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USGS1995

Preliminary Geologic Map of the Topanga 7.5' Quadrangle, Southern California: A Digital Database

INTRODUCTION This Open-File report is a digital geologic map database. This pamphlet serves to introduce and describe the digital data. There is no paper map included in the Open-File report. This digital map database is compiled from previously published sources combined with some new mapping and modifications in nomenclature. The geologic map database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U. S. Geological Survey. For detailed descriptions of the units, their stratigraphic relations and sources of geologic mapping consult Yerkes and Campbell (1994). More specific information about the units may be available in the original sources. The content and character of the database and methods of obtaining it are described herein. The geologic map database itself, consisting of three ARC coverages and one base layer, can be obtained over the Internet or by magnetic tape copy as described below. The processes of extracting the geologic map database from the tar file, and importing the ARC export coverages (procedure described herein), will result in the creation of an ARC workspace (directory) called 'topnga.' The database was compiled using ARC/INFO version 7.0.3, a commercial Geographic Information System (Environmental Systems Research Institute, Redlands, California), with version 3.0 of the menu interface ALACARTE (Fitzgibbon and Wentworth, 1991, Fitzgibbon, 1991, Wentworth and Fitzgibbon, 1991). It is stored in uncompressed ARC export format (ARC/INFO version 7.x) in a compressed UNIX tar (tape archive) file. The tar file was compressed with gzip, and may be uncompressed with gzip, which is available free of charge via the Internet from the gzip Home Page (http://w3.teaser.fr/~jlgailly/gzip). A tar utility is required to extract the database from the tar file. This utility is included in most UNIX systems, and can be obtained free of charge via the Internet from Internet Literacy's Common Internet File Formats Webpage http://www.matisse.net/files/formats.html). ARC/INFO export files (files with the .e00 extension) can be converted into ARC/INFO coverages in ARC/INFO (see below) and can be read by some other Geographic Information Systems, such as MapInfo via ArcLink and ESRI's ArcView (version 1.0 for Windows 3.1 to 3.11 is available for free from ESRI's web site: http://www.esri.com). 1. Different base layer - The original digital database included separates clipped out of the Los Angeles 1:100,000 sheet. This release includes a vectorized scan of a scale-stable negative of the Topanga 7.5 minute quadrangle. 2. Map projection - The files in the original release were in polyconic projection. The projection used in this release is state plane, which allows for the tiling of adjacent quadrangles. 3. File compression - The files in the original release were compressed with UNIX compression. The files in this release are compressed with gzip.

Open-File Report↗

USGS2014

Preliminary geologic map of the eastern Willapa Hills, Cowlitz, Lewis, and Wahkiakum Counties, Washington

This digital map database and the PDF derived from the database were created from the analog geologic map: Wells, R.E. (1981), “Geologic map of the eastern Willapa Hills, Cowlitz, Lewis, and Wahkiakum Counties, Washington.” The geodatabase replicates the geologic mapping of the 1981 report with minor exceptions along water boundaries and also along the north and south map boundaries. Slight adjustments to contacts along water boundaries were made to correct differences between the topographic base map used in the 1981 compilation (analog USGS 15-minute series quadrangle maps at 1:62,500 scale) and the base map used for this digital compilation (scanned USGS 7.5-minute series quadrangle maps at 1:24,000 scale). These minor adjustments, however, did not materially alter the geologic map. No new field mapping was performed to create this digital map database, and no attempt was made to fit geologic contacts to the new 1:24,000 topographic base, except as noted above. We corrected typographical errors, formatting errors, and attribution errors (for example, the name change of Goble Volcanics to Grays River Volcanics following current State of Washington usage; Walsh and others, 1987). We also updated selected references, substituted published papers for abstracts, and cited published radiometric ages for the volcanic and plutonic rocks. The reader is referred to Magill and others (1982), Wells and Coe (1985), Walsh and others (1987), Moothart (1993), Payne (1998), Kleibacker (2001), McCutcheon (2003), Wells and others (2009), Chan and others (2012), and Wells and others (in press) for subsequent interpretations of the Willapa Hills geology.

Washington↗

USGS2002

Geologic map of the Tetilla Peak Quadrangle, Santa Fe and Sandoval counties, New Mexico

This digital geologic map summarizes all available geologic information for the Tetilla Peak quadrangle located immediately southwest of Santa Fe, New Mexico. The geologic map consists of new polygon (geologic map units) and line (contact, fault, fold axis, dike, flow contact, hachure) data, as well as point data (locations for structural measurements, geochemical and geochronologic data, geophysical soundings, and water wells). The map database has been generated at 1:24,000 scale, and provides significant new geologic information for an area of the southern Cerros del Rio volcanic field, which sits astride the boundary of the Espanola and Santo Domingo basins of the Rio Grande rift. The quadrangle includes the west part of the village of La Cienega along its eastern border and includes the southeasternmost part of the Cochiti Pueblo reservation along its northwest side. The central part of the quadrangle consists of Santa Fe National Forest and Bureau of Land Management lands, and parts of several Spanish-era land grants. Interstate 25 cuts through the southern half of the quadrangle between Santa Fe and Santo Domingo Pueblo. Canada de Santa Fe, a major river tributary to the Rio Grande, cuts through the quadrangle, but there is no dirt or paved road along the canyon bottom. A small abandoned uranium mine (the La Bajada mine) is found in the bottom of the Canada de Santa Fe about 3 km east of the La Bajada fault zone; it has been partially reclaimed. The surface geology of the Tetilla Peak quadrangle consists predominantly of a thin (1-2 m generally, locally as thick as 10? m) layer of windblown surficial deposits that has been reworked colluvially. Locally, landslide, fluvial, and pediment deposits are also important. These colluvial deposits mantle the principal bedrocks units, which are (from most to least common): (1) basalts, basanites, andesite, and trachyte of the Pliocene (2.7-2.2 Ma) Cerros del Rio volcanic field; (2) unconsolidated deposits of the Santa Fe Group, mainly along the western border, in the hanging wall of the La Bajada fault zone, but locally extending 2-3 km east under the Cerros del Rio volcanic field; (3) older Tertiary volcanic and sedimentary rocks (Abiquiu?, Espinaso, and Galisteo Formations); (4) intrusive rocks of the Cerrillos intrusive center that are roughly coeval with the Espinaso volcanic rocks; and (5) Mesozoic sedimentary rocks ranging in age from the Upper Triassic Chinle Formation to the Upper Cretaceous Mancos Shale.

New Mexico↗

USGS1999

Preliminary geologic map of the San Guillermo Mountain Quadrangle, Ventura County, California

New 1:24,000-scale geologic mapping in the Cuyama 30' x 60' quadrangle, in support of the USGS Southern California Areal Mapping Project (SCAMP), is contributing to a more complete understanding of the stratigraphy, structure, and tectonic evolution of the complex junction area between the NW-striking Coast Ranges and EW-striking western Transverse Ranges. The 1:24,000-scale geologic map of the San Guillermo Mountain quadrangle is one of six contiguous 7 1/2' quadrangle geologic maps in the eastern part of the Cuyama map area being compiled for a more detailed portrayal and reevaluation of geologic structures and rock units shown on previous geologic maps of the area (e.g., Dibblee, 1979). The following observations and interpretations are based on the new San Guillermo Mountain geologic compilation: (1) The new geologic mapping in the northern part of the San Guillermo Mountain quadrangle allows for reinterpretation of fault architecture that bears on potential seismic hazards of the region. Previous mapping had depicted the eastern Big Pine fault (BPF) as a northeast-striking, sinistral strike-slip fault that extends for 30 km northeast of the Cuyama River to its intersection with the San Andreas fault (SAF). In contrast the new mapping indicates that the eastern BPF is a thrust fault that curves from a northeast strike to an east strike, where it is continuous with the San Guillermo thrust fault, and dies out further east about 15 km south of the SAF. This redefined segment of the BPF is a south-dipping, north-directed thrust, with dominantly dip slip components (rakes > 60 deg.), that places Middle Eocene marine rocks (Juncal and Matilija Formations) over Miocene through Pliocene(?) nonmarine rocks (Caliente, Quatal, and Morales Formations). Although a broad northeast-striking fault zone, exhibiting predominantly sinistral components of slip (rakes < 45 deg.), extends to the SAF as previously mapped, the fault zone does not connect to the southwest with the BPF but instead curves into a southwest-directed thrust fault system a short distance north of the BPF. Oligocene to Pliocene(?) nonmarine sedimentary and volcanic rocks of the Plush Ranch, Caliente, and Morales(?) Formations are folded on both sides of this fault zone (informally named the Lockwood Valley fault zone [LVFZ] on the map). South-southeast of the LVFZ overturned folds have southward vergence. Several moderate-displacement (< 50 m), mainly northwest-dipping thrust and reverse faults, exhibiting mostly sinistral-oblique slip, flank and strike parallel to the overturned folds. The fold vergence and thrust direction associated with the LVFZ is opposite to that of the redefined BPF, providing further evidence that the two faults are distinct structures. These revised fault interpretations bring into question earlier estimates of net sinistral strike-slip displacement of as much as 13 km along the originally defined eastern BPF, which assumed structural connection with the LVFZ. Also, despite sparse evidence for repeated Quaternary movement on the LVFZ (e.g., Dibblee, 1982), the potential for a large earthquake involving coseismic slip on both the LVFZ and the central BPF to the southwest may not be as great as once believed. (2) Several generations of Pleistocene and younger dissected alluvial terrace and fan deposits sit at various levels above modern stream channels throughout the quadrangle. These deposits give testimony to the recent uplift and related fault deformation that has occurred in the area. (3) A vast terrane of Eocene marine sedimentary rocks (Juncal and Matilija Formations and Cozy Dell Shale) exposed south of the Big Pine fault forms the southern two-thirds of the San Guillermo Mountain quadrangle. Benthic foraminifers collected from various shale intervals within the Juncal Formation indicate a Middle Eocene age (Ulatisian) for the entire formation (K. McDougall, unpub. data, 1998) and deposition at paleodepths as great as 2,000 m (i.e., lowe

California↗

USGS1999

Digital Geologic Map of the Nevada Test Site and Vicinity, Nye, Lincoln, and Clark Counties, Nevada, and Inyo County, California

This digital geologic map of the Nevada Test Site (NTS) and vicinity, as well as its accompanying digital geophysical maps, are compiled at 1:100,000 scale. The map compilation presents new polygon (geologic map unit contacts), line (fault, fold axis, metamorphic isograd, dike, and caldera wall) and point (structural attitude) vector data for the NTS and vicinity, Nye, Lincoln, and Clark Counties, Nevada, and Inyo County, California. The map area covers two 30 x 60-minute quadrangles-the Pahute Mesa quadrangle to the north and the Beatty quadrangle to the south-plus a strip of 7.5-minute quadrangles on the east side-72 quadrangles in all. In addition to the NTS, the map area includes the rest of the southwest Nevada volcanic field, part of the Walker Lane, most of the Amargosa Desert, part of the Funeral and Grapevine Mountains, some of Death Valley, and the northern Spring Mountains. This geologic map improves on previous geologic mapping of the same area (Wahl and others, 1997) by providing new and updated Quaternary and bedrock geology, new geophysical interpretations of faults beneath the basins, and improved GIS coverages. Concurrent publications to this one include a new isostatic gravity map (Ponce and others, 1999) and a new aeromagnetic map (Ponce, 1999).

Open-File Report↗

USGS2000

Geologic map database of the El Mirage Lake area, San Bernardino and Los Angeles Counties, California

This geologic map database for the El Mirage Lake area describes geologic materials for the dry lake, parts of the adjacent Shadow Mountains and Adobe Mountain, and much of the piedmont extending south from the lake upward toward the San Gabriel Mountains. This area lies within the western Mojave Desert of San Bernardino and Los Angeles Counties, southeastern California. The area is traversed by a few paved highways that service the community of El Mirage, and by numerous dirt roads that lead to outlying properties. An off-highway vehicle area established by the Bureau of Land Management encompasses the dry lake and much of the land north and east of the lake. The physiography of the area consists of the dry lake, flanking mud and sand flats and alluvial piedmonts, and a few sharp craggy mountains. This digital geologic map database, intended for use at 1:24,000-scale, describes and portrays the rock units and surficial deposits of the El Mirage Lake area. The map database was prepared to aid in a water-resource assessment of the area by providing surface geologic information with which deepergroundwater-bearing units may be understood. The area mapped covers the Shadow Mountains SE and parts of the Shadow Mountains, Adobe Mountain, and El Mirage 7.5-minute quadrangles. The map includes detailed geology of surface and bedrock deposits, which represent a significant update from previous bedrock geologic maps by Dibblee (1960) and Troxel and Gunderson (1970), and the surficial geologic map of Ponti and Burke (1980); it incorporates a fringe of the detailed bedrock mapping in the Shadow Mountains by Martin (1992). The map data were assembled as a digital database using ARC/INFO to enable wider applications than traditional paper-product geologic maps and to provide for efficient meshing with other digital data bases prepared by the U.S. Geological Survey's Southern California Areal Mapping Project.

California↗

USGS2004

Geologic map of the Reyes Peak quadrangle, Ventura County, California

Open-File Report↗

USGS2004

Preliminary integrated geologic map databases for the United States: Minnesota, Wisconsin, Michigan, Illinois, and Indiana

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps attributed with age and lithology information. Such maps can be conveniently used to generate derivative maps for purposes including mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This Open-File Report is a preliminary version of part of a series of integrated state geologic map databases that cover the entire United States. The only national-scale digital geologic maps that portray most or all of the United States for the conterminous U.S. are the digital version of the King and Beikman (1974a, b) map at a scale of 1:2,500,000, as digitized by Schruben and others (1994) and the generalized digital version (Reed and Bush, 2004) of the Geologic Map of North America (Reed and others, 2005a, b) compiled at a scale of 1:5,000,000. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis for this product. In a few cases, new digital compilations were prepared (e.g. Ohio, South Carolina, South Dakota) or existing paper maps were digitized (e.g. Kentucky, Texas). Also as part of this series, new regional maps for Alaska and Hawaii are being compiled and ultimately new state maps will be produced. The digital geologic maps are presented in standardized formats as ARC/INFO export (.e00) files and as ArcView shape (.shp) files. Accompanying these spatial databases are a set of five supplemental attribute tables that relate the map units to detailed lithologic and age information. The maps for the CONUS have been fitted to a common set of state boundaries based on the 1:100,000 topographic map series of the United States Geological Survey (USGS). When the individual state maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps. No attempt has been made to reconcile differences in mapped geology across state lines.

Illinois, Indiana, Michigan, Minnesota, Wisconsin↗

USGS2005

Preliminary integrated geologic map databases for the United States: Kentucky, Ohio, Tennessee, and West Virginia

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps attributed with age and lithology information. Such maps can be conveniently used to generate derivative maps for purposes including mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This Open-File Report is a preliminary version of part of a series of integrated state geologic map databases that cover the entire United States. The only national-scale digital geologic maps that portray most or all of the United States for the conterminous U.S. are the digital version of the King and Beikman (1974a, b) map at a scale of 1:2,500,000, as digitized by Schruben and others (1994) and the generalized digital version (Reed and Bush, 2004) of the Geologic Map of North America (Reed and others, 2005a, b) compiled at a scale of 1:5,000,000. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis for this product. In a few cases, new digital compilations were prepared (e.g. Ohio, South Carloina, South Dakota) or existing paper maps were digitized (e.g. Kentucky, Texas). Also as part of this series, new regional maps for Alaska and Hawaii are being compiled and ultimately new state maps will be produced. The digital geologic maps are presented in standardized formats as ARC/INFO export (.e00) files and as ArcView shape (.shp) files. Accompanying these spatial databases are a set of five supplemental attribute tables that relate the map units to detailed lithologic and age information. The maps for the CONUS have been fitted to a common set of state boundaries based on the 1:100,000 topographic map series of the United States Geological Survey (USGS). When the individual state maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps. No attempt has been made to reconcile differences in mapped geology across state lines.

Kentucky, Ohio, Tennessee, West Virginia↗

USGS2007

Geologic Map of the Goleta Quadrangle, Santa Barbara County, California

This map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying those parts of the Santa Barbara coastal plain and adjacent southern flank of the Santa Ynez Mountains within the Goleta 7 ?? quadrangle at a compilation scale of 1:24,000 (one inch on the map = 2,000 feet on the ground) and with a horizontal positional accuracy of at least 20 m. The Goleta map overlaps an earlier preliminary geologic map of the central part of the coastal plain (Minor and others, 2002) that provided coverage within the coastal, central parts of the Goleta and contiguous Santa Barbara quadrangles. In addition to new mapping in the northern part of the Goleta quadrangle, geologic mapping in other parts of the map area has been revised from the preliminary map compilation based on new structural interpretations supplemented by new biostratigraphic data. All surficial and bedrock map units are described in detail in the accompanying map pamphlet. Abundant biostratigraphic and biochronologic data based on microfossil identifications are presented in expanded unit descriptions of the marine Neogene Monterey and Sisquoc Formations. Site-specific fault-kinematic observations (including slip-sense determinations) are embedded in the digital map database. The Goleta quadrangle is located in the western Transverse Ranges physiographic province along an east-west-trending segment of the southern California coastline about 100 km (62 mi) northwest of Los Angeles. The Santa Barbara coastal plain surface, which spans the central part of the quadrangle, includes several mesas and hills that are geomorphic expressions of underlying, potentially active folds and partly buried oblique and reverse faults of the Santa Barbara fold and fault belt (SBFFB). Strong earthquakes have occurred offshore within 10 km of the Santa Barbara coastal plain in 1925 (6.3 magnitude), 1941 (5.5 magnitude) and 1978 (5.1 magnitude). These and numerous smaller seismic events located beneath and offshore of the coastal plain, likely occurred on reverse-oblique-slip faults that are similar to, or continuous with, Quaternary reverse faults crossing the coastal plain. Thus, faults of the SBFFB pose a significant earthquake hazard to the approximately 200,000 people living within the major coastal population centers of Santa Barbara and Goleta. In addition, numerous Quaternary landslide deposits along the steep southern flank of the Santa Ynez Mountains indicate the potential for continued slope failures and mass movements in developed areas. Folded, faulted, and fractured sedimentary rocks in the subsurface of the coastal plain and adjacent Santa Barbara Channel are sources and form reservoirs for economic deposits of oil and gas, some of which are currently being extracted offshore. Shallow, localized sedimentary aquifers underlying the coastal plain provide limited amounts of water for the urban areas, but the quality of some of this groundwater is compromised by coastal salt-water contamination. The present map compilation provides a set of uniform geologic digital coverages that can be used for analysis and interpretation of these and other geologic hazards and resources in the Goleta region.

Open-File Report↗

USGS2008

Three-Dimensional Geologic Map of the Hayward Fault Zone, San Francisco Bay Region, California

A three-dimensional (3D) geologic map of the Hayward Fault zone was created by integrating the results from geologic mapping, potential field geophysics, and seismology investigations. The map volume is 100 km long, 20 km wide, and extends to a depth of 12 km below sea level. The map volume is oriented northwest and is approximately bisected by the Hayward Fault. The complex geologic structure of the region makes it difficult to trace many geologic units into the subsurface. Therefore, the map units are generalized from 1:24,000-scale geologic maps. Descriptions of geologic units and structures are offered, along with a discussion of the methods used to map them and incorporate them into the 3D geologic map. The map spatial database and associated viewing software are provided. Elements of the map, such as individual fault surfaces, are also provided in a non-proprietary format so that the user can access the map via open-source software. The sheet accompanying this manuscript shows views taken from the 3D geologic map for the user to access. The 3D geologic map is designed as a multi-purpose resource for further geologic investigations and process modeling.

