1–888–ASK–USGS

Digital files available at http://dx.doi.org/10.3133/ofr20151191

Suggested Citation: Hartwell, S.R., Johnson, S.Y., and Davenport, C.W., 2015, Offshore and onshore geology and geomorphology, 

Offshore of Scott Creek map area, California, sheet 10 in Cochrane, G.R., Dartnell, P., Johnson, S.Y., Greene, H.G., Erdey, M.D., Dieter, 

B.E., Golden, N.E., Endris, C.A., Hartwell, S.R., Kvitek, R.G., Davenport, C.W., Watt, J.T., Krigsman, L.M., Ritchie, A.C., Sliter, R.W., 

Finlayson, D.P., and Maier, K.L. (G.R. Cochrane and S.A. Cochran, eds.), California State Waters Map Series—Offshore of Scott Creek, 

California: U.S. Geological Survey Open-File Report 2015–1191, pamphlet 40 p., 10 sheets, scale 1:24,000, http://dx.doi.org/10.3133/

ofr20151191.

ISSN 2331-1258 (online) 

http://dx.doi.org/10.3133/ofr20151191

37°

36°40'

122°20' 122°

SANTA CRUZ

MONTEREY

MOSS 

LANDING

PIGEON

POINT

Limit of California’s

State Waters

Area of

Map

CALIF.

MAP LOCATION

0 5 10 Kilometers

0 5 10Nautical Miles

121°40'

Monterey

Bay

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McCulloch (1987) considered the San Gregorio Fault Zone to be the eastern margin of the Outer Santa Cruz Basin 

(see fig. 8–1 in pamphlet). Farther offshore, outside California’s State Waters but within the map area, this basin is cut by 

the northwest-striking Ascension Fault (Greene and others, 2002; U.S. Geological Survey and California Geological 

Survey, 2010).

The seafloor outcrops of the Miocene Monterey Formation (unit Tm) and the upper Miocene and Pliocene Purisima 

Formation (unit Tp; Powell and others, 2007) that are found along the north edge of the map area are continuous with 

onshore and nearshore outcrops at Point Año Nuevo to the north (see fig. 1–1 in pamphlet). Outcrops of the Monterey 

Formation are characterized by differentially eroded layers (harder and softer interbeds) that are folded and densely 

fractured, creating an overall “shattered” appearance on shaded-relief maps (see sheets 1, 2). Adjacent seafloor outcrops of 

the Purisima Formation are similarly folded but notably are much less fractured and, thus, have a distinctly different 

geomorphic expression. Outcrops of both the Monterey Formation and the Purisima Formation are found west of the 

Coastways Fault, and outcrops of the Purisima Formation straddle the Frijoles Fault.

The upper Miocene Santa Cruz Mudstone (unit Tsc) forms onshore and nearshore outcrops on the east flank of the 

Coastways Fault, and it notably does not crop out west of the Coastways Fault. Seafloor outcrops reveal both folding and 

fracturing, although not to the extent of that of the Monterey Formation to the west. Four midshelf bedrock outcrops in the 

central part of the map area (in the outer reaches of California’s State Waters) are mapped as the undivided Miocene and 

Pliocene sedimentary rocks unit (Tu); these outcrops may consist of rocks of the Monterey Formation (Tm), the Santa 

Cruz Mudstone (Tsc), or the Purisima Formation (Tp).

Modern nearshore and inner shelf to midshelf sediments are mostly sand (unit Qms) and a mix of sand and gravel 

(units Qmsc and Qmsd). Unit Qms notably is also present in well-defined channels that cut through nearshore bedrock 

exposures at the mouths of Waddell Creek, Scott Creek, Agua Puera Creek, and San Vicente Creek (see fig. 1–2 in 

pamphlet). These distinct channels, which extend to water depths of 20 to 40 m, were formed by subaerial erosion during 

sea-level lowstands (Anima and others, 2002). The coarser grained sands and gravels (units Qmsc and Qmsd) are 

recognized primarily on the basis of bathymetry and (or) high backscatter (see sheets 1, 2, 3). Unit Qmsc mainly is found 

adjacent to bedrock, in water depths of less than 40 m. 

Unit Qmsd typically is mapped as erosional lags in scour depressions (see, for example, Cacchione and others, 1984) 

that are bounded by relatively sharp or, less commonly, diffuse contacts with the horizontal sand sheets of unit Qms. 

