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  1. Title: Sediment Thickness: Salt Point to Drakes Bay, California, 2009

    Contributors:

    Summary: This layer is a georeferenced raster image containing sediment-thickness data for the areas within the 3-nautical mile limit between Salt Point and Drakes Bay, in California. As part of the USGS's California State Waters Mapping Project, a 50 meter grid of sediment thickness for the seafloor within the 3-nautical mile limit was generated from seismic-reflection data collected in 2009. The resulting grid covers an area of approximately 717 sq km. The volume of sediment accumulated since the Last Glacial Maximum is approximately 6,800 million cubic meters. Contours at 2.5-meter intervals were derived from this grid. This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Johnson, S.Y., Hartwell, S.R., Watt, J.T., and Sliter, R.W. (2014). Sediment Thickness: Salt Point to Drakes Bay, California, 2009. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/nk085bf7278. Sediment thickness and volume within each of the map areas > Salt Point 38.639622 38.479620 -123.482704 -123.278809 > Fort Ross 38.556494 38.396794 -123.305678 -123.102404 > Bodega Bay 38.411542 38.252067 -123.172536 -122.969899 > Tomales Point 38.255180 38.095716 -123.097226 -122.895023 > Point Reyes 38.098263 37.938810 -123.094511 -122.892742 > Drakes Bay 38.038192 37.878737 -122.966411 -122.764735 > > -----sediment thickness-------- > Area Volume > Map block (sq km) Mean (million cu m) > Salt Point 117 12.5 1464 > Fort Ross 100 21.5 2157 > Bodega Bay 128 8.5 1084 > Tomales Point 108 2.1 230 > Point Reyes 175 7.9 1387 > Drakes Bay 89 5.3 476 Additional information about the field activities from which this data set was derived are available online at > http://walrus.wr.usgs.gov/infobank/s/s809nc/html/s-8-09-nc.meta.html Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  2. Title: Folds: Offshore of Pacifica, California, 2010

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    Summary: This line shapefile contains geologic folds in the offshore area of Pacifica, California. The Offshore of Pacifica 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 (sheets 8, 9; 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 (sheet 8). 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 Pacifica 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 (sheet 9; 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 S-15-10-NC and F-2-07-NC). The seismic reflection profiles were collected between 2007 and 2010. A map which shows these data is published in Scientific Investigations Map 3302, "California State Waters Map Series--Offshore of Coal Oil Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Additionally, this coverage can provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the coastal region and sufficient geologic information for land-use and land-management decisions both onshore and offshore. Greene, H.G., Hartwell, S.R., Manson, M.W., Johnson, S.Y., Dieter, B.E., Phillips, E.L., and Watt, J.T. (2014). Folds: Offshore of Pacifica, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/mh718dy4756. Map political location: San Mateo County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see Bathymetry--Offshore of Pacifica map area, California, DS 781, for more information). 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/. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  3. Title: Faults: Offshore of Bolinas, California, 2009

    Contributors:

    Summary: This line shapefile contains fault lines for the offshore area of Bolinas, California. The 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 sediment (mostly unit Qms) with no seafloor expression, and are mapped using seismic-reflection data (see field activities S-8-09-NC and L-1-06-SF). The San Andreas Fault is the primary plate-boundary structure and extends northwest through the southern part of the map area before passing onshore at Bolinas Lagoon. 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 south of this map area offshore of San Francisco (e.g., Bolt, 1968; Lomax, 2005). The San Andreas Fault forms the boundary between two distinct basement terranes, Upper Jurassic and Lower Cretaceous melange and graywacke sandstone 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 adjacent to the shoreline southeast of Stinson Beach that are commonly continuous with onshore coastal outcrops. Faults were primarily mapped by interpretation of seismic reflection profile data (see field activities S-8-09-NC and L-1-06-SF). The seismic reflection profiles were collected between 2006 and 2009. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Additionally, this coverage can provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the coastal region and sufficient geologic information for land-use and land-management decisions both onshore and offshore. This information is not intended for navigational purposes. Johnson, S.Y., Greene, H.G., Manson, M.W., Hartwell, S.R., Endris, C.A., and Watt, J.T. (2014). Faults: Offshore of Bolinas, California, 2009. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/hv220sb1684. Map political location: Marin County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see Bathymetry Hillshade--Offshore Bolinas, California, DS 781, for more information). 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. Tectonphysics, 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/. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  4. Title: Faults: Offshore of Point Reyes, California, 2009

    Contributors:

    Summary: This line shapefile represents fault lines in the offshore region of Point Reyes, California, Faults in the Point Reyes map area are identified on seismic-reflection data based on abrupt truncation or warping of reflections and (or) juxtaposition of reflection panels with different seismic parameters such as reflection presence, amplitude, frequency, geometry, continuity, and vertical sequence. The Point Reyes Fault Zone runs through the map area and is an offshore curvilinear reverse fault zone with predominantly north-side-up motion (Hoskins and Griffiths, 1971; McCulloch, 1987; Heck and others, 1990; Stozek, 2012) that likely connects with the western San Gregorio fault further to the south (Ryan and others, 2008), making it part of the San Andreas Fault System. The Point Reyes Fault Zone is characterized by a 5 to 11 km-wide zone of deformation in the shallow subsurface that is associated with two main fault structures, the Point Reyes Fault and the western Point Reyes Fault. Near the Point Reyes headland, vertical displacement of granitic basement across the Point Reyes Fault is at least 1.4 km (McCulloch, 1987). Offshore Double Point, vertical displacement on the Point Reyes Fault is difficult to assess because subsurface age constraints from nearby wells are lacking, and there are few offset horizons across the fault imaged on available seismic data. However, warping and folding of Neogene strata are clearly visible on high-resolution seismic data . The western Point Reyes Fault is defined by a broad anticlinal structure visible in both industry and high-resolution seismic datasets that exhibits that same sense of vergence (north-side-up) as the Point Reyes Fault. Faults were primarily mapped by interpretation of seismic reflection profile data (see field activity S-8-09-NC). The seismic reflection profiles were collected in 2009. The map that show these data are published in Open-File Report 2015-1114, "California State Waters Map Series—Offshore of Point Reyes, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Watt, J.T., Manson, M.W., and Greene, H.G. (2014). Faults: Offshore of Point Reyes, California, 2009. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/pz354gs3764. Map political location: Marin County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see see Bathymetry--Offshore Point Reyes, California, DS 781 for more information). References Cited Heck, R.G., Edwards, E.B., Kronen, J.D., Jr., and Willingham, C.R., 1990, Petroleum potential of the offshore outer Santa Cruz and Bodega basins, 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: Pacific Section, American Association of Petroleum Geologists Bulletin GB67, p. 143-164. Hoskins E.G., Griffiths, J.R., 1971, Hydrocarbon potential of northern and central California offshore: American Association of Petroleum Geologists Memoir 15, p. 212-228. 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 Oceans Beaufort Sea to Baja California: Houston, Texas, Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series, v. 6., p. 353-401. Ryan, H.F., Parsons, T., and Sliter, R.W., 2008, Vertical tectonic deformation associated with the San Andreas Fault offshore of San Francisco, California: Tectonophysics, v. 475, p. 209-223. Stozek, B.A., 2012, Geophysical evidence for Quaternary deformation within the offshore San Andreas fault system, northern California: Masters Thesis, San Francisco State University, 141 p. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  5. Title: Geology: Offshore of Bolinas, California, 2009

    Contributors:

    Summary: This polygon shapefile represents geologic features within the offshore area of Bolinas, California. The continental shelf within California's State waters in the Bolinas area is relatively flat (less than 0.3 degrees) and shallow (less than 30 m) in the entire area, however the seafloor of the "Marin shelf" east of the San Andreas Fault (see below) is smooth and covered with sediment, whereas the seafloor of the "Bolinas shelf" west of this fault has extensive bedrock outcrop from the nearshore to depths of about 25 m and much less sediment cover. The morphology and geology of this shelf result from the interplay between local tectonics, sea-level rise, sedimentary processes, and oceanography. Tectonic influences are related to local faulting, folding, uplift, and subsidence (see below). Sea level has risen about 125 to 130 m over about the last 21,000 years (for example, Lambeck and Chappel, 2001; Gornitz, 2009), leading to progressive eastward migration (a few tens of km) of the shoreline and wave-cut platform, and associated transgressive erosion and deposition (for example, Catuneanu, 2006). The Offshore of Bolinas map area is now subjected to full, and sometimes severe, Pacific Ocean wave energy and strong currents. Given their relatively shallow depths and exposure to high wave energy, modern shelf sediments are mostly sand (unit Qms). More coarse-grained sands and gravels (units Qmsc and Qmss) are primarily recognized on the basis of bathymetry and high backscatter (see Bathymetry--Offshore Bolinas, California and Backscattter A to E--Offshore Bolinas, California, DS 781, for more information). Unit Qmsc occurs in two areas, on the east flank of Bolinas shelf bedrock exposures, and as three mounds south of Bolinas near the outer boundary of Californiaâs State Waters at water depths of about 25 m. The largest of these mounds is about 450 m long and 70 m wide, and has 80 cm of positive relief above the seafloor. Unit Qmss is much more extensive and forms erosional lags in rippled scour depressions (for example, Cacchione and others, 1984) that are typically a few tens of centimeters deep and bounded by mobile sand sheets. The depressions occur in four distinct locations. (1) The first location lies adjacent to bedrock outcrops within 2 km of the shoreline south of Double Point (along the western edge of the map area) at water depths of 10 to 25 m. (2) The second unit Qmss location is about 2 to 6 km south of Bolinas Lagoon at similar water depths, along the eastern flank of the Bolinas shelf. (3) The third, more restricted location, occurs about 3 km southeast of Rocky Point at water depths of about 10 to 12 m along the eastern edge of the map area, adjacent to and offshore of small bedrock uplifts. (4) The fourth location, 2 km south of Stinson Beach, is notably different. The polygon on the map encloses a field that includes more than one hundred, much smaller (length less than 20 m) oval depressions and intervening sand flats, perhaps an originally much larger field that has been almost completely filled in by sediment. Similar unit Qmss rippled-scour depressions are common along this stretch of the California coast where offshore sandy sediment can be relatively thin (thus unable to fill the depressions) due to both lack of river input and to significant erosion and transport of sediment during large northwest winter swells. Although the general areas in which both unit Qmss scour depressions and surrounding mobile sand sheets occur are not likely to change substantially, the boundaries of the unit(s) are likely ephemeral, changing seasonally and during significant storm events. Areas where shelf sediments form thin (less than 2.5 m) veneers over low-relief Neogene bedrock (see below) occur in the western half of the map and are mapped as units Qms/Tsc (Santa Cruz Mudstone) and Qms/Tp? (Purisima Formation, queried). These hybrid units are recognized and delineated based on the combination of flat relief, continuity with moderate to high relief onshore or offshore bedrock outcrops, high-resolution seismic-reflection data (see field activities S-8-09-NC and L-1-06-SF), and in some cases moderate to high backscatter. The thin sediment layer is regarded as ephemeral and dynamic, and may or may not be present at a specific location based on storms, seasonal/annual patterns of sediment movement, or longer-term climate cycles. In a nearby, similarly high-energy setting, Storlazzi and others (2011) have described seasonal burial and exhumation of submerged bedrock in northern Monterey Bay. The southeastern corner of the map area includes a portion of the outer flank of the horseshoe-shaped "San Francisco Bar" (unit Qmsb), which has formed at the mouth of the San Francisco ebb-tidal delta (Barnard and others, 2007; Dallas and Barnard, 2011). This delta-mouth bar is shaped by both tidal currents and waves, resulting in a variably hummocky, mottled, and rilled seafloor, and this surface texture is used as a primary criteria for mapping the unit and defining its contacts. Map unit polygons were digitized over underlying 2-meter base layers developed from multibeam bathymetry and backscatter data (see Bathymetry--Offshore Bolinas, California and Backscattter A to E--Offshore Bolinas, California, DS 781, for more information). The bathymetry and backscatter data were collected between 2006 and 2010. This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Additionally, this coverage can provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the coastal region and sufficient geologic information for land-use and land-management decisions both onshore and offshore. This information is not intended for navigational purposes. Johnson, S.Y., Greene, H.G., Manson, M.W., Hartwell, S.R., Endris, C.A., and Watt, J.T. (2014). Geology: Offshore of Bolinas, California, 2009. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/zp799xw8630. Map political location: Marin County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see Bathymetry Hillshade--Offshore Bolinas, California, California, DS 781, for more information). References Cited Barnard, P.L., Eshelman, J., Erikson, L., and Hanes, D.M., 2007, Coastal processes study at Ocean Beach, San Francisco, CA: Summary of data collection 2004-2006: U.S. Geological Survey Open-File Report 2007-1217, 165 p. Cacchione, D.A., Drake, D.E., Grant, W.D., and Tate, G.B., 1984. Rippled scour depressions of the inner continental shelf off central California: Journal of Sedimentary Petrology, v 54, p. 1280-1291. Catuneanu, O., 2006, Principles of Sequence Stratigraphy: Amsterdam, Elsevier, 375 p. Dallas, K.L., and Barnard, P.L., 2011, Anthropogenic influences on shoreline and nearshore evolution in the San Francisco coastal system: Estuarine Coastal and Shelf Science, v. 92, p. 195-204. Gornitz, V., 2009, Sea level change, post-glacial, in Gornitz, V., ed., Encyclopedia of Paleoclimatology and Ancient Environments: Encyclopedia of Earth Sciences Series. Springer, pp. 887-893. Lambeck, K., and Chappell, J., 2001, Sea level change through the last glacial cycle: Science, v. 292, p. 679-686. Storlazzi, C.D., Fregoso, T.A., Golden, N.E., and Finlayson, D.P., 2011, Sediment dynamics and the burial and exhumation of bedrock reefs along on emergent coastline as elucidated by repretitive sonar surveys, northern Monterey Bay, CA: Marine Geology, v. 289, p. 46-59.</SPAN></P></DIV></DIV></DIV> This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  6. Title: Transgressive Contours: Salt Point to Drakes Bay, California, 2009

    Contributors:

    Summary: This line shapefile contains transgressive contours at 5 and 10 meter intervals for the area within the 3-nautical mile limit between Salt Point and Drakes Bay in California. As part of the USGS's California State Waters Mapping Project, a 20-m grid of depth to the transgressive surface of the last glacial maximum was generated for the 3-mile offshore region. The resulting grid covers an area of approximately 550 sq km. The depth to the transgressive surface of the Last Glacial Maximum ranges between 0 and 102 meters. This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Johnson, S.Y., Hartwell, S.R., Watt, J.T., and Sliter, R.W. (2014). Transgressive Contours: Salt Point to Drakes Bay, California, 2009. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/mx615hn8123. Sediment thickness and volume within each of the map areas > Salt Point 38.639622 38.479620 -123.482704 -123.278809 > Fort Ross 38.556494 38.396794 -123.305678 -123.102404 > Bodega Bay 38.411542 38.252067 -123.172536 -122.969899 > Tomales Point 38.255180 38.095716 -123.097226 -122.895023 > Point Reyes 38.098263 37.938810 -123.094511 -122.892742 > Drakes Bay 38.038192 37.878737 -122.966411 -122.764735 > depth to transgressive surface > Area > Map block (sq km) MIN MAX MEAN STD > Salt Point 117 -110.0 -0.2 -82.8 21.7 > Fort Ross 100 -102.1 0.0 -65.6 26.0 > Bodega Bay 128 -100.7 2.2 -52.2 28.3 > Tomales Point 108 -86.5 -4.4 -49.2 19.5 > Point Reyes 175 -89.5 -0.1 -52.1 22.7 > Drakes Bay 89 -75.8 -1.1 -38.0 12.2 Additional information about the field activities from which this data set was derived are available online at > http://walrus.wr.usgs.gov/infobank/s/s809nc/html/s-8-09-nc.meta.html Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  7. Title: Isopachs: Salt Point to Drakes Bay, California, 2009

    Contributors:

    Summary: This line shapefile contains isopachs (contour lines of equal thickness) for the areas within the 3-nautical mile limit between Salt Point and Drakes Bay in California. As part of the USGS's California State Waters Mapping Project, a 20-m grid of depth to the transgressive surface of the last glacial maximum was generated for the 3-mile offshore region. The resulting grid covers an area of approximately 600 sq km. The volume of sediment accumulated since the Last Glacial Maximum is approximately 9,000 million cubic meters. Contours at 2.5-meter intervals were derived from this grid. This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Johnson, S.Y., Hartwell, S.R., Watt, J.T., and Sliter, R.W. (2014). Isopachs: Salt Point to Drakes Bay, California, 2009. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/yf846vt5234. Sediment thickness and volume within each of the map areas > Salt Point 38.639622 38.479620 -123.482704 -123.278809 > Fort Ross 38.556494 38.396794 -123.305678 -123.102404 > Bodega Bay 38.411542 38.252067 -123.172536 -122.969899 > Tomales Point 38.255180 38.095716 -123.097226 -122.895023 > Point Reyes 38.098263 37.938810 -123.094511 -122.892742 > Drakes Bay 38.038192 37.878737 -122.966411 -122.764735 > > -----sediment thickness-------- > Area Volume > Map block (sq km) Mean (million cu m) > Salt Point 117 12.5 1464 > Fort Ross 100 21.5 2157 > Bodega Bay 128 8.5 1084 > Tomales Point 108 2.1 230 > Point Reyes 175 7.9 1387 > Drakes Bay 89 5.3 476 Additional information about the field activities from which this data set was derived are available online at > http://walrus.wr.usgs.gov/infobank/s/s809nc/html/s-8-09-nc.meta.html Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  8. Title: Geology: Offshore of Point Reyes, California, 2010

    Contributors:

