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At least 1,351 records · Page 75Linked to original sources
USGS1990

Map showing the distribution of thorium in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of thorium in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of tin in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of tin in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of uranium in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of uranium in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of zinc in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of zinc in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1953

Geologic map of Lake Valley manganese district, Sierra County, New Mexico

The Lake Valley district was originally developed as a manganese-silver district, but the known silver-bearing ore bodies have long since been worked out. The critical shortage of manganese during World War II renewed interest in the manganese deposits; from October 1941 through June 1942 the U. S. Geological Survey and the U.S. Bureau of Mines conducted a cooperative exploration program in the district. This exploration demonstrated that the Lake Valley district contained about 175,000 tons of ore; approximately 37,000 tons has subsequently been mined. The present reserves are estimated to be approximately 140,000 tones of ore with a manganese content of more than 10 percent and an average content of 16.4 percent; about 75,000 tons of the ore has manganese content of more than 15 percent and an average content of 20.7 percent.

New Mexico↗
USGS1975

Map showing fluorspar deposits in Colorado

Increased fluorine consumption (U.S. Bureau of Mines, 1946-1971) coupled with limited proved reserves has stimulated extensive exploration for fluorine and intensive research into developing new sources of fluorine or substitutes. A summary of the distribution, geochemical and geologic environments, and production history of selected fluorspar occurrences, deposits, and districts is provided here with the hope that this information will help to stimulate exploration and discovery of additional fluorspar resources in Colorado to augment our dwindling domestic supply.

Colorado↗
USGS2000

Analytical results for total-digestions, EPA-1312 leach, and net acid production for twenty-three abandoned metal-mining related wastes in the Boulder River watershed, northern Jefferson County, Montana

Introduction Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana, have been implicated in their detrimental effects on water quality with regard to acid generation and toxic-metal solubilization during snow melt and storm water runoff events. This degradation of water quality is defined chiefly by the “Class 1 Aquatic Life Standards” that give limits for certain dissolved metal concentrations according to water alkalinity. Veins enriched in base- and precious metals were explored and mined in the Basin, Cataract Creek, and High Ore Creek drainages over a period of more than 70 years. Extracted minerals included galena, sphalerite, pyrite, chalcopyrite, tetrahedrite and arsenopyrite. Most of the metal-mining wastes in the study area were identified and described by the Montana Bureau of Mines and Geology. In 1997, the U.S. Geological Survey collected 20 composite samples of mine-dump or tailings waste from ten sites in the Basin and Cataract Creek drainages, and two samples from one site in the High Ore Creek drainage. Desborough and Fey presented data concerning acid generation potential, mineralogy, concentrations of certain metals by energy-dispersive X-ray fluorescence (EDXRF), and trace-element leachability of mine and exploration wastes from the ten sites of the Basin and Cataract Creek drainages. The present report presents total-digestion major- and trace-element analyses, net acid production (NAP), and results from the EPA-1312 synthetic precipitation leach procedure (SPLP) performed on the same composite samples from the ten sites from the Basin and Cataract Creek drainages, and two composite samples from the site in the High Ore Creek drainage.

Montana↗
USGS2003

Descriptions of mineral occurrences and interpretation of mineralized rock geochemical data in the Stikine geophysical survey area, Southeastern Alaska