These depressions typically are irregular to lenticular and a few tens of centimeters deep, and they range in size from a few 

tens of square meters to as much as about 290,000 m2. They most commonly are found adjacent to seafloor bedrock 

exposures, at water depths that range from about 15 to 55 m. Such scour depressions are common along this stretch of the 

California coast (see, for example, Cacchione and others, 1984; Hallenbeck and others, 2012; Davis and others, 2013), 

where offshore sandy sediment can be relatively thin (and, thus, is unable to fill the depressions) owing to low sediment 

supply from rivers and also to significant erosion and offshore transport of sediment during large northwest winter swells. 

Such features have been referred to as “rippled scour depressions” (see, for example, Cacchione and others, 1984) or 

“sorted bedforms” (see, for example, Goff and others, 2005; Trembanis and Hume, 2011). Although the general areas in 

which both unit Qmsd scour depressions and surrounding Qms sand sheets are found are not likely to change substantially, the boundaries of the unit(s) likely are ephemeral, changing seasonally and during significant storm events. 

An offshore transition from unit Qms to the finer grained marine sediments of unit Qmsf is present at water depths 

of 50 to 65 m. Unit Qmsf primarily consists of mud and muddy sand and commonly is extensively bioturbated. These 

fine-grained shelf sediments are derived from local coastal watersheds, bluff erosion, and the northward advection of 

sediment from fluvial sources within Monterey Bay (Edwards, 2002).

REFERENCES CITED

Anima, R.J., Eittreim, S.L., Edwards, B.D., and Stevenson, A.J., 2002, Nearshore morphology and late Quaternary 

geologic framework of the northern Monterey Bay Marine Sanctuary, California: Marine Geology, v. 181, p. 35–54.

Brabb, E.E., 1997, Geologic map of Santa Cruz County, California—A digital database: U.S. Geological Survey 

Open-File Report 97–489, scale 1:62,500, available at http://pubs.usgs.gov/of/1997/of97-489/.

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, scale 1:62,500, available at http://pubs.usgs.gov/

of/1998/of98-137/.

Bruns, T.R., Cooper, A.K., Carlson, P.R., and McCulloch, D.S., 2002, Structure of the submerged San Andreas and San 

Gregorio Fault zones in the Gulf of Farallones as inferred from high-resolution seismic-reflection data, in Parsons, T., 

ed., Crustal structure of the coastal and marine San Francisco Bay region, California: U.S. Geological Survey 

Professional Paper 1658, p. 77–117, available at http://pubs.usgs.gov/pp/1658/.

Cacchione, D.A., Drake, D.E., Grant, W.D., and Tate, G.B., 1984, Rippled scour depressions of the inner continental shelf 

off central California: Journal of Sedimentary Petrology, v. 54, p. 1,280–1,291.

California Geological Survey, 1982, Alquist-Priolo earthquake fault zone map of Año Nuevo quadrangle: California 

Geological Survey, State of California Special Studies Zone Map, scale 1:24,000, available at 

http://www.quake.ca.gov/gmaps/WH/regulatorymaps.htm.

Davis, A.C.D., Kvitek, R.G., Mueller, C.B.A., Young, M.A., Storlazzi, C.D., and Phillips, E.L., 2013, Distribution and 

abundance of rippled scour depressions along the California coast: Continental Shelf Research, v. 69, p. 88–100, 

doi:10.1016/j.csr.2013.09.010.

Dickinson, W.R., Ducea, M., Rosenberg, L.I., Greene, H.G., Graham, S.A., Clark, J.C., Weber, G.E., Kidder, S., Ernst, 

W.G., and Brabb, E.E., 2005, Net dextral slip, Neogene San Gregorio–Hosgri fault zone, coastal California—

Geologic evidence and tectonic implications: Geological Society of America Special Paper 391, 43 p. 

Edwards, B.D., 2002, Variations in sediment texture on the northern Monterey Bay National Marine Sanctuary continental 

shelf: Marine Geology, v. 181, p. 83–100.

Graymer, R.W., Moring, B.C., Saucedo, G.J., Wentworth, C.M., Brabb, E.E., and Knudsen, K.L., 2006, Geologic map of 

the San Francisco Bay region: U.S. Geological Survey Scientific Investigations Map 2918, available at 

http://pubs.usgs.gov/sim/2006/2918/.