    Summary: This polygon shapefile represents geologic features within the offshore region of Point Reyes, California. Marine geology and geomorphology was mapped in the Point Reyes offshore area from approximate Mean High Water (MHW) to the 3-nautical-mile limit of California's State Waters. MHW is defined at an elevation of 1.46 m above the North American Vertical Datum of 1988 (NAVD 88) (Weber and others, 2005). Offshore geologic units were delineated on the basis of integrated analyses of adjacent onshore geology with multibeam bathymetry and backscatter imagery, seafloor-sediment and rock samples (Reid and others, 2006), digital camera and video imagery, and high-resolution seismic-reflection profiles. The onshore bedrock mapping was compiled from Galloway (1977), Clark and Brabb (1997), and Wagner and Gutierrez (2010). Quaternary mapping was compiled from Witter and others (2006) and Wagner and Gutierrez (2010), with unit contacts modified based on analysis of 2012 LiDAR imagery; and additional Quaternary mapping by M.W. Manson. The morphology and the geology of the Offshore of Point Reyes map area result from the interplay between tectonics, sea-level rise, local sedimentary processes, and oceanography. The Point Reyes Fault Zone runs through the map area and is an offshore curvilinear reverse Fault Zone (Hoskins and Griffiths, 1971; McCulloch, 1987; Heck and others, 1990; Stozek, 2012) that likely connects with the western San Gregorio fault further to the south (Ryan and others, 2008), making it part of the San Andreas Fault System. The Point Reyes Fault Zone is characterized by a 5 to 11 km-wide zone that is associated with two main fault structures, the Point Reyes Fault and the Western Point Reyes Fault (fig. 1). Tectonic influences impacting shelf morphology and geology are related to local faulting, folding, uplift, and subsidence. Granitic basement rocks are offset about 1.4 km on the Point Reyes thrust fault offshore of the Point Reyes headland (McCulloch, 1987), and this uplift combined with west-side-up offset of the San Andreas Fault (Grove and Niemi, 2005) resulted in uplift of the Point Reyes Peninsula, including the adjacent Bodega and Tomales shelf. The Western Point Reyes Fault is defined by a broad anticlinal structure visible in both industry and high-resolution seismic datasets and exhibits that same sense of vergence as the Point Reyes Fault. The deformation associated with north-side-up motion across the Point Reyes Fault Zone has resulted in a distinct bathymetric gradient across the Point Reyes Fault, with a shallow bedrock platform to the north and east, and a deeper bedrock platform to the south. Late Pleistocene uplift of marine terraces on the southern Point Reyes Peninsula suggests active deformation west of the San Andreas Fault (Grove and others, 2010) on offshore structures. The Point Reyes Fault and related structures may be responsible for this recent uplift of the Point Reyes Peninsula, however, the distribution and age control of Pleistocene strata in the Offshore of Point Reyes map area is not well constrained and therefore it is difficult to directly link the uplift onshore with the offshore Point Reyes Fault structures. Pervasive stratal thinning within inferred uppermost Pliocene and Pleistocene (post-Purisima) units above the Western Point Reyes Fault anticline suggests Quaternary active shortening above a curvilinear northeast to north-dipping Point Reyes Fault zone. Lack of clear deformation within the uppermost Pleistocene and Holocene unit suggests activity along the Point Reyes Fault zone has diminished or slowed since 21,000 years ago. In this map area the cumulative (post-Miocene) slip-rate on the Point Reyes Fault Zone is poorly constrained, but is estimated to be 0.3 mm/yr based on vertical offset of granitic basement rocks (McCulloch, 1987; Wills and others, 2008). With the exception of the bathymetric gradient across the Point Reyes Fault, the offshore part of this map area is largely characterized by a relatively flat (<0.8°) bedrock platform. The continental shelf is quite wide in this area, with the shelfbreak located west of the Farallon high , about 35 km offshore. Sea level has risen about 125 to 130 m over about the last 21,000 years (for example, Lambeck and Chappell, 2001; Peltier and Fairbanks, 2005), leading to broadening of the continental shelf, progressive eastward migration of the shoreline and wave-cut platform, and associated transgressive erosion and deposition (for example, Catuneanu, 2006). Land-derived sediment was carried into this dynamic setting, and then subjected to full Pacific Ocean wave energy and strong currents before deposition or offshore transport. Much of the inner shelf bedrock platform is composed of Tertiary marine sedimentary rocks, which are underlain by Salinian granitic and metamorphic basement rocks, including the Late Cretaceous porphyritic granite (unit Kgg), which outcrops on the seafloor south of the Point Reyes headland. Unit Kgg appears complexly fractured, similar to onshore exposures, with a distinct massive, bulbous texture in multibeam imagery. The Tertiary strata overlying the granite form the core of the Point Reyes syncline (Weaver, 1949) and include the early Eocene Point Reyes Conglomerate (unit Tpr), mid- to late Miocene Monterey Formation (unit Tm), late Miocene Santa Margarita Formation (unit Tsm), late Miocene Santa Cruz Mudstone (unit Tsc), and late Miocene to early Pliocene Purisima Formation (unit Tp). The Point Reyes Conglomerate is exposed on the seafloor adjacent to onshore outcrops on the Point Reyes headland and has a distinct massive texture with some bedding planes visible, but the strata are highly fractured. Based on stratigraphic correlations from seismic reflection data and onshore wells, combined with multibeam imagery, we infer rocks of the early Eocene Point Reyes Conglomerate extend at least 6 km northwest from onshore exposures at Point Reyes headland. The absence of unit Tsc in onshore wells (Clark and Brabb, 1997) suggests these rocks are unlikely to occur within the Tertiary section of this map area, north of the Point Reyes Fault. In this map area, unit Tu represents seafloor outcrops of a middle Miocene to upper Pliocene sequence overlying unit Tpr, that may include units Tm, Tsm, and Tp. Seafloor exposures of unit Tu are characterized by distinct rhythmic bedding where beds are dipping and by a mottled texture where those beds become flat-lying. Modern nearshore sediments are mostly sand (unit Qms and Qsw) and a mix of sand, gravel, and cobbles (units Qmsc and Qmsd). The more coarse-grained sands and gravels (units Qmsc and Qmsd) are primarily recognized on the basis of bathymetry and high backscatter. The emergent bedrock platform north and west of the Point Reyes headland is heavily scoured, resulting in large areas of unit Qmsc and associated Qmsd. Both Qmsc and Qmsd typically have abrupt landward contacts with bedrock and form irregular to lenticular exposures that are commonly elongate in the shore-normal direction. Contacts between units Qmsc and Qms are typically gradational. Unit Qmsd forms erosional lags in scoured depressions that are bounded by relatively sharp and less commonly diffuse contacts with unit Qms horizontal sand sheets. These depressions are typically a few tens of centimeters deep and range in size from a few 10's of meters to more than 1 km2. There is an area of high-backscatter, and rough seafloor southeast of the Point Reyes headland that is notable in that it includes several small, irregular "lumps", with as much as 1 m of positive relief above the seafloor (unit Qsr). Unit Qsr occurs in water depths between 50 and 60 meters, with individual lumps randomly distributed to west-trending. This area on seismic-reflection data shows this lumpy material rests on several meters of latest Pleistocene to Holocene sediment and is thus not bedrock outcrop. Rather, it seems likely that this lumpy material is marine debris, possibly derived from one (or more) of the more than 60 shipwrecks offshore of the Point Reyes Peninsula between 1849 and 1940 (National Park Service, 2012). It is also conceivable that this lumpy terrane consists of biological "hardgrounds". Video transect data crossing unit Qsr near the Point Reyes headland was of insufficient quality to distinguish between these above alternatives. A transition to more fine-grained marine sediments (unit Qmsf) occurs around 50â60 m depth within most of the map area, however, directly south and east of Drakes Estero, backscatter and seafloor sediment samples (Chin and others, 1997) suggest fine-grained sediments extend into water depths as shallow as 30 m. Unit Qmsf is commonly extensively bioturbated and consists primarily of mud and muddy sand. These fine-grained sediments are inferred to have been derived from the Drakes Estero estuary or from the San Francisco Bay to the south, via predominantly northwest flow at the seafloor (Noble and Gelfenbaum, 1990). The map that show these data are published in Open-File Report 2015-1114, "California State Waters Map Series—Offshore of Point Reyes, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Watt, J.T., Manson, M.W., and Greene, H.G. (2014). Geology: Offshore of Point Reyes, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/fr148tw1471. Map political location: Marin County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore. References Cited Catuneanu, O., 2006, Principles of Sequence Stratigraphy: Amsterdam, Elsevier, 375 p. Chin, J.L., Karl, H.A., and Maher, N.M., 1997, Shallow subsurface geology of the continental shelf, Gulf of the Farallones, California, and its relationship to surficial seafloor characteristics: Marine Geology, v. 137, p. 251-269. Clark, J.C., and Brabb, E.E., 1997, Geology of the Point Reyes National Seashore and vicinity: U.S. Geological Survey Open-File Report 97-456, scale 1:48,000. Galloway, A.J., 1977, Geology of the Point Reyes Peninsula Marin County, California: California Geological Survey Bulletin 202, scale 1:24,000. Grove, K. and Niemi, T., 2005, Late Quaternary deformation and slip rates in the northern San Andreas fault zone at Olema Valley, Marin County, California: Tectonophysics, v. 401, p. 231-250. Grove, K., Sklar, L.S., Scherer, A.M., Lee, G., and Davis, J., 2010, Accelerating and spatially-varying crustal uplift and its geomorphic expression, San Andreas Fault zone north of San Francisco, California: Tectonophysics, v. 495, p. 256-268. Heck, R.G., Edwards, E.B., Kronen, J.D., Jr., and Willingham, C.R., 1990, Petroleum potential of the offshore outer Santa Cruz and Bodega basins, 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: Pacific Section, American Association of Petroleum Geologists Bulletin GB67, p. 143-164. Hoskins E.G., Griffiths, J.R., 1971, Hydrocarbon potential of northern and central California offshore: American Association of Petroleum Geologists Memoir 15, p. 212-228. 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. 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. National Park Service, 2012, Shipwrecks at Point Reyes, available at: http://www.nps.gov/pore/historyculture/upload/map_shipwrecks.pdf Noble, M.A. and Gelfenbaum, G., 1990, A pilot study of currents and suspended sediment in the Gulf of the Farallones: U.S. Geological Survey Open-File Report 90-476, 30 p. Peltier, W.R., and Fairbanks, R.G., 2006, Global glacial ice volume and Last Glacial Maximum duration from an extended Barbados sea level record: Quaternary Science Reviews, v. 25, p. 3,322-3,337. Reid, J.A., Reid, J.M., Jenkins, C.J., Zimmerman, M., Williams, S.J., and Field, M.E., 2006, usSEABED Pacific Coast (California, Oregon, Washington) offshore surficial-sediment data release: U.S. Geological Survey Data Series 182, available at http://pubs.usgs.gov/ds/2006/182/. Ryan, H.F., Parsons, T., and Sliter, R.W., 2008, Vertical tectonic deformation associated with the San Andreas Fault offshore of San Francisco, California: Tectonophysics, v. 475, p. 209-223. Stozek, B.A., 2012, Geophysical evidence for Quaternary deformation within the offshore San Andreas fault system, northern California: Masters Thesis, San Francisco State University, 141 p. Wagner, D.L., and Gutierrez, C.I., 2010, Preliminary Geologic Map of the Napa 30â x 60â Quadrangle, California: California Geological Survey, scale 1:100,000. 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/. Wills, C.J., Weldon, R.J., II, and Bryant, W.A., 2008, Appendix A California fault parameters for the National Seismic Hazard Maps and Working Group on California Earthquake Probabilities 2007: U.S. Geological Survey Open-File Report 2007 1437A, 48 p., available at http://pubs.usgs.gov/of/2007/1437/a/. Witter, R.C., Knudsen, K.L., Sowers, J.M., Wentworth, C.M., Koehler, R.D., Randolph, C.E., Brooks, S.K., and Gans, K.D., 2006, Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California, U.S. Geological Survey Open-File Report 06-1037, scale 1:24,000.Bulletin of the Seismological Society of America, v. 95, p. 861-877. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  9. Title: Faults: Offshore of Pacifica, California, 2010

    Contributors:

    Summary: This line shapefile contains fault lines in the offshore area of Pacifica, California. These data were generated from data collected by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), by the U.S. Geological Survey (USGS) and by Fugro Pelagos. The Offshore of Pacifica 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 (sheets 8, 9; 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 (sheet 8). 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 Pacifica 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 (sheet 9; 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. Faults were primarily mapped by interpretation of seismic reflection profile data (see S-15-10-NC and F-2-07-NC). The seismic reflection profiles were collected between 2007 and 2010. A map which shows these data is published in Scientific Investigations Map 3302, "California State Waters Map Series--Offshore of Coal Oil Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Additionally, this coverage can provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the coastal region and sufficient geologic information for land-use and land-management decisions both onshore and offshore. Greene, H.G., Hartwell, S.R., Manson, M.W., Johnson, S.Y., Dieter, B.E., Phillips, E.L., and Watt, J.T. (2014). Faults: Offshore of Pacifica, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/rq178pr7048. Map political location: San Mateo County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see Bathymetry--Offshore of Pacifica map area, California, DS 781, for more information). 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/. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  10. Title: Geology: Offshore of Pacifica, California, 2010

    Contributors:

    Summary: This polygon shapefile depictss geologic features in the offshore area of Pacifica, California. The continental shelf within California's State waters in the Pacifica area is shallow (water depths of 0 to about 40 m) and flat continental shelf with a very gentle (less than 0.5 degrees) offshore dip. The morphology and geology of this shelf result from the interplay between local tectonics, sea-level rise, sedimentary processes, and oceanography. Tectonic influences are related to local faulting and uplift (see below). Sea level has risen about 125 to 130 m over the last about 21,000 years (for example, Lambeck and Chappel, 2001; Gornitz, 2009), leading to progressive eastward migration (a few tens of km) of the shoreline and wave-cut platform, and associated transgressive erosion and deposition (for example, Catuneanu, 2006). The Offshore of Pacifica map area is now mainly an open shelf that is subjected to full, and sometimes severe, Pacific Ocean wave energy and strong currents. Most of the offshore map area is covered by marine sediments; artificial fill (unit af) occurs only at the site of the Pacifica Pier. Given their relatively shallow depths and exposure to high wave energy, modern shelf deposits are mostly sand (unit Qms). More coarse-grained sands and gravels (units Qmss and Qmsc) are primarily recognized on the basis of bathymetry and high backscatter (Bathymetry--Offshore of Pacifica map area, California, and Backscatter--Offshore of Pacifica map area, California). Unit Qmsc occurs as nearshore bars (less than 12 m water depth) for about two kilometers north of Mussel Rock and more locally offshore Pacifica, and in two isolated patches farther offshore at about 25 m water depth. Unit Qmss forms erosional lags in features known as ârippled scour depressionsâ (for example, Cacchione and others, 1984) or âsorted bedformsâ (for example, Trembanis and Hume, 2011), at water depths of about 15 to 25 m, in contact with offshore bedrock uplifts and unit Qms. Such features are common along this stretch of the California coast where offshore sandy sediment can be relatively thin (thus unable to fill the depressions) due to both lack of sediment supply from rivers and to significant sediment erosion and offshore transport during large winter storms. Although the general areas in which both unit Qmss scour depressions and unit Qmsc bars occur are not likely to change substantially, the boundaries of the unit(s) are likely ephemeral, changing seasonally and during significant storm events. Areas where shelf sediments form thin (less than 2 m) veneers over low relief bedrock of the Franciscan Complex (see below) occur in the northern half of the map and are mapped as unit Qms/KJf. This hybrid unit is recognized and delineated based on the combination of flat relief, continuity with moderate to high relief onshore or offshore bedrock outcrops, high-resolution seismic-reflection data, and in some cases moderate to high backscatter. The thin sediment layer is regarded as ephemeral and dynamic, and may or may not be present at a specific location based on storms, seasonal to annual patterns of sediment movement, or longer-term climate cycles. In a nearby, similarly high-energy setting, Storlazzi and others (2011) have described seasonal burial and exhumation of submerged bedrock in northern Monterey Bay. Offshore bedrock exposed at the seafloor is mapped as Jurassic and Cretaceous Franciscan Complex, undivided (unit KJf); Cretaceous granite (unit Kgr); Tertiary and (or) Cretaceous rock, undivided (unit TKu); unnamed sansdstone, shale and conglomerate of Paleocene age (unit Tss); and the Upper Miocene and Pliocene Purisima Formation (unit Tp). These units are delineated by extending outcrops and trends from mapped onshore geology and from their distinctive surface textures as revealed by high-resolution bathymetry (Bathymetry--Offshore of Pacifica map area, California). Purisima Formation outcrops in the southernmost part of the offshore map area form distinctive "ribs," caused by differential erosion of variably resistant, interbedded lithologies (for example, sandstone and mudstone). In contrast, granitic rocks have a densely cross-fractured, rough surface texture, and both the Franciscan Complex and the unnamed Paleocene sedimentary unit have a more masssive, irregular, and smoother surface texture. Purisima Formation outcrops occur in water as deep as 35 m, whereas other bedrock units occur in shallower (less than 20 m) water depths, most commonly adjacent to coastal points underlain by bedrock (for example, Pedro Point and Montara Point). Map unit polygons were digitized over underlying 2-meter base layers developed from multibeam bathymetry and backscatter data. The bathymetry and backscatter data were collected between 2006 and 2010. A map which shows these data is published in Scientific Investigations Map 3302, "California State Waters Map Series--Offshore of Coal Oil Point, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Additionally, this coverage can provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the coastal region and sufficient geologic information for land-use and land-management decisions both onshore and offshore. This information is not intended for navigational purposes. Greene, H.G., Hartwell, S.R., Manson, M.W., Johnson, S.Y., Dieter, B.E., Phillips, E.L., and Watt, J.T. (2014). Geology: Offshore of Pacifica, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/zg982fx5597. Map political location: San Mateo County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (Bathymetry--Offshore of Pacifica map area, California, DS 781, for more information). References Cited Cacchione, D.A., Drake, D.E., Grant, W.D., and Tate, G.B., 1984. Rippled scour depressions of the inner continental shelf off central California: Journal of Sedimentary Petrology, v 54, p. 1280-1291. Catuneanu, O., 2006, Principles of Sequence Stratigraphy: Amsterdam, Elsevier, 375 p. Gornitz, V., 2009, Sea level change, post-glacial, in Gornitz, V., ed., Encyclopedia of Paleoclimatology and Ancient Environments: Encyclopedia of Earth Sciences Series. Springer, pp. 887-893. Lambeck, K., and Chappell, J., 2001, Sea level change through the last glacial cycle: Science, v. 292, p. 679-686. Trembanis, A.C., and Hume, T.M., 2011, Sorted bedforms on the inner shelf off northeastern New Zealand: spatiotemporal relationships and potential paleo-evironmental implications: Geo-Marine Letters, v. 31, p. 203-214. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  11. Title: Folds: Offshore of Point Reyes, California, 2009

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    Summary: This line shapefile contains geologic folds within the offshore region of Point Reyes map area, California. Folds in the Point Reyes map area are identified on seismic-reflection data based on abrupt truncation or warping of reflections and (or) juxtaposition of reflection panels with different seismic parameters such as reflection presence, amplitude, frequency, geometry, continuity, and vertical sequence. The Point Reyes Fault Zone runs through the map area and is an offshore curvilinear reverse fault zone with predominantly north-side-up motion (Hoskins and Griffiths, 1971; McCulloch, 1987; Heck and others, 1990; Stozek, 2012) that likely connects with the western San Gregorio fault further to the south (Ryan and others, 2008), making it part of the San Andreas Fault System. The Point Reyes Fault Zone is characterized by a 5 to 11 km-wide zone of deformation in the shallow subsurface that is associated with two main fault structures, the Point Reyes Fault and the western Point Reyes Fault. Near the Point Reyes headland, vertical displacement of granitic basement across the Point Reyes Fault is at least 1.4 km (McCulloch, 1987). Offshore Double Point, vertical displacement on the Point Reyes Fault is difficult to assess because subsurface age constraints from nearby wells are lacking, and there are few offset horizons across the fault imaged on available seismic data. However, warping and folding of Neogene strata are clearly visible on high-resolution seismic data. The western Point Reyes Fault is defined by a broad anticlinal structure visible in both industry and high-resolution seismic datasets that exhibits that same sense of vergence (north-side-up) as the Point Reyes Fault. Folds were primarily mapped by interpretation of seismic reflection profile data (see field activity S-8-09-NC). The seismic reflection profiles were collected in 2009. The map that show these data are published in Open-File Report 2015-1114, "California State Waters Map Series—Offshore of Point Reyes, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Watt, J.T., Manson, M.W., and Greene, H.G. (2014). Folds: Offshore of Point Reyes, California, 2009. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/mr840rd2952. Map political location: Marin County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore see see Bathymetry--Offshore Point Reyes, California, DS 781 for more information, California, DS 781, for more information). References Cited Heck, R.G., Edwards, E.B., Kronen, J.D., Jr., and Willingham, C.R., 1990, Petroleum potential of the offshore outer Santa Cruz and Bodega basins, 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: Pacific Section, American Association of Petroleum Geologists Bulletin GB67, p. 143-164. Hoskins E.G., Griffiths, J.R., 1971, Hydrocarbon potential of northern and central California offshore: American Association of Petroleum Geologists Memoir 15, p. 212-228. 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 Oceans Beaufort Sea to Baja California: Houston, Texas, Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series, v. 6., p. 353-401. Ryan, H.F., Parsons, T., and Sliter, R.W., 2008, Vertical tectonic deformation associated with the San Andreas Fault offshore of San Francisco, California: Tectonophysics, v. 475, p. 209-223. Stozek, B.A., 2012, Geophysical evidence for Quaternary deformation within the offshore San Andreas fault system, northern California: Masters Thesis, San Francisco State University, 141 p. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  12. Title: Sediment Thickness: Bolinas to Pescadero, California, 2010

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    Summary: This layer is a georeferenced raster image containing sediment-thickness data for the areas within the 3-nautical mile limit between Bolinas and Pescadero, in California. As part of the USGS's California State Waters Mapping Project, a 50 meter grid of sediment thickness for the seafloor within the 3-nautical mile limit was generated from seismic-reflection data collected in 2009. The resulting grid covers an area of approximately 717 sq km. The volume of sediment accumulated since the Last Glacial Maximum is approximately 6,800 million cubic meters. Isopachs for the Bolinas to Pescadero region are published in Scientific Investigations Map 3306, "California State Waters Map Series--Offshore San Gregorio, California" (see sheet 9). This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Johnson, S.Y., Hartwell, S.R., Sliter, R.W., Watt, J.T., Phillips, E.L., Ross, S.L., Ross, S. L., and Chin, J.L.. (2014). Sediment Thickness: Bolinas to Pescadero, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/xy816ng1922. -----sediment thickness-------- Area Volume Map block (sq km) Mean (million cu m) Bolinas 121 8.1 975 San Francisco 102 16.5 1693 Pacifica 106 4.4 468 Half Moon Bay 123 2.5 309 San Gregorio 102 3.1 320 Additional information about the field activities from which this data set was derived are available online at > http://walrus.wr.usgs.gov/infobank/s/s809nc/html/s-8-09-nc.meta.html Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  13. Title: Folds: Offshore of Bolinas, California, 2009

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    Summary: This line shapefile represents geologic folds within the offshore area of Bolinas, California. The 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 sediment (mostly unit Qms) with no seafloor expression, and are mapped using seismic-reflection data (see field activities S-8-09-NC and L-1-06-SF). The San Andreas Fault is the primary plate-boundary structure and extends northwest through the southern part of the map area before passing onshore at Bolinas Lagoon. 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 south of this map area offshore of San Francisco (e.g., Bolt, 1968; Lomax, 2005). The San Andreas Fault forms the boundary between two distinct basement terranes, Upper Jurassic and Lower Cretaceous melange and graywacke sandstone 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 adjacent to the shoreline southeast of Stinson Beach that are commonly continuous with onshore coastal outcrops. Folds were primarily mapped by interpretation of seismic reflection profile data (see field activities S-8-09-NC and L-1-06-SF). The seismic reflection profiles were collected between 2006 and 2009. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. Additionally, this coverage can provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the coastal region and sufficient geologic information for land-use and land-management decisions both onshore and offshore. This information is not intended for navigational purposes. Johnson, S.Y., Greene, H.G., Manson, M.W., Hartwell, S.R., Endris, C.A., and Watt, J.T. (2014). Folds: Offshore of Bolinas, California, 2009. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/xd152xm7498. Map political location: Marin County, California Compilation scale: 1:24,000 Base maps used are hillshades generated from IfSAR, LiDAR, and multibeam mapping both onshore and offshore (see Bathymetry Hillshade--Offshore Bolinas, California, DS 781, for more information). . 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. Tectonphysics, 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/. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  14. Title: Folds: Offshore of San Gregorio, California, 2010

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    Summary: This line shapefile depicts geologic folds within the offshore area of San Gregorio, California. The offshore San Gregorio map area lies about 15 to 25 km southwest of the San Andreas Fault, the dominant structure in the distributed transform boundary between the North American and Pacific plates. The map area straddles the right-lateral San Gregorio Fault zone, a prominent structure west of the San Andreas Fault in the broader San Andreas Fault system. The San Gregorio Fault zone occurs predominantly in the offshore and extends 400 km from Point Conception on the south to Bolinas and Point Reyes on the north (Dickinson and others, 2005), coming onland at coastal promontories such as Pescadero Point in the map area and Pillar Point, a few km north of Half Moon Bay (sheet 9). In the offshore, the San Gregorio Fault system forms a distributed shear zone about 2 to 4 km wide that includes two main diverging fault strands. The western strand (also known as the Frijoles Fault) extends offshore from Pescadero Point. The eastern strand (also known as the Coastways Fault or Seal Cove Fault), is mostly onshore in this map area. Cumulative lateral slip on the San Gregorio Fault zone is thought to range from 4 to 10 mm/yr in this region (U.S. Geological Survey, 2010). The western strand of the San Gregorio Fault zone (i.e., Frijoles Fault) forms the eastern boundary of the Pigeon Point high. A map that shows these data is published in Scientific Investigations Map 3306, "California State Waters Map Series--Offshore of San Gregorio, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. U.S. Geological Survey. (2013). Folds: Offshore of San Gregorio, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/pb119xp8428. Map political location: San Mateo 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 3306, for more information). References Cited Dickinson, W.R., Ducea, M., Rosenberg, L.I., Greene, H.G., Graham, S.A., Clark, J.C., Weber, G.E., Kidder, S., Ernst, W.G., and Brabb, E.E., 2005, Net dextral slip, Neogene San Gregorio-Hosgri fault zone, coastal California: Geologic evidence and tectonic implications: Geological Society of America Special Paper 391, 43 p. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  15. Title: Geology: Offshore of San Gregorio, California, 2010

