This publication provides digital flight line data for a high-resolution magnetic and radiometric survey over an area of southeast Illinois, western Kentucky, and southern Indiana. 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 EON Geosciences 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 Paducah, Kentucky airport from October of 2019 to December of 2019. The survey covers a 91-kilometer x 128-kilometer area centered on the igneous complex around Hicks Dome in Hardin County, Illinois. Data were collected along east-west flight lines spaced 200 meters apart with north-south tie lines flown every 3,000 meters. A mean terrain clearance of 116 meters was maintained except where safety dictated a higher elevation. A total of 61,974-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. A zip file is provided that contains the contractor's deliverable products that includes Geosoft databases and grids for the magnetic and radiometric survey and the report describing the survey and data reduction.

This data release contains digital radiometric flight line data for a high-resolution airborne magnetic and radiometric survey over southeastern Illinois, western Kentucky, and southern Indiana, 2019 (version 2.0, August 2025). Data and documentation for the original version, including associated airborne magnetic data, can be found at https://doi.org/10.5066/P9R05B0M. The airborne geophysical survey was funded by the Earth Mapping Resources Initiative and was designed to meet the complementary needs related to geologic mapping and mineral resource research. The survey covers a 91-kilometer x 128-kilometer area centered on the igneous complex around Hicks Dome in Hardin County, Illinois. Data were collected along east-west flight lines spaced 200 meters apart with north-south tie lines flown every 3,000 meters. A mean terrain clearance of 116 meters was maintained except where safety dictated a higher elevation. A total of 61,974-line kilometers of data were collected. Data for this survey were collected by EON Geosciences 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 Paducah, Kentucky airport from October of 2019 to December of 2019. This version (version 2.0, August 2025) of the radiometric data has been reprocessed from the original dataset by New Resolution Geophysics (NRG) in 2024 under contract by the USGS using noise-adjusted singular value decomposition (NASVD) spectral component analysis procedure for improving the signal-to-noise ratio of the radiometric data. This website includes the reprocessed radiometric data, with and without spectra, provided in ASCII (.csv) and NetCDF (.nc) files; GeoTIFF images showing the total count (K, U, Th), percent potassium (%K), equivalent uranium (eU), equivalent thorium (eTh), and ternary (%K, eU, eTh); 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 including Geosoft databases and grids for this radiometric dataset and the report describing the survey and data reduction. These files are provided as received from the contractor. The files in this package are readable using the free software Geosoft Viewer or the commercial Oasis Montaj software.

This publication provides digital flight line data for a high-resolution magnetic and radiometric survey over an area of southeast Illinois, western Kentucky, and southern Indiana. 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 EON Geosciences 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 Paducah, Kentucky airport from October of 2019 to December of 2019. The survey covers a 91-kilometer x 128-kilometer area centered on the igneous complex around Hicks Dome in Hardin County, Illinois. Data were collected along east-west flight lines spaced 200 meters apart with north-south tie lines flown every 3,000 meters. A mean terrain clearance of 116 meters was maintained except where safety dictated a higher elevation. A total of 61,974-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. A zip file is provided that contains the contractor's deliverable products that includes Geosoft databases and grids for the magnetic and radiometric survey and the report describing the survey and data reduction.

This publication provides digital flight line data for a high-resolution magnetic and radiometric survey over an area of southeast Illinois, western Kentucky, and southern Indiana. 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 EON Geosciences 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 Paducah, Kentucky airport from October of 2019 to December of 2019. The survey covers a 91-kilometer x 128-kilometer area centered on the igneous complex around Hicks Dome in Hardin County, Illinois. Data were collected along east-west flight lines spaced 200 meters apart with north-south tie lines flown every 3,000 meters. A mean terrain clearance of 116 meters was maintained except where safety dictated a higher elevation. A total of 61,974-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. A zip file is provided that contains the contractor's deliverable products that includes Geosoft databases and grids for the magnetic and radiometric survey and the report describing the survey and data reduction.

This publication provides digital flight line data for a high-resolution magnetic survey over an area of northwest Arkansas. The airborne geophysical survey was jointly funded by the USGS National Cooperative Geologic Mapping Program and the Earth Mapping Resource Initiative and was designed to meet the complimentary needs related to geologic mapping and mineral resource research. The survey covers an irregular area 225 by 110 kilometers over the transition between the Ouachita and Ozarks Plateau physiographic provinces and includes 67,614 line-kilometers of magnetic data. Data were collected from a fixed-wing aircraft flown at mean terrain clearance of 167 meters above topography along N-S flight lines spaced at 200 meter intervals. Tie lines were flown in an E-W direction every 3000 meters. Data were collected by EON Geosciences under contract with the USGS using a fixed wing aircraft with a magnetometer mounted in the tail stinger. The survey operated out of the Branson, Missouri airport from October of 2019 to March of 2020. Files that are available in this child item include flight line data for the magnetic survey.

This publication provides digital flight line data for a high-resolution horizontal magnetic gradient and radiometric survey over an area of southeast Missouri and western Illinois. The survey represents the first airborne geophysical survey conducted 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 Terraquest, Ltd. under contract with the USGS using a fixed wing aircraft with magnetometers mounted in the tail stinger and each wing tip pod and a fully calibrated gamma ray spectrometer. The survey operated out of the Farmington, Missouri airport from December of 2018 to May of 2019. The survey covers a 146-kilometer x 154-kilometer area centered on the town of Ironton, Missouri. Data were collected along north-south flight lines spaced 300 meters (m) apart with east-west tie lines flown every 3000 m. A mean terrain clearance of 117 m was maintained except where safety dictated a higher elevation. A total of 68,375-line kilometers (km) of data were collected. Files that are available in this publication include flight line data for the magnetic gradient 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 the magnetic and radiometric survey and the report describing the survey and data reduction. The 2018-2019 survey was designed to augment and connect two previous USGS airborne geophysical surveys. Adjacent surveys include a magnetic and gravity gradiometry helicopter survey flown in 2014 (McCafferty, 2016a) centered on the Pea Ridge iron mine and a magnetic and radiometric survey flown in 2016 and centered on Ironton, Missouri (McCafferty, 2016b).

This data release provides digital flight line data for a high-resolution airborne magnetic and radiometric survey over parts of northwestern Minnesota near the town of Mentor. The airborne survey was funded by the Earth Mapping Resources Initiative and was designed to meet complementary needs related to geologic mapping and characterization of mineral resource potential. A total of 40,139-line km of magnetic and radiometric data were acquired over an irregular-shaped area of 9140 km2. Data were collected from a fixed-wing aircraft flown at mean terrain clearance of 120 meters (m) above topography along N-S flight lines spaced at 250 m intervals. Tie lines were flown in an E-W direction every 2500 m. Data were collected by EDCON-PRJ and NV5 Geospatial, 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 Crookston, Minnesota airport from May of 2021 to July of 2021. 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 the magnetic and radiometric survey and the report describing the survey and data reduction.