Airborne magnetic and radiometric survey over northwest Arkansas, 2019-2020

This publication provides digital flight line data for a high-resolution magnetic and radiometric 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 kilometer over the transition between the Ouachita and Ozarks Plateau physiographic provinces and includes 67,614 line-kilometers of magnetic and radiometric data. Data were collected from a fixed-wing aircraft flown at mean terrain clearance of 167 meters (m) above topography along N-S flight lines spaced at 200-m intervals. Tie lines were flown in an E-W direction every 3000 m. Data 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 Branson, Missouri airport from October of 2019 to March of 2020. 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.