The Midwestern Basins and Arches regional aquifer system in parts of Indiana, Ohio, Michigan, and Illinois — Summary

The Midwestern Basins and Arches aquifer system is composed of surficial deposits of Pleistocene and Holocene age and of Silurian and Devonian age carbonate rock in parts of Indiana, Illinois, Michigan, and Ohio. The study area encompasses a complex of structural arches--the Cincinnati, Findlay, and Kankakee arches--and it is bounded on the east, north, and west by the Appalachian, Michigan, and Illinois basins, respectively. This report describes the hydrogeologic framework, hydrology, and geochemistry of the Midwestern Basins and Arches.