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At least 325 records · Page 18Linked to original sources
USGS2007

Petroleum systems of the San Joaquin Basin Province, California -- geochemical characteristics of oil types: Chapter 9 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

New analyses of 120 oil samples combined with 139 previously published oil analyses were used to characterize and map the distribution of oil types in the San Joaquin Basin, California. The results show that there are at least four oil types designated MM, ET, EK, and CM. Most of the oil from the basin has low to moderate sulfur content (less than 1 weight percent sulfur), although a few unaltered MM oils have as much as 1.2 weight percent sulfur. Reevaluation of source rock data from the literature indicate that the EK oil type is derived from the Eocene Kreyenhagen Formation, and the MM oil type is derived, in part, from the Miocene to Pliocene Monterey Formation and its equivalent units. The ET oil type is tentatively correlated to the Eocene Tumey formation of Atwill (1935). Previous studies suggest that the CM oil type is derived from the Late Cretaceous to Paleocene Moreno Formation. Maps of the distribution of the oil types show that the MM oil type is restricted to the southern third of the San Joaquin Basin Province. The composition of MM oils along the southern and eastern margins of the basin reflects the increased contribution of terrigenous organic matter to the marine basin near the Miocene paleoshoreline. EK oils are widely distributed along the western half of the basin, and ET oils are present in the central and west-central areas of the basin. The CM oil type has only been found in the Coalinga area in southwestern Fresno County. The oil type maps provide the basis for petroleum system maps that incorporate source rock distribution and burial history, migration pathways, and geologic relationships between hydrocarbon source and reservoir rocks. These petroleum system maps were used for the 2003 U.S. Geological Survey resource assessment of the San Joaquin Basin Province.

California↗
USGS2007

The National Assessment of Shoreline Change: A GIS compilation of vector cliff edges and associated cliff erosion data for the California coast

The U.S. Geological Survey has generated a comprehensive data clearinghouse of digital vector cliff edges and associated rates of cliff retreat along the open-ocean California coast. These data, which are presented herein, were compiled as part of the U.S. Geological Survey's National Assessment of Shoreline Change Project. Cliff erosion is a chronic problem along many coastlines of the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information including rates and trends of coastal cliff retreat. There is also a critical need for these data to be consistent from one region to another. One objective of this work is to a develop standard, repeatable methodology for mapping and analyzing cliff edge retreat so that periodic, systematic, and internally consistent updates of cliff edge position and associated rates of erosion can be made at a national scale. This data compilation for open-ocean cliff edges for the California coast is a separate, yet related study to Hapke and others, 2006 documenting shoreline change along sandy shorelines of the California coast, which is itself one in a series that includes the Gulf of Mexico and the Southeast Atlantic coast (Morton and others, 2004; Morton and Miller, 2005). Future reports and data compilations will include coverage of the Northeast U.S., the Great Lakes, Hawaii and Alaska. Cliff edge change is determined by comparing the positions of one historical cliff edge digitized from maps with a modern cliff edge derived from topographic LIDAR (light detection and ranging) surveys. Historical cliff edges for the California coast represent the 1920s-1930s time-period; the most recent cliff edge was delineated using data collected between 1998 and 2002. End-point rate calculations were used to evaluate rates of erosion between the two cliff edges. Please refer to our full report on cliff edge erosion along the California coastline at http://pubs.usgs.gov/of/2007/1133/ for additional information regarding methods and results (Hapke and others, 2007). Data in this report are organized into downloadable layers by region (Northern, Central and Southern California) and are provided as vector datasets with accompanying metadata. Vector cliff edges may represent a compilation of data from one or more sources and the sources used are included in the dataset metadata. This project employs the Environmental Systems Research Institute's (ESRI) ArcGIS as it's Geographic Information System (GIS) mapping tool and contains several data layers (shapefiles) that are used to create a geographic view of the California coast. The vector data form a basemap comprising polygon and line themes that include a U.S. coastline (1:80,000), U.S. cities, and state boundaries.

California↗
USGS2014

Geologic logs of geotechnical cores from the subsurface Sacramento-San Joaquin Delta, California

This report presents and summarizes descriptive geologic logs of geotechnical cores collected from 2009–12 in the Sacramento–San Joaquin Delta, California, by the California Department of Water Resources. Graphic logs are presented for 1,785.7 ft of retained cores from 56 borehole sites throughout the Sacramento-San Joaquin Delta. Most core sections are from a depth of ~100–200 feet. Cores primarily contain mud, silt, and sand lithologies. Tephra (volcanic ash and pumice), paleosols, and gravels are also documented in some core sections. Geologic observations contained in the core logs in this report provide stratigraphic context for subsequent sampling and data for future chronostratigraphic subsurface correlations.

California↗
USGS1962

Geophysical study of Cenozoic geologic structures of northern Owens Valley, California

A narrow gravity minimum anomaly of amplitude 30 mgals indicates that northern Owens Valley , California , a narrow fault-bounded trough or graben filled with Cenozoic clastic deposits to a depth of as much as 8,000 ft. Seismic-refraction measurements support this conclusion. Aeromagnetic and gravity measurements define a small, dense, and magnetic body buried by the valley fill of northern Owens Valley .

California↗
USGS1986

Reconnaissance surficial geologic map of northern Death Valley, California and Nevada

Sedimentary deposits of northern Death Valley include units of alluvial, eolian, lacustrine, and spring origin. The alluvial deposits, which include both fan and pediment deposits, predominate. Fan deposits are divided into four major units; locally one of these is further divided into three subunits. Pediment deposits may be divided into two subunits. Hyphenated map symbols (for example, Qf 4-3 ) are used where two deposits cannot be separated at the map scale; symbols separated by a slash indicate areas where thin veneers of younger deposits overlie old deposits (for example, Qf 3 /Qp 2 ).

California, Nevada↗