Airborne magnetic and radiometric survey, northwestern Minnesota, 2021

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.