Detailed descriptions of some of the more significant mineral occurrences in the Stikine Airborne Geophysical Survey Project Area are presented based upon site-specific examinations by the U.S. Geological Survey in May of 1998. Reconnaissance geochemical data on unmineralized igneous and sedimentary host rocks, and mineralized rocks are also presented and are accompanied by a brief analysis of geochemical signatures typical of each occurrence. Consistent with the stated goal of the geophysical survey; to stimulate exploration for polymetallic massive sulfides similar to the Greens Creek deposit, the majority of the described occurrences are possible members of a belt of Late Triassic mineral deposits that are distributed along the eastern edge of the Alexander terrane in southeastern Alaska. Many of the described occurrences in the Duncan Canal-Zarembo Island area share similarities to the Greens Creek deposit. When considered as a whole, the geology, mineralogy, and geochemistry of these occurrences help to define a transitional portion of the Late Triassic mineral belt where changes in shallow to deeper water stratigraphy and arc-like to rift-related igneous rocks are accompanied by concomitant changes in the size, morphology, and metal endowments of the mineral occurrences. As a result, Late Triassic mineral occurrences in the area appear as: 1) small, discontinuous, structurally controlled stockwork veins in mafic volcanic rocks, 2) small, irregular replacements and stratabound horizons of diagenetic semi-massive sulfides in dolostones and calcareous shales, and as 3) larger, recognizably stratiform accumulations of baritic, semi-massive to massive sulfides at and near the contact between mafic volcanic rocks and overlying sedimentary rocks. Empirical exploration guidelines for Greens Creek-like polymetallic massive sulfide deposits in southeastern Alaska include: 1) a Late Triassic volcano-sedimentary host sequence exhibiting evidence of succession from tectonic activity to quiescence (such as conglomeratic and/or mafic volcaniclastics or flows overlain by platform carbonate or shale sequences), 2) presence and proximity to Late Triassic mafic-ultramafic intrusions, 3) presence of quartz-carbonate-fuchsite altered ultramafic bodies, 4) pyritic, graphitic shales, 5) presence of barite and/or iron-manganese-rich carbonates, 6) low-iron sphalerite and antimony-rich sulfosalt minerals, 7) a geochemical signature including Fe-Zn-Pb-Cu-Ag-Au-Sb-Hg-As-Cd-Ba-Mn-Mo-Tl and the ultramafic-related suite of elements Ni-Cr-Co, and 8) a geophysical signature characterized by the coincidence of a sharp resistivity contrast with evidence for buried intrusive rocks. Critical factors for the development of larger, economic orebodies are significant thickness of pyritic, graphitic shale indicating that a locally reducing sedimentary setting was established and that accumulation of an insulating shale blank occurred, and proximity to Late Triassic aged hypabyssal mafic-ultramafic intrusive rocks.

Open-File Report↗
USGS2003

Assessment of the Mesaverde Total Petroleum System in Southwestern Wyoming Province: a petroleum system approach to assessing undiscovered oil and gas resources

The U.S. Geological Survey, in a recent assessment of the undiscovered oil and gas resources in the Southwestern Wyoming Province using a Total Petroleum System (TPS) approach, estimated a mean of 84.6 trillion cubic feet of gas (TCFG), 131 million barrels of oil (MMBO) and 2.6 billion barrels of natural gas liquids (BBNGL) that have the potential to be added to reserves over the next 30 years. Only a fraction of this, however, may be economically recoverable . Of the total estimate of 84.6 TCFG, a mean of 25.78 TCFG is in continuous-type reservoirs in the Mesaverde TPS. The Mesaverde TPS is defined as all reservoirs predominantly containing gas derived from the Mesaverde Group east of the pinchout of the Lewis Shale, which acts as a top seal separating the Mesaverde TPS from the overlying Lewis TPS. Continuous-type reservoirs in the Mesaverde TPS were subdivided into the Almond Continuous Gas Assessment Unit (AU) (mean of 13.35 TCFG), Rock Springs-Ericson Continuous Gas AU (mean of 12.18 TCFG), and the Mesaverde Coalbed Gas AU (mean of 0.25 TCFG). Geologic analysis was used to determine the favorable ?sweet spots? for potential gas resources. The Almond AU has been heavily explored at depths less than 11,000 ft, thus additions to reserves will most likely be the result of infill drilling in existing fields and the discovery of sweet spots at depths greater than 11,000 ft. There is much uncertainty in the size of undiscovered resource in the Rock Springs-Ericson AU because potential reservoirs are only sparsely explored. Only a small fraction of in-place coal-bed gas is considered to be recoverable because of low permeability and problems posed by produced water.

Open-File Report↗
USGS2000

Geology and coastal hazards in the northern Monterey Bay, California: Field trip guidebook, November 4, 2000

