This report presents the results of analyses and interpretation of aerial gamma-ray, Landsat TM, geologic, and digital elevation data of the Big Bend area in Texas.

The USGS had an aerial survey flown over parts of Cameron, Hidalgo, and Willacy Counties in Texas. The aerial survey included measurements of the earth's magnetic field and of the radioactivity of the surface rocks and soils.

Measurements indicating abundance of radioactive elements in near-surface rocks. Grids and flight-line data from surveys flown 1976-1980.

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

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.

Aeromagnetic surveys of Idaho, merged to form seamless grids across the state. Data provided in a variety of formats.

Digital files and descriptions of airborne and ground collected magnetic data in Afghanistan

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.

Airborne electromagnetic and magnetic survey data were collected during 2016 along 4,212 line-kilometers over this area. The survey was flown with a nominal line spacing of 450 meters or less, and mean flight height about 48 m providing depth of investigation about 500m. Data are provided in CSV format, flight lines in shapefile format.

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.

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

Digital flight line data for a high-resolution airborne magnetic and radiometric survey of this area. A total of 40,139-line km of magnetic and radiometric data were acquired over an irregular-shaped area of 9140 sq km. Data are provided in CSV, GeoTIFF, and Geosoft formats.

Digital flight line data for a high-resolution magnetic survey with line spacing 150 meters and nominal terrain clearance 80 meters over most of the study area. Data are provided as Geosoft databases and grids. Data over two small areas (less than 1 sq km combined) were redacted because those areas include multiple tracts of Native American lands.

The long-wavelength (50-2,500 km) content of the regional magnetic anomaly compilation was improved by utilizing a nearly homogeneous a nearly homogeneous set of NURE magnetic surveys flown from 1975 to 1981

Estimates thickness of sand and gravel resources available in this broad area using geology, topography, land cover, and ground-water level.

Gravity measured from 1958-2005, with standard gravity reduction calculations applied to correct for latitude, elevation, topography, and isostasy.

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.

Aeromagnetic surveys of Georgia, merged to form seamless grids across the state. Gravity anomaly data are provided as well.

Mathematical analysis of gravity and aeromagnetic data, with basic and derived grids and vector data and maps.

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.

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

Grids, line data, and imagery derived from them covering the small study area.

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.

Airborne measurement of the earth's magnetic field over all of North America provides gridded data describing the magnetic anomaly caused by variations in earth materials and structure.

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.

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 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.

Preliminary data (grids and images) and maps for a new aeromagnetic survey

Radiometric (uranium, thorium, potassium content and gamma-ray intensity) and related data were digitized from radiometric and survey route location maps of western Afghanistan previously published by others in 1976.

Grid and flight-line data files provided by the geophysical survey contractors.

Grid and flight-line data files provided to USGS by contract geophysical surveyors

Gridded data for aeromagnetic surveys with contractors' reports describing the data collection

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.

Data generated by aerial sensing of radiation emanating from the earth's surface provides general estimates of the geographic distribution of Uranium, Thorium, and Potassium in surficial and bedrock units. Covers the conterminous United States, southeaste

Flight-line databases and derived grids from aeroradiometric surveys across the US carried out during the 1970s

Grids and flight-line data for the surveys of this area

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 Wisconsin, merged to form seamless grids across the state. Gravity anomaly data are provided as well.