Scientific Investigations Map↗

USGS2001

Geologic map of the Sunnymead 7.5' quadrangle, Riverside County, California

Open-File Report 01-450 contains a digital geologic map database of the Sunnymead 7.5’ quadrangle, Riverside County, California that includes: ARC/INFO (Environmental Systems Research Institute, http:/www.esri.com) version 7.2.1 coverages of the various elements of the geologic map. A Postscript file to plot the geologic map on a topographic base, containing a Correlation of Map Units diagram (CMU), a Description of Map Units (DMU), and an index map. Portable Document Format (.pdf) files of: a. This Readme; includes in Appendix I, data contained in sun_met.txt b. The same graphic as plotted in 2 above. Test plots have not produced 1:24,000-scale map sheets. Adobe Acrobat page size setting influences map scale. The Correlation of Map Units and Description of Map Units is in the editorial format of USGS Geologic Investigations Series (I-series) maps but has not been edited to comply with I-map standards. Within the geologic map data package, map units are identified by standard geologic map criteria such as formation-name, age, and lithology. Where known, grain size is indicated on the map by a subscripted letter or letters following the unit symbols as follows: lg, large boulders; b, boulder; g, gravel; a, arenaceous; s, silt; c, clay; e.g. Qyfa is a predominantly young alluvial fan deposit that is arenaceous. Multiple letters are used for more specific identification or for mixed units, e.g., Qfysa is a silty sand. In some cases, mixed units are indicated by a compound symbol; e.g., Qyf2sc. Marine deposits are in part overlain by local, mostly alluvial fan, deposits and are labeled Qomf. Grain size follows f. Even though this is an Open-File Report and includes the standard USGS Open-File disclaimer, the report closely adheres to the stratigraphic nomenclature of the U.S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the postscript file (2 above).

California↗

USGS2005

Preliminary integrated geologic map databases for the United States: Delaware, Maryland, New York, Pennsylvania, and Virginia

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps attributed with age and lithology information. Such maps can be conveniently used to generate derivative maps for purposes including mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This Open-File Report is a preliminary version of part of a series of integrated state geologic map databases that cover the entire United States. The only national-scale digital geologic maps that portray most or all of the United States for the conterminous U.S. are the digital version of the King and Beikman (1974a, b) map at a scale of 1:2,500,000, as digitized by Schruben and others (1994) and the generalized digital version (Reed and Bush, 2004) of the Geologic Map of North America (Reed and others, 2005a, b) compiled at a scale of 1:5,000,000. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis for this product. In a few cases, new digital compilations were prepared (e.g. Ohio, South Carloina, South Dakota) or existing paper maps were digitized (e.g. Kentucky, Texas). Also as part of this series, new regional maps for Alaska and Hawaii are being compiled and ultimately new state maps will be produced. The digital geologic maps are presented in standardized formats as ARC/INFO export (.e00) files and as ArcView shape (.shp) files. Accompanying these spatial databases are a set of five supplemental attribute tables that relate the map units to detailed lithologic and age information. The maps for the CONUS have been fitted to a common set of state boundaries based on the 1:100,000 topographic map series of the United States Geological Survey (USGS). When the individual state maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps. No attempt has been made to reconcile differences in mapped geology across state lines.

Delaware, Maryland, New York, Pennsylvania, Virgin↗

USGS2003

Preliminary geologic map of the Elsinore 7.5' quadrangle, Riverside County, California

Open-File Report 03-281 contains a digital geologic map database of the Elsinore 7.5’ quadrangle, Riverside County, California that includes: 1. ARC/INFO (Environmental Systems Research Institute, http://www.esri.com) version 7.2.1 coverages of the various elements of the geologic map. 2. A Postscript file to plot the geologic map on a topographic base, and containing a Correlation of Map Units diagram (CMU), a Description of Map Units (DMU), and an index map. 3. Portable Document Format (.pdf) files of: a. This Readme; includes in Appendix I, data contained in els_met.txt b. The same graphic as plotted in 2 above. Test plots have not produced precise 1:24,000-scale map sheets. Adobe Acrobat page size setting influences map scale. The Correlation of Map Units and Description of Map Units is in the editorial format of USGS Geologic Investigations Series (I-series) maps but has not been edited to comply with I-map standards. Within the geologic map data package, map units are identified by standard geologic map criteria such as formation-name, age, and lithology. Where known, grain size is indicated on the map by a subscripted letter or letters following the unit symbols as follows: lg, large boulders; b, boulder; g, gravel; a, arenaceous; s, silt; c, clay; e.g. Qyfa is a predominantly young alluvial fan deposit that is arenaceous. Multiple letters are used for more specific identification or for mixed units, e.g., Qfysa is a silty sand. In some cases, mixed units are indicated by a compound symbol; e.g., Qyf2sc. Even though this is an Open-File Report and includes the standard USGS Open-File disclaimer, the report closely adheres to the stratigraphic nomenclature of the U.S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the postscript file (2 above).

California↗

USGS2003

Preliminary geologic map of the Perris 7.5' quadrangle, Riverside County, California

Open-File Report 03-270 contains a digital geologic map database of the Perris 7.5’ quadrangle, Riverside County, California that includes: 1. ARC/INFO (Environmental Systems Research Institute, http://www.esri.com) version 7.2.1 coverages of the various elements of the geologic map. 2. A Postscript file to plot the geologic map on a topographic base, and containing a Correlation of Map Units diagram (CMU), a Description of Map Units (DMU), and an index map. 3. Portable Document Format (.pdf) files of: a. A Readme file b. The same graphic as described in 2 above. Test plots have not produced precise 1:24,000- scale map sheets. Adobe Acrobat page size setting influences map scale. The Correlation of Map Units and Description of Map Units is in the editorial format of USGS Geologic Investigations Series (I-series) maps but has not been edited to comply with I-map standards. Within the geologic map data package, map units are identified by standard geologic map criteria such as formationname, age, and lithology. Where known, grain size is indicated on the map by a subscripted letter or letters following the unit symbols as follows: lg, large boulders; b, boulder; g, gravel; a, arenaceous; s, silt; c, clay; e.g. Qyfa is a predominantly young alluvial fan deposit that is arenaceous. Multiple letters are used for more specific identification or for mixed units, e.g., Qfysa is a silty sand. In some cases, mixed units are indicated by a compound symbol; e.g., Qyf2sc.

California↗

USGS2017

Geologic map of the Dusar area, Herat Province, Afghanistan; Modified from the 1973 original map compilations of V.I. Tarasenko and others

The geologic maps and cross sections presented in this report are redrafted and modified versions of the Geologic map and map of useful minerals of the Dusar area (scale 1:50,000) and Geologic sketch map of the Dusar and Namak-sory ore occurrences (scale 1:10,000), located in the Herat Province, Afghanistan. The original maps and cross sections are contained in unpublished Soviet report no. 0290 (Tarasenko and others, 1973) prepared in cooperation with the Ministry of Mines and Industries of the Royal Government of Afghanistan, in Kabul during 1973 under contract no. 50728. The redrafted maps and cross sections (modified from Tarasenko and others, 1973) illustrate the geological structure and mineral occurrences of the Dusar copper-gold-silver-lead-zinc prospect area of western Afghanistan, located within the Dusar-Shaida copper and tin area of interest (AOI), Herat Province, Afghanistan. Mineralization in the Dusar area is hosted within Early Jurassic to Early Cretaceous stratified volcanic and sedimentary rocks associated with numerous diabase and gabbro-diabase intrusive bodies and is generally near a major northeast-trending system of faults and quartz veins. Host rocks consist of quartz keratophyre and quartz-feldspar porphyry, with layers of schist, phyllite, and quartz-chlorite and chlorite-sericite slate; and limestone and shale, with schist and carbonate-chlorite and chlorite slate. Known mineralization includes an extensive quartz vein system, shown on the map as the “northern occurrence,” as well as the Dusar and Namak-sory gossan zones, interpreted to have formed from remnant pyrite mineralization. The veins of the northern occurrence and their altered host rocks are known to contain anomalous to economic concentrations of precious and base metals, with concentrations locally in excess of 2 parts per million gold, 100 parts per million silver, 5 percent copper, and 1 percent lead. These veins occur in swarms, and are hosted along structures that are approximately concordant with the plane of the metamorphic fabric. The veins consist mostly of quartz, with minor carbonate and sulfide minerals, and display weak alteration halos along their margins. The gossans are locally anomalous in these metals, but their size and extent makes them attractive exploration targets for potential massive sulfide mineralization. The Dusar gossan zone is a massive, ochreous, and siliceous limonitic rock, approximately 2,200 meters long, 30 to 250 meters wide, and 2.0 to 7.2 meters thick. Drilling below the Dusar gossan intersected a siliceous, sericitic, and limonitic rock underlain by quartz keratophyre with abundant disseminated pyrite. Mineralized sections grade 0.06 weight percent copper and up to 0.05 weight percent zinc. The Namak-sory gossan zone contains a similar deposit with anomalous concentrations of copper, zinc, and gold. The redrafted maps and cross sections reproduce the topology of rock units, contacts, and faults of the original Soviet maps and cross sections, and include minor modifications based on examination of the originals and observations made during two brief field visits by USGS staff in August, 2010, and June, 2013.

