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: Johnson, S.Y., Hartwell, S.R., Watt, J.T., Sliter, R.W., and Maier, K.L., 2015, Local (Offshore of Scott Creek map 

area) and regional (offshore from Pigeon Point to southern Monterey Bay) shallow-subsurface geology and structure, California, 

sheet 9 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

Figure 1. USGS high-resolution minisparker seismic-reflection profile MBS–25 (collected in 2009 on survey S–N1–09–MB; see fig. 4 on sheet 8), which crosses 

shelf west of Davenport (see Maps A, B for location). Profile highlights faulted and folded strata beneath continental shelf, including San Gregorio Fault Zone. 

Dashed red lines show faults. Magenta symbols show fold axes (diverging arrows, anticlines; converging arrows, synclines). Blue and pink shading shows 

inferred uppermost Pleistocene and Holocene strata, deposited in last about 30,000 years during final stages of sea-level fall and subsequent sea-level rise. 

Underlying reflectors are of inferred Neogene age. Dashed green lines highlight some continuous reflections that reveal structure (not distinctive stratigraphic 

markers). Dashed purple lines show unconformities. Dashed yellow line is seafloor multiple (echo of seafloor reflector). Purple triangle shows location of 

California’s State Waters limit (yellow line on Maps A, B).

1 km

VERTICAL EXAGGERATION ~ 12.5

Two-way travel time, in seconds

0

0.1

0.2

SOUTHWEST

0.3

NORTHEAST

160

0 

Approximate depth, in meters

80

240

San Gregorio Fault Zone

clinoforms

Coastways 

 Fault Frijoles

 Fault

bedrock (Santa 

Cruz Mudstone)

DISCUSSION

This sheet includes maps that show the interpreted thickness and the depth to base of uppermost 

Pleistocene and Holocene deposits in California’s State Waters for the Offshore of Scott Creek map 

area (Maps A, B), as well as for a larger area that extends about 91 km along the coast from the 

Pigeon Point area to southern Monterey Bay (Maps C, D) to establish regional context. Highresolution seismic-reflection profiles (fig. 1; see also, sheet 8) show a lower unit of deformed 

Neogene bedrock and one or two upper units that consist of upper Quaternary sediments. The 

bedrock-sediment contact is an angular unconformity that commonly is marked by minor channeling, 

an eastward onlap onto reflection-free bedrock, and an upward change to lower amplitude, more 

diffuse reflections. 

Two upper Quaternary units are recognized on high-resolution seismic-reflection profiles (fig. 1; 

see also, figs. 1, 2, 3, 4, 6, 7, 9, 10 on sheet 8). The lower unit (pink shading in profiles), which is 

present only in the south half of the map area, notably includes low-amplitude, low-angle (1° to 3°), 

offshore-dipping clinoforms (Catuneanu, 2006) that are as thick as 15 m. The upper unit (blue shading 

in profiles) typically is characterized by low-amplitude, continuous to moderately continuous, diffuse, 

subparallel reflections, and it has a maximum thickness of about 12 m. Our preferred hypothesis is 

that the clinoforms in the lower (pink shading) of the two upper Quaternary units represent a progradational shoreface that formed between about 30,000 and 21,000 years ago, during the pre–Last 

Glacial Maximum (LGM) sea-level drop of marine-isotope stage 2 (Waelbroeck and others, 2002). 

The overlying upper unit (blue shading) represents shelf deposits that formed during the post-LGM 

sea-level rise of the last about 21,000 years (Stanford and others, 2011). In this interpretation, the 

surface at the top of the lower, clinoform-bearing unit (pink shading) is a transgressive surface of 

erosion that formed as the shoreface migrated landward. Because these two upper Quaternary units 

each consist of unconsolidated upper Quaternary sediments and together overlie the prominent 

angular unconformity with bedrock, we have combined their thicknesses on Maps B and D.

To make these maps, water bottom and depth to base of the uppermost Pleistocene and Holocene 

sediment layer were mapped from seismic-reflection profiles (fig. 1; see also, sheet 8). The difference 

between the two horizons was exported for every shot point as XY coordinates (UTM zone 10) and 

two-way travel time (TWT). The thickness of the post-LGM unit (Maps B, D) was determined by 

applying a sound velocity of 1,600 m/sec to the TWT. The thickness points were interpolated to a 

preliminary continuous surface, overlaid with zero-thickness bedrock outcrops (see sheet 10), and 

contoured, following the methodology of Wong and others (2012). 

The thickness of the uppermost Pleistocene and Holocene sediments in the Offshore of Scott 

Creek map area ranges from 0 to 24 m (Map B), and the depth to the unconformity at the base of this 

unit ranges from less than 10 to 87 m (Map A). Mean sediment thickness for the map area is 7.3 m, 

and the total sediment volume is 885×106 m3 (table 7–1 in pamphlet). The thickest sediment in the 

map area is found in two discrete depocenters. The more northern of the two depocenters, the “Waddell Creek depocenter,” has a maximum sediment thickness of 19 m and consists entirely of younger, 

post-LGM deposits (Map B; see also, fig. 3 on sheet 8). This depocenter overlies a uniformly 

offshore-dipping basement surface (Map A), indicating that it forms a low-relief mound on the 

seafloor. This low-relief mound is continuous with a lowstand fluvial channel cut into bedrock at the 

mouth of Waddell Creek (Map B), the presumed primary sediment source for this depocenter. Preservation of this low-relief sediment mound is due, in part, to its more protected (from wave energy) 

location on the south flank of the protruding bedrock high associated with Point Año Nuevo and Año 

Nuevo Island (see fig. 1–1 in pamphlet). 

The more southern of the two depocenters, the “Davenport depocenter,” is found southwest of 

Davenport, and it has a maximum sediment thickness of 24 m (Map B). Most of this sediment is part 

of the lower clinoform-bearing unit (pink shading in fig. 1; see also, figs. 2, 4, 7 on sheet 8) of 

inferred pre-LGM, regressive origin. The upper Quaternary sediments in the depocenter form a lens 

that thins in both the onshore and offshore directions (see, for example, fig. 1), and the axis of the 

depocenter coincides with an offshore decrease in slope of the underlying unconformity, from about 

1.0° to 0.5°. The thicker sediment effectively fills the accommodation space above the slope change, 

giving the modern continental shelf a relatively smooth, offshore-dipping (about 0.6° to 0.8°) profile. 

The clinoforms are not present at the mouths of significant coastal watersheds and, thus, are inferred 

to represent an offshore-prograding shoreface, rather than prograding delta foresets. 

The decreased thickness of upper Quaternary sediments between the two shelf depocenters in the 

map area results primarily from decreased depths to the underlying bedrock unconformity (Maps A, 

C). Elevated bedrock between the depocenters locally crops out on the seafloor (see sheet 10) and 

coincides with a broad anticline. As with the southeastern depocenter, accommodation space is created 

by a decrease in slope on the unconformity (from 1.0° to as low as 0.2°); however, this space is not 

filled with sediment, presumably because of its shallower water depths and also its greater exposure to 

erosive wave energy during the transgression. 

Six different informal “domains” of thickness of uppermost Pleistocene to Holocene sediment 

(see table 7–1 in pamphlet) are recognized on the regional sediment-thickness map (Map D), each 

with its own diverse set of geologic and (or) oceanographic controls. Note that data from within the 

Monterey Canyon system (including Soquel Canyon), in the southern part of the Pigeon Point to 

southern Monterey Bay region, were excluded from this analysis because available seismic-reflection 

data are insufficient to map sediment distribution in this extremely variable environment. 

(1) The southern Monterey Bay domain is bounded by the Monterey Bay shoreline on the south 

and east, the Monterey Canyon on the north, and the limit of California’s State Waters on the west. 

Sediment derived from the Salinas River forms a large, shore-parallel, subaqueous delta (thickness of 

as much as 32 m) that progrades across a thinly sediment-mantled bedrock shelf. Small changes in 

sediment thickness on the shelf are controlled by irregular bedrock relief that is at least partly attributable to the Monterey Bay Fault Zone (Greene, 1990).

(2) The northern Monterey Bay domain is bounded on the south by Monterey Canyon, on the 

north and east by the Monterey Bay shoreline, and on the west by the limit of California’s State 

Waters. The head of Monterey Canyon extends nearly to the shoreline, and the canyon forms a 

sediment trap that effectively separates the littoral- and shelf-sediment transport systems of the two 

(northern and southern) Monterey Bay domains. The northern Monterey Bay domain is characterized 

by (a) a sediment-poor inner shelf cut by paleochannels of the San Lorenzo River, the Pajaro River, 

and Soquel Creek; (b) a midshelf depocenter that has sediment as thick as 32 m, much of which was 

deposited in a pre-LGM prograding delta and (or) shoreface complex and was preserved above a 

decrease in slope on the underlying unconformity; and (c) a midshelf to outer shelf zone in which 

sediment generally becomes progressively thinner in the offshore direction. 

 (3) The Davenport shelf domain extends from the northern limit of Monterey Bay northward to 

the southern margin of the Waddell Creek depocenter. The Davenport shelf domain, as well as the 

three domains farther north, occupy a section of open, wave-dominated coast that is exposed to wave 

energy higher than that of the Monterey Bay domains to the south. The Davenport shelf domain 

includes the Davenport depocenter, a prominent midshelf, shore-parallel depocenter present between 

Davenport and Santa Cruz that mostly consists of a lower, pre-LGM, clinoform-bearing unit of 

inferred prograding-shoreface origin. Sediment in this depocenter also is preserved in accommodation 

space linked to an offshore decrease in the slope of the underlying unconformity. Sediment thickness 

within the Davenport shelf domain decreases to both the northwest and southeast of this depocenter, 

owing to the presence of elevated bedrock and (or) the related absence of the lower clinoform-bearing 

unit.

(4) The Waddell Creek delta domain lies offshore of the mouth of the Waddell Creek coastal 

watershed, and it is connected to it by a submerged channel. The domain is both distinguished and 

delineated by the significant Waddell Creek depocenter (maximum sediment thickness of 19 m), 

which forms a moundlike delta that consists entirely of inferred post-LGM deposits whose primary 

source is Waddell Creek. Sediment thins both north and south of this moundlike delta; its preservation 

is attributable to its semiprotected (from erosive wave energy) location on the south flank of Point 

Año Nuevo.

(5) The Año Nuevo shelf domain lies offshore of Point Año Nuevo, from just north of Franklin 

Point on the north to just north of the mouth of Waddell Creek on the south. Bedrock exposures, 

which locally reach water depths of 45 m, cover a substantial part of this wave-exposed domain; in 

deeper waters farther offshore, sediment cover is relatively thin. Sediment thickness in this domain 

appears to be limited both by the lack of sediment supply (because of its distance from large coastal 

watersheds) and by the presence of uplifted bedrock, which is linked to a local zone of transpression 

in the San Gregorio Fault Zone (Weber, 1990). The uplift has raised this domain and exposed it to the 

high wave energy that is characteristic of this area (Storlazzi and Wingfield, 2005).

(6) The Pigeon Point shelf domain lies on the west flank of the Pigeon Point high (McCulloch, 

1987). Sediment in the Pigeon Point shelf domain is thickest in a shore-parallel band that overlies a 

slope break in the underlying bedrock surface. Much of the sediment probably was derived from 

Pescadero Creek, a large coastal watershed that enters the Pacific Ocean about 3 km north of the 

Pigeon Point to southern Monterey Bay regional map area (see Maps C, D). The Pigeon Point shelf 

domain is transitional to the Pacifica-Pescadero shelf domain just north of it (see Watt and others, 

2014).

Map E shows the regional pattern of major faults and earthquakes occurring between 1967 and 

April 2014 that have inferred or measured magnitudes of 2.0 and greater. Fault locations, which have 

been simplified, are compiled from our mapping within California’s State Waters (see sheet 10), from 

Wagner and others (2002), and from the U.S. Geological Survey’s Quaternary fault and fold database 

(U.S. Geological Survey and California Geological Survey, 2010). Earthquake epicenters are from the 

Northern California Earthquake Data Center (2014), which is maintained by the U.S. Geological 

Survey and the University of California, Berkeley, Seismological Laboratory. The 1989 Loma Prieta 

earthquake (M6.9, 10/17/1989), on the San Andreas Fault Zone in the Santa Cruz Mountains 

(Spudich, 1996), is the most significant event in the region. The largest recorded earthquake in the 

Offshore of Scott Creek map area (M3.8, 12/24/1979) occurred within the San Gregorio Fault Zone. 

REFERENCES CITED

Catuneanu, O., 2006, Principles of sequence stratigraphy: Amsterdam, Elsevier, 375 p.