The purpose of this field trip is to explore the relationships between local geology, coastal hazards, and human influences in the northern Monterey Bay, which is a tectonically active high wave energy coastal environment. Seacliffs, shore platforms, pocket beaches and a headland/embayment morphology characterize this rocky coastline. Many studies of the onshore and offshore geology and geophysics, the local wave climate, and the effects of large storm events and earthquakes on the coastline have been conducted in this region (see Related Reading section). This field trip summarizes many of the findings of these research investigations, and also considers the relationship between the rates and styles of seacliff erosion and the variations in the local geology. The field trip stops allow the participant to examine seacliff sites of different geological lithologies, geographic orientations, and varying protection from wave attack, and consider how these variables affect not only the rate or magnitude of seacliff retreat but also the styles of retreat. In general the two primary forcing factors in the retreat of seacliffs are marine and terrestrial processes. At the various field trip stops, the relative importance of these processes in shaping the coastline at that particular location will be explored. Where beaches have developed, whether naturally or by emplacement of man-made structures, field trip stops are designed to look at the occurrence of the beaches (why they exist where they do) and to understand the response of the beaches to large storm events. Finally, this trip focuses on the various coastline protection structures that have been built in the area, and their effectiveness in protecting development on the beaches or at the tops of the seacliffs. The first stop of the trip is the Long Marine Lab facility where the seacliffs are composed of the most resistant geological unit in the area, the Miocene Santa Cruz Mudstone. This stop also includes discussion of some of the interesting geological features associated with this part of the Bay, including the arches at Natural Bridges State Beach. The field trip stops are progressively east and south, moving into the inner Monterey Bay, as well as into the less resistant lithologies of the late Miocene to Pliocene Purisima Formation, and finally the Pleistocene Aromas Sand. The route will follow the coast wherever possible so participants can get a full perspective of the northern Monterey Bay coastline, even where stops have not been planned.

California↗
USGS2002

Geology, Geochemistry and Geophysics of Sedimentary Rock-Hosted Au Deposits in P.R. China

This is the second report concerning results of a joint project between the U.S. Geological Survey and the Tianjin Geological Academy to study sedimentary rock-hosted Au deposits in P.R. China. Since the 1980s, Chinese geologists have devoted a large-scale exploration and research effort to the deposits. As a result, there are more than 20 million oz of proven Au reserves in sedimentary rock-hosted Au deposits in P.R. China. Additional estimated and inferred resources are present in over 160 deposits and occurrences, which are undergoing exploration. This makes China second to Nevada in contained ounces of Au in Carlin-type deposits. It is likely that many of the Carlin-type Au ore districts in China, when fully developed, could have resource potential comparable to the multi-1,000-tonne Au resource in northern Nevada. The six chapters of this report describe sedimentary rock-hosted Au deposits that were visited during the project. Chapters 1 and 2 provide an overview of sedimentary rock-hosted Au deposits and Carlin-type Au deposits and also provide a working classification for the sedimentary rock-hosted Au deposits. Chapters 3, 4, and 5 provide descriptions that were compiled from the literature in China in three main areas: the Dian-Qian-Gui, the Qinling fold belt, and Middle-Lower Yangtze River areas. Chapter 6 contains a weights-of-evidence (WofE), GIS-based mineral assessment of sedimentary rock-hosted Au deposits in the Qinling fold belt and Dian-Qian-Gui areas. Appendices contain scanned aeromagnetic (Appendix I) and gravity (Appendix II) geophysical maps of south and central China. Data tables of the deposits (Appendix III) also are available in the first report as an interactive database at http://geopubs.wr.usgs.gov/open-file/of98-466/. Geochemical analysis of ore samples from the deposits visited are contained in Appendix IV.

Open-File Report↗
USGS2003

Archive of Boomer and Chirp Seismic Reflection Data Collected During USGS Cruise 01RCE02, Southern Louisiana, April and May 2001

In April and May of 2001, the U.S. Geological Survey conducted a geophysical study of the Mississippi River Delta, Atchafalaya River Delta, and Shell Island Pass in southern Louisiana. This study was part of a larger USGS River Contaminant Evaluation (RCE) Project. This disc serves as an archive of unprocessed digital seismic reflection data, trackline navigation files, shotpoint navigation maps, observers' logbooks, GIS information, and formal Federal Geographic Data Committee (FGDC) metadata. In addition, a filtered and gained digital GIF-formatted image of each seismic profile is provided. For your convenience, a list of acronyms and abbreviations frequently used in this report has also been provided. This DVD (Digital Versatile Disc) document is readable on any computing platform that has standard DVD driver software installed. Documentation on this DVD was produced using Hyper Text Markup Language (HTML) utilized by the World Wide Web (WWW) and allows the user to access the information by using a web browser (i.e. Netscape or Internet Explorer). To access the information contained on this disc, open the file 'index.htm' located at the top level of the disc using your web browser. This report also contains WWW links to USGS collaborators and other agencies. These links are only accessible if access to the internet is available while viewing the DVD. The archived boomer and chirp seismic reflection data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry et al., 1975) and may be downloaded for processing with public domain software such as Seismic Unix (SU), currently located at http://www.cwp.mines.edu/cwpcodes. Examples of SU processing scripts are provided in the boom.tar and chirp.tar files located in the SU subfolder of the SOFTWARE folder located at the top level of this DVD. In-house (USGS) DOS and Microsoft Windows compatible software for viewing SEG-Y headers - DUMPSEGY.EXE (Zilhman, 1992) - is provided in the USGS subfolder of the SOFTWARE folder. Processed profile images, shotpoint navigation maps, logbooks, and formal metadata may be viewed with your web browser.