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    Summary: This poygon shapefile depicts geologic features within the offshore area of San Gregorio, California. The continental shelf within California's State waters in the San Gregorio map area is shallow (0 to ~55 m) and flat with a very gentle (less than 0.5 degrees) offshore dip. Shelf morphology and evolution result from the interplay between local tectonics and sedimentation as sea level rose about 125 to 130 m over the last ~ 21,000 years (Lambeck and Chappel, 2001). Shelf deposits are almost exclusively sand (unit Qms) at depths less than 60 m and transition to more fine grained, muddy sediment (unit Qmsf) at greater depths in the southwestern most part of the map area. The boundary between units Qms and Qmsf was determined based on seafloor sediment samples (Reid and others, 2006) and video observations (sheet 6) from the Offshore of San Gregorio and adjacent map area. This boundary likely shifts seaward or landward based on seasonal to decadal changes in sediment supply, sediment transport, and wave climate. More coarse-grained sands and gravels (units Qmss and Qmsc) are primarily recognized on the basis of high backscatter (sheet 3). Unit Qmsc occurs as a nearshore, shore-parallel bar at typical water depths between 5 and 10 meters. Unit Qmss forms erosional lags in rippled scour depressions (for example, Cacchione and others, 1984) at water depths of about 25 to 35 m, in contact with offshore bedrock uplifts and unit Qms. Although the general areas in which unit Qmsc and unit Qmss occur are not likely to change substantially, the boundaries of the unit(s) are likely ephemeral, changing seasonally and during significant storm events. Unit Qmss deposits are common along this stretch of the California coast where offshore sandy sediment can be relatively thin (thus unable to fill the depressions) due to both lack of river input and to significant sediment erosion and offshore sediment transport during large northwest winter swells. Areas where shelf sediments form thin (< 2.5 m or less) veneers over low relief, undivided Cretaceous and (or) Tertiary bedrock are mapped as units Qms/TKu and Qms/Tp. These areas are recognized based on the combination of flat relief, continuity with moderate to high relief bedrock outcrops, high-resolution seismic-reflection data (sheet 8), and in some cases moderate backscatter. These units are regarded as ephemeral and dynamic sediment layers that may or may not be present based on storms, seasonal/annual patterns of sediment movement, or climate cycles. Tertiary deposits mapped in the offshore include two units of the Purisima Formation (units Tp and Tpt). The Purisima units are characterized by high backscatter (sheet 3) and distinct bedding recognized in multibeam imagery and/or seismic-reflection data (sheet 8). These Tertiary rocks are underlain by or in fault contact with Upper Cretaceous basement rocks, including sedimentary rocks of the Pigeon Point Formation (unit Kpp). The Pigeon Point Formation is mapped on the basis of high backscatter, massive and (or) rugged texture on multibeam imagery (sheets 1, 2), and reflection-free character on seismic-reflection data (sheet 8). Offshore outcrops of the Pigeon Point Formation form the offshore Pigeon Point high, a major structural feature that extends ~30 km to the northwest and represents the northeast boundary of the Outer Santa Cruz Basin (McCulloch, 1987). Areas where bedrock is exposed on the seafloor but there is less certainty regarding age are mapped as Cretaceous and Tertiary, undivided (unit TKu). Map unit polygons were digitized over underlying 2-meter base layers developed from multibeam bathymetry and backscatter data (see sheets 1 and 2, SIM 3306). The bathymetry and backscatter data were collected between 2006 and 2010. A map that shows these data is published in Scientific Investigations Map 3306, "California State Waters Map Series--Offshore of San Gregorio, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. U.S. Geological Survey. (2013). Geology: Offshore of San Gregorio, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/dr534cf4984. Map political location: San Mateo 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 3306, for more information). References Cited Cacchione, D.A., Drake, D.E., Grant, W.D., and Tate, G.B., 1984. Rippled scour depressions of the inner continental shelf off central California: Journal of Sedimentary Petrology, v 54, p. 1280-1291. Lambeck, K., and Chappell, J., 2001, Sea level change through the last glacial cycle: Science, v. 292, p. 679â686. 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 basinsâBeaufort Sea to Baja California: Circum-Pacific Council for Energy and Mineral Resources Earth Science Series, v. 6, p. 353â401. Reid, J.A., Reid, J.M., Jenkins, C.J., Zimmerman, M., Williams, S.J., and Field, M.E., 2006, usSEABED: Pacific Coast (California Oregon, Washington) offshore surficial-sediment data release: U.S. Geological Survey Data Series 182, http://pubs.usgs.gov/ds/2006/182/. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  16. Title: Faults: Offshore of San Gregorio, California, 2010

    Contributors:

    Summary: This line shapefile depicts fault lines within the offshore area of San Gregorio, California. The offshore San Gregorio map area lies about 15 to 25 km southwest of the San Andreas Fault, the dominant structure in the distributed transform boundary between the North American and Pacific plates. The map area straddles the right-lateral San Gregorio Fault zone, a prominent structure west of the San Andreas Fault in the broader San Andreas Fault system. The San Gregorio Fault zone occurs predominantly in the offshore and extends 400 km from Point Conception on the south to Bolinas and Point Reyes on the north (Dickinson and others, 2005), coming onland at coastal promontories such as Pescadero Point in the map area and Pillar Point, a few km north of Half Moon Bay (sheet 9). In the offshore, the San Gregorio Fault system forms a distributed shear zone about 2 to 4 km wide that includes two main diverging fault strands. The western strand (also known as the Frijoles Fault) extends offshore from Pescadero Point. The eastern strand (also known as the Coastways Fault or Seal Cove Fault), is mostly onshore in this map area. Cumulative lateral slip on the San Gregorio Fault zone is thought to range from 4 to 10 mm/yr in this region (U.S. Geological Survey, 2010). The western strand of the San Gregorio Fault zone (i.e., Frijoles Fault) forms the eastern boundary of the Pigeon Point high. Faults were primarily mapped by interpretation of seismic reflection profile data (see sheet 8, SIM 3306). The seismic reflection profiles were collected between 2007 and 2010. A map that shows these data is published in Scientific Investigations Map 3306, "California State Waters Map Series--Offshore of San Gregorio, California." This layer is part of USGS Data Series 781. In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. This coverage can be used to to aid in assessments and mitigation of geologic hazards in the coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. U.S. Geological Survey. (2013). Faults: Offshore of San Gregorio, California, 2010. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/pw824xt0743. Map political location: San Mateo 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 3306, for more information). References Cited Dickinson, W.R., Ducea, M., Rosenberg, L.I., Greene, H.G., Graham, S.A., Clark, J.C., Weber, G.E., Kidder, S., Ernst, W.G., and Brabb, E.E., 2005, Net dextral slip, Neogene San Gregorio-Hosgri fault zone, coastal California: Geologic evidence and tectonic implications: Geological Society of America Special Paper 391, 43 p. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.

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  17. Title: Geologic atlas of Winona County, Minnesota, C-2, Plate 5, Sinkhole Probability

    Contributors:

    Summary: Map showing location of sinkholes and likelihood of future sinkhole development, scale 1:100,000, Winona County.

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  18. Title: St. Louis, Missouri and vicinity, 1903 (Raster Image)

    Contributors:

    Summary: This layer is a georeferenced raster image of the historic, topographic paper map entitled: Saint Louis quadrangle, Missouri - Illinois, [by the] Department of the Interior, U.S. Geological Survey; H. M. Wilson, geographer; topography by Chas. E. Cooke, Wm. O. Tufts, Gilbert Young and City of St. Louis; control by U.S.C. and G.S. and Geo. T. Hawkins. Ed. of Apr. 1904, reprinted 1932. Surveyed 1903. It was published by U.S.G.S. Scale 1:62,500. Covers City of Saint Louis, and portions of Saint Louis County, Missouri, and Saint Clair and Madison Counties, Illinois. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Missouri East State Plane Coordinate System NAD27 (in Feet) (Fipszone 2401). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This is a typical topographic map portraying both natural and manmade features. It shows and names works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. It also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 feet and spot heights. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.

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  19. Title: View of Fort Wayne Inda

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    Summary: Bird's-eye view. Facsimile. Left and right sides of original cut off creating the following texts: 'lished by J.T. Palmatary' and 'Drawn on stone & printed in oil colors by Middleton, Wallace & 115 wa.' Scale not given. Published by J.T. Palmatary.

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  20. Title: Robinson's standard map of South Africa

    Contributors:

    Summary: Relief shown by hachures.; Title in English and Russian. Text, legend, and place-names in English. Statement in upper margin in English and 2 languages in Arabic alphabet.; "Entered at Stationers Hall, London, Saturday 20th May, 1854."; "Corr. to 1855 from general Schubert's official map."; Originally printed on 10 sheets.; Includes text, notes, population table, and hand col. inset of geology of Crimea and adjacent regions. 164 x 220 centimeters, sheets 88 x 115 centimeters Scale [1:1,267,200] General Map Collection

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