Dusar Area, Herat Province↗

USGS2006

Digital database of the geologic map of the Island of Hawai'i

This online publication (DS 144) provides the digital database for the printed map by Edward W. Wolfe and Jean Morris (I-2524-A; 1996). This digital database contains all the information used to publish U.S. Geological Survey Geologic Investigations Series I-2524-A (available only in paper form; see http://pubs.er.usgs.gov/pubs/i/i2524A ). The database contains the distribution and relationships of volcanic and surficial-sedimentary deposits on the island of Hawai‘i. This dataset represents the geologic history for the five volcanoes that comprise the Island of Hawai'i. The volcanoes are Kohala, Mauna Kea, Hualalai, Mauna Loa and Kīlauea. This database of the geologic map contributes to understanding the geologic history of the Island of Hawai‘i and provides the basis for understanding long-term volcanic processes in an intra-plate ocean island volcanic system. In addition the database also serves as a basis for producing volcanic hazards assessment for the island of Hawai‘i. Furthermore it serves as a base layer to be used for interdisciplinary research. This online publication consists of a digital database of the geologic map, an explanatory pamphlet, description of map units, correlation of map units diagram, and images for plotting. Geologic mapping was compiled at a scale of 1:100,000 for the entire mapping area. The geologic mapping was compiled as a digital geologic database in ArcInfo GIS format.

Hawai'i↗

USGS2001

Geologic map of the Riverside West 7.5' quadrangle, Riverside County, California

Open-File Report 01-451 contains a digital geologic map database of the Riverside West 7.5’ quadrangle, Riverside County, California that includes: ARC/INFO (Environmental Systems Research Institute, http://www.esri.com) version 7.2.1 coverages of the various elements of the geologic map. A PostScript file to plot the geologic map on a topographic base, containing a Correlation of Map Units diagram (CMU), a Description of Map Units (DMU), and an index map. Portable Document Format (.pdf) files of: a. This Readme; includes in Appendix I, data contained in rsw_met.txt b. The same graphic as plotted in 2 above. Test plots have not produced 1:24,000-scale map sheets. Adobe Acrobat page size setting influences map scale. The Correlation of Map Units and Description of Map Units is in the editorial format of USGS Geologic Investigations Series (I-series) maps but has not been edited to comply with I-map standards. Within the geologic map data package, map units are identified by standard geologic map criteria such as formation-name, age, and lithology. Where known, grain size is indicated on the map by a subscripted letter or letters following the unit symbols as follows: lg, large boulders; b, boulder; g, gravel; a, arenaceous; s, silt; c, clay; e.g. Qyfa is a predominantly young alluvial fan deposit that is arenaceous. Multiple letters are used for more specific identification or for mixed units, e.g., Qfysa is a silty sand. In some cases, mixed units are indicated by a compound symbol; e.g., Qyf2sc. Marine deposits are in part overlain by local, mostly alluvial fan, deposits and are labeled Qomf. Grain size follows f.Even though this is an Open-File Report and includes the standard USGS Open-File disclaimer, the report closely adheres to the stratigraphic nomenclature of the U.S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the postscript file (2 above).

California↗