Open-File Report↗
USGS2003

Archive of chirp seismic reflection data collected during USGS cruises 01SCC01 and 01SCC02, Timbalier Bay and offshore East Timbalier Island, Louisiana, June 30 - July 9 and August 1 - 12, 2001

In June, July, and August of 2001, the U.S. Geological Survey (USGS), in cooperation with the University of New Orleans, the U.S. Army Corps of Engineers, and the Louisiana Department of Natural Resources, conducted a shallow geophysical and sediment core survey of Timbalier Bay and the Gulf of Mexico offshore East Timbalier Island, Louisiana. This report serves as an archive of unprocessed digital seismic reflection data, trackline navigation files, trackline navigation maps, observers' logbooks, Geographic Information Systems (GIS) information, and formal Federal Geographic Data Committee (FGDC) metadata. In addition, a gained digital Graphics Interchange Format (GIF) image of each seismic profile is provided. Please see Kulp and others (2002), Flocks and others (2003), and Kulp and others (in prep.) for further information about the sediment cores collected and the geophysical results. For convenience, a list of acronyms and abbreviations frequently used in this report is also included. This Digital Versatile Disc (DVD) document is readable on any computing platform that has standard DVD driver software installed. Documentation on this DVD was produced using Hyper Text Markup Language (HTML) utilized by the World Wide Web (WWW) and allows the user to access the information using a web browser (i.e. Netscape, Internet Explorer). To access the information contained on these discs, open the file 'index.htm' located at the top level of each disc using a web browser. This report also contains WWW links to USGS collaborators and other agencies. These links are only accessible if access to the internet is available while viewing these DVDs. The archived chirp seismic reflection data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry et al., 1975) and may be downloaded for processing with public domain software such as Seismic Unix (SU), currently located at http://www.cwp.mines.edu/cwpcodes/index.html. Examples of SU processing scripts are provided in the CHIRP.tar file located in the SU subfolder of the SOFTWARE folder located at the top level of each disc. In-house (USGS) DOS and Microsoft Windows compatible software for viewing SEG-Y headers - DUMPSEGY.EXE (Zihlman, 1992) - is provided in the USGS subfolder of the SOFTWARE folder. Processed profile images, trackline navigation maps, logbooks, and formal metadata may be viewed with a web browser.

Louisiana↗
USGS2003

Archive of boomer seismic reflection data collected during USGS cruises 01SCC01 and 01SCC02, Timbalier Bay and offshore East Timbalier Island, Louisiana, June - August, 2001

In June, July, and August of 2001, the U.S. Geological Survey (USGS), in cooperation with the University of New Orleans (UNO), the U.S. Army Corps of Engineers, and the Louisiana Department of Natural Resources, conducted a shallow geophysical and sediment core survey of Timbalier Bay and the Gulf of Mexico offshore East Timbalier Island, Louisiana. This report serves as an archive of unprocessed digital seismic reflection data, trackline navigation files, trackline navigation maps, observers' logbooks, Geographic Information Systems (GIS) information, and formal Federal Geographic Data Committee (FGDC) metadata. In addition, a filtered and gained digital Graphics Interchange Format (GIF) image of each seismic profile is provided. Please see Kulp and others (2002), Flocks and others (2003), and Kulp and others (in prep.) for further information about the sediment cores collected and the geophysical results. For convenience, a list of acronyms and abbreviations frequently used in this report is also included. This Digital Versatile Disc (DVD) document is readable on any computing platform that has standard DVD driver software installed. Documentation on this DVD was produced using Hyper Text Markup Language (HTML) utilized by the World Wide Web (WWW) and allows the user to access the information using a web browser (i.e. Netscape, Internet Explorer). To access the information contained on this disc, open the file 'index.htm' located at the top level of the disc using a web browser. This report also contains WWW links to USGS collaborators and other agencies. These links are only accessible if access to the Internet is available while viewing this DVD. The archived boomer seismic reflection data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry et al., 1975) and may be downloaded for processing with public domain software such as Seismic Unix (SU), currently located at http://www.cwp.mines.edu/cwpcodes/index.html. Examples of SU processing scripts are provided in the BOOM.tar file located in the SU subfolder of the SOFTWARE folder located at the top level of this disc. In-house (USGS) DOS and Microsoft Windows compatible software for viewing SEG-Y headers - DUMPSEGY.EXE (Zihlman, 1992) - is provided in the USGS subfolder of the SOFTWARE folder. Processed profile images, trackline navigation maps, logbooks, and formal metadata may be viewed with a web browser.