Greene, H.G., Maher, N.M., and Paull, C.K., 2002, Physiography of the Monterey Bay National Marine Sanctuary and 

implications about continental margin development: Marine Geology, v. 181, p. 55–82.

Hallenbeck, T.R., Kvitek, R.G., and Lindholm, J., 2012, Rippled scour depressions add ecologically significant 

heterogeneity to soft-bottom habitats on the continental shelf: Marine Ecology Progress Series, v. 468, p. 119–133, 

doi:10.3354/meps09948.

McCulloch, D.S., 1987, Regional geology and hydrocarbon potential of offshore central California, in Scholl, D.W., 

Grantz, A., and Vedder, J.G., eds., Geology and resource potential of the continental margin of western North 

America and adjacent ocean basins—Beaufort Sea to Baja California: Circum-Pacific Council for Energy and 

Mineral Resources Earth Science Series, v. 6, p. 353–401.

Powell, C.L., II, Barron, J.A., Sarna-Wojcicki, A.M., Clark, J.C., Perry, F.A., Brabb, E.E., and Fleck, R.J., 2007, Age, 

stratigraphy, and correlations of the late Neogene Purisima Formation, central California Coast Ranges: U.S. 

Geological Survey Professional Paper 1740, 32 p., available at http://pubs.usgs.gov/pp/2007/1740/.

Reid, J.A., Reid, J.M., Jenkins, C.J., Zimmerman, M., Williams, S.J., and Field, M.E., 2006, usSEABED—Pacific Coast 

(California, Oregon, Washington) offshore surficial-sediment data release: U.S. Geological Survey Data Series 182, 

available at http://pubs.usgs.gov/ds/2006/182/.

Smith, T.C., 1981, Fault evaluation report, Año Nuevo and Franklin Point quadrangles, California: California Division of 

Mines and Geology FER-116, April 1981, available at http://www.quake.ca.gov/gmaps/WH/regulatorymaps.htm.

Stanford, J.D., Hemingway, R., Rohling, E.J., Challenor, P.G., Medina-Elizalde, M., and Lester, A.J., 2011, Sea-level 

probability for the last deglaciation—A statistical analysis of far-field records: Global and Planetary Change, v. 79, p. 

193–203, doi:10.1016/j.gloplacha.2010.11.002.

Trembanis, A.C., and Hume, T.M., 2011, Sorted bedforms on the inner shelf off northeastern New Zealand—

Spatiotemporal relationships and potential paleo-environmental implications: Geo-Marine Letters, v. 31, p. 203–214, 

doi:10.1007/s00367-010-0225-8.

U.S. Geological Survey and California Geological Survey, 2010, Quaternary fault and fold database of the United States: 

U.S. Geological Survey database, accessed April 5, 2014, at http://earthquake.usgs.gov/hazards/qfaults/.

Wagner, D.L., Greene, H.G., Saucedo, G.J., and Pridmore, C.L., 2002, Geologic map of the Monterey 30' × 60' quadrangle 

and adjacent areas, California: California Geological Survey Regional Geologic Map Series, scale 1:100,000, 

available at http://www.quake.ca.gov/gmaps/RGM/monterey/monterey.html. 

Weber, G.E., 1994, Late Pleistocene slip rates on the San Gregorio fault zone at Point Año Nuevo, San Mateo County, 

California, in Lettis, W.R., ed., Field trip guidebook—Transpressional deformation in the San Francisco Bay region: 

Friends of the Pleistocene, Pacific Southwest Cell, Guidebook, 1994 fall field trip, Sept. 30–Oct. 2, 1994, 101 p.

Weber, G.E., and Lajoie, K.R., 1980, Map of Quaternary faulting along the San Gregorio fault zone, San Mateo and Santa 

Cruz Counties, California: U.S. Geological Survey Open-File Report 80–907, 3 sheets, scale 1:24,000, available at 

http://pubs.er.usgs.gov/publication/ofr80907.

Weber, K.M., List, J.H., and Morgan, K.L.M., 2005, An operational mean high water datum for determination of shoreline 

position from topographic lidar data: U.S. Geological Survey Open-File Report 2005–1027, available at 

http://pubs.usgs.gov/of/2005/1027/.

LIST OF MAP UNITS

[See Description of Map Units (chapter 8, in pamphlet) for complete map-unit descriptions]

OFFSHORE GEOLOGIC AND GEOMORPHIC UNITS

[Note that composite units (gray-stippled areas) are designated on map by composite label indicating both overlying 

sediment cover and lower (older) unit, separated by slash (for example, Qms/Tp indicates that thin sheet of Qms overlies 

Tp)]

Marine nearshore and shelf deposits (late Holocene)—Mostly sand; ripples common

Marine shelf scour depressions (late Holocene)—Inferred to be coarse sand and gravel, in low-relief scours

Coarse-grained marine nearshore and shelf deposits (late Holocene)—Predominantly coarse sand and 

gravel 

Fine-grained marine shelf deposits (late Holocene)—Mostly mud to muddy sand

Purisima Formation (Pliocene and late Miocene)—Mostly medium-grained to very fine-grained, poorly 

indurated to friable sandstone, siltstone, and claystone

Sedimentary rocks, undivided (Pliocene and Miocene)—May consist of rocks of the Purisima Formation 

(Tp), the Santa Cruz Mudstone (Tsc), or the Monterey Formation (Tm)

Santa Cruz Mudstone (late Miocene)—Siliceous organic mudstone and nonsiliceous mudstone, siltstone, and 

minor amounts of sandstone

Monterey Formation (late and middle Miocene)—Porcelaneous shale and chert, porcelaneous mudstone, 

calcareous claystone, and small amounts of siltstone and sandstone

ONSHORE GEOLOGIC AND GEOMORPHIC UNITS

[Units compiled from Smith (1981), California Geological Survey (1982), Brabb (1997), and Graymer and others (2006); 

unit ages, which are from these sources, reflect local stratigraphic relations. In addition, some units modified by C.W. 

Davenport on basis of analysis of 2009 lidar imagery]

Artificial fill (late Holocene)—Material placed by humans

Stream-channel deposits (late Holocene)—Sand and gravel deposits within active stream channels

Beach-sand deposits (late Holocene)—Fine to very coarse sand that forms active beaches in coastal 

environments; may form veneer over bedrock platform

Alluvial fan deposits (late Holocene)—Sediments derived from hillslopes in lower valley of Scott Creek; may 

include debris-flow and braided-stream deposits

Stream-terrace deposits (Holocene)—Relatively smooth and undissected, low-lying terraces; found 

immediately adjacent to lower reaches of active stream channels

Alluvial deposits, undivided (Holocene)—Alluvium deposited along stream channels; mapped in valley 

bottoms along small- to medium-sized streams. Locally, may include small terrace and channel deposits

Dune-sand deposits (Holocene)—Very well-sorted, fine to medium sand that forms both active and stabilized 

dunes in coastal environments

Colluvium (Holocene)—Loose to firm, unsorted sand, silt, clay, gravel, rock debris, and organic material, in 

varying proportions; typically mapped in hillside swales and narrow immature drainages

Landslide deposits (Holocene and Pleistocene)—Weathered and disintegrated rocks and soil

Alluvial fan deposits (Holocene)—Sediment (sand, gravel, silt, clay) deposited by streams emanating from 

canyons onto alluvial plains; identified primarily by fan morphology and topographic expression

Stream-terrace deposits (Holocene)—Relatively smooth, undissected, relatively low-lying terraces adjacent 

to active stream channels

Alluvial deposits, undivided (Holocene and late Pleistocene)—Found on gently sloping to level terrace 

surfaces adjacent to stream channels, where separate units could not be delineated at map scale

Stream-terrace deposits (Holocene and late Pleistocene)—Sand, gravel, silt, and minor clay of uncertain 

age; underlies relatively flat platforms adjacent to, and elevated above, stream channels

Alluvial fan deposits (late Pleistocene)—Sediment deposited by streams emanating from canyons; late 

Pleistocene age indicated by more dissection and higher elevations than adjacent Holocene fans 

Lowest emergent marine-terrace deposits (Pleistocene)—Semiconsolidated sand and less common gravel 

deposits, on uplifted marine-abrasion platforms along coast

Marine-terrace deposits, undivided (Pleistocene)—Semiconsolidated sand and less common gravel deposits, 

on uplifted marine-abrasion platforms along coast; found at higher elevations than Qmt2

