Geologic units in Harrison county, Indiana

Blue River Group (Mississippian) at surface, covers 75 % of this area

Mostly micritic, skeletal, and oolitic limestone

Sanders Group (Mississippian) at surface, covers 12 % of this area

Mostly skeletal limestone, cherty in lower part

West Baden Group (Mississippian) at surface, covers 8 % of this area

Shale, sandstone, and micritic and skeletal limestone

Borden Group (Mississippian) at surface, covers 4 % of this area

Mostly siltstone; lenses of crinodial limestone in upper part. Much cherty and silty limestone and dolomite in northwest. NP, top of New Providence Shale

Stephensport Group (Mