DISCUSSION

This map shows seismic-reflection profiles from three different surveys of the Hueneme Canyon and 

vicinity map area, providing imagery of the subsurface geology. The dominant offshore physical features in the 

map area are the continental shelf and Hueneme Canyon. The seismic-reflection data reveal that the shelf is 

underlain by thick upper Pleistocene and Holocene deposits derived mainly from the nearby Santa Clara and 

Ventura Rivers and Calleguas Creek (Dahlen, 1992; Slater and others, 2002). Correlative strata in Hueneme 

Canyon, which bisects the shelf and serves as a major conduit of sediment to offshore basins, consist primarily 

of hummocky landslide deposits and incised canyon fill. 

The Montalvo Fault and Anticline (Yeats and others, 1988; Fisher and others, 2005) system is the most 

important tectonic feature in the map area. Figure 2A shows fault offset of a horizon inferred to represent the 

base of a section that has been deposited over the last about 21,000 years, following the last major sea-level 

lowstand (see, for example, Fleming and others, 1998). Deeper, older faults and folds likely are present in the 

map area, but the limited amount of deeper seismic-reflection data in the map area (for example, fig. 9) preclude 

their mapping. 

Data for most profiles displayed on this map sheet (figs. 1, 2B, 3, 4, 5, 6, 7, 8, 10) were collected in 2007 

on USGS cruise Z–3–07–SC (Sliter and others, 2008). Single-channel seismic-reflection data were acquired 

using the SIG 2Mille minisparker. The SIG minisparker system used a 500-Joule, high-voltage electrical 

discharge fired 1 to 4 times per second, which, at normal survey speed of 4 to 4.5 nautical miles per hour, gives 

a data trace every 0.5 to 2.0 meters. The data were digitally recorded in standard SEG-Y 32-bit floating-point 

format using PC-based Triton Subbottom Logger (SBL) software that merges seismic-reflection data with 

differential GPS-navigation data. After the survey, a short-window (20 ms) automatic gain control (AGC) 

algorithm and a 160- to 1,200-Hz bandpass filter was applied to the minisparker data.

Data for line 2 (fig. 2A) were collected in 2002 on USGS cruise A–1–02–SC. Profiles were collected using 

the 500-Joule sparker source from a Huntec deep-tow fish and a single-channel surface-towed streamer as the 

receiver. The source was towed at a minimum depth of about 5 m, well below boat-propeller wash. The 

sparker produced an effective frequency range of 1 to 6 kHz, with peak power at about 1 kHz. The data were 

recorded by a Delph recording system using a sampling frequency of 16 kHz. Additional information is 

available at http://walrus.wr.usgs.gov/infobank/a/a102sc/html/a-1-02-sc.seis.html.

Figure 9 shows a deep-penetration, migrated, multichannel seismic-reflection profile collected in 1981 by 

WesternGeco on cruise W–23–81–SC. This profile and other similar data were collected in many areas offshore 

of California in the 1970s and 1980s when the area was considered a frontier for oil and gas exploration. Much 

of these data have been publicly released and are now archived at the USGS National Archive of Marine 

Seismic Surveys (U.S. Geological Survey, 2009). These data were acquired with a large-volume air-gun source 

that has a frequency range of 3 to 40 Hz and recorded with a multichannel hydrophone streamer about 2 km 

long; shot spacing was about 30 m. These data can resolve geologic features that are 20 to 30 m thick, down to 

subbottom depths of about 4 km.

REFERENCES CITED

Dahlen, M.Z., 1992, Sequence stratigraphy, depositional history, and middle to late Quaternary sea levels of the 

Ventura shelf, California: Quaternary Research, v. 38, p. 234–245.

Fisher, M.A., Greene, H.G., Normark, W.R., and Sliter, R.W., 2005, Neotectonics of the offshore Oak Ridge 

fault near Ventura, southern California: Bulletin of the Seismological Society of America, v. 95, p. 

739–744.

Fleming, K., Johnston, P., Zwartz, D., Yokoyama, Y., Lambeck, K., and Chappell, J., 1998, Refining the eustatic 

sea-level curve since the Last Glacial Maximum using far- and intermediate-field sites: Earth and Planetary 

Science Letters, v. 163, p. 327–342, doi:10.1016/S0012-821X(98)00198-8.

