Preliminary Map of the Bedrock Geology of the Southern Half of the Bloomington 30- x 60-Minute Quadrangle Map

Abstract

The Preliminary Map of the Bedrock Geology of the Southern Half of the Bloomington 30- x 60-minute Quadrangle shows Pennsylvanian and Mississippian bedrock units distributed over six counties. The mapped area includes six physiographic provinces within the Southern Hills and Lowlands Region in south-central Indiana. Bedrock units were characterized with the use of field observations (outcrops) and new and archived borehole data. All bedrock data was consolidated into a single mapping database which was then processed using gridding contour tools contained within ArcGIS Pro, resulting in rock formation contact lines, mappable at 1:100,000 scale. The mapped bedrock units generally strike from northeast to the southwest and range in age from the lower Mississippian (the Borden Group) to the lower Pennsylvanian (Raccoon Creek Group). The map contains brief summaries of all mapped bedrock units, bedrock survey drill hole data points, field observation data points, and a cross section.  

This geologic map was funded in part through the STATEMAP program supported by the U.S. Geological Survey under Cooperative Agreement No. G23AC00406.