Louisiana↗
USGS2004

Bedrock geology and mineral resources of the Knoxville 1° x 2° quadrangle, Tennessee, North Carolina, and South Carolina

The Knoxville 1°x 2° quadrangle spans the Southern Blue Ridge physiographic province at its widest point from eastern Tennessee across western North Carolina to the northwest corner of South Carolina. The quadrangle also contains small parts of the Valley and Ridge province in Tennessee and the Piedmont province in North and South Carolina. Bedrock in the Valley and Ridge consists of unmetamorphosed, folded and thrust-faulted Paleozoic miogeoclinal sedimentary rocks ranging in age from Cambrian to Mississippian. The Blue Ridge is a complex of stacked thrust sheets divided into three parts: (1) a west flank underlain by rocks of the Late Proterozoic and Early Cambrian Chilhowee Group and slightly metamorphosed Late Proterozoic Ocoee Supergroup west of the Greenbrier fault; (2) a central part containing crystalline basement of Middle Proterozoic age (Grenville), Ocoee Supergroup rocks east of the Greenbrier fault, and rocks of the Murphy belt; and (3) an east flank containing the Helen, Tallulah Falls, and Richard Russell thrust sheets and the amphibolitic basement complex. All of the east flank thrust sheets contain polydeformed and metamorphosed sedimentary and igneous rocks of mostly Proterozoic age. The Blue Ridge is separated by the Brevard fault zone from a large area of rocks of the Inner Piedmont to the east, which contains the Six Mile thrust sheet and the ChaugaWalhalla thrust complex. All of these rocks are also polydeformed and metamorphosed sedimentary and igneous rocks. The Inner Piedmont rocks in this area occupy both the Piedmont and part of the Blue Ridge physiographic provinces. The intensity of deformation and metamorphism increases from west to east in the Blue Ridge. The west flank is mostly chlorite grade or relatively unmetamorphosed, and the central part of the Blue Ridge is mostly staurolite, garnet, or biotite grade, although sillimanite grade rocks occur along the eastern part of the central Blue Ridge in the vicinity of the leading edge of the Hayesvil Ie fault. The east flank of the Blue Ridge and much of the Inner Piedmont are at kyanite or silli manite grade of Manuscript approved for publication February 22, 1991. regional metamorphism except for a zone of retrograde rocks in the Brevard fault zone and a small area of biotite-grade rocks in the extreme southwest part of the Grandfather Mountain window in the northeast corner of the quadrangle. The major mineral resources in the Knoxville 1°x2° quadrangle are construction materials and a variety of industrial minerals mostly related to either granite and pegmatite or ultramafic rocks. Past production in the quadrangle of metals, which are of secondary importance relative to construction materials and industrial minerals, include copper in massive sulfides of the Besshi type, gold-bearing quartz veins, and residual iron and manganese deposits. Resources are discussed in relation to the Valley and Ridge, Blue Ridge, and Piedmont provinces. The following resources are the most important: A. Construction materials: Dimension stone of the Tennessee marble district in the Valley and Ridge. Limestone and dolomite of the Valley and Ridge. Sand and gravel and crushed stone, widespread throughout the quadrangle. B. Industrial minerals: Feldspar, flake mica, and quartz produced by flotation methods from the Spruce Pine Alaskite (muscovite granodiorite) in the east flank of the Blue Ridge. The district produces about half of the U.S. feldspar and significant amounts of the U.S. flake mica. Olivine produced from alpine-type dunite bodies in the east flank of the Blue Ridge. Talc and marble from the Murphy belt in the central part of the Blue Ridge, Vermiculite produced from a large deposit near Tigerville, S.C-, in the Inner Piedmont. Deposit worked out and mine backfilled. Smaller deposits associated with ultramafic rocks in the east flank of the Blue Ridge are now uneconomic and have not been worked in the past 20 years. C. Metals: Copper in three deposits, the Fontana and Hazel Creek mines in the Great Smoky Mountains Abstract Figure 1. Location of the Knoxville 1ºx2º quadrangle, with state and county boundaries National Park in the Central Blue Ridge, and the Cullowhee mine in the east flank of the Blue Ridge. D. Organic fuels: The rocks of the quadrangle contain no coal and probably lie outside the maximum range in thermal maturity permitting the survival of oil. The rocks in the Valley and Ridge and for a short distance eastward below the west flank of the Blue Ridge probably lie within a zone of thermal maturity permitting the survival of natural gas. Consequently the western part of the quadrangle is an area of high risk for hydrocarbon exploration. No exploration drilling has been done in this belt.