Santa Cruz Mudstone (late Miocene)—Pale-yellowish-brown, siliceous mudstone and nonsiliceous 

mudstone, siltstone, and minor sandstone

Santa Margarita Sandstone (late Miocene)—Yellowish-grey to white, friable, medium- to fine-grained 

arkosic sandstone; locally calcareous and bituminous; pebble conglomerate at base of section locally 

Quartz diorite (Cretaceous)

Metasedimentary rocks (Mesozoic or Paleozoic)—Mainly pelitic schist and quartzite

EXPLANATION OF MAP SYMBOLS

Contact—Solid where location is certain; dashed where location is approximate, inferred, or concealed

Fault—Solid where location is certain, long-dashed where location is approximate, short-dashed where 

location is inferred, dotted where location is concealed, queried where uncertain

Folds—Solid where location is certain; dotted where location is approximate, inferred, or concealed

Anticline

Syncline 

Approximate modern shoreline—Defined as Mean High Water (MHW) (+1.46 m), North American Vertical 

Datum of 1988 (NAVD 88)

3-nautical-mile limit of California’s State Waters 

Area of “no data”—Areas beyond 3-nautical-mile limit of California’s State Waters were not mapped as part 

of California Seafloor Mapping Program

DISCUSSION

Marine geology and geomorphology were mapped in the Offshore of Scott Creek map area from approximate Mean 

High Water (MHW) to the 3-nautical-mile limit of California’s State Waters. MHW is defined at an elevation of 1.46 m 

above the North American Vertical Datum of 1988 (NAVD 88) (Weber and others, 2005). Offshore geologic units were 

delineated on the basis of integrated analyses of adjacent onshore geology with multibeam bathymetry and backscatter 

imagery (sheets 1, 2, 3), seafloor-sediment and rock samples (Reid and others, 2006), digital camera and video imagery 

(sheet 6), and high-resolution seismic-reflection profiles (sheet 8). Aerial photographs taken in multiple years were used to 

map the nearshore area (0 to 10 m water depth) and to link the offshore and onshore geology.

Onshore geology was compiled from Smith (1981), California Geological Survey (1982), Brabb (1997), and Graymer 

and others (2006); unit ages, which are from these sources, reflect local stratigraphic relations. In addition, some units 

were modified by C.W. Davenport on the basis of analysis of 2009 lidar imagery. 

The offshore part of the map area lies southwest of the southwest flank of the Santa Cruz Mountains, extending from 

the shoreline to water depths of about 60 to 75 m on the gently dipping (about 0.6° to 0.8°) continental shelf. The shelf is 

underlain by Neogene bedrock and a variably thick (as much as 24 m) veneer of upper Quaternary sediment (see sheet 9). 

Sea level has risen 120 to 130 m during the last about 21,000 years (see, for example, Stanford and others, 2011), leading 

to a broadening of the continental shelf, progressive eastward migration of the shoreline and wave-cut platform, and 

associated transgressive erosion and deposition. The Offshore of Scott Creek map area is now an open-ocean shelf that is 

subjected to full, and sometimes severe, wave energy. Shelf morphology and geology also are affected by local faulting, 

folding, uplift, and possibly subsidence.

The Offshore of Scott Creek map area straddles the right-lateral San Gregorio Fault Zone, an important structure in 

the distributed transform boundary between the North American and Pacific plates (see, for example, Dickinson and 

others, 2005). This fault zone is part of a regional fault system that is present predominantly in the offshore for about 400 

km, from Point Conception in the south (where it is known as the Hosgri Fault; Johnson and Watt, 2012) to Bolinas and 

Point Reyes in the north (Bruns and others, 2002; Ryan and others, 2008). The San Gregorio Fault Zone in the map area is 

part of a 90-km-long offshore segment that extends northward from Point Sur (about 75 km south of the map area), across 

outer Monterey Bay to Point Año Nuevo (1 km north of the map area) (see sheet 9; see also, Weber and Lajoie, 1980; 

Brabb and others, 1998; Wagner and others, 2002). Offshore parts of this fault zone are identified in seismic-reflection 

profiles on the basis of abrupt truncation or warping of reflections and (or) the juxtaposition of reflection panels that have 

differing seismic parameters (see sheet 8). In this map area, the San Gregorio Fault forms a distributed shear zone about 2 

km wide that includes two main fault strands. The nearshore east strand, known as the Coastways Fault, partly coincides 

with a prominent bathymetric lineament on the outer flank of nearshore bedrock outcrops present between Davenport and 

the mouth of Waddell Creek (see sheets 1, 2). The west strand, known as the Frijoles Fault, cuts across the flat, sedimentcovered shelf. Cumulative lateral slip on the San Gregorio Fault Zone is thought to range from 4 to 10 mm/yr on the basis 

of field observations at Point Año Nuevo (Weber, 1994).

