Project report, interpretation maps, EM anomalies, stacked multi-channel profiles, and other products of the airborne geophysical survey for the Southern Dishna River, Fox Hills, and Beaver Creek survey areas, Iditarod, Ophir, and Holy Cross quadrangles, western Alaska

This digital publication, GPR 2014-3, contains CGG's analysis and interpretation of data produced from airborne geophysical surveys published by DGGS in 2013 (GPR 2013-1) for the Southern Dishna River, Fox Hills, and Beaver Creek survey areas. These three survey areas are informally referred to as the Five Spot survey in places in this publication. CGG's frequency-domain DIGHEM V system was used for the EM data. GPR 2014-3 includes (1) CGG's project report with interpretation and detailed EM Anomalies, and (2) Multi-channel stacked profiles in pdf format. Interpretation maps and EM anomalies are provided in various formats (e.g., Geotiffs, KMZs, and others) and are listed in detail in GPR2014-003 ReadMe (.txt and...

Tags: Aeromagnetic Map, Aeromagnetic Survey, Airborne Geophysical Survey, Alaska, State of, Aniak Mining District, All tags... Apparent Resistivity Data, DIGHEM V EM System, Electromagnetic Anomalies, Electromagnetic Data, Electromagnetic Survey, Geophysics, HEM Survey, Holy Cross Quadrangle, Iditarod Mining District, Iditarod Quadrangle, Innoko Mining District, Interpretation, Magnetic Survey, Magnetics, Ophir Quadrangle, geoscientificInformation, Fewer tags

Sediment Texture and Geomorphology of the Sea Floor from Fenwick Island, Maryland to Fisherman's Island, Virginia

These data are a qualitatively derived interpretive polygon shapefile defining surficial sediment type and distribution, and geomorphology, for nearly 1,400 square kilometers of sea floor on the inner-continental shelf from Fenwick Island, Maryland to Fisherman’s Island, Virginia, USA. These data are classified according to Barnhardt and others (1998) bottom-type classification system, which was modified to highlight changes in secondary sediment-types such as mud and gravel across this primarily sandy shelf. Most of the geophysical and sample data used to create this interpretive layer were collected as part of the Linking Coastal Processes and Vulnerability: Assateague Island Regional Study project (GS2-2C), supported...

Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Assateague Island, Assateague Island National Seashore, Assawoman Island, Atlantic Ocean, Backscatter, All tags... Bathymetry, Bottom Photographs, Bottom Type, Cape Henlopen, Cedar Island, Chincoteague Inlet, Chincoteague Island, Chincoteague National Wildlife Refuge, Cobb Island, Delaware, Delmarva Peninsula, Delmarva Peninsula, Fenwick Island, Fisherman's Island, Hog Island, Interpretation, Marine Geology, Maryland, Metompkin Island, Mid-Atlantic Bight, Mink Island, Mockhorn Island, Myrtle Island, Ocean City, Parramore Island, Rehoboth, Sea floor, Sediment Cover, Sediment Distribution, Sediment Samples, Sediment Texture, Ship Shoal Island, Sidescan Sonar, Slope, Smith Island, Virginia, Wallops Island, Wreck Island, carbonate, geomorphology, interpretation, marine geology, marine geophysics, sea-floor characteristics, sediment texture, Fewer tags

Geophysical interpretation of U, Th, and rare earth element mineralization of the Bokan Mountain peralkaline granite complex, Prince of Wales Island, southeast Alaska

A prospectivity map for rare earth element (REE) mineralization at the Bokan Mountain peralkaline granite complex, Prince of Wales Island, southeastern Alaska, was calculated from high-resolution airborne gamma-ray data. The map displays areas with similar radioelement concentrations as those over the Dotson REE-vein-dike system, which is characterized by moderately high %K, eU, and eTh (%K, percent potassium; eU, equivalent parts per million uranium; and eTh, equivalent parts per million thorium). Gamma-ray concentrations of rocks that share a similar range as those over the Dotson zone are inferred to locate high concentrations of REE-bearing minerals. An approximately 1300-m-long prospective tract corresponds...

Categories: Publication; Types: Citation; Tags: Interpretation

40Ar/39Ar data from rocks collected in the 2015 Wrangellia mineral assessment project area, Mount Hayes A-5, Mount Hayes B-6, and Talkeetna Mountains D-2 quadrangles, Alaska

This report presents 40Ar/39Ar step-heating geochronology results for igneous and metamorphic rocks from the Alaska Division of Geological & Geophysical Surveys' (DGGS) Wrangellia Mineral Assessment project, part of a multi-year effort focusing on improving the publicly available geoscientific information for the western Wrangellia terrane. The samples described in this report were selected and analyzed to improve our understanding of the geology and structural history of the Wrangellia Mineral Assessment project area. A metagabbro rock sample returned a Late Triassic crystallization age consistent with regional ages for Nikolai Greenstone-related magmatism; however, the two amphibole separates ages do not overlap,...

Tags: 40Ar/39Ar, Analyses, Analyses and Sampling, Analytical Lab Results, Analytical Results, All tags... Ar-Ar, Basalt, Bedrock, Bedrock Geology, Copper, Crystals, Geochronology, Geologic, Geology, Greenstone, Hayes, Hornblende, Igneous, Igneous Rocks, Interpretation, Lab Methods, Methods, Mica, Mineral Composition, Mineral Resources, Mineralogy, Minerals, Mount Hayes Quadrangle, Muscovite, Plutonic Rocks, Porphyry, Resources, Rocks, Sample Location, Strategic Minerals, Strategic and Critical Minerals Assessment Project, Stratigraphy, Structural Geology, Talkeetna, Talkeetna Mountains, Talkeetna Mountains Quadrangle, Thrust, Volcanic Rocks, geoscientificInformation, Fewer tags

Physiographic Zones of the Sea Floor offshore of western and southern Martha's Vineyard and north of Nantucket, Massachusetts

Geologic, sediment texture, and physiographic zone maps characterize the sea floor south and west of Martha's Vineyard and north of Nantucket, Massachusetts. These maps were derived from interpretations of seismic-reflection profiles, high-resolution bathymetry, acoustic-backscatter intensity, bottom photographs, and surficial sediment samples. The interpretation of the seismic stratigraphy and mapping of glacial and Holocene marine units provided a foundation on which the surficial maps were created. This mapping is a result of a collaborative effort between the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management to characterize the surface and subsurface geologic framework offshore of...

Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Aquinnah, Atlantic Ocean, Backscatter, Bathymetry, CMGP, All tags... CZM, Cape Cod, Chappaquiddick Island, Children's Beach, Chilmark, Coastal Embayment, Coastal and Marine Geology Program, Coatue, Dionis Beach, Ebb-tidal Delta, Eel Point, Esri Shapefile, Gay Head, Great Point, Hard-bottom Plain, Interpretation, Katama Beach, Long Point Wildlife Refuge, Lucy Vincent Beach, Marine Geology, Martha's Vineyard, Massachusetts, Massachusetts Office of Coastal Zone Management, Muskeget Channel, Muskeget Island, Nantucket, Nantucket Harbor, Nantucket Sound, Nearshore Basin, Nearshore Ramp, Nomans Land, Outer Basin, Physiographic Zones, Rocky Zone, Sea floor, Shell Zone, Shoal\Sand Wave, Shovelful Shoal, Slope, South Beach, Squibnocket Beach, Squibnocket Point, Tisbury, Tisbury Great Pond Beach, Topography, Tuckernuck Bank, Tuckernuck Island, Tuckernuck Shoal, U.S. Geological Survey, U.S. Geological Survey Open-File Report 2008-1288, U.S. Geological Survey Open-File Report 2012-1006, U.S. Geological Survey Open-File Report 2016-1168, USGS, Vineyard Sound, WHCMSC, Wasque Shoal, Wasque point, Woods Hole Coastal and Marine Science Center, geoscientificInformation, geospatial datasets, marine geology, oceans, scientific information, sea-floor characteristics, sedimentology, sieve-size analysis, unconsolidated deposits, Fewer tags

Interpretation of sea floor geologic units for offshore of western and southern Martha's Vineyard and north of Nantucket, Massachusetts

Geologic, sediment texture, and physiographic zone maps characterize the sea floor south and west of Martha's Vineyard and north of Nantucket, Massachusetts. These maps were derived from interpretations of seismic-reflection profiles, high-resolution bathymetry, acoustic-backscatter intensity, bottom photographs, and surficial sediment samples. The interpretation of the seismic stratigraphy and mapping of glacial and Holocene marine units provided a foundation on which the surficial maps were created. This mapping is a result of a collaborative effort between the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management to characterize the surface and subsurface geologic framework offshore of...

Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: 3200, 424, 512i, Aquinnah, Atlantic Ocean, All tags... Boomer, CMGP, CZM, Cape Cod, Chappaquiddick Island, Children's Beach, Chilmark, Coastal and Marine Geology Program, Coatue, Dionis Beach, EdgeTech, Eel Point, Esri Shapefile, Gay Head, Geologic Framework, Great Point, Holocene, Interpretation, Katama Beach, Knudsen, Long Point Wildlife Refuge, Lucy Vincent Beach, Marine Geology, Martha's Vineyard, Massachusetts, Massachusetts Office of Coastal Zone Management, Muskeget Channel, Muskeget Island, Nantucket, Nantucket Harbor, Nantucket Sound, Nomans Land, Pleistocene, Sea floor, Seismic Interpretation, Seismic-reflection Profiles, Shovelful Shoal, South Beach, Squibnocket Beach, Squibnocket Point, Surficial Geology, Tisbury, Tisbury Great Pond Beach, Tuckernuck Bank, Tuckernuck Island, Tuckernuck Shoal, U.S. Geological Survey, U.S. Geological Survey Open-File Report 2008-1288, U.S. Geological Survey Open-File Report 2012-1006, U.S. Geological Survey Open-File Report 2016-1168, USGS, Vineyard Sound, WHCMSC, Wasque Shoal, Wasque point, Woods Hole Coastal and Marine Science Center, geoscientificInformation, geospatial datasets, marine geology, oceans, scientific interpretation, sea-floor characteristics, sedimentation, unconsolidated deposits, Fewer tags

Introduction to special section: China shale gas and shale oil plays

In the last 10 years, the success of shale gas and shale oil productions as a result of technological advances in horizontal drilling, hydraulic fracturing and nanoscale reservoir characterization have revolutionized the energy landscape in the United States. Resource assessment by the China Ministry of Land and Resources in 2010 and 2012 and by the U.S. Energy Information Administration in 2011 and 2013 indicates China’s shale gas resource is the largest in the world and shale oil resource in China is also potentially significant. Inspired by the success in the United States, China looks forward to replicating the U.S. experience to produce shale gas to power its economy and reduce greenhouse gas emissions. By...

Categories: Publication; Types: Citation; Tags: Interpretation

Statistical approach to neural network imaging of karst systems in 3D seismic reflection data

The current lack of a robust, standardized technique for geophysical mapping of karst systems can be attributed to both the complexity of the environment and prior technological limitations. Abrupt lateral variations in physical properties that are inherent to karst systems generate significant geophysical noise, challenging conventional seismic signal processing and interpretation. Modern application of neural networks to multi-attribute seismic interpretation now provide a semiautomated method for identifying and leveraging the nonlinear relationships exhibited among seismic attributes. The ambiguity generally associated with designing neural networks for seismic object detection can be reduced via statistical...

Categories: Publication; Types: Citation; Tags: Interpretation

Surficial geologic map of the Shaktoolik area, Norton Bay Quadrangle, Alaska

This 1:50,000 scale geologic map describes the distribution of unconsolidated deposits, identifies local geologic hazards, and provides information about the depositional environment and basic engineering properties of common surficial-geologic materials in and around Shaktoolik, Alaska. Map units are the result of combined field observations and aerial imagery interpretation. A suite of local ground observations were collected over a two-week period in July 2011 by a helicopter-supported team of DGGS geologists and collaborators. Field investigations included soil test pits, sample collection, soil and rock description, oblique aerial photography, and documentation of landscape morphology.

Tags: Alluvial, Alluvium, Analyses and Sampling, C14, Clay, All tags... Coastal, Coastal and River, Colluvium, Conglomerate, Construction Materials, Engineering, Engineering Geology, Eolian, Erosion, Fan, Flood, Floodplain, Fluvial, Gelifluction, Geochronology, Geologic, Geologic Hazards, Geologic Map, Geology, Geomorphology, Geotechnical, Gravel, Hazards, Ice, Image Interpretation, Interpretation, Inundation, Lacustrine, Lakes, Meltwater, Norton Bay Quadrangle, Permafrost, Permafrost and Periglacial, Resource Assessment, Resources, Rocks, Sand, Sand and Gravel, Sediment, Sedimentation, Shaktoolik, Silt, Slope, Slump, Surface, Surficial, Surficial Geologic Map, Surficial Geology, Terrace, Thaw Lakes, Thawing Permafrost, Thermokarst, geoscientificInformation, Fewer tags

Geomorphic provinces in the Hudson Canyon region (polyline shapefile, geographic, WGS 84)

The Hudson Canyon begins on the outer continental shelf off the east coast of the United States at about 100-meters (m) water depth and extends offshore southeastward across the continental slope and rise. A multibeam survey was carried out in 2002 to map the bathymetry and backscatter intensity of the sea floor of the Hudson Canyon and adjacent slope and rise. The survey covered an area approximately 205 kilometers (km) in the offshore direction, extending from about 500 m to about 4,000 m water depth, and about 110 km in the alongshore direction, centered on the Hudson Canyon. The sea floor was mapped using a SeaBeam Instruments 2112 multibeam echosounder aboard the National Oceanic and Atmospheric Administration...

Categories: Data; Types: Citation, Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Coastal and Marine Geology Program (CMGP), Hudson Canyon, Middle Atlantic Bight, NOAA ship Ronald H. Brown, National Oceanic and Atmospheric Administration (NOAA), All tags... New York Bight, North Atlantic Ocean, Rutgers Institute of Coastal and Marine Sciences, SeaBeam Instruments 2112 multibeam, U.S. Geological Survey (USGS), USGS Open-File Report 2004-1441, WHCMSC field activity 2002-050-FA, Woods Hole Coastal and Marine Science Center (WHCMSC), base of slope, canyon floor, canyon floor - filled, canyon wall, geoscientificInformation, imageryBaseMapsEarthCover, interpretation, lower rise, marine geology, morphology, multibeam, ocean sciences, oceans, polyline shapefile, rise valley, sea floor, sea floor mapping, sea-floor characteristics, upper rise, Fewer tags

Elevation of the late Wisconsinan to early Holocene regressive unconformity (Ur) offshore of western and southern Martha's Vineyard and north of Nantucket, Massachusetts

Geologic, sediment texture, and physiographic zone maps characterize the sea floor south and west of Martha's Vineyard and north of Nantucket, Massachusetts. These maps were derived from interpretations of seismic-reflection profiles, high-resolution bathymetry, acoustic-backscatter intensity, bottom photographs, and surficial sediment samples. The interpretation of the seismic stratigraphy and mapping of glacial and Holocene marine units provided a foundation on which the surficial maps were created. This mapping is a result of a collaborative effort between the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management to characterize the surface and subsurface geologic framework offshore of...

Categories: Data; Types: Downloadable, GeoTIFF, Map Service, Raster; Tags: 32-bit GeoTIFF, 512i, Aquinnah, Atlantic Ocean, CMGP, All tags... CZM, Cape Cod, Chappaquiddick Island, Children's Beach, Chilmark, Coastal and Marine Geology Program, Coatue, Depth to glacial deposits, Dionis Beach, EdgeTech, Eel Point, Gay Head, Geologic Framework, Great Point, Holocene, Holocene, Interpretation, Katama Beach, Long Point Wildlife Refuge, Lucy Vincent Beach, Marine Geology, Martha's Vineyard, Massachusetts, Massachusetts Office of Coastal Zone Management, Muskeget Channel, Muskeget Island, Nantucket, Nantucket Harbor, Nantucket Sound, Nomans Land, Pleistocene, Regressive Unconformity, Sea floor, Seismic Interpretation, Seismic-reflection Profiles, Shovelful Shoal, South Beach, Squibnocket Beach, Squibnocket Point, Tisbury, Tisbury Great Pond Beach, Tuckernuck Bank, Tuckernuck Island, Tuckernuck Shoal, U.S. Geological Survey, U.S. Geological Survey Open-File Report 2008-1288, U.S. Geological Survey Open-File Report 2012-1006, U.S. Geological Survey Open-File Report 2016-1168, USGS, Vineyard Sound, WHCMSC, Wasque Shoal, Wasque point, Wisconsinan, Woods Hole Coastal and Marine Science Center, geologic contacts, geologic structure, geoscientificInformation, geospatial datasets, imageryBaseMapsEarthCover, marine geology, oceans, scientific interpretation, sea-floor characteristics, sedimentation, unconsolidated deposits, Fewer tags

Characterization of gas hydrate distribution using conventional 3D seismic data in the Pearl River Mouth Basin, South China Sea

A new 3D seismic reflection data volume acquired in 2012 has allowed for the detailed mapping and characterization of gas hydrate distribution in the Pearl River Mouth Basin in the South China Sea. Previous studies of core and logging data showed that gas hydrate occurrence at high concentrations is controlled by the presence of relatively coarse-grained sediment and the upward migration of thermogenic gas from the deeper sediment section into the overlying gas hydrate stability zone (BGHSZ); however, the spatial distribution of the gas hydrate remains poorly defined. We used a constrained sparse spike inversion technique to generate acoustic-impedance images of the hydrate-bearing sedimentary section from the newly...

Categories: Publication; Types: Citation; Tags: Interpretation

Top Mesozoic unconformity subcrop map, Cook Inlet basin, Alaska

This map shows the subcrop pattern of the Mesozoic rock units present at the top Mesozoic unconformity (also commonly referred to as the base Tertiary unconformity) in Cook Inlet basin, Alaska. The subcrop is projected onto the top Mesozoic unconformity depth surface of Cook Inlet basin, Alaska, published by Shellenbaum and others (2010). Publicly available geologic and geophysical data from multiple sources were collected, interpreted, and integrated into the subcrop map. Formation picks at the top Mesozoic unconformity were determined for 109 wells. Mesozoic horizons from two regional marine two-dimensional (2-D) seismic datasets (approximately 3,300 miles) were interpreted. Eight map units were established for...

Tags: Anchorage, Anchorage Quadrangle, Bedrock Geologic Map, Bedrock Geology, Bibliography, All tags... Biostratigraphy, Cook Inlet, Cook Inlet Basin, Core Logs, Correlation, Depth Interpretation, Drill Logs, Drilling, Energy, Energy Resources, Folds, Forearc Basin, Geologic, Geologic Map, Geology, Geophysical Logs, Geophysics, Gis, Homer, Hydrocarbon, Hydrocarbon Potential, Igneous Rocks, Iliamna Quadrangle, Iniskin Bay, Inoceramus, Interpretation, Kenai, Kenai Peninsula, Kenai Quadrangle, Lake Clark Quadrangle, Matanuska River, Matanuska Valley, Metamorphic Rocks, Mount Katmai Quadrangle, Oil Basins, Oil and Gas, Oil and Gas Basin, Palmer, Palynology, Petroleum, Petroleum Basin Study, Port Graham, Reservoir, Resources, Rock Units, Saddle Mountain, Sedimentary Rocks, Seismic Interpretation, Seldovia, Seward, Seward Quadrangle, Source Rock, Southcentral Alaska, Stratigraphy, Strike-Slip, Structural Geology, Structure, Structure Contours, Structure Map, Subsurface, Surface, Susitna River, Talkeetna Mountains Quadrangle, Talkeetna Quadrangle, Thrust, Tuxedni Bay, Tyonek, Tyonek Quadrangle, Unconformity, Volcanic Rocks, Wasilla, Well Logs, geoscientificInformation, Fewer tags

Iditarod survey area: Airborne magnetic and electromagnetic data in line, grid, vector, and map formats, and descriptive project report, Innoko, Iditarod, and McGrath mining districts, Iditarod and Ophir quadrangles, western Alaska

This digital publication, GPR 2011-4, contains Fugro Airborne Surveys' analysis and interpretation of data produced from airborne geophysical surveys published by DGGS in 2011 (GPR 2011-2) of the Iditarod survey area. Fugro Airborne Surveys' frequency-domain DIGHEM V system was used for the EM data. GPR 2011-4 includes (1) Fugro's project report with interpretation and detailed EM Anomalies in tabular format, (2) Multi-channel stacked profiles in pdf format, and (3) interpretation and em anomalies are each provided as Geotiffs and maps. The document gpr2011_004_readme (.txt and .pdf) lists all files included in this publication. Other supporting files include gpr2011-4_browsegraphic.pdf, gpr2011-4_emanomaly_readme.pdf....

Tags: Aeromagnetic, Aeromagnetic Data, Aeromagnetic Map, Aeromagnetic Survey, Airborne Geophysical / Geological Mineral Inventory, All tags... Airborne Geophysical Survey, Alaska, State of, Apparent Resistivity Data, Apparent Resistivity Map, Apparent Resistivity Survey, DIGHEM V EM System, Electromagnetic Anomalies, Electromagnetic Data, Electromagnetic Survey, Geophysical Survey, Geophysics, Geophysics Search Tag, HEM Survey, Iditarod Mining District, Iditarod Quadrangle, Innoko Mining District, Interpretation, Magnetic Survey, Magnetics, McGrath Mining District, Ophir Quadrangle, Project Report, Stacked Multi-Channel Profiles, geoscientificInformation, Fewer tags

Farewell and Middle Styx survey areas: Project report, interpretation maps, EM anomalies, stacked multi-channel profiles, and other products of the airborne geophysical surveys, parts of the McGrath, Lime Hills, and Tyonek quadrangles, south-central Alaska

This digital publication, GPR 2014-4, contains CGG's analysis and interpretation of data produced from airborne geophysical surveys published by DGGS in 2013 (GPR 2013-1) and 2014 (GPR 2014-5) for the Middle Styx and Farewell survey areas respectively. The two survey blocks Farewell and Middle Styx are referred to as the 'Farewell' survey in the project report as these blocks were flown under one contract. Elsewhere the separate block names, Farewell and Middle Styx, are typically used. CGG's frequency-domain DIGHEM V system was used for the EM data. GPR 2014-4 includes (1) CGG's project report with interpretation and detailed EM Anomalies, and (2) Multi-channel stacked profiles in pdf format. Interpretation maps...

Tags: Aeromagnetic Map, Aeromagnetic Survey, Airborne Geophysical Survey, Alaska, State of, Apparent Resistivity Data, All tags... DIGHEM V EM System, Electromagnetic Anomalies, Electromagnetic Data, Electromagnetic Survey, Geophysics, HEM Survey, Interpretation, Lime Hills Quadrangle, Magnetic Survey, Magnetics, McGrath Mining District, McGrath Quadrangle, Project Report, Stacked Multi-channel Profiles, Strategic and Critical Minerals Assessment Project, Tyonek Quadrangle, Yentna Mining District, geoscientificInformation, Fewer tags

Prospecting for marine gas hydrate resources

As gas hydrate energy assessment matures worldwide, emphasis has evolved away from confirmation of the mere presence of gas hydrate to the more complex issue of prospecting for those specific accumulations that are viable resource targets. Gas hydrate exploration now integrates the unique pressure and temperature preconditions for gas hydrate occurrence with those concepts and practices that are the basis for conventional oil and gas exploration. We have aimed to assimilate the lessons learned to date in global gas hydrate exploration to outline a generalized prospecting approach as follows: (1) use existing well and geophysical data to delineate the gas hydrate stability zone (GHSZ), (2) identify and evaluate potential...

Categories: Publication; Types: Citation; Tags: Interpretation

Free-air gravity of Long Island and Block Island Sounds

This GIS layer contains an interpretive layer represented by contour lines (2-mgal intervals) of the free-air gravity of Long Island and Block Island Sounds

Categories: Web Site; Tags: ArcView, Block Island Sound, Coastal and Marine Geology Program, Coastal and Marine Geology Team, Connecticut, All tags... Connecticut Department of Environmental Protection, Long Island Sound, Long Island Sound Resource Center, New York, U.S. Geological Survey, USGS, University of Connecticut, Woods Hole Field Center, arcview, contour lines, free-air gravity, geoscientificInformation, interpretation, shapefile, vectors, Fewer tags

Geophysical expression of a buried niobium and rare earth element deposit: the Elk Creek carbonatite, Nebraska, USA

The lower Paleozoic Elk Creek carbonatite is a 6–8-km-diameter intrusive complex buried under 200 m of sedimentary rocks in southeastern Nebraska. It hosts the largest known niobium deposit in the U.S. and a rare earth element (REE) deposit. The carbonatite is composed of several lithologies, the relations of which are poorly understood. Niobium mineralization is most enriched within a magnetite beforsite (MB) unit, and REE oxides are most concentrated in a barite beforsite unit. The carbonatite intrudes Proterozoic country rocks. Efforts to explore the carbonatite have used geophysical data and drilling. A high-resolution airborne gravity gradient and magnetic survey was flown over the carbonatite in 2012. The...

Categories: Publication; Types: Citation; Tags: Interpretation

Holocene fluvial and estuarine (Qfe) and nearshore marine (Qmn) sediment thickness offshore of western and southern Martha's Vineyard and north of Nantucket, Massachusetts

Geologic, sediment texture, and physiographic zone maps characterize the sea floor south and west of Martha's Vineyard and north of Nantucket, Massachusetts. These maps were derived from interpretations of seismic-reflection profiles, high-resolution bathymetry, acoustic-backscatter intensity, bottom photographs, and surficial sediment samples. The interpretation of the seismic stratigraphy and mapping of glacial and Holocene marine units provided a foundation on which the surficial maps were created. This mapping is a result of a collaborative effort between the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management to characterize the surface and subsurface geologic framework offshore of...

Categories: Data; Types: Downloadable, GeoTIFF, Map Service, Raster; Tags: 32-bit GeoTIFF, 512i, Aquinnah, Atlantic Ocean, CMGP, All tags... CZM, Cape Cod, Chappaquiddick Island, Children's Beach, Chilmark, Coastal and Marine Geology Program, Coatue, Dionis Beach, EdgeTech, Eel Point, Gay Head, Geologic Framework, Great Point, Holocene, Holocene, Interpretation, Katama Beach, Long Point Wildlife Refuge, Lucy Vincent Beach, Marine Geology, Martha's Vineyard, Massachusetts, Massachusetts Office of Coastal Zone Management, Muskeget Channel, Muskeget Island, Nantucket, Nantucket Harbor, Nantucket Sound, Nomans Land, Pleistocene, Sea floor, Sediment thickness, Seismic Interpretation, Seismic-reflection Profiles, Shovelful Shoal, South Beach, Squibnocket Beach, Squibnocket Point, Tisbury, Tisbury Great Pond Beach, Tuckernuck Bank, Tuckernuck Island, Tuckernuck Shoal, U.S. Geological Survey, U.S. Geological Survey Open-File Report 2008-1288, U.S. Geological Survey Open-File Report 2012-1006, U.S. Geological Survey Open-File Report 2016-1168, USGS, Vineyard Sound, WHCMSC, Wasque Shoal, Wasque point, Woods Hole Coastal and Marine Science Center, geologic contacts, geologic structure, geoscientificInformation, geospatial datasets, imageryBaseMapsEarthCover, marine geology, oceans, scientific interpretation, sea-floor characteristics, sedimentation, unconsolidated deposits, Fewer tags

Seismic attribute detection of faults and fluid pathways within an active strike-slip shear zone: New insights from high-resolution 3D P-Cable™ seismic data along the Hosgri Fault, offshore California

Poststack data conditioning and neural-network seismic attribute workflows are used to detect and visualize faulting and fluid migration pathways within a 13.7 km2 13.7 km2 3D P-Cable™ seismic volume located along the Hosgri Fault Zone offshore central California. The high-resolution 3D volume used in this study was collected in 2012 as part of Pacific Gas and Electric’s Central California Seismic Imaging Project. Three-dimensional seismic reflection data were acquired using a triple-plate boomer source (1.75 kJ) and a short-offset, 14-streamer, P-Cable system. The high-resolution seismic data were processed into a prestack time-migrated 3D volume and publically released in 2014. Postprocessing, we employed dip-steering...

Categories: Publication; Types: Citation; Tags: Interpretation