Greene, H.G., 1990, Regional tectonics and structural evolution of the Monterey Bay region, central 

California, 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: 

American Association of Petroleum Geologists, Pacific Section, Guidebook GB67, p. 31–56.

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.

Northern California Earthquake Data Center, 2014, Northern California earthquake catalog: Northern 

California Earthquake Data Center database, accessed April 5, 2014, at http://www.ncedc.org/

ncsn/.

Spudich, P., ed., 1996, The Loma Prieta, California, earthquake of October 17, 1989—Main shock 

characteristics: U.S. Geological Survey Professional Paper 1550–A, 297 p., available at 

http://pubs.usgs.gov/pp/pp1550/pp1550a/. 

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.

Storlazzi, C.D., and Wingfield, D.K., 2005, Spatial and temporal variations in oceanographic and 

meteorologic forcing along the central California coast, 1980–2002: U.S. Geological Survey 

Scientific Investigations Report 2005–5085, 39 p., available at http://pubs.usgs.gov/sir/2005/

5085/.

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/.

Waelbroeck, C., Labeyrie, L., Michel, E., Duplessy, J.C., McManus, J.F., Lambeck, K., Balbon, E., 

and Labracherie, M., 2002, Sea-level and deep water temperature changes derived from benthic 

foraminifera isotopic records: Quaternary Science Reviews, v. 21, p. 295–305. 

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. 

Watt, J.T., Hartwell, S.R., Johnson, S.Y., Sliter, R.W., Phillips, E.L., Ross, S.L., and Chin, J.L., 2014, 

Local (Offshore of San Gregorio map area) and regional (offshore from Bolinas to Pescadero) 

shallow-subsurface geology and structure, California, sheet 9 in Cochrane, G.R., Dartnell, P., 

Greene, H.G., Watt, J.T., Golden, N.E., Endris, C.A., Phillips, E.L., Hartwell, S.R., Johnson, 

S.Y., Kvitek, R.G., Erdey, M.D., Bretz, C.K., Manson, M.W., Sliter, R.W., Ross, S.L., Dieter, 

B.E., and Chin, J.L. (G.R. Cochrane and S.A. Cochran, eds.), California State Waters Map 

Series—Offshore of San Gregorio, California: U.S. Geological Survey Scientific Investigations 

Map 3306, pamphlet 38 p., 10 sheets, scale 1:24,000, http://dx.doi.org/10.3133/sim3306.

Weber, G.E., 1990, Late Pleistocene slip rates on the San Gregorio fault zone at Point Año Nuevo, San 

Mateo County, California, in Greene, H.G., Weber, G.E., Wright, T.L., and Garrison, R.E., eds., 

Geology and tectonics of the central California coast region—San Francisco to Monterey: 

American Association of Petroleum Geologists, Pacific Section, volume and guidebook, v. 67, p. 

193–204.

Wong, F.L., Phillips, E.L., Johnson, S.Y., and Sliter, R.W., 2012, Modeling of depth to base of Last 

Glacial Maximum and seafloor sediment thickness for the California State Waters Map Series, 

eastern Santa Barbara Channel, California: U.S. Geological Survey Open-File Report 

2012–1161, 16 p., available at http://pubs.usgs.gov/of/2012/1161/.

Local (Offshore of Scott Creek Map Area) and Regional (Offshore from Pigeon Point to Southern Monterey Bay) Shallow-Subsurface Geology and Structure, California

By

Samuel Y. Johnson, Stephen R. Hartwell, Janet T. Watt, Ray W. Sliter, and Katherine L. Maier

2015

CALIF.

MAP LOCATION

CALIF.

MAP LOCATION

ONE MILE = 0.869 NAUTICAL MILES

10 5 0 10 KILOMETERS

40000 30000 20000 10000 0 40000 FEET

10 5 0 10 MILES

SCALE 1:200 000

ONE MILE = 0.869 NAUTICAL MILES

1 0.5 0 1 KILOMETER

7000 3500 0 7000 FEET

2 1 0 2 MILES

SCALE 1:50 000

APPROXIMATE MEAN

DECLINATION, 2015

MAGNETIC NORTH

13 / ° 1 2

TRUE NORTH

APPROXIMATE MEAN

DECLINATION, 2015

MAGNETIC NORTH

13 / ° 1 2

TRUE NORTH

Depth and thickness mapped by Samuel Y. Johnson and 

Stephen R. Hartwell, 2011–2012

GIS database and digital cartography by Stephen R. 

Hartwell

Manuscript approved for publication September 30, 2015

Onshore elevation data from U.S. Geological Survey’s 

2012 National Elevation Dataset (available at 

http://ned.usgs.gov/). California's State Waters limit from 

NOAA Office of Coast Survey

Universal Transverse Mercator projection, Zone 10N

Depth and thickness mapped by Samuel 

Y. Johnson and Stephen R. Hartwell, 

2011–2012

GIS database and digital cartography by 

Stephen R. Hartwell

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/). California's State 

Waters limit from NOAA Office of Coast Survey

Universal Transverse Mercator projection, Zone 10N

122°35'

122°30'

122°25'

122°20'

122°15'

121°55'

121°50'

121°45'

121°40'

121°35'

37°20'

37°15'

37°10'

37°5'

37°5'

37°

37°

36°55'

36°55'

36°50'

36°50'

36°45'

36°40'

36°35'

122°15'

122°20'

122°25'

122°30'

122°35'

122°10'

122°10'

122°5'

122°5'

122°

122°

121°55'

121°50'

121°45'

121°40'

121°35'

37°10'

37°15'

37°20'

36°35'

36°45'

EXPLANATION

Regional faults and earthquake 

epicenters, 1967 - 2014

Earthquake magnitude

2.0 - 2.5

2.5 - 3.0

3.0 - 3.5

3.5 - 4.0

4.0 - 5.5

1989 Loma Prieta earthquake

M6.9

Fault—Abbreviations: 

MBFZ, Monterey Bay Fault 

Zone; SAFZ, San Andreas 

Fault Zone; SGFZ, San 

Gregorio Fault Zone

Limit of California’s State 

Waters

Offshore of 

Scott Creek

map area and 

area of Maps A, B

Santa

Cruz

Monterey Marina

Capitola

Watsonville

Aptos

Davenport

Pigeon

Point

SGFZ

SGFZ

SAFZ

MBFZ

MBFZ

Pacific Ocean

Monterey Bay

Map E

36°40'

Monterey Marina

Moss 

Landing

Watsonville

Aptos

Santa

Cruz

Davenport

Pigeon

Point

Monterey Canyon

Monterey Bay

WADDELL

CREEK DELTA

DOMAIN

PIGEON POINT

SHELF DOMAIN

SOUTHERN MONTEREY

BAY DOMAIN

NORTHERN MONTEREY

BAY DOMAIN

DAVENPORT

SHELF DOMAIN

Offshore of 

Scott Creek

map area and 

area of Maps A, B

AÑO NUEVO

SHELF DOMAIN

122°35'

122°30'

122°25'

122°20'

122°15'

121°55'

121°50'

121°45'

121°40'

121°35'

37°20'

37°15'

37°10'

37°5'

37°5'

37°

37°

36°55'

36°55'

36°50'

36°50'

36°45'

36°40'

36°35'

122°15'

122°20'

122°25'

122°30'

122°35'

122°10'

122°10'

122°5'

122°5'

122°

122°

121°55'

121°50'

121°45'

121°40'

121°35'

37°10'

37°15'

37°20'

36°35'

36°45'

0 – 0.1

0.1 – 2.5

2.5 – 5

5 – 7.5

7.5 – 10

10 – 12.5

12.5 – 15

15 – 17.5

17.5 – 20

20 – 22.5

22.5 – 25

25 – 27.5

27.5 – 30

30 – 32.5

32.5 – 35

35 – 37.5

37.5 – 40

40 – 42.5

EXPLANATION

Thickness of uppermost Pleistocene and 

Holocene sediment, in meters

Thickness contours

Index (5-m intervals)

Intermediate

Approximate shoreline

Limit of California’s State Water

Boundary of sediment-thickness domai

Area of “no data”—Areas where data are 

insufficient for contouring

Map D

Soquel

Creek

Scott

Creek

Waddell

 Creek

San Lorenzo

 River

Salinas

 River

Pajaro

 River

Pacific Ocean

Point

Año Nuevo

36°40'

Monterey Marina

Moss 

Landing

Watsonville

Aptos

Santa

Cruz

Davenport

Pigeon

Point

Soquel

Creek

Scott

Creek

Waddell

 Creek

San Lorenzo

 River

Salinas

 River

Pajaro

 River

Monterey Bay

Pacific Ocean

122°35'

122°30'122°25'

122°20'

122°15'

121°55'

121°50'

121°45'

121°40'

121°35'

37°20'

37°15'

37°10'

37°5'

37°5'

37°

37°

36°55'

36°55'

36°50'

36°50'

36°45'

36°40'

36°35'

122°15'

122°20'

122°25'

122°30'

122°35'

122°10'

122°10'

122°5'

122°5'

122°

122°

121°55'

121°50'

121°45'

121°40'

121°35'

37°10'

37°15'

37°20'

36°35'

36°45'

-75 – -70

-70 – -65

-65 – -60

-60 – -55

-55 – -50

-50 – -45

-45 – -40

-40 – -35

-35 – -30

-30 – -25

-25 – -20

-20 – -15

-15 – -10

-10 – -5

-5 – 0

-150 – -145

-145 – -140

-140 – -135

-135 – -130

-130 – -125

-125 – -120

-120 – -115

-115 – -110

-110 – -105

-105 – -100

-100 – -95

-95 – -90

-90 – -85

-85 – -80

-80 – -75

EXPLANATION

Depth to base of uppermost Pleistocene and 

Holocene sediment, in meters

Depth-to-base contours

Index (10-m intervals)

Intermediate

Approximate shoreline

Limit of California’s State Waters

Area of “no data”—Areas where data are 

insufficient for contouring

Map C

Offshore of 

Scott Creek

map area and 

area of Maps A, B Point

Año Nuevo

36°40'

122°15'

122°15'

122°20'

122°20'

37°05'

37°05'

37°

37°

Davenport

 WADDELL

CREEK DELTA

 DAVENPORT 

 SHELF

 AÑO NUEVO

 SHELF 

San Gregorio Fault Zone

Map B

0 – 0.1

0.1 – 2.5

2.5 – 5

5 – 7.5

7.5 – 10

10 – 12.5

12.5 – 15

15 – 17.5

17.5 – 20

20 – 22.5

22.5 – 25

25 – 27.5

27.5 – 30

30 – 32.5

EXPLANATION

Thickness of uppermost Pleistocene and 

Holocene sediment, in meters

Thickness contours

Index (5-m intervals)

Intermediate

Fault—Solid where location is certain; 

dashed where location is inferred; 

dotted where location is concealed

Folds—Solid where location is certain; 

dotted where location is concealed

Anticline

Syncline

Approximate shoreline

Trackline of seismic-reflection profile 

shown in figure 1

3-nautical-mile limit of California’s 

State Waters

Area of “no data”—Areas where data are 

insufficient for contouring

 Creek

Waddell

Scott Creek

Agua Puera 

 Creek

San Vicente 

 Creek

Figure 1

lowstand

paleochannel

lowstand

paleochannel

122°15'

122°15'

122°20'

122°20'

37°05'

37°05'

37°

37°

-75 – -70

-70 – -65

-65 – -60

-60 – -55

-55 – -50

-50 – -45

-45 – -40

-40 – -35

-35 – -30

-30 – -25

-25 – -20

-20 – -15

-15 – -10

-10 – -5

-5 – 0

-150 – -145

-145 – -140

-140 – -135

-135 – -130

-130 – -125

-125 – -120

-120 – -115

-115 – -110

-110 – -105

-105 – -100

-100 – -95

-95 – -90

-90 – -85

-85 – -80

-80 – -75

EXPLANATION

Depth to base of uppermost Pleistocene and 

Holocene sediment, in meters

Depth-to-base contours

Index (10-m intervals)

Intermediate

Fault—Solid where location is certain; 

dashed where location is inferred; 

dotted where location is concealed

Folds—Solid where location is certain; 

dotted where location is concealed

Anticline

Syncline

Approximate shoreline

Trackline of seismic-reflection profile 

shown in figure 1

3-nautical-mile limit of California’s 

State Waters

Area of “no data”—Areas where data are 

insufficient for contouring

Map A

Davenport

 WADDELL

CREEK DELTA

 DAVENPORT 

 SHELF

 AÑO NUEVO

 SHELF 

San Gregorio Fault Zone

 Creek

Waddell

Scott Creek

Figure 1

Agua Puera 

 Creek

San Vicente 

 Creek

Open-File Report 2015–1191

Sheet 9 of 10

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey