Filters: Tags: gravitational field (earth) (X)60 results (255ms)
Estimated thickness of unconsolidated basin-fill sediments, middle Carson River basin, Nevada (from U.S. Geological Survey Scientific Investigations Report 2011-5055, figure 9)
This dataset consists of polyline estimates of the thickness of basin-fill sediments at 200-foot contour intervals for the middle Carson River basin as published on figure 9 in the U.S. Geological Survey Scientific Investigations Report 2011-5055. The estimates were made using gravity data collected at 736 stations in the middle Carson River basin reduced to a residual complete Bouguer anomaly. A relation between residual gravity and depth to bedrock was developed from descriptions on drillers logs of 25 wells that encountered bedrock.
Gravity station data, middle Carson River basin, Nevada (from U.S. Geological Survey Scientific Investigations Report 2011-5055, figure 7)
This dataset consists of point gravity station data for 95 stations in the middle Carson River basin as published on figure 7 in the U.S. Geological Survey Scientific Investigations Report 2011-5055. The points have values of the complete Bouguer anomaly and observed gravity. In addition, 641 selected gravity stations from the U.S. Geological Survey Data Series 42 titled "Gravity data of Nevada" used in this study are included for reference and users are advised to reference that publication for information on those data. Reference cited Ponce, D.A., 1997, Gravity data of Nevada: U.S. Geological Survey Data Series 42, 27 p., https://doi.org/10.3133/ds42.
Gravity data were collected from 2006 through 2015 to assist in mapping subsurface geology in the southern San Luis Basin, northern New Mexico. This data release provides principal facts for 566 new gravity stations that were acquired to fill in gaps in the existing public gravity data coverage.
This dataset contains absolute-gravity measurements made using an A-10 absolute gravity meter (Micro-g Lacoste, Inc.) in 2019 in Pinal County, Arizona. Measurements were made at a total of 19 different stations used by the Arizona Department of Water Resources (ADWR) to monitor aquifer-storage changes. Data are presented in tabular and spatial vector (point) form, including relevant parameters used for processing. Data were output by g software (Micro-g Lacoste, Inc.) version 9.12.04.23. A correction for laser-frequency drift was applied, based on regular calibration of the HeNe laser used in the A-10 against an iodine-stabilized laser.
Geologic Map of the Mound Spring Quadrangle, Nye and ClarkCounties, Nevada, and Inyo County, California
The Mound Spring quadrangle, the southwestern-most 7.5'quadrangle of the area of the Las Vegas 1:100,000-scalequadrangle, is entirely within the Pahrump Valley, spanning theNevada/California State line. New geologic mapping of thepredominantly Quaternary materials is combined with new studiesof gravity and geochronology in this quadrangle. Elevenpredominantly fine-grained units are delineated, including playasediment, dune sand, and deposits associated with several cyclesof past groundwater discharge and distal fan sedimentation.These units are intercalated with 5 predominantly coarse-grainedalluvial-fan and wash gravel units mainly derived from the SpringMountains. The gravel units are distinguished on the basis...
Aeromagnetic surveys of Nevada, merged to form seamless grids across the state. Gravity anomaly data are provided as well. Data provided in a variety of formats.
Aeromagnetic surveys of Illinois, Indiana, and Ohio, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
A set of geophysical maps with anomalies that are labeled and keyed to tables containing information on each anomaly and its source.
These data represent the network-adjusted results of relative- and absolute-gravity surveys. Relative-gravity surveys were carried out using two ZLS Corporation Burris relative-gravity meters. The effect of solid Earth tides and ocean loading were removed from the data. Instrument drift was removed by evaluating gravity change during repeated measurements at one or more base stations. Absolute-gravity surveys were carried out using a Micro-g LaCoste, Inc. A-10 absolute-gravity meter. Vertical gradients between the different measuring heights of the absolute- and relative-gravity meters were measured using a relative-gravity meter and fully-adjustable tripod, and used to correlate the measurements between the two...
Aeromagnetic surveys of South Carolina, merged to form seamless grids across the state. Gravity anomaly data are provided as well. Data provided in a variety of formats.
Gravity station data and hand-held magnetometer measurements withanalysis and description of methodology.
Principal facts (gravity observations) for 185 new stations
Physical properties of geologic units are important for geophysical interpretation because they provide the tie between lithology and geophysical fields. For gravity data, the applicable physical property is bulk density, which is the overall mass per unit volume of rocks, sediments, and their pore spaces. Bulk dry density is the mass per unit volume measured when the sample is dry. Saturated density is the mass per unit volume measured when the sample is saturated with fresh water, which has a density of 1,000 kg/m^3. The two values are commonly compared in order to determine the porosity of a sample, that is, the percentage of the volume that is composed of open space. Density is commonly reported in kilograms...
Gravity data were collected from 2016 through 2018 to assist in mapping subsurface geology in northeastern Iowa. This data release provides principal facts for 1080 new gravity stations that were acquired to supplement existing public gravity data coverage. References cited: Blakely, R.J., 1995, Potential Theory in Gravity and Magnetic Applications, Cambridge University Press, 441 p. International Association of Geodesy, 1971, Geodetic reference system 1967: International Association of Geodesy Special Publication No. 3, 116 p. Morelli, C., ed., 1974, the International gravity standardization net 1971: International Association of Geodesy Special Publication no.4, 194 p. Plouff, Donald, 1977, Preliminary documentation...
Gravity data were collected during three separate campaigns during July of 2013, August and September of 2014, and September and October of 2020 at 168 sites on and around the Stillwater layered mafic complex in southern Montana. Measurements were taken with Lacoste & Romberg G-64, G-550, and G-161 gravimeters and reduced to obtain the complete Bouguer anomaly, with reference ties to absolute base stations at U.S. Post Offices in Spokane, Washington (2014), Billings (2013-2014) and Livingston (2020), Montana. This data release includes principal facts for 168 new gravity stations and shapefiles with field locations.
Surface electrical resistivity tomography, magnetic, and gravity surveys were conducted in July 2017 in the greater East River Watershed near Crested Butte Colorado with a focused effort in Redwell Basin as part of a broader study of the role of bedrock groundwater in the hydrogeology of mineralized mountain watersheds. Approximately ten kilometers of total field magnetics data were acquired on July 29, 2017 with a Geometrics G-858 cesium vapor magnetometer that detects changes in deep (tens of meters to kilometers) geologic structure based on variations in the magnetic properties of different formations. This data release includes the raw and processed magnetics data. They are provided as digital data, and data...
New gravity compilation has been compiled for the Lake Superior region. The gravity compilation includes survey stations available from Natural Resources Canada, National Centers for Environmental Information (formerly National Geophysical Data Center), Minnesota Geological Survey, and U.S. Geological Survey. Individual databases were combined and duplicates were removed resulting in a database of 63,880 gravity stations. The gravity station data were reprocessed from observed gravity to simple Bouguer anomaly following standard methods that depend on the station type (for example, land, lake surface, or lake bottom observation) and used a reduction density of 2,670 kg/m3. The compilation provides a consistent dataset...
The datasets include gravity measurements and anomalies and physical property measurements of the northern Harrat Rahat, Saudi Arabia.
Regional surface elevation grid files (provided in Grid eXchange File format) were used to study crustal architecture beneath the Southern Midcontinent (USA) by McCafferty and others (2019). The study covered a rectangular, multi-state area of 924 by 924 kilometers centered on Missouri, and a corresponding volume extending from the topographic surface to a depth of 50 kilometers below sea level. The grid files (magnetic field observation surface, topographic surface, Precambrian basement surface, and Moho interface) were used to construct templates and initial physical property models for 3D inversions. A masked version of the Precambrian basement surface grid was used to remove inverted densities and magnetic susceptibilities...
Density and magnetic susceptibility measurements on Precambrian rocks in the Iron Mountain-Menominee region, Michigan-Wisconsin
The U.S. Geological Survey (USGS) collected rock physical property measurements to help understand causative sources of gravity and magnetic survey anomalies in the Iron Mountain-Menominee region, Michigan-Wisconsin. A total of 2,356 measurements of magnetic susceptibility and density from 152 locations have been conducted on Precambrian rocks. The measurements aid in interpretation of newly acquired ground-based gravity and airborne magnetic data that are helping to understand concealed Precambrian geology and potential mineral resources. Multiple measurements were made at each location and sample lithology units were derived from existing USGS geologic maps noted in the supplemental information section of the...