This publication provides digital flight line data for a high resolution magnetic and radiometric survey over an area of central Idaho, USA. The survey includes airborne geophysical data collected as part of the U.S. Geological Survey (USGS) Earth Mapping Resource Initiative (Earth MRI) effort (Day, 2019). Earth MRI is a cooperative effort between the USGS, the Association of American State Geologists, and other federal, state, and private sector organizations to improve our knowledge of the geologic framework of the United States. Data for this survey were collected by Sander Geophysics Ltd. under contract with the USGS using a rotary wing aircraft with a magnetometer mounted in the forward stinger and a fully calibrated gamma ray spectrometer. The survey operated out of the Salmon Idaho airport from September of 2021 to October of 2021. The survey covers an approximately 65 kilometer by 90 kilometer area centered on the igneous complex underlying the Salmon Challis National Forest. Data were collected along east west flight lines spaced 200 meters apart with north south tie lines flown every 2,000 meters. A mean terrain clearance of 200 meters was maintained except where safety dictated a higher elevation. A total of 16,950 line kilometers of data were collected. Files that are available in this publication include flight line data for the magnetic survey, flight line data for the radiometric survey and a report describing the survey parameters, field operations, quality control and data reduction procedures.

This publication provides digital flight line data for a high resolution magnetic and radiometric survey over an area of central Idaho, USA. The survey includes airborne geophysical data collected as part of the U.S. Geological Survey (USGS) Earth Mapping Resource Initiative (Earth MRI) effort (Day, 2019). Earth MRI is a cooperative effort between the USGS, the Association of American State Geologists, and other federal, state, and private sector organizations to improve our knowledge of the geologic framework of the United States. Data for this survey were collected by Sander Geophysics Ltd. under contract with the USGS using a rotary wing aircraft with a magnetometer mounted in the forward stinger and a fully calibrated gamma ray spectrometer. The survey operated out of the Salmon Idaho airport from September of 2021 to October of 2021. The survey covers an approximately 65 kilometer by 90 kilometer area centered on the igneous complex underlying the Salmon Challis National Forest. Data were collected along east west flight lines spaced 200 meters apart with north south tie lines flown every 2,000 meters. A mean terrain clearance of 200 meters was maintained except where safety dictated a higher elevation. A total of 16,950 line kilometers of data were collected. Files that are available in this publication include flight line data for the magnetic survey, flight line data for the radiometric survey and a report describing the survey parameters, field operations, quality control and data reduction procedures.

This publication provides digital flight line data for a high resolution magnetic and radiometric survey over an area of central Idaho, USA. The survey includes airborne geophysical data collected as part of the U.S. Geological Survey (USGS) Earth Mapping Resource Initiative (Earth MRI) effort (Day, 2019). Earth MRI is a cooperative effort between the USGS, the Association of American State Geologists, and other federal, state, and private sector organizations to improve our knowledge of the geologic framework of the United States. Data for this survey were collected by Sander Geophysics Ltd. under contract with the USGS using a rotary wing aircraft with a magnetometer mounted in the forward stinger and a fully calibrated gamma ray spectrometer. The survey operated out of the Salmon Idaho airport from September of 2021 to October of 2021. The survey covers an approximately 65 kilometer by 90 kilometer area centered on the igneous complex underlying the Salmon Challis National Forest. Data were collected along east west flight lines spaced 200 meters apart with north south tie lines flown every 2,000 meters. A mean terrain clearance of 200 meters was maintained except where safety dictated a higher elevation. A total of 16,950 line kilometers of data were collected. Files that are available in this publication include flight line data for the magnetic survey, flight line data for the radiometric survey and a report describing the survey parameters, field operations, quality control and data reduction procedures.

This publication provides digital flight line data for a high resolution magnetic and radiometric survey over an area of central Idaho, USA. The survey includes airborne geophysical data collected as part of the U.S. Geological Survey (USGS) Earth Mapping Resource Initiative (Earth MRI) effort (Day, 2019). Earth MRI is a cooperative effort between the USGS, the Association of American State Geologists, and other federal, state, and private sector organizations to improve our knowledge of the geologic framework of the United States. Data for this survey were collected by Sander Geophysics Ltd. under contract with the USGS using a rotary wing aircraft with a magnetometer mounted in the forward stinger and a fully calibrated gamma ray spectrometer. The survey operated out of the Salmon Idaho airport from September of 2021 to October of 2021. The survey covers an approximately 65 kilometer by 90 kilometer area centered on the igneous complex underlying the Salmon Challis National Forest. Data were collected along east west flight lines spaced 200 meters apart with north south tie lines flown every 2,000 meters. A mean terrain clearance of 200 meters was maintained except where safety dictated a higher elevation. A total of 16,950 line kilometers of data were collected. Files that are available in this publication include flight line data for the magnetic survey, flight line data for the radiometric survey and a report describing the survey parameters, field operations, quality control and data reduction procedures.

This publication provides digital flight line data for a high resolution magnetic and radiometric survey over an area of central Idaho, USA. The survey includes airborne geophysical data collected as part of the U.S. Geological Survey (USGS) Earth Mapping Resource Initiative (Earth MRI) effort (Day, 2019). Earth MRI is a cooperative effort between the USGS, the Association of American State Geologists, and other federal, state, and private sector organizations to improve our knowledge of the geologic framework of the United States. Data for this survey were collected by Sander Geophysics Ltd. under contract with the USGS using a rotary wing aircraft with a magnetometer mounted in the forward stinger and a fully calibrated gamma ray spectrometer. The survey operated out of the Salmon Idaho airport from September of 2021 to October of 2021. The survey covers an approximately 65 kilometer by 90 kilometer area centered on the igneous complex underlying the Salmon Challis National Forest. Data were collected along east west flight lines spaced 200 meters apart with north south tie lines flown every 2,000 meters. A mean terrain clearance of 200 meters was maintained except where safety dictated a higher elevation. A total of 16,950 line kilometers of data were collected. Files that are available in this publication include flight line data for the magnetic survey, flight line data for the radiometric survey and a report describing the survey parameters, field operations, quality control and data reduction procedures.

This data release provides digital flight-line and gridded data for a high-resolution airborne magnetic and radiometric survey over the southwestern portion of the Colorado Mineral Belt, southwestern Colorado. The Colorado Mineral Belt is a broad, northeast-southwest trending alignment of historic mining districts that have produced multiple types of commodities, including critical minerals that are vital to the Nation's security and economy. The survey was acquired as part of the UGSS Earth Mapping Resource Initiative (Earth MRI) to improve our understanding of the fundamental geologic framework underpinning the Colorado Mineral Belt. This release covers the southwestern portion of the belt (southwest block), which includes a wide swath from the Gunnison and San Juan mining districts on the northeast to the La Plata mining district on the southwest, including parts of Chaffee, Gunnison, Saguache, Hinsdale, Mineral, Ouray, San Miguel, San Juan, Dolores, Montezuma, and La Plata Counties. Previous reports have identified several critical minerals in this region, including aluminum, antimony, fluorspar, manganese, tungsten, vanadium, and zinc. Data for this survey were acquired by NV5 Geospatial, Inc. and is sub-contractors Precision GeoSurveys, Inc. and EDCON-PRJ, Inc under contract with the USGS. The survey was flown in September and October of 2023 using a helicopter equipped with a magnetometer mounted in a stinger extending from the nose of the aircraft and a gamma-ray spectrometer stowed onboard. The helicopter pilots followed pre-planned flight paths in a grid-like pattern, with north-south lines spaced 200 meters apart and east-west lines spaced 1,000 meters apart. Lines were flown 100 meters above ground as much as possible to maximize detection of gamma-rays and resolve details of the magnetic field. This clearance could be realized in areas of low relief but higher clearances, as much as 200-500 meters, were required over rugged terrain and populated areas for safety reasons. Areas with restricted airspace, such as Wilderness Areas, were avoided. A total of 28,472 linear kilometers of data were collected along the lines, covering a 4,719 square-kilometer irregular area. EDCON-PRJ performed extensive data processing after completion of flying and delivered the final data and report in April 2024.

This data release provides digital flight-line and gridded data for a high-resolution airborne magnetic and radiometric survey over the southwestern portion of the Colorado Mineral Belt, southwestern Colorado. The Colorado Mineral Belt is a broad, northeast-southwest trending alignment of historic mining districts that have produced multiple types of commodities, including critical minerals that are vital to the Nation's security and economy. The survey was acquired as part of the UGSS Earth Mapping Resource Initiative (Earth MRI) to improve our understanding of the fundamental geologic framework underpinning the Colorado Mineral Belt. This release covers the southwestern portion of the belt (southwest block), which includes a wide swath from the Gunnison and San Juan mining districts on the northeast to the La Plata mining district on the southwest, including parts of Chaffee, Gunnison, Saguache, Hinsdale, Mineral, Ouray, San Miguel, San Juan, Dolores, Montezuma, and La Plata Counties. Previous reports have identified several critical minerals in this region, including aluminum, antimony, fluorspar, manganese, tungsten, vanadium, and zinc. Data for this survey were acquired by NV5 Geospatial, Inc. and is sub-contractors Precision GeoSurveys, Inc. and EDCON-PRJ, Inc under contract with the USGS. The survey was flown in September and October of 2023 using a helicopter equipped with a magnetometer mounted in a stinger extending from the nose of the aircraft and a gamma-ray spectrometer stowed onboard. The helicopter pilots followed pre-planned flight paths in a grid-like pattern, with north-south lines spaced 200 meters apart and east-west lines spaced 1,000 meters apart. Lines were flown 100 meters above ground as much as possible to maximize detection of gamma-rays and resolve details of the magnetic field. This clearance could be realized in areas of low relief but higher clearances, as much as 200-500 meters, were required over rugged terrain and populated areas for safety reasons. Areas with restricted airspace, such as Wilderness Areas, were avoided. A total of 28,472 linear kilometers of data were collected along the lines, covering a 4,719 square-kilometer irregular area. EDCON-PRJ performed extensive data processing after completion of flying and delivered the final data and report in April 2024.

Magnetic data collected as part of a high-resolution airborne magnetic and radiometric survey over the southwest portion of the Colorado Mineral Belt in southwestern Colorado are provided as digital flight-line and grid files. Magnetic surveys measure subtle variations in the Earth’s magnetic field and are sensitive to differences in the magnetic properties of rocks from ground level to many kilometers below. Data for this survey were acquired by NV5 Geospatial, Inc. and is sub-contractors Precision GeoSurveys, Inc. and EDCON-PRJ, Inc under contract with the USGS. The survey was flown by helicopter in September and October of 2023. Magnetic data were measured from a magnetometer mounted in a stinger extending from the nose of the aircraft. The helicopter pilots followed pre-planned flight paths in a grid-like pattern, with north-south lines spaced 200 meters apart and east-west lines spaced 1,000 meters apart. Lines were flown 100 meters above ground as much as possible to resolve details of the magnetic field. This clearance could be realized in areas of low relief but higher clearances, as much as 200-500 meters, were required over rugged terrain and populated areas for safety reasons. Areas with restricted airspace, such as Wilderness Areas, were avoided. A total of 28,472 linear kilometers of data were collected along the lines, covering a 4,719 square-kilometer irregular area. EDCON-PRJ performed extensive data processing after completion of flying and delivered the final data and report in April 2024.

Magnetic data collected as part of a high-resolution airborne magnetic and radiometric survey over the southwest portion of the Colorado Mineral Belt in southwestern Colorado are provided as digital flight-line and grid files. Magnetic surveys measure subtle variations in the Earth’s magnetic field and are sensitive to differences in the magnetic properties of rocks from ground level to many kilometers below. Data for this survey were acquired by NV5 Geospatial, Inc. and is sub-contractors Precision GeoSurveys, Inc. and EDCON-PRJ, Inc under contract with the USGS. The survey was flown by helicopter in September and October of 2023. Magnetic data were measured from a magnetometer mounted in a stinger extending from the nose of the aircraft. The helicopter pilots followed pre-planned flight paths in a grid-like pattern, with north-south lines spaced 200 meters apart and east-west lines spaced 1,000 meters apart. Lines were flown 100 meters above ground as much as possible to resolve details of the magnetic field. This clearance could be realized in areas of low relief but higher clearances, as much as 200-500 meters, were required over rugged terrain and populated areas for safety reasons. Areas with restricted airspace, such as Wilderness Areas, were avoided. A total of 28,472 linear kilometers of data were collected along the lines, covering a 4,719 square-kilometer irregular area. EDCON-PRJ performed extensive data processing after completion of flying and delivered the final data and report in April 2024.

This publication provides digital flight line data for a high-resolution magnetic and radiometric survey over part of western Arkansas. The airborne geophysical survey was jointly funded by the USGS National Cooperative Geologic Mapping Program and the Earth Mapping Resource Initiative. The survey covers a rectangular area 91.55 by 92.15 kilometers (km) over the transition between the Ouachita Mountains and Ozark Plateau physiographic provinces and includes 31,006 line-km of magnetic and radiometric data. Data were collected from a fixed-wing aircraft flown at a median terrain clearance of 170 meters (m) above topography along north-south flight lines spaced at 300-m intervals. Tie lines were flown in an east-west direction every 3,000 m. Data were collected by EON Geosciences Inc. under contract with the USGS using a fixed-wing aircraft with a magnetometer mounted in the tail stinger and a fully calibrated gamma-ray spectrometer. The survey operated out of the Branson, Missouri airport from April of 2022 to May of 2022. Files that are available in this publication include flight line data for the magnetic survey, flight line data for the radiometric survey and a report describing the survey parameters, field operations, quality control and data reduction procedures. A zip file is provided that contains the contractor's deliverable products that includes Geosoft databases and grids for this magnetic and radiometric survey and the report describing the survey and data reduction. These products can be accessed using the free software Geosoft Viewer or the commercial Oasis Montaj software.