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Pliocene

Pleistocene

Holocene

QUATERNARY

TERTIARY

OFFSHORE GEOLOGIC 

AND GEOMORPHIC UNITS ONSHORE GEOLOGIC AND GEOMORPHIC UNITS

CORRELATION OF MAP UNITS

Miocene

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1

U.S. Geological Survey;

2

California Geological Survey

Offshore and Onshore Geology and Geomorphology, Offshore of Scott Creek Map Area, California

 By

Stephen R. Hartwell,1 Samuel Y. Johnson,1 and Clifton W. Davenport2

2015 

ONE MILE = 0.869 NAUTICAL MILES

BATHYMETRIC CONTOUR INTERVAL 10 METERS

1 .5 0 1 KILOMETER

1000 0 1000 2000 3000 4000 5000 6000 7000 FEET

1 1/2 0 1 MILE

SCALE 1:24 000

APPROXIMATE MEAN

DECLINATION, 2015

MAGNETIC NORTH

13 / ° 1 2

TRUE NORTH

Offshore geology and geomorphology mapped by Stephen R. Hartwell and Samuel Y. 

Johnson, 2013–2014. Onshore geology and geomorphology compiled by Clifton W. 

Davenport, 2014, from Smith (1981), California Geological Survey (1982), Brabb (1997), 

and Graymer and others (2006). Bathymetric contours by Mercedes D. Erdey, 2014

GIS database and digital cartography by Stephen R. Hartwell and Peter Dartnell 

Manuscript approved for publication September 30, 2015

Onshore elevation data from California Coastal Conservancy (available 

from National Oceanic and Atmospheric Administration [NOAA] Coastal 

Service Center’s Digital Coast at http://www.csc.noaa.gov/digitalcoast/

data/coastallidar/) and from U.S. Geological Survey’s National Elevation 

Dataset (available at http://ned.usgs.gov/). Offshore shaded-relief 

bathymetry from map on sheet 2, this report. California's State Waters 

limit from NOAA Office of Coast Survey

Universal Transverse Mercator projection, Zone 10N

NOT INTENDED FOR NAVIGATIONAL USE

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Qmt2?

Qmt1

Qt

Qyf

Qa

Qcl

af

Qmt1

Qmt1?

Qa

Qt Qyt

Qms

Tsc

Tsc

Qmsf

Qmsf

Tsc

Tp

Tm

Tsc

Tp

Qms

Qmsd

Tsc

Tsc

Qmsd

Tu

Qms

Tu

Tu

Qmsc

Tu

Qmsd

Qms

Qmsd

Qmsd

Qmsc

Qms

Qmsd

Tsc

Tsc

Tsc

Qmsc

Tsc

Qmsd

Qmsd

Qmsd

Qmsd

Qmsd

Tsc

Qmsc

Tsc

Tsc

Qmsd

Qms

Qmsd

Tsc

Qmsd

Qmsd

Qmsd

Qmsd

Tsc

Qmsf

Qmsd

Qmsd

Qmsd

Qmsd

Qmsd

Qmsd

Tm

Qmsc

Qmsd

Qmsc

Qmsc

Qmsc

Qmsc

Qms

Qmsc

Qmsc

Qmsc

Qmsc

Qmsc

Qmsc

Qmsc

Qmsc

Qmsc

Qms

Qms

Qms

Qms

Qms

Qmsc

Qms Qms

Qms

Tm

Qms/Tp

Qms

Qmt2

Qmt2

Qa

Qds

Qmt2?

|}

Qms

Qa

Qmsf

?

122°15'

122°15'

122°20'

122°20'

37°5'

37°5'

37°0'

37°0'

San Gregorio Fault Zone

Frijoles Fault 

Coastways Fault 

Scott Creek

Davenport

Open-File Report 2015–1191

Sheet 10 of 10

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey