Filters: Tags: Bedrock (X)
124 results (362ms)|
Filters
Date Range
Extensions Types Contacts
Categories Tag Types
|
This Division of Geological & Geophysical Surveys (DGGS) Raw Data File presents U-Pb geochronology and Lu-Hf isotopic compositions, age-dating results, and additional trace-elemental composition of zircons from four granitoids sampled during investigations by DGGS geologists in the western Alaska Range and the Talkeetna Mountains. The purpose of the Lu-Hf and U-Pb isotopic study was to better understand the Jurassic through early Tertiary magmatic and tectonic evolution of the Alaska Range and the significance of that magmatism for the formation of metallic mineral deposits. The U-Pb isotopic data also serve to further refine the crystallization age of plutons, which were previously ambiguous in 40Ar/39Ar geochronology...
This child item dataset contains horizontal-to-vertical spectral ratio (HVSR) data from Broome County, New York, for 15 measurements, BMHVSR81 through BMHVSR95. Raw and processed HVSR data for each HVSR measurement are included in zipped directories named by the measurement site identifier. Site identifiers are designated by a county sequential numbering system (BMVSR81, BMHVSR82, etc. where "BM" indicates Broome County).
This page contains horizontal-to-vertical spectral ratio (HVSR) data for 28 measurements, LVHVSR1 through LVHVSR97. In October and November of 2016 and 2017, the U.S. Geological Survey collected horizontal-to-vertical spectral ratio (HVSR) data at 104 sites in the Genesee Valley, Livingston County, New York as part of a saline-groundwater investigation in cooperation with the New York State Department of Environmental Resources. The HVSR technique, commonly referred to as the passive-seismic method, is used to estimate the thickness of unconsolidated sediments and the depth to bedrock (Lane and others, 2008). The passive-seismic method uses a single, broad-band three-component (two horizontal and one vertical)...
This raster depicts the percentage of lithological sulfur (S) content in surface or near surface geology. We derived these rasters by calculating the average percent S content for each map unit in combined surficial-bedrock geologic maps. We used state geologic maps (Preliminary Integrated Geologic Map Databases for the United States, Open File Reports 2004-1355, 2005-1305, 2005-1323, 2005-1324, 2005-1325, 2005-1351, and 2006-1272), which depict surficial geology instead of bedrock when the surficial layers are sufficiently deep. For the state maps that do not incorporate surficial geology (i.e., midwestern states), we overlaid surficial geologic map units with thicknesses greater than 100 feet (from Soller et al....
Categories: Data,
Map;
Types: ArcGIS REST Map Service,
ArcGIS Service Definition,
Citation,
Downloadable,
GeoTIFF,
Map Service;
Tags: Bedrock,
Conterminous U.S.,
Geochemistry,
Geology,
sulfur
This raster depicts the percentage of lithological nitrogen (N) content in surface or near surface geology. We derived these rasters by calculating the average percent N content for each map unit in combined surficial-bedrock geologic maps. We used state geologic maps (Preliminary Integrated Geologic Map Databases for the United States, Open File Reports 2004-1355, 2005-1305, 2005-1323, 2005-1324, 2005-1325, 2005-1351, and 2006-1272), which depict surficial geology instead of bedrock when the surficial layers are sufficiently deep. For the state maps that do not incorporate surficial geology (i.e., midwestern states), we overlaid surficial geologic map units with thicknesses greater than 100 feet (from Soller et...
Categories: Data,
Map;
Types: ArcGIS REST Map Service,
ArcGIS Service Definition,
Citation,
Downloadable,
GeoTIFF,
Map Service;
Tags: Bedrock,
Conterminous U.S.,
Geochemistry,
Geology,
nitrogen
These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. The hydrogeologic framework for the Lake Michigan Basin model was developed by grouping the bedrock geology of the study area into hydrogeologic units on the basis of the functioning of each unit as an aquifer or confining layer within the basin. Available data were evaluated based on the areal extent of coverage within the study area, and procedures were established to characterize areas with sparse data coverage. Top and bottom...
Categories: pre-SM502.8;
Tags: Great Lakes Basin,
Lake Michigan,
Lake Michigan Basin,
Michigan,
NSDI,
These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This geospatial data set describes bedrock geology of the Turkey Creek drainage basin in Jefferson County, Colorado. It was digitized from maps of fault locations and geologic map units based on age and lithology. Created for use in the Jefferson County Mountain Ground-Water Resources Study, it is to be used at a scale no more detailed than 1:50,000.
Thirteen geospatial datasets were developed to characterize the shallow groundwater system in the Lower Gunnison River Basin, Colorado. These geospatial datasets provide information about regolith thickness and altitude of the bedrock surface underlying regolith and display, in vector and raster formats, the generalized extent and thickness of regolith sediments that comprise the shallow groundwater system in the Lower Gunnison River Basin; display, in raster and vector format, the generalized altitude and configuration of the bedrock surface that comprises the base of the shallow groundwater system in the Lower Gunnison River Basin; provide information about depth to water, altitude of the potentiometric surface,...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Colorado,
Delta,
Gunnison,
Hydrogeology,
Montrose, Colo.,
This point dataset contains geologic information concerning regolith thickness and top-of-bedrock altitude at selected well and test-hole locations in the Lower Gunnison River Basin in Delta, Montrose, Ouray, and Gunnison Counties, Colorado. Regolith-thickness data were compiled from lithologic logs of wells and boreholes reported by the Colorado Division of Water Resources, U.S. Geological Survey, and Bureau of Reclamation. Bedrock-altitude values were computed from the bedrock altitude raster dataset (bralt). The U.S. Geological Survey prepared this dataset in cooperation with the Colorado Water Conservation Board.
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Colorado,
Delta,
Gunnison,
Montrose,
Ouray,
The Rio Icacos basin, in Puerto Rico, is the site of the highest measured chemical solute fluxes for a catchment on granodiorite; this is partly attributable to high annual rainfall (4300 mm), high average temperature (23 °C), and moderate relief. The bulk of these fluxes is contributed by dissolution of plagioclase and amphiboles in zones of partially weathered rock (0.5–1.5 m thick) underlying saprolite. These zones are characterized by systems of onion-skin “rindlets” (each 3–10 cm thick) in which porosity development is dominated by weathering of plagioclase to kaolinite. Fe-bearing aluminosilicate minerals hornblende, augite, and biotite persist in the weathered rock after plagioclase has weathered to completion,...
This map is the result of field investigations by DGGS in 1997 and 1998. This geologic map and report supersede the previously released Public Data File 99-24B, Preliminary interpretive bedrock geologic map of the Healy A-6 Quadrangle, southcentral Alaska. The current map has been updated to include mapping of areas adjacent to the Healy A-6 Quadrangle, newly interpreted bedrock units based on newly acquired analytical, paleontologic, and Ar40/Ar39 data. Ages for the rock units were modified. Field investigations were part of a two-year mapping program to provide geologic ground truth for airborne geophysical surveys flown by DGGS in the Chulitna region of southcentral Alaska during 1996.
Geologic polygon features within the Casper, Wyoming 30' x 60' quadrangle. It is a digitized version of bedrock geology map series developed by the Wyoming Geological Survey. The information provides basic bedrock geologic information and features to include named and geologic map units based on the rock types present. It is a STATEMAP product. This dataset is available for purchase through the WSGS, Digital Product MS-65, http://sales.wsgs.uwyo.edu/catalog/index.php
Geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) Mineral Resources Section conducted four weeks of helicopter-supported mapping and fieldwork from June 26 through July 24, 2013. The Styx River project in the Lime Hills C-1 Quadrangle was part of the State-funded Airborne Geophysical/Geological Mineral Inventory (AGGMI) program as part of the State's Strategic Minerals Assessment Project, an initiative designed to evaluate Alaska's potential for rare-earth elements, PGEs, and other similarly supply-challenged resources. The Styx River project area has active and ongoing mineral exploration for deposit types including porphyry copper/molybdenum/gold, reduced intrusion-related gold, and...
In April 2015, approximately 22 miles of continuous seismic profiling (CSP) surveys were collected on the Cedar River in Iowa. The swept frequency (chirp) CSP subbottom profiler was used to characterize the unconsolidated materials above the bedrock. The CSP subbottom profiler is an acoustic sound source that travels through the water column and reflects off the bottom and sub-bottom layers and is received at the transducer. (see Collecting resistivity and seismic data Cedar River IA 2.JPG. Applying a water column velocity, the two-way travel time can be converted to distance. CSP methods provide the depth to water bottom, and when sufficient signal penetration is achieved, CSP can be used to delineate the depth...
In October and November of 2016 and 2017, the U.S. Geological Survey collected horizontal-to-vertical spectral ratio (HVSR) data at 104 sites in the Genesee Valley, Livingston County, New York as part of a saline-groundwater investigation in cooperation with the New York State Department of Environmental Resources. The HVSR technique, commonly referred to as the passive-seismic method, is used to estimate the thickness of unconsolidated sediments and the depth to bedrock (Lane and others, 2008). The passive-seismic method uses a single, broad-band three-component (two horizontal and one vertical) seismometer to record ambient seismic noise. In areas that have a strong acoustic contrast between the bedrock and overlying...
Geologic polygon features within the Devils Tower, Wyoming 30' x 60' quadrangle. It is a digitized version of bedrock geology map series developed by the Wyoming Geological Survey. The information provides basic bedrock geologic information and features to include named and geologic map units based on the rock types present. It is a STATEMAP product This dataset is available for purchase through the WSGS, Digital Product MS-81, http://sales.wsgs.uwyo.edu/catalog/index.php
Types: Offline Data;
Tags: Bedrock,
Devils Tower,
Geologic polygon,
Wyoming,
geoscientificInformation
Geologic polygon features within the Howell, Wyoming 1:24,000 quadrangle. It is a digitized version of bedrock geology map series developed by the Wyoming Geological Survey. The information provides basic bedrock geologic information and features to include named and geologic map units based on the rock types present. It is a STATEMAP product. This dataset is available for purchase through the WSGS, Digital Product MS-75. http://sales.wsgs.uwyo.edu/catalog/index.php
Mineral-resources personnel from the Alaska Division of Geological & Geophysical Surveys (DGGS) carried out a helicopter-supported geological and geochemical resource assessment project in the Beaver, Bettles, Livengood, and Tanana quadrangles from June 23 through August 5, 2012. The objectives of DGGS's resource assessment are to improve the trace-element geochemical coverage of selected watersheds; to obtain modern, quantitative geochemical analyses; to understand the petrogenesis of the granites; and to better document established mineral occurrences. Stream-sediment, pan-concentrate, and rock sampling were conducted as part of the State's Rare Earth Elements and Strategic Minerals Assessment project, which is...
In 2012, the State of Alaska established its Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), to evaluate Alaska's statewide potential for SCM resources. The project is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. For decades, the Ray Mountains area of west-central Alaska has been explored for its potential mineral resources. To further assess the rare-earth-element (REE) potential of the State-selected and top-filed lands in the Ray Mountains area, mineral-resource geologists at DGGS carried out a helicopter-supported geological and...
This report presents 40Ar/39Ar step-heating geochronology results for igneous and metamorphic rocks from the Alaska Division of Geological & Geophysical Surveys' (DGGS) Talkeetna Mountains C-4 Quadrangle and Adjoining Areas geologic mapping project. Hornblende-bearing gabbro returned a Late Triassic crystallization age consistent with regional results for Nikolai Greenstone-related magmatism. We determined Early Jurassic metamorphic ages for hornblende and sericite from two samples of upper greenschist to amphibolite grade metavolcanic rocks. Our results indicate that a granodiorite pluton intruding Wrangellia in the study area has a Middle Jurassic age consistent with the Talkeetna Arc, indicating that the Wrangellia...
|
|
