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: Ritchie, A.C., Johnson, S.Y., and Clahan, K.B., 2012, Offshore and onshore geology and geomorphology, Hueneme 

Canyon and vicinity, California, sheet 10 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/.

US Army Corps

of Engineers

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

Qff

Qa1

Qw1

Qa2

Qw2

Qa3

Qt3

Qw3

Qa

Qes

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Qb

alf

af

Qcft

Qcfl

Qcfa

Qlss

Qls

Qls1

Qls2

Qls3

Qcwo2

Qcwo1

Qcwi

Qccw

Qccb

Qccf

Qcch

Qwpr1

Qwp1

Qwpr2

Qwp2

Qwpr3

Qwp3

Qwpr4

Qwp4

Qmss

Tbu

Qmr

Qmp

Qmsl

Qmsh

Qms

af

DISCUSSION

GEOLOGIC AND GEOMORPHIC SUMMARY—OFFSHORE

Marine geology and geomorphology was mapped in the Hueneme Canyon and vicinity map area from Mean High 

Water (MHW) to the 3-nautical-mile limit of California's State Waters and even farther offshore on the east and west 

flanks of Hueneme Canyon. MHW is defined at an elevation of 1.33 m above the North American Vertical Datum of 1988 

(NAVD 88) (Weber and others, 2005). 

The offshore map area is characterized by two major physiographic features: (1) the nearshore, the inner and outer 

continental shelf, and the upper slope, and (2) Hueneme Canyon and parts of three smaller, unnamed submarine canyons 

incised into the shelf southeast of Hueneme Canyon. The nearshore, shelf, and slope, which are underlain by recent 

sediments, are characterized by active sediment transport. Nearshore and inner shelf deposits are predominantly sand (unit 

Qms), which locally exhibits scour depressions (unit Qmss) and hummocky relief (unit Qmsh). Outer shelf and slope 

deposits consist of mixed sand and mud (unit Qmsl), which locally contains solitary or groups of pockmarks (unit Qmp) 

or is incised by narrow rills (unit Qmr). 

The morphology and evolution of shelf and slope result from drainage incision into deltaic sediments of the Oxnard 

Plain during sea-level lowstand, followed by sedimentation as sea level rose about 125 to 130 m over the last approximately 18,000 to 20,000 years (Lambeck and Chappell, 2001). Sea-level rise (controlled by both eustasy and tectonic 

land-level change) was apparently not steady during this period, leading to development of shorelines during periods of 

relative sea-level stability. These paleoshorelines, which are characterized by shoreline angles and adjacent submerged 

wave-cut platforms and risers (Kern, 1977), commonly are buried by shelf sediment. However, their original morphology 

is at least partly preserved on the outer shelf and upper slope on the east flank of Hueneme Canyon. Four wave-cut 

platforms (units Qwp1, Qwp2, Qwp3, Qwp4) and risers (units Qwpr1, Qwpr2, Qwpr3, Qwpr4) are mapped here, 

separated by shoreline angles at depths of approximately 65 m, 75 to 85 m, 95 to 100 m, and 120 to 125 m. 

Hueneme Canyon extends about 15 km offshore from its nearshore canyon head. The canyon is relatively deep (about 

150 m deep at the California’s State Waters limit) and steep (canyon walls as steep as 25° to 30°). The heads of the three 

smaller unnamed canyons southeast of Hueneme Canyon are not connected to the nearshore; however, during the last 

sea-level lowstand, these smaller canyons were connected to coastal watersheds that fed coarse-grained sediment directly 

to the Hueneme submarine fan (Normark and others, 2009). In the ensuing transgression, Hueneme Canyon maintained its 

connection with the shoreline as it eroded headward, whereas these smaller canyons became isolated and, thus, were 

abandoned.

Outer canyon walls, which extend upward to the shelf edge, in both Hueneme Canyon and the smaller canyons vary 

from smooth (sediment draped) (unit Qcwo1) to deeply incised (unit Qcwo2). Inner canyon walls (unit Qcwi) occupy an 

intermediate position between the shelf edge and canyon floor. 

Both outer and inner canyon walls were formed primarily by landsliding. Three different landslide-deposit units are 

mapped in Hueneme Canyon on the basis of their morphology and relative age, inferred from crosscutting and (or) draping 

relations: unit Qls1 (oldest), unit Qls2, and unit Qls3 (youngest). A fourth undifferentiated landslide-deposit unit (Qls) is 

mapped where morphology and relative-age indicators are not distinct. The landslide map units commonly include steep 

erosional scarps paired with hummocky landslide deposits; this genetic pairing (scarps and landslide deposits) distinguishes the internal scarps within landslide units from the head scarps within canyon-wall units. Lower relief, sedimentdraped, deep-seated slumps are mapped as a fifth landslide-deposit unit (Qlss). 

Submarine-canyon channel heads (unit Qcch) are delineated on the basis of their incision into the nearshore 

(Hueneme Canyon) or outer shelf (three smaller canyons southeast of Hueneme Canyon), as well as their relatively steep 

gradients and their V-shaped profiles. These channel heads merge into lower gradient and more flat-bottomed canyon-floor 

channel deposits (unit Qccf). The Hueneme Canyon channel floor is a zone of active sediment transport characterized by 

large, asymmetric bedforms bounded by steep channel walls (unit Qccw). Narrow, elongate channel-flanking bars (unit 

Qccb) are elevated above, and are morphologically distinct from, the channel floors and, thus, are broken out as separate 

map units. 

In addition to landslide and canyon-channel deposits, three additional canyon-fill map units are recognized. Axialsubmarine-canyon-fill deposits (unit Qcfa), which form elevated surfaces 20 to 50 m above the floors of Hueneme Canyon 

and the smaller submarine canyons and which dip gently downcanyon, are composed of well-stratified sediment (sand, 

mud, gravel?), recognized on the basis of its seismic-reflection data (high frequency, moderate amplitude, and parallel 

reflections). Lateral-submarine-canyon-fill deposits (unit Qcfl), located on the east flank of Hueneme Canyon near its 

head, consist of west-dipping, stratified sediment (recognized on the basis of its seismic-reflection facies) that probably 

formed as distributed fluvial input into the canyon in the middle to late Holocene. Tributary-submarine-canyon-fill 

deposits (unit Qcft) are inferred to have formed as direct fluvial entrants into the canyons in the middle to late Holocene 

and, subsequently, were partly filled by nearshore and shelf sediment during sea-level rise. 

One area of undifferentiated bedrock (unit Tbu) is recognized in the map area, on the slope on the west flank of 

Hueneme Canyon channel, at a depth of about 300 to 350 m. This unit is recognized on the basis of its high backscatter 

(see sheet 3) and its massive character on seismic-reflection data (Sliter and others, 2008; profiles HC–14, HC–15). 

Greene and others (1978; their plate 2) previously mapped this bedrock as the Miocene Monterey Formation.

GEOLOGIC AND GEOMORPHIC SUMMARY—ONSHORE

The onshore geology and geomorphology of the Hueneme Canyon and vicinity map area was compiled from Clahan 

(2003). The onshore part of the map area is in the southern part of the Western Transverse Ranges province, north of the 

California Continental Borderland (Fisher and others, 2009). Onshore deltaic and offshore shelf deposits are deformed in 

the northernmost part of the map area by the west-trending Montalvo Fault and Anticline (Fisher and others, 2005). The 

Montalvo structures are part of a band of active deformation that includes the west-trending Oak Ridge Fault (Fisher and 

others, 2005), which extends offshore just a few kilometers north of the map area. The zone of faulting that contains the 

Oak Ridge and Montalvo Faults, which forms the southern boundary of the Ventura Basin, is considered an earthquake 

hazard because it extends along strike for about 130 km, and it appears to be the westward continuation of the fault system 

responsible for the 1994 M6.7 Northridge earthquake. 

REFERENCES CITED

Clahan, K.B., 2003, Geologic map of the Oxnard 7.5' quadrangle, Ventura County, California—a digital database: 

California Geological Survey Preliminary Geologic Map, accessed April 5, 2011, at http://www.conservation.ca.gov/

cgs/rghm/rgm/preliminary_geologic_maps.htm.

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.

Fisher, M.A., Sorlien, C.C., and Sliter, R.W., 2009, Potential earthquake faults offshore southern California from the 

eastern Santa Barbara channel to Dana Point, in Lee, H.J., and Normark, W.R., eds., Earth science in the urban 

ocean—The Southern California Continental Borderland: Geological Society of America Special Paper 454, p. 

271–290.

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.

Kern, J.P., 1977, Origin and history of upper Pleistocene marine terraces, San Diego, California: Geological Society of 

America Bulletin, v. 88, p. 1,553–1,566.

Lambeck, K., and Chappell, J., 2001, Sea level change through the last glacial cycle: Science, v. 292, p. 679–686, doi: 

10.1126/science.1059549.

Normark, W.R., Piper, D.J.W., Romans, B.W., Covault, J.A., Dartnell, P., and Sliter, R.W., 2009, Submarine canyon and 

fan systems of the California Continental Borderland, in Lee, H.J., and Normark, W.R., eds., Earth science in the 

urban ocean—The Southern California Continental Borderland: Geological Society of America Special Paper 454, p. 

141–168.

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/.

Weber, K.M., List, J.H., and Morgan, K.L., 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, accessed April 5, 2011, 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

NEARSHORE, SHELF, AND SLOPE

Artificial fill (Holocene)—Rock, sand, and mud; placed and (or) dredged. Also includes seafloor significantly 

modified by human activity

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

Marine shelf scour depressions (Holocene)—Inferred to be coarse sand and gravel

Marine shelf hummocky deposits (Holocene)—Sand forming hummocky surface relief

Marine slope deposits (Holocene)—Sand and mud

Marine pockmarks (Holocene)—Sand and mud

Marine rill (Holocene)—Probably sand and mud

Bedrock, undivided (Pliocene? and Miocene)

Paleoshorelines

Submerged wave-cut platform, about 65 m deep (latest Pleistocene)—Inferred to be sand and gravel

Submerged wave-cut platform riser, base about 65 m deep (latest Pleistocene)—Inferred to be sand and 

gravel

Submerged wave-cut platform, about 75 to 85 m deep (latest Pleistocene)—Inferred to be sand and gravel

Submerged wave-cut platform riser, base about 75 to 85 m deep (latest Pleistocene)—Inferred to be sand 

and gravel

Submerged wave-cut platform, about 95 to 100 m deep (latest Pleistocene)—Inferred to be sand and gravel

Submerged wave-cut platform riser, base about 95 to 100 m deep (latest Pleistocene)—Inferred to be sand 

and gravel

Submerged wave-cut platform, about 120 to 125 m deep (latest Pleistocene)—Inferred to be sand and 

gravel

Submerged wave-cut platform riser, base about 120 to 125 m deep (latest Pleistocene)—Inferred to be 

sand and gravel

SUBMARINE CANYON

Channels

Submarine-canyon channel-head deposits (Holocene)—Probably sand and gravel(?)

Submarine-canyon channel-floor deposits (Holocene)—Inferred to be sand and gravel

Submarine-canyon channel-flanking bar deposits (Holocene)—Inferred to be sand, mud, and gravel

Submarine-canyon channel-wall deposits (Holocene)—Inferred to be sand, mud, and gravel

Walls

Inner submarine-canyon-wall deposits (Holocene and latest Pleistocene)—Inferred to be sand, mud, and 

gravel; slopes mostly more than 12° and commonly more than 20°

Outer submarine-canyon-wall deposits (Holocene and latest Pleistocene)—Inferred to be sand, mud, and 

gravel; slopes mostly more than 30°; erosional and deeply incised

Outer submarine-canyon-wall deposits (Holocene and latest Pleistocene)—Inferred to be sand, mud, and 

gravel; slopes generally more than 18° but rarely more than 30°; relatively smooth, and commonly 

sediment draped

Landslides

Landslide deposits, third generation (Holocene)—Inferred to be sand and gravel

Landslide deposits, second generation (Holocene and latest Pleistocene)—Inferred to be sand and gravel

Landslide deposits, first generation (Holocene and latest Pleistocene)—Inferred to be sand and gravel

Landslide deposits, undifferentiated (Holocene and latest Pleistocene; historical)—Inferred to be sand and 

gravel; presently active

Slump deposits on canyon walls (Holocene and latest Pleistocene)—Probably sand

Fill

Tributary-submarine-canyon fill (Holocene)—Inferred to be sand and gravel

Lateral-submarine-canyon fill (Holocene)—Inferred to be mud, sand, and gravel

Axial-submarine-canyon fill (Holocene)—Inferred to be sand and gravel

ONSHORE GEOLOGIC AND GEOMORPHIC UNITS

OXNARD PLAIN

Artificial fill (Holocene)—Engineered and (or) nonengineered

Artificial-levee fill (Holocene)—Engineered and (or) nonengineered

Beach deposits (Holocene)—Unconsolidated, loose, fine- to coarse-grained sand; well sorted

Coastal eolian sand-dune deposits (Holocene)—Well-sorted, loose sand and silt

Coastal-estuarine deposits (Holocene)—Silty clay

Alluvial deposits (Holocene)—Unconsolidated, poorly sorted, clayey sand and some gravel; deposited as 

overbank material associated with unit Qw3; recognized by scour and incised channels

Alluvial deposits (Holocene)—Unconsolidated, poorly sorted, clayey sand and some gravel; deposited as 

overbank material associated with unit Qw3; recognized by scour and incised channels

Wash deposits (Holocene)—Unconsolidated sand, silt, and gravel. Located in major abandoned river channels

Stream-terrace deposits (Holocene)—Unconsolidated clayey sand, sandy clay, and gravel; deposited in 

point-bar and overbank settings associated with unit Qw3

Alluvial deposits (Holocene)—Unconsolidated, poorly sorted, clayey sand and some gravel; deposited as 

overbank material associated with unit Qw2; recognized by scour and incised channels

Wash deposits (Holocene)—Unconsolidated sand, silt, and gravel. Located in major abandoned river channels

Alluvial deposits (Holocene)—Unconsolidated, sandy clay and some gravel; deposited as overbank material 

associated with unit Qw1; recognized by scour and incised channels

Wash deposits (Holocene)—Unconsolidated sand, silt, and gravel. Located in major abandoned river channels

Alluvial fan deposits (Holocene)—Fine-grained alluvial fan and floodplain overbank deposits. Fine facies; 

predominantly clay and interbedded lenses of coarser sand and gravel. Located on very gently sloping 

parts of valley floor

EXPLANATION OF MAP SYMBOLS

Contact—Approximately located 

Fluvial-terrace scarp—Denotes fluvial terrace within unit Qt3; in places, also forms contact between unit 

Qt3 and units Qa2 and Qa3. Hachures point downscarp

Fault—Solid where location is certain, dotted where location is concealed

Folds—Solid where location is certain, dotted where location is concealed

Antiform

Synform

Head scarp of submarine landslide—Sharp, distinct. In places, forms contact between landslide deposits or 

other units. Hachures point downscarp

Internal scarp in submarine landslide—Sharp, distinct. Hachures point downscarp

Inferred former marine shoreline

Approximate modern shoreline—Defined as Mean High Water (MHW) (+1.33 m), North American Vertical 

Datum of 1988 (NAVD 1988)

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”—Area not mapped owing to insufficient high-resolution seafloor-mapping data

Qt3

Qw1

Qw2

Qw3

Qa1

Qa2

Qa3

af alf Qb Qe Qes Qa Qff

Qcfl Qcfa

Qcft

Qlss

Qls

Qls1

Qls2

Qls3

Qcwo1

Qcwo2

Qcwi

Qccb Qccw

Qccf

Qcch

Qwp1 Qwpr1

Qwp2 Qwpr2

Qwp3 Qwpr3

Qwp4 Qwpr4

Tbu

af Qms Qmss Qmsh Qmsl Qmp Qmr

Paleoshorelines

CORRELATION OF MAP UNITS

ONSHORE GEOLOGIC AND GEOMORPHIC UNITS

NEARSHORE, SHELF, AND SLOPE OXNARD PLAIN

OFFSHORE GEOLOGIC AND GEOMORPHIC UNITS

SUBMARINE CANYON

Channels Walls Landslides Fill

QUATERNARY

Holocene

TERTIARY

Late

Pleistocene

Pliocene(?) 

and Miocene

1

U.S. Geological Survey;

2

California Geological Survey 

Offshore and Onshore Geology and Geomorphology, Hueneme Canyon and Vicinity, California

By

Andrew C. Ritchie,1 Samuel Y. Johnson,1 and Kevin B. Clahan2

2012

1000 0 1000 2000 3000 4000 5000 6000 7000 FEET

1 .5 0 1 KILOMETER

SCALE 1:24 000

BATHYMETRIC CONTOUR INTERVAL 10 METERS AND 50 METERS

ONE MILE = 0.869 NAUTICAL MILES

1 1/2 0 1 MILE

APPROXIMATE MEAN

DECLINATION, 2012

13°

MAGNETIC NORTH

TRUE NORTH

Offshore geology and geomorphology mapped by Andrew C. Ritchie and Samuel 

Y. Johnson, 2010-2011. Onshore geology and geomorphology compiled by Kevin 

B. Clahan, 2003 (Clahan, 2003). Bathymetric contours by Andrew C. Ritchie, 2011 

GIS database and digital cartography by Andrew C. Ritchie, Eleyne L. Phillips, 

and Marina T. Mascorro

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

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af?

af

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af

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119°20' 119°15' 119°10'

119°20' 119°15' 119°10'

34°5'

34°10'

34°5'

34°10'

Oxnard

Port of Hueneme

Channel Islands Harbor

H u e n e m e C a n y o n

Montalvo Fault

Montalvo Anticline

Scientific Investigations Map 3225

Sheet 10 of 12

Pamphlet accompanies map

U.S. Department of the Interior

U.S. Geological Survey