Airborne horizontal magnetic gradient and radiometric survey over parts of southeast Missouri, southern Illinois and western Kentucky - The Gap survey, 2021

This publication provides digital flight line data for a high-resolution horizontal magnetic gradient and radiometric survey over an area of southeast Missouri, southern Illinois, and western Kentucky. The survey was conducted in collaboration with the Missouri Geological Survey 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 [...]