Fortran code to facilitate correction and interpretation of gravity observations
Geophysical study of the sediment under a river intended to help assess the susceptibility of this material to scour and the erosion of levees adjacent to the river.
The purpose of the data collection was to investigate possible changes in gravity across mapped Quaternary faults and to improve regional gravity coverage, adding to the existing national gravity database.
The data consist of major- and trace-element whole-rock geochemical analyses and major- and trace-element analyses of sulfide minerals determined by electron microprobe and laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) techniques
Geological and borehole geophysical data and observations collected to characterize the basin and its surface and groundwater flow systems with primary focus on the physical characteristics of the fault vein, related mine workings, and surrounding bedrock
Software for simulating electromagnetic waves from a borehole antenna
Data from seismic reflection and refraction, electromagnetic sounding, and resistivity profiling in a study area in Indiana. Exact location is not provided.
Field notes, locations, rock descriptions, and geochemical analyses from a 1988 to 1994 study to facilitate new research efforts in IOCG (iron-oxide deposits in context with other iron oxide-copper ± uranium) deposit types.
To help understand the hydrogeologic controls in the basin and how they affect surface and groundwater interactions with nearby mine workings, electrical resistivity profile, self–potential, and magnetic measurement data are provided herein.
Report describing detailed interpretation of geophysical survey data to draw inferences about subsurface geologic features and likely consequences for the hydrogeologic system.
This large producer of mercury operated from 1933 to 1971. As part of remediation work, this survey used electromagnetic methods to study subsurface resistivity.
321 observed gravity values with free-air, simple Bouguer, and complete Bouguer anomaly values; high-precision relative-gravity surveys repeated over time, useful for aquifer-storage-change monitoring; and absolute gravity values for use as base stations.
The objective of the survey was to improve the understanding of the relationship between surface water and groundwater systems critical to developing management programs for water resources.
Explanation of the Earth's gravitational field, emphasizing how USGS scientists measure gravity and portray these measurements on maps. Explains terminology of gravity anomaly maps and their relationship to the rock types and other geologic features.
Explanation of the Earth's magnetic field and how USGS measures it. Defines magnetic anomaly, induced and remanent magnetism in rocks, and describes magnetic anomaly maps.
Software for interactively picking of S-wave data
Gravity station data from three separate surveys
Results of mathematical modeling of gravity and magnetic anomaly data to infer the geologic structure of the area
Gravity data were collected in support of geologic mapping of the quadrangle. In addition, older gravity data were reprocessed for consistency and included, as well as 250 measurements of density and magnetic susceptibility.
Study aids understanding of local geologic structure and ground-water flow, includes principal facts for 266 gravity stations and physical properties of representative rock samples.
Geophysical modeling used to study mineral deposit geometry. Includes 227 new gravity stations.
Geophysical surveying data used to infer subsurface configuration of impermeable layers in this Pliocene-Pleistocene lake bed.
Maps showing aeromagnetic survey results, locations of gravity station data, and discussions of processing within the report
USGS collaboration included providing analysis of Landsat imagery; gravity measurements of sediment and rock samples; oversight of passive seismic data collection and subsequent analysis; and analysis of the chemistry and mineralogy of subsurface samples.
Maps, grids, and flight-line databases of a detailed aerial survey and maps and grids of satellite data
Gridded and tabular magnetic data and gravity station observations. Maps depicting the data are included in the report.
Collection of historical gravity and aeromagnetic data in Afghanistan (1911 through 1967)
Gridded aeromagnetic and ground-based gravity station data
Digital files and descriptions of airborne and ground collected magnetic data in Afghanistan
Flight-line data from the aeromagnetic survey
A simplified geologic map, raw gravity and magnetic data, with derivative products including depth-to-source and rock densities, with limited interpretations of the underlying geology, structures, and mineral resources.
Study to estimate the 3-D distribution of permafrost, to evaluate the effectiveness of these methods at mapping permafrost geometry, and to better define the physical properties of the subsurface in discontinuous permafrost areas.
Releases airborne survey data, resistivity cross-sections and depth slices derived from data inversion. Resulting resistivity models confirm geologic framework, constrain hydrostratigraphy and depth to basement, and reveal fault and fold distribution.
Gridded data used to revise base of aquifer, with supporting elevation data.
Airborne surveys measuring the earth's magnetic field, resistivity or other electomagnetic properties, or gamma ray emission over parts of North America.
Three contractor reports and data files for an airborne electromagnetic survey describing data aquisition and processing. Processed geophysical data were inverted to produce resistivity depth sections along flight lines. Results are described herein.
Data release and processing description of airborne and ground gravity data collected over Afghanistan
Grids and flight-line magnetic and conductivity data
Includes application-specific radar data files.
Aeromagnetic surveys of Arizona, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Aeromagnetic surveys of Arkansas and Louisiana, merged to form seamless grids across the states. Gravity anomaly data are provided as well.
Measurements of the gravitational field vary slightly from place to place due to the composition and structure of Earth's crust. This digital grid describes the Bouguer gravity anomaly for the conterminous US.
Includes a wide variety of geological and geophysical data: geologic, aeromagnetic, and gravity maps with SLAR, DEM, TM, and NDVI imagery.
Software for checking the travel time picks of crosswell seismic and radar data
Aeromagnetic surveys of Colorado, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Gravity measured from 1958-2005, with standard gravity reduction calculations applied to correct for latitude, elevation, topography, and isostasy.
Report discussing application of specialized instrumentation for detecting unexploded ordnance.
A regional profile on the Utah-Nevada State line reveals a deeply penetrating, broad electrical conductor suggesting the southwestern limit of intact Archean crust is farther north than previously reported with implications for future mineral exploration.
Data derived from the 1994 map "Latest Cretaceous and Cenozoic magmatic rocks of Alaska" compiled by E.J. Moll-Stalcup, D.A. Brew, and T.L. Vallier, published (at 1:2,500,000 scale) in volume G-1 of "The Geology of Alaska" (GSA)
The purpose of this paper is to present new sedimentological, paleontological, and geochemical data that allow us to define the geographic and stratigraphic extent and depositional setting of these temporally unusual phosphorites.
Grids and flight-line data for three airborne geophysical surveys
GIS data for geologic units and structural features, with aeromagnetic and gravity maps in PDF
This report makes available a large well dataset so that subsurface stratigraphic data are available in digital form for use within a GIS and in construction of three-dimensional models to address regional stratigraphic and structural questions.
Surveys originally carried out by Soviet geophysicists from 1972 through 1974 were digitized. Georeferencing was problematic as were some of the measured characteristics; we explain what we did and how we have understood these data.
As part of a mineral resource assessment, imagery data were used to help target areas where exposed rocks might be hydrothermally altered, providing an indication of the location of potentially mineralized areas that may contain mineral deposits.
Maps and geospatial data for (a) geology; (b) tectonics; (c) isostatic gravity anomaly; (d) aeromagnetic anomaly; (e) depth to pre-Cenozoic basement.
A digital version of the Geologic Map of the United States, originally published at a scale of 1:2,500,000 (King and Beikman, 1974b). It excludes Alaska and Hawaii.
Chemical analyses of water and sediment samples, images depicting resistivity.
Uninterpreted geophysical measurements and geochemical and mineralogical analytical data from samples collected during the summer field seasons from 2007 to 2010. Data are available in a single Geographic Information System (GIS) database.
Existing and new gravity station data and magnetometer measurements used to infer geologic structure of this area
Geophysical interpretation of the southern Española basin for the purpose of understanding the hydrogeologic framework including shallow faults, igneous units, and basement rocks
Gravity and aeromagnetic data analysis described in a report, with a few physical property analyses
Data from more than 660 gravity stations, 100 line-km of truck-towed magnetometer traverses, and 260 physical-property sites in this area.
Gravity station data and physical property measurements used to infer subsurface geologic structure
Gravity map and data used to infer details of the geologic structure of the area. Surveys were conducted during or prior to 1975.
Detailed bathymetry, lake-floor acoustic imaging, and sample characteristics to infer bottom sediment characteristics.
Aeromagnetic surveys of Georgia, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Maps of aeromagnetic data and a table of gravity station data now available for download
Report with gravity station data in a spreadsheet
Field measurements: 548 gravity and 6484 magnetic anomaly locations, data in fixed-format text files.
Gravity station and rock physical property data used to infer geologic structure of the area
Report with generalized interpretation and Excel tables of gravity and physical property data including an explanations of their formats.
Gravity station data and hand-held magnetometer measurements with analysis and description of methodology
Data taken across the San Fernando Basin and Transverse Ranges to help characterize the structure underlying this area
Principal facts (gravity observations) for 185 new stations
Gravity station data, isostatic anomaly map, and depth to basement map derived from geophysical inverse modeling.
Gravity anomaly with physical property measurements in support of structural geologic investigation
Data on the southern portion of the Marine Corps Air Ground Combat Center (MCAGCC) Twentynine Palms and the Yucca Valley-Joshua Tree-Twentynine Palms area and presents the map and basin analyses.
Gravity observations throughout Nevada combined to provide a consistent collection of point measurements and generate maps.
Gravity surveys and structural interpretation of anomaly data in support of ground-water studies
Gravity measurements and surveyed topography data
Provides a view of alluvial basins, shapes, areal extents, and approximate thicknesses of alluvial fill. Gravity field is separated into density variations in the basement complex and distribution of Cenozoic fill with its 3-D thickness representation.
Aerial, truck-towed, and hand-held magnetometer measurements, gravity station data, and sample density and magnetic susceptibility measures
Electromagnetic, resistivity, and magnetic surveys used to determine the extent of contamination in an abandoned mine area.
Results of a detailed ground magnetic survey
Hand-held magnetometer and sample magnetic susceptibility measurements used to help interpret complex patterns in the magnetic anomaly of this area.
Mathematical analysis of gravity and aeromagnetic data, with basic and derived grids and vector data and maps.
Flight line data, grids, and inversions for these surveys are intended to help understand shallow groundwater and develop groundwater resource plans for the aquifer.
Electrical resistivity depicted in georeferenced grids and maps, representing different approximate depths of investigation for each area. The range of subsurface investigation is comparable to the depth of shallow aquifers.
Geophysical surveys to map shallow hydrogeologic features of the southwestern part of the Sand Hills that contain a mix of fresh to saline lakes.
The objective of the contracted survey was to improve the understanding of the relation between surface water and groundwater systems critical to developing groundwater models used in management programs for water resources.
Grids, images, and flight-line paths for magnetic and resistivity surveys
Airborne geophysical data and a summary of the hydrologic application.
Survey to determine location of the freshwater-saltwater boundary in a coastal area.
Flight-line and gridded data, with description of methodology and interpretation
Survey to map concealed faults that may be related to geothermal resources, such as hot springs; data given are surface locations of faults interpreted from the survey.
These data were acquired to determine the thickness of valley-fill deposits and to delineate geologic structures that might influence groundwater flow beneath this area.
Using geophysical and remote-sensing data, previously unrecognized targets of potential mineralization were identified; this report shows those targets along with the evidence for their potential.
Aeromagnetic surveys of Illinois, Indiana, and Ohio, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Aeromagnetic surveys of Iowa, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Includes principal facts (gravity observations) for 2,506 stations.
Gravity measurements to support regional mapping and hydrologic studies
Includes 802 gravity station measurements with isostatic, free-air, simple and complete Bouguer anomalies, and terrain correction.
Contour map of isostatic gravity anomaly with bedrock geology, and principal facts for the gravity stations as a separate data file.
Includes detailed point measurements of gravity
Measurements of the gravitational field vary slightly from place to place due to the composition and structure of Earth's crust. This digital grid describes the isostatic residual gravity anomaly for the conterminous US.
Aeromagnetic surveys of West Virginia, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Magnetic and gravity investigations were undertaken in Mono Lake to study regional crustal structures and to aid in understanding the geologic framework, in particular regarding potential geothermal resources and volcanic hazards throughout Mono Basin.
Database includes new helicopter aeromagnetic data, point locations of the local maximum horizontal gradient derived from the aeromagnetic data, and physical property data.
Magnetic susceptibility measurements with statistical analysis
In-place rock magnetic susceptibility measurements for 746 sites are reported in a database. These data, collected from 1991 through 2012, are intended to help improve geophysical modeling of the Earth’s crust in the Western United States.
The purpose of this report is to release one north-south and two east-west regional magnetotelluric sounding profiles collected where drillhole data are sparse. No interpretation of the data is included.
Spreadsheets containing geochemical data for soils
Best available public-domain aeromagnetic and gravity data in the State of Michigan merged into composite grids. Magnetic data compiled from 25 separate magnetic surveys.
Aeromagnetic surveys of Missouri, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Aeromagnetic surveys of Montana, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Gridded geophysical data in a variety of formats.
Aeromagnetic surveys of Nebraska, Kansas, and Oklahoma, merged to form seamless grids across the states. Gravity anomaly data are provided as well.
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 New England, 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 New Jersey, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Aeromagnetic surveys of New Mexico, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Aeromagnetic surveys of North Dakota, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Aeromagnetic surveys of Oregon, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Terrain-corrected US gravity station data using NAD83 and NGVD88 downloadable from a map interface.
Software for interactively picking crosswell seismic and radar data
Report with excel tables showing principal facts (gravity observation data) and ground magnetic data.
Map with excel tables showing principal facts (gravity observation data).
Includes 2,604 (170 not previously published) gravity station measurements with calculations of free-air, simple Bouguer, complete Bouguer, and isostatic anomaly.
Data collected as part of a geological and geophysical framework study
New gravity stations combined here with older measurements taken by other USGS survey trips
Data and associated physical property measurements were collected as part of on-going studies to help determine the earthquake hazard potential of major faults within the San Francisco Bay region
Gravity anomaly measurements throughout the state
New data incorporated with existing data complete overall coverage of the basin, one of the largest associated with the Rio Grande rift.
Gravity anomaly surveys of Wisconsin, both separately by survey and combined.
Gravity station data for several surveys of this area.
Gravity observations from 99 locations in this area, with free-air, isostatic, and complete Bouguer anomalies.
Physical property data for selected rock samples accompany these gravity observations
Gravity measurements used for determining geologic structure to aid in understanding ground-water flow
Gravity study to help define the shapes of young basins filled with Cenozoic rocks and alluvium, and to identify any possible faults within these basins that might influence the movement of groundwater.
Gravity measurements collected to help define the characteristics of the Rialto-Colton fault, with rock properties such as lithology, magnetic susceptibility and density.
Multi-chapter report combining geologic, geochemical, geophysical, and mining activity data. Downloadable data for coal resource information only.
A study to investigate subsurface geologic conditions as they relate to ground-water flow in an abandoned landfill.
DC resistivity soundings were made to map subsurface lithologic, structural and hydrologic features important in controlling possible ground water contamination from mining activities and for design of remediation efforts.
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.
Aeromagnetic surveys of South Dakota, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Magnetic and gravity anomaly and structure contour data
Aeromagnetic surveys of Texas, merged to form seamless grids across the state. Gravity anomaly data are provided as well. Data provided in a variety of formats.
Data sets include drill-hole from core and geophysical logs, surface geology and elevation, and helicopter electromagnetic survey data. The model may be explored and .jpg or .tiff images or using specialized software provided.
Study to help constrain 3-dimensional geologic maps of surficial materials in these glacial deposits
Describes electromagnetic sounding locations, data acquisition, calibration, and modeling; compares data to borehole data, correlating model results; and summarizes the applications and limitations of the TEM method. Examples of models are provided.
Aeromagnetic surveys of Utah, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Aeromagnetic surveys of Virginia, 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 Washington state, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Aeromagnetic surveys of Wisconsin, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Aeromagnetic surveys of Wyoming, merged to form seamless grids across the state. Gravity anomaly data are provided as well.
Computer program for calculating crosswell radar traces for layered media