SUPERIOR, WI (AP)-- Researchers with the U.S. Geological Survey are leading two aerial surveys of
northern Wisconsin, Minnesota and Michigan in an effort to better define the geology of the Upper Midwest.
Wisconsin Public Radio reports that two geophysicists with the federal agency are using helicopters to conduct electromagnetic and magnetic surveys. Both surveys will map rocks down as far as 1,500 feet beneath the ground's surface.
The regions that will be surveyed include iron-rich areas where there's been renewed interest in mining.
The electromagnetic survey will map 100-mile lines from north to south to measure the electrical conductivity of rocks. The survey's range runs from the Twin Ports in Duluth, Minnesota, and Superior, Wisconsin, to Escanaba, Michigan.
Local governments will be able to use the data to guide land use decisions.