North Carolina, South Carolina, Tennessee↗
USGS2006

Sensitivity of Earthquake Loss Estimates to Source Modeling Assumptions and Uncertainty

Introduction: This report explores how uncertainty in an earthquake source model may affect estimates of earthquake economic loss. Specifically, it focuses on the earthquake source model for the San Francisco Bay region (SFBR) created by the Working Group on California Earthquake Probabilities. The loss calculations are made using HAZUS-MH, a publicly available computer program developed by the Federal Emergency Management Agency (FEMA) for calculating future losses from earthquakes, floods and hurricanes within the United States. The database built into HAZUS-MH includes a detailed building inventory, population data, data on transportation corridors, bridges, utility lifelines, etc. Earthquake hazard in the loss calculations is based upon expected (median value) ground motion maps called ShakeMaps calculated for the scenario earthquake sources defined in WGCEP. The study considers the effect of relaxing certain assumptions in the WG02 model, and explores the effect of hypothetical reductions in epistemic uncertainty in parts of the model. For example, it addresses questions such as what would happen to the calculated loss distribution if the uncertainty in slip rate in the WG02 model were reduced (say, by obtaining additional geologic data)? What would happen if the geometry or amount of aseismic slip (creep) on the region's faults were better known? And what would be the effect on the calculated loss distribution if the time-dependent earthquake probability were better constrained, either by eliminating certain probability models or by better constraining the inherent randomness in earthquake recurrence? The study does not consider the effect of reducing uncertainty in the hazard introduced through models of attenuation and local site characteristics, although these may have a comparable or greater effect than does source-related uncertainty. Nor does it consider sources of uncertainty in the building inventory, building fragility curves, and other assumptions adopted in the loss calculations. This is a sensitivity study aimed at future regional earthquake source modelers, so that they may be informed of the effects on loss introduced by modeling assumptions and epistemic uncertainty in the WG02 earthquake source model.

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USGS2013

Final report and archive of the swath bathymetry and ancillary data collected in the Puerto Rico Trench region in 2002 and 2003

In 2002 and 2003, the U.S. Geological Survey (USGS), in cooperation with the National Oceanic and Atmospheric Administration (NOAA), conducted three exploration cruises that mapped for the first time the morphology of the entire tectonic plate boundary stretching from the Dominican Republic in the west to the Lesser Antilles in the east, a distance of approximately 700 kilometers (430 miles). Observations from these three exploration cruises, coupled with computer modeling and published Global Positioning System (GPS) results and earthquake focal mechanisms, have provided new information that is changing the evaluation of the seismic and tsunami hazard from this plate boundary. The observations collected during these cruises also contributed to the basic understanding of the mechanisms that govern plate tectonics, in this case, the creation of the island of Puerto Rico and the deep trench north of it. Results of the sea floor mapping have been an important component of the study of tsunami and earthquake hazards to the northeastern Caribbean and the U.S. Atlantic coast off the United States.

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USGS2006

Reserve Growth in Oil Fields of West Siberian Basin, Russia

Although reserve (or field) growth has proven to be an important factor contributing to new reserves in mature petroleum basins, it is still a poorly understood phenomenon. Limited studies show that the magnitude of reserve growth is controlled by several major factors, including (1) the reserve booking and reporting requirements in each country, (2) improvements in reservoir characterization and simulation, (3) application of enhanced oil recovery techniques, and (4) the discovery of new and extensions of known pools in discovered fields. Various combinations of these factors can affect the estimates of proven reserves in particular fields and may dictate repeated estimations of reserves during a field's life. This study explores the reserve growth in the 42 largest oil fields in the West Siberian Basin, which contain about 55 percent of the basin's total oil reserves. The West Siberian Basin occupies a vast swampy plain between the Ural Mountains and the Yenisey River, and extends offshore into the Kara Sea; it is the richest petroleum province in Russia. About 600 oil and gas fields with original reserves of 144 billion barrels of oil (BBO) and more than 1,200 trillion cubic feet of gas (TCFG) have been discovered. The principal oil reserves and most of the oil fields are in the southern half of the basin, whereas the northern half contains mainly gas reserves. Sedimentary strata in the basin consist of Upper Triassic through Tertiary clastic rocks. Most oil is produced from Neocomian (Lower Cretaceous) marine to deltaic sandstone reservoirs, although substantial oil reserves are also in the marine Upper Jurassic and continental to paralic Lower to Middle Jurassic sequences. The majority of oil fields are in structural traps, which are gentle, platform-type anticlines with closures ranging from several tens of meters to as much as 150 meters (490 feet). Fields producing from stratigraphic traps are generally smaller except for the giant Talin field which contains oil in Jurassic river-valley sandstones. Principal source rocks are organic-rich marine shales of the Volgian (uppermost Jurassic) Bazhenov Formation, which is 30-50 m (98- 164 feet) thick. Bazhenov-derived oils are mostly of medium gravity, and contain 0.8-1.3 percent sulfur and 2-5 percent paraffin. Oils in the Lower to Middle Jurassic clastics were sourced from lacustrine and estuarine shales of the Toarcian Togur Bed. These oils are medium to low gravity, with low sulfur (less than 0.25 percent) and high paraffin (commonly to 10 percent) contents. Among the 42 fields analyzed for reserve growth, 30 fields are located in the Middle Ob region, which includes the Samotlor field with reserves of more than 25 BBO and the Fedorov field with reserves of about 5 BBO. Data used in the study include year of discovery, year of first production, annual and cumulative production, and remaining reserves reported by Russian reserve categories (A+B+C1 and C2) in January of each year. Correlation of these Russian resource categories to U.S. categories of the Society of Petroleum Engineers classification is complex and somewhat uncertain. Reserve growth in oil fields of West Siberia was calculated using a newly developed Group Growth method, which requires that the total reserve (proven reserve plus cumulative production) of individual fields with an equal length of reserve record be added together starting with discovery year or the first production year. Then the annual growth factor (AGF), which is the ratio of total reserves of two consecutive years, is calculated for all years. Once AGFs have been calculated, the cumulative growth factor (CGF) is calculated by multiplying the AGFs of all the previous years. The CGF data are used to develop reserve growth models. The West Siberian oil fields show a 13-fold reserve growth 20 years after the discovery year and only about a 2-fold growth after the first production year. This difference is attributed to extensive exploration and field delineation activities between the discovery and the first production years. Because of uncertainty in the length of evaluation time and in reported reserves during this initial period, reserve growth based on the first production year is more reliable for model development. However, reserve growth models based both on discovery year and first production year show rapid growth in the first few years and slower growth in the following years. In contrast, the reserve growth patterns for the conterminous United States and offshore Gulf of Mexico show a steady reserve increase throughout the productive lives of the fields. The different reserve booking requirements and the lack of capital investment for improved reservoir management and production technologies in West Siberian fields relative to U.S. fields are the probable causes for the difference in growth patterns. Reserve growth models based on the first production year predict that the reserve growth potential in the 42 largest oil fields of West Siberia over a five-year period (1998-2003) ranges from 270-330 million barrels or 0.34-0.42 percent per year. For a similar five-year period (1996-2001), models for the conterminous United States predict a growth of 0.54-0.75 percent per year. This abstract presents the contents of a poster prepared for the AAPG Hedberg Research Conference on Understanding World Oil Resources, November 12-17, 2006 - Colorado Springs, Colorado. A paper 'Reserve Growth in Oil Fields of West Siberian Basin, Russia' was published in Natural Resources Research, v. 12, no. 2, June, 2003.

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