A.C. Ritchie
S.Y. Johnson
2013
Faults--Offshore of Ventura, California
1.0
vector digital data
Samuel Y. Johnson
Peter Dartnell
Guy R. Cochrane
Nadine E. Golden
Eleyne L. Phillips
Andrew C. Ritchie
Rikk G. Kvitek
H. Gary Greene
Lisa M. Krigsman
Charles A. Endris
Gordon G. Seitz
Carlos I. Gutierrez
Ray W. Sliter
Mercedes D. Erdey
Florence L. Wong
Mary M. Yoklavich
Amy E. Draut
Patrick E. Hart
Susan A. Cochran
2013
California State Waters Map Series--Offshore of Ventura, California
map
Scientific Investigations Map
SIM 3254
Reston, VA
U.S. Geological Survey
https://pubs.usgs.gov/sim/3254/
Nadine E. Golden
2013
California State Waters Map Series Data Catalog
database
Data Series
DS 781
Reston, VA
U.S. Geological Survey
https://pubs.usgs.gov/ds/781/
This part of SIM 3254 presents data for faults for the geologic and geomorphic map (see sheet 10, SIM 3254) of the Offshore of Ventura map area, California. The vector data file is included in "Faults_OffshoreVentura.zip," which is accessible from https://pubs.usgs.gov/ds/781/OffshoreVentura/data_catalog_OffshoreVentura.html.
The Offshore of Ventura map area is in the Ventura Basin, in the southern part of the Western Transverse Ranges geologic province, which is north of the California Continental Borderland (Fisher and others, 2009). This province has undergone significant north-south compression since the Miocene, and recent GPS data suggest north-south shortening of about 6 to 10 mm/yr (Larson and Webb, 1992; Donnellan and others, 1993). The active, north-verging Oak Ridge Fault and the south-verging Pitas Point-Ventura Fault are two of the structures on which this shortening occurs (for example, Sorlien and others, 2000; Fisher and others, 2005, 2009). High-resolution seismic-reflection profiles (sheet 8, SIM 3254) reveal that neither fault ruptures the surface; instead, the surface expression of each fault is a narrow, asymmetric fold that involves the uppermost Pleistocene and Holocene (less than 21 ka) sedimentary section. Both structures are inferred to be parts of long fault systems that extend for more than 100 km, representing important potential earthquake hazards (for example, Fisher and others, 2009). Shortening is also occurring on the Montalvo Fault and Anticline system along the southeast edge of the map area (part of the broader Oak Ridge Fault Zone; Yeats, 1998) and on the Rincon-Ventura Avenue Anticline (for example, Rockwell and others, 1988), which crosses the northwest edge of the map area.
References Cited
Donnellan, A., Hager, B.H., and King, R.W., 1993, Discrepancy between geologic and geodetic deformation rates in the Ventura basin: Nature, v. 346, p. 333?336.
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., 2009, Earth science in the urban ocean--The Southern California Continental Borderland: Geological Society of America Special Paper 454, p. 271-290.
Larson, K.M., and Webb, F.H., 1992, Deformation in the Santa Barbara Channel from GPS measurements 1987-1991: Geophysical News Letters, v. 19, p. 1,491-1,494.
Rockwell, T.K., Keller, E.A., and Dembroff, G.R., 1988, Quaternary rate of folding of the Ventura Avenue anticline, western Transverse Ranges, southern California: Geological Society of America Bulletin, v. 100, p. 850-858.
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.
Yeats, R.S., 1998, North-vergent thick-skinned or south-vergent thin-skinned Oak Ridge fault--A view from the coast, in Kunitomi, D.S., Hopps, T.E., and Galloway, J.M., eds., Structure and petroleum geology, Santa Barbara Channel, California: American Association of Petroleum Geologists, Pacific Section and Coast Geological Society, Miscellaneous Publication 46, p. 143-152.
To expand geologic mapping to the seafloor within California's State
Waters, to update coastal geologic mapping, and to contribute to a
uniform regional geologic database. Additionally, to provide a geologic
map for the public and geoscience community to aid in assessments and
mitigation of geologic hazards in the Santa Barbara coastal plain region
and to provide sufficient geologic information for land-use and
land-management decisions both onshore and offshore.
Map political location: Ventura County, California
Compilation scale: 1:24,000
Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam
mapping both onshore and offshore (see sheet 2, SIM 3254, for more information).
2013
Publication Date
none planned
-119.4481
-119.2494
34.3761
34.2187
Global Change Master Directory (GCMD)
Oceans > Bathymetry/SeafloorTopography > Bathymetry
Oceans > Bathymetry/SeafloorTopography > Seafloor Topography
ISO 19115 Topic Category
geoscientificinformation
environment
oceans
imageryBaseMapsEarthCover
Geographic Names Information System (GNIS)
Pacific Ocean
California
Santa Barbara Channel
Ventura
Ventura County
Ventura Harbor
Ventura River
Santa Clara River
If physical samples or materials are available, constraints on their on-site access are described in "WR CMG Sample Distribution Policy"
at URL: https://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html
This information is not intended for navigational purposes.
Read and fully comprehend the metadata prior to data use. Uses of these
data should not violate the spatial resolution of the data. Where
these data are used in combination with other data of different resolution, the resolution of the combined output will be limited by the lowest resolution of all the data.
Acknowledge the U.S. Geological Survey in products derived from these data. Share data products developed using these data with the U.S. Geological Survey.
This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.
Although this Federal Geographic Data Committee-compliant metadata file is intended to document these data in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology.
USGS Pacific Coastal and Marine Science Center
Stephen Hartwell
Geologist
physical address
400 Natural Bridges Drive
Santa Cruz
CA
95060
USA
(831) 460-7814
(831) 427-4748
shartwell@usgs.gov
Microsoft Windows Server 2008 R2 Version 6.1 (Build 7601) Service Pack 1; ESRI ArcGIS 10.0.0.2414
Map elements were visually checked for overshoots,
undershoots, duplicate features, and other errors by the
lead authors and by the GIS technician(s) who created the digital database.
Review drafts of the map were reviewed internally by at least two other geologists for consistency
with basic geologic principles and general conformity to USGS mapping
standards.
Data are complete: no offshore features that could be accurately identified and
represented at the compilation scale of 1:24,000 were eliminated or
generalized. The smallest area represented is approximately 100 square
meters. All geospatial database elements are attributed.
Faults were primarily mapped by interpretation of seismic reflection profile data (see sheet 8, SIM 3254).
Faults lines were digitized by heads-up screen digitization on to shot-point picks from seismic-
line navigation data - each shot point has an associated lat/long in the survey data. Error is introduced
from layback, as well as from interpretation of oblique features, so horizontal accuracy of fault and fold
location is estimated to be on the order of 10 to 20 meters.
Ray W. Sliter, Peter J. Triezenberg, Patrick E. Hart,
Amy E. Draut, William R. Normark, and James E. Conrad
2008
High-resolution chirp and mini-sparker seismic-reflection data
from the southern California continental shelf--Gaviota to
Mugu Canyon
seismic reflection profile section
U.S. Geological Survey Open-File Report
2008-1246
Menlo Park, CA
U.S. Geological Survey
https://pubs.usgs.gov/of/2008/1246/
seismic data files (.sgy files)
ASCII lat/long shot point files
TIFF images of processed seismic lines
20070912
20080701
ground condition
Sliter and others, 2008
Digital seismic data used to interpret subsurface geologic structure
Faults were mapped onto shot lines based on the latitude and longitude of seismic picks from Sliter and others (2008).
2010
Vector
String
17
WGS 1984 UTM Zone 11N
0.9996
-117.0
0.0
500000.0
0.0
coordinate pair
0.0001
0.0001
Meter
D WGS 1984
WGS 1984
6378137.0
298.257223563
Faults
lines representing mapped faults
This report
OBJECTID
Internal feature number.
ESRI
Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry.
ESRI
Coordinates defining the features.
Label
feature label
This report
text field containing feature names if they are named
RuleID
Representation rule identifier
This report
This field contains the representation rule in the ArcGIS file geodatabase that applied dashed or solid lines to faults.
The line is dashed if faults are mapped in sediment and solid if they are mapped over rock or a visible scarp.
Shape_Length
Length of feature in internal units.
ESRI
Positive real numbers that are automatically generated.
2012
U.S. Geological Survey, Coastal and Marine Geology Program
Stephen R. Hartwell
mailing and physical address
400 Natural Bridges Drive
Santa Cruz
CA
95060-5792
US
831-460-7814
831-427-4748
shartwell@usgs.gov
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998