Dataset Identification:
Resource Abstract:
- description: This part of DS 781 presents data for folds for the geologic and geomorphic map of the Offshore of San Francisco
map area, California. The vector data file is included in "Folds_OffshoreSanFrancisco.zip," which is accessible
from http://pubs.usgs.gov/ds/781/OffshoreSanFrancisco/data_catalog_OffshoreSanFrancisco.html. The Offshore of San Francisco
map area straddles the right-lateral transform boundary between the North American and Pacific plates and is cut by several
active faults that cumulatively form a distributed shear zone, including the San Andreas Fault, the eastern strand of the
San Gregorio Fault, the Golden Gate Fault, and the Potato Patch Fault (Bruns and others, 2002; Ryan and others, 2008). These
faults are covered by Holocene sediments (mostly units Qms, Qmsb, Qmst) with no seafloor expression, and are mapped using
seismic-reflection data. The San Andreas Fault is the primary plate-boundary structure and extends northwest across the map
area; it intersects the shoreline 10 km north of the map area at Bolinas Lagoon, and 3 km south of the map area at Mussel
Rock. This section of the San Andreas Fault has an estimated slip rate of 17 to 24 mm/yr (U.S. Geological Survey, 2010), and
the devastating Great 1906 California earthquake (M 7.8) is thought to have nucleated on the San Andreas a few kilometers
offshore of San Francisco within the map area (Bolt, 1968; Lomax, 2005). The San Andreas Fault forms the boundary between
two distinct basement terranes, Upper Jurassic to Lower Cretaceous rocks of the Franciscan Complex to the east, and Late Cretaceous
granitic and older metamorphic rocks of the Salinian block to the west. Franciscan Complex rocks (unit KJf, undivided) form
seafloor outcrops at and north of Point Lobos adjacent to onland exposures. The Franciscan is divided into 13 different units
for the onshore portion of this geologic map based on different lithologies and ages, but the unit cannot be similarly divided
in the offshore because of a lack of direct observation and (or) sampling. Folds were primarily mapped by interpretation of
seismic reflection profile data (see field activities S-15-10-NC and F-2-07-NC). The seismic reflection profiles were collected
between 2007 and 2010. References Cited Bolt, B.A., 1968, The focus of the 1906 California earthquake: Bulletin of the Seismological
Society of America, v. 58, p. 457-471. 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. Lomax, A., 2005, A reanalysis of the hypocentral location and related observations
for the Great 1906 California earthquake: Bulletin of the Seismological Society of America, v. 95, p. 861-877. Ryan, H.F.,
Parsons, T., and Sliter, R.W., 2008. Vertical tectonic deformation associated with the San Andreas fault zone offshore of
San Francisco, California. Tectonophysics, 429 (1-2), p. 209-224. U.S. Geological Survey and California Geological Survey,
2010, Quaternary fault and fold database for the United States, accessed April 5, 2012, from USGS website: http://earthquake.usgs.gov/hazards/qfaults/.;
abstract: This part of DS 781 presents data for folds for the geologic and geomorphic map of the Offshore of San Francisco
map area, California. The vector data file is included in "Folds_OffshoreSanFrancisco.zip," which is accessible
from http://pubs.usgs.gov/ds/781/OffshoreSanFrancisco/data_catalog_OffshoreSanFrancisco.html. The Offshore of San Francisco
map area straddles the right-lateral transform boundary between the North American and Pacific plates and is cut by several
active faults that cumulatively form a distributed shear zone, including the San Andreas Fault, the eastern strand of the
San Gregorio Fault, the Golden Gate Fault, and the Potato Patch Fault (Bruns and others, 2002; Ryan and others, 2008). These
faults are covered by Holocene sediments (mostly units Qms, Qmsb, Qmst) with no seafloor expression, and are mapped using
seismic-reflection data. The San Andreas Fault is the primary plate-boundary structure and extends northwest across the map
area; it intersects the shoreline 10 km north of the map area at Bolinas Lagoon, and 3 km south of the map area at Mussel
Rock. This section of the San Andreas Fault has an estimated slip rate of 17 to 24 mm/yr (U.S. Geological Survey, 2010), and
the devastating Great 1906 California earthquake (M 7.8) is thought to have nucleated on the San Andreas a few kilometers
offshore of San Francisco within the map area (Bolt, 1968; Lomax, 2005). The San Andreas Fault forms the boundary between
two distinct basement terranes, Upper Jurassic to Lower Cretaceous rocks of the Franciscan Complex to the east, and Late Cretaceous
granitic and older metamorphic rocks of the Salinian block to the west. Franciscan Complex rocks (unit KJf, undivided) form
seafloor outcrops at and north of Point Lobos adjacent to onland exposures. The Franciscan is divided into 13 different units
for the onshore portion of this geologic map based on different lithologies and ages, but the unit cannot be similarly divided
in the offshore because of a lack of direct observation and (or) sampling. Folds were primarily mapped by interpretation of
seismic reflection profile data (see field activities S-15-10-NC and F-2-07-NC). The seismic reflection profiles were collected
between 2007 and 2010. References Cited Bolt, B.A., 1968, The focus of the 1906 California earthquake: Bulletin of the Seismological
Society of America, v. 58, p. 457-471. 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. Lomax, A., 2005, A reanalysis of the hypocentral location and related observations
for the Great 1906 California earthquake: Bulletin of the Seismological Society of America, v. 95, p. 861-877. Ryan, H.F.,
Parsons, T., and Sliter, R.W., 2008. Vertical tectonic deformation associated with the San Andreas fault zone offshore of
San Francisco, California. Tectonophysics, 429 (1-2), p. 209-224. U.S. Geological Survey and California Geological Survey,
2010, Quaternary fault and fold database for the United States, accessed April 5, 2012, from USGS website: http://earthquake.usgs.gov/hazards/qfaults/.
Citation
- Title Folds--Offshore of San Francisco Map Area, California.
-
- creation Date
2018-06-08T06:07:22.136654
Resource language:
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- Linkage for online resource
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- name Dublin Core references URL
- URL: https://pubs.usgs.gov/ds/781/
- protocol WWW:LINK-1.0-http--link
- link function information
- Description URL provided in Dublin Core references element.
Linkage for online resource
- name Dublin Core references URL
- URL: http://pubs.usgs.gov/ds/781/
- protocol WWW:LINK-1.0-http--link
- link function information
- Description URL provided in Dublin Core references element.
Metadata data stamp:
2018-08-06T22:31:42Z
Resource Maintenance Information
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- notes: This metadata record was generated by an xslt transformation from a dc metadata record; Transform by Stephen M. Richard, based
on a transform by Damian Ulbricht. Run on 2018-08-06T22:31:42Z
Metadata contact
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pointOfContact
- organisation Name
CINERGI Metadata catalog
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- Address
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- electronic Mail Address cinergi@sdsc.edu
Metadata language
eng
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ISO 19139 Geographic Information - Metadata - Implementation Specification
standard version:
2007
Metadata record identifier:
urn:dciso:metadataabout:48878314-cd39-425d-99d1-594c5bbf582b
Metadata record format is ISO19139 XML (MD_Metadata)