Greene, H.G., Wolf, S.C., and Blom, K.G., 1978, The marine geology of the eastern Santa Barbara Channel 

with particular emphasis on the ground water basins offshore from the Oxnard Plain, southern California: 

U.S. Geological Survey Open-File Report 78–305, 104 p., 13 plates.

Huftile, G.J., and Yeats, R.S., 1995, Convergence rates across a displacement transfer zone in the western 

Transverse Ranges, Ventura basin, California: Journal of Geophysical Research, v. 100, p. 2,043–2,067.

Shaw, J.H., and Suppe, J., 1994, Active faulting and growth folding in the eastern Santa Barbara Channel, 

California: Geological Society of America Bulletin, v. 106, p. 607–626.

Slater, R.A., Gorsline, D.S., Kolpack, R.L., and Shiller, G.I., 2002, Post-glacial sediments of the California shelf 

from Cape San Martin to the US-Mexico border: Quaternary International, v. 92, p. 45–61.

Sliter, R.W., Triezenberg, P.J., Hart, P.E., Draut, A.E., Normark, W.R., and Conrad, J.E., 2008, High-resolution 

chirp and mini-sparker seismic reflection data from the southern California continental shelf - Gaviota to 

Mugu Canyon: U.S. Geological Survey Open-File Report 2008–1246, accessed April 5, 2011, at 

http://pubs.usgs.gov/of/2008/1246/.

Sorlien, C.C., Gratier, J.P., Luyendyk, B.P., Hornafius, J.S., and Hopps, T.E., 2000, Map restoration of folded 

and faulted late Cenozoic strata across the Oak Ridge fault, onshore and offshore Ventura basin, California: 

Geological Society of America Bulletin, v. 112, p. 1,080–1,090.

U.S. Geological Survey, 2009, National Archive of Marine Seismic Surveys: U.S. Geological Survey database, 

accessed April 5, 2011, at http://walrus.wr.usgs.gov/NAMSS/.

Yeats, R.S., Huftile, G.J., and Grigsby, F.B., 1988, Oak Ridge fault, Ventura fold belt, and the Sisar decollement, Ventura basin, California: Geology, v. 16, p. 1,112–1,116.

120° 119°40' 119°20' 119°

34°

34°20'

Kilometers 0 5 10

0 4 8 Nautical Miles

Santa Barbara Channel

Santa Barbara

Ventura

CALIF.

MAP LOCATION

Limit of California’s

 State Waters

Santa Cruz Island Santa Rosa Island

Area of

 Map

Anacapa

 Island

Seismic-Reflection Profiles, Hueneme Canyon and Vicinity, California

By

Samuel Y. Johnson, Ray W. Sliter, William R. Normark, and Andrew C. Ritchie

2012

shelf break

 (~75 m)

 hummocky

landslide deposits

landslide mound

submerged “bank” on north

flank of Anacapa Island

 EASTERNMOST SANTA BARBARA BASIN

onlapping

unconformities

paleo–shelf breaks

0

80

160

240

320

Southwest Northeast 0

0.1

0.2

0.3

0.4

~7° slope

SOUTH

1 km

NORTH

0.5

shoreline 

 angle

Figure 10. USGS minisparker seismic-reflection profile HC–12 (survey Z–3–07–SC; Sliter and 

others, 2008), which extends across Ventura–Oxnard shelf downslope into easternmost Santa 

Barbara Basin; see trackline map for location. Blue shading shows inferred Pleistocene and 

Holocene shelf and deltaic strata, as thick as about 50 m, deposited during sea-level rise in 

last about 21,000 years. Dashed orange lines show offshore-dipping clinoforms. Dashed blue 

lines show erosional unconformities, including buried channel under Ventura–Oxnard shelf 

and two onlapping unconformities on south flank of Santa Barbara Basin. Dashed green lines 

show dips of bedding in folded strata near unconformities; fold axes are shown above profile 

by symbols with outward-pointing arrows (anticline) and inward-pointing arrows (syncline). 

Upper Quaternary strata are inferred to be largely underlain by upper part of the Pliocene and 

Pleistocene Saugus Formation. Folded strata imaged beneath lower erosional unconformity 

on south end of profile are probably the Monterey Formation (Greene and others, 1978). 

Dashed yellow line is seafloor multiple.

400

Two-way travel time, in seconds

Approximate depth, in meters

VERTICAL EXAGGERATION ~ 8

Fig. 9Fig. 7

Fig. 6

Fig. 5

Fig. 4

buried channel

0

VENTURA–OXNARD SHELF

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://pubs.usgs.gov/sim/3225/

Suggested Citation: Johnson, S.Y., Sliter, R.W., Normark, W.R., and Ritchie, A.C., 2012, Seismic-reflection profiles, Hueneme Canyon 

and vicinity, California, sheet 8 in Johnson, S.Y., Dartnell, P., Cochrane, G.R., Golden, N.E., Phillips, E.L., Ritchie, A.C., Kvitek, R.G., 

Greene, H.G., Krigsman, L.M., Endris, C.A., Clahan, K.B., Sliter, R.W., Wong, F.L., Yoklavich, M.M., and Normark, W.R. (S.Y. Johnson, 

ed.), California State Waters Map Series—Hueneme Canyon and vicinity: U.S. Geological Survey Scientific Investigations Map 3225, 

pamphlet 41 p., 12 sheets, available at http://pubs.usgs.gov/sim/3225/.

SOUTH NORTH

1 km

0

0.5

1.0

1.5

2.0

2.5

3.0

section shown in

figure 10

seaward-dipping clinoforms 

angular

unconformity(?)

Fig. 10

Fig. 7

Figure 9. Industry 2-D migrated multichannel air-gun seismic-reflection profile WC81–614 (survey W–23–81–SC, 

collected in 1981), which extends south across Ventura continental shelf into eastern Santa Barbara Basin; see 

trackline map for location. Note that profile is aligned with southern part of subparallel high-resolution 

seismic-reflection profile shown in figure 10; however, this industry profile has much less vertical exaggeration 

(1.1:1 vs. 8:1). Note also that profile has not been depth converted and so no depth scale is shown, but it 

probably extends to depths of 4 to 5 km. Dashed blue lines show downlap surfaces of clinoforms that document 

Pleistocene progradation of shelf and subaqueous delta of Santa Clara River. Dashed green line highlights 

important continuous horizon for which two distinctly different interpretations have been made: (1) Huftile and 

Yeats (1995) and Sorlien and others (2000) suggested that strata imaged on this profile lie entirely within folded 

upper plate of steeply south-dipping Oak Ridge Fault; in this interpretation, horizon shown by dashed green line 

is prominent angular unconformity. (2) In contrast, Shaw and Suppe (1994) suggested that strata lie entirely 

within upper plate of north-dipping Pitas Point–Montalvo Thrust Fault system; in this interpretation, horizon 

marked by lower dashed green line is north-dipping, low-angle thrust fault. Greene and others (1978) assigned 

strata beneath this horizon to the Miocene Conejo Volcanics and Monterey Formation and strata above it to the 

Pliocene and Pleistocene Pico and Saugus Formations. Dashed yellow line is seafloor multiple.

Two-way travel time, in seconds

VERTICAL EXAGGERATION ~ 1.1

in upper one second of data

EASTERNMOST SANTA

BARBARA BASIN

0

80

160

240

320

400

canyon wall

0

0.1

0.2

0.3

0.4

0.5

thalweg

thalweg

thalweg

16° slope

18° slope 18° slope

landslide 14° slope

SOUTHEAST

1 km

NORTHWEST

stratified

erosional east-facing

 canyon wall Fig. 7

Fig. 6

Fig. 5

Fig. 4

gullied

stratified

canyon

fill

lowstand

lateral

canyon fill(?)

lateral

canyon fill(?)

slope

scarp, 24°

landslide

deposits

Figure 8. USGS minisparker seismic-reflection profile HC–21 (survey Z–3–07–SC; Sliter and others, 2008), which 

extends down Hueneme Canyon, obliquely crossing canyon axis and both canyon walls; see trackline map for 

location (note locations of crossing profile lines). Note that apparent slopes of canyon walls are much greater 

than actual slopes, owing to vertical exaggeration; true slope values are indicated on figure. Blue shading 

shows inferred upper Pleistocene and Holocene deposits, as thick as about 27 m on shelf but thinner within 

canyon; strata beneath blue shading are inferred to be shallow-marine facies of upper part of the Pliocene and 

Pleistocene Saugus Formation (Greene and others, 1978). Dashed blue lines show erosional channels within, 

and at base of, blue-shaded unit, as well as in underlying strata. Dashed green lines show south-dipping 

reflections and angular unconformity; strata beneath unconformity may be the Miocene “Topanga–Vaqueros 

undifferentiated unit” of Greene and others (1978). Dashed yellow line is seafloor multiple.

canyon tributary channel

Approximate depth, in meters

angular unconformity

angular unconformity

nose of ridge extending from

shelf on east canyon flank

 nose of ridge extending from

shelf on west canyon flank

landslide

deposits

HUENEME CANYON

Two-way travel time, in seconds

VERTICAL EXAGGERATION ~ 6.5

Two-way travel time

0

0.1

0.2

0.3

0.4

0 

80

160

240

320

HUENEME 

CANYON

thalweg

19° slope,

gullied

18° slope, variably 

sediment draped

canyon fill

0.5

0.6 480

400

Fig. 9

Fig. 8

1 km

NORTHWEST SOUTHEAST Fig. 10

erosional 

unconformity

18° slope

perched

landslide

deposits

erosional 

unconformity

incised

shelf

shelf

Figure 7. USGS minisparker seismic-reflection profile HC–02 (survey Z–3–07–SC; Sliter and others, 2008), which 

extends across Hueneme Canyon; see trackline map for location. Note that apparent slopes of canyon walls are 

much greater than actual slopes, owing to vertical exaggeration; true slope values are indicated on figure. Dashed 

red line shows inferred fault. Blue shading shows inferred upper Pleistocene and Holocene shelf and deltaic strata 

deposited during sea-level rise in last about 21,000 years; strata are about 25 to 35 m thick beneath shelf and as 

thick as about 48 m in channel fills along canyon edge; strata beneath blue shading are inferred to be shallowmarine facies of the Pliocene and Pleistocene Saugus Formation (Greene and others, 1978). Dashed blue lines 

show erosional surfaces at base of blue-shaded unit (including beneath canyon axis). Dashed magenta lines show 

possible failure planes for landslides. Dashed yellow line is seafloor multiple. Note changes in depth and canyon 

morphology from that seen upcanyon in figures 4, 5, and 6.

VERTICAL EXAGGERATION ~ 6.5

Two-way travel time, in seconds

Approximate depth, in meters

1 km

NORTHWEST SOUTHEAST Fig. 10 Fig. 8

0 

80

160

240

320

0

0.1

0.2

0.3

0.4

 HUENEME 

CANYON

thalweg

25° slope,

gullied

18° slope, gullied

variably sedimentdraped

deposits

landslide wall inner canyon

21° slope

shelf shelf

buried canyon floor landslide deposits

Figure 6. USGS minisparker seismic-reflection profile HC–20 (survey Z–3–07–SC; Sliter and others, 2008), which extends across Hueneme 

Canyon; see trackline map for location. Note that apparent slopes of canyon walls are much greater than actual slopes, owing to vertical 

exaggeration; true slope values are indicated on figure. Dashed red lines show inferred faults. Blue shading shows inferred upper 

Pleistocene and Holocene shelf and deltaic strata deposited during postglacial sea-level rise; strata beneath blue shading are inferred to 

be shallow-marine facies of upper part of the Pliocene and Pleistocene Saugus Formation (Greene and others, 1978). Dashed blue line 

shows channels and erosional surfaces at base of uppermost unit, within underlying Pleistocene(?) unit, and along buried channel floor 

beneath canyon axis. Dashed magenta lines show possible failure planes for deep-seated landslides. Dashed green lines show bedding 

dips, erosion surface, and angular unconformity in pre-Holocene strata. Dashed yellow line is seafloor multiple. Note changes in depth 

and canyon morphology from that seen upcanyon in figures 4 and 5 and downcanyon in figure 7.

Two-way travel time, in seconds

canyon fill

incised

angular unconformity

VERTICAL EXAGGERATION ~ 6.5

Approximate depth, in meters

0

0.1

0.2

0.3

0.4

0 

80

160

240

320

thalweg

14° 14° slope

slope

HUENEME CANYON

 canyon fill

shelf shelf

NORTHWEST SOUTHEAST

landslide

headwall

Fig. 10

Fig. 8

stratified

lowstand

lateral

canyon fill(?)

1 km

buried canyon floor landslide deposits

Figure 5. USGS minisparker seismic-reflection profile HC–09T (survey Z–3–07–SC; Sliter and others, 2008), which extends 

across Hueneme Canyon; see trackline map for location. Note that apparent slopes of canyon walls are much greater than 

actual slopes, owing to vertical exaggeration; true slope values are indicated on figure. Blue shading shows inferred upper 

Pleistocene and Holocene shelf and deltaic strata, as thick as about 35 to 40 m, deposited during sea-level rise in last about 

21,000 years; strata beneath blue shading are inferred to be shallow-marine facies of upper part of the Pliocene and 

Pleistocene Saugus Formation (Greene and others, 1978). Dashed green lines show dipping beds and angular unconformity. 

Dashed blue line shows channels and erosional surfaces, including buried channel floor beneath canyon axis. Dashed 

magenta line shows possible landslide failure plane. Dashed yellow line is seafloor multiple. Note changes in depth and 

canyon morphology from that seen upcanyon in figure 4 and downcanyon in figures 6 and 7.

Approximate depth, in meters

Two-way travel time, in seconds

angular unconformity

VERTICAL EXAGGERATION ~ 8

1 km

0

0.1

0.2

0.3

0

80

160

240

~28° slope

WEST

landslide 

shelf shelf

thalweg

headwall,

 canyon fill 

HUENEME CANYON

Fig. 10

VERTICAL EXAGGERATION ~ 6.5 EAST

landslide 

deposit incised

slope

gullied

buried canyon floor

Figure 4. USGS minisparker seismic-reflection profile HC–10 (survey Z–3–07–SC; Sliter and others, 2008), which extends 

across Hueneme Canyon; see trackline map for location. Note that apparent slopes of canyon walls are much greater than 

actual slopes, owing to vertical exaggeration; true slope values are indicated on figure. Dashed red line shows inferred 

fault. Blue shading shows inferred uppermost Pleistocene and Holocene shelf and deltaic strata, as thick as about 35 to 40 

m beneath shelf, deposited during postglacial sea-level rise; strata beneath blue shading are inferred to be shallow-marine 

facies of upper part of the Pliocene and Pleistocene Saugus Formation (Greene and others, 1978). Dashed blue lines show 

channels and erosional unconformities, including buried canyon floor beneath canyon axis. Dashed yellow line is seafloor 

multiple. Note changes in depth and canyon morphology from that seen downcanyon in figures 5, 6, and 7.

Two-way travel time, in seconds

Approximate depth, in meters

 Fig. 8

0 

80

160

240

320

1 km

Montalvo Fault and Anticline

NORTHWEST SOUTHEAST

0

0.1

0.2

0.3

0.4

Fig. 1

Figure 3. USGS minisparker seismic-reflection profile SB–51T 

(survey Z–3–07–SC; Sliter and others, 2008), which crosses 

Ventura continental shelf in eastern Santa Barbara Channel; 

see trackline map for location. Red line (dashed where inferred) 

shows Montalvo Fault in core of Montalvo Anticline (Greene 

and others, 1978; Fisher and others, 2005). Dashed green lines 

highlight flat strata underlying much of shelf and dipping strata 

on anticlinal flanks, as well as angular unconformity lower in 

section; stratal thinning on southeast flank of anticline 

indicates that some deposition occurred during fold growth. 

Folded strata, which are inferred to be the Pliocene and 

Pleistocene Saugus Formation (upper part), are unconformably 

overlain by about 40 m of uppermost Pleistocene and Holocene 

shelf and deltaic strata (blue shading). Dashed blue line shows 

low-relief erosion surface at base of shelf and deltaic strata. 

Dashed yellow line is seafloor multiple.

Two-way travel time, in seconds

Approximate depth, in meters

angular unconformity

VERTICAL EXAGGERATION ~ 8

VENTURA–OXNARD SHELF

1 km

NORTHWEST

0

0.1

0.2

0.3

SOUTHEAST

Montalvo Fault VENTURA–OXNARD SHELF

NORTHWEST

0 

80

160

240

SOUTHEAST

MF

A B

Figure 2. Two USGS seismic-reflection profiles that cross Montalvo Fault (dashed red lines) (Greene and others, 

1978; Yeats and others, 1988; Fisher and others, 2005); see trackline map for locations. Blue shading shows 

inferred upper Pleistocene and Holocene strata (as much as about 40 m thick), deposited since last sea-level 

lowstand about 21,000 years ago. Dashed green lines show dipping strata and angular unconformity earlier in 

Pleistocene(?) section. A, Huntec minisparker seismic-reflection-profile HC–1850 (USGS survey A–1–02–SC; 

note that survey extends 330 m farther to northwest, beyond north edge of map area). Interpretation suggests 

that Montalvo Fault has as much as 7 m of south-side-up vertical offset or warping above unconformity. B, Part 

of minisparker seismic- reflection profile SB–57 (survey Z–3–07–SC; Sliter and others, 2008). Profile does not 

obviously show similar displacement along Montalvo Fault (MF).

Two-way travel time, in seconds

Approximate depth, in meters

angular unconformity

VERTICAL EXAGGERATION ~ 8

80

160

240

0 

WEST EAST

Two-way travel time, in seconds

0

0.1

0.2

0.3

Montalvo Anticline

1 km

 Fig. 3

Figure 1. USGS minisparker seismic-reflection profile SB–58 (survey Z–3–07–SC; Sliter and others, 

2008), which obliquely crosses Montalvo Anticline (Greene and others, 1978; Fisher and others, 

2005); see trackline map for location. Blue shading shows inferred uppermost Pleistocene and 

Holocene deltaic and shelf deposits. Dashed green lines highlight dipping beds and angular 

unconformity. Dashed orange lines highlight areas of reflections that have offshore-dipping 

clinoforms. Dashed yellow line is seafloor multiple. 

Approximate depth, in meters

angular unconformity

VERTICAL EXAGGERATION ~ 8

SCALE 1:50 000

1 0.5 0 1 KILOMETER

7 000 3 500 0 7 000 FEET

2 1 0 2 MILES

ONE MILE = 0.869 NAUTICAL MILES APPROXIMATE MEAN

DECLINATION, 2012

13°

MAGNETIC NORTH

TRUE NORTH

GIS database and digital cartography by Eleyne L. 

Phillips and Florence L. Wong

Edited by Taryn A. Lindquist

Manuscript approved for publication July 25, 2012

Onshore elevation data from NOAA Coastal Services Center 

(data collected by EarthData International in 2002-2003) and 

from U.S. Army Corps of Engineers (data collected by Fugro 

Pelagos in 2009). 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 11N

NOT INTENDED FOR NAVIGATIONAL USE

Oxnard

Port of Hueneme

Channel Islands Harbor

Fig. 1

Fig. 2B

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Fig. 10

Fig. 9

Fig. 2A

34°10'

34°10'

34°5'

34°5'

119°10'

119°10'

119°15'

119°15'

119°20'

119°20'

Trackline Map

EXPLANATION

Tracklines of select seismic-reflection 

surveys—Thick lines show locations 

of profile lines depicted in figures; 

thin lines show full extent of surveys

Survey Z–3–07–SC (USGS)

Survey A–1–02–SC (USGS)

Survey W–23–81–SC (WesternGeco)

3-nautical-mile limit of California’s State 

Waters—Line in southwest corner of 

map area is limit surrounding Anacapa 

Island (outside of map area)

Area of “no data”—Areas where highresolution multibeam bathymetric data 

are not available

Figure 5

Figure 9

Figure 2A

Scientific Investigations Map 3225

Sheet 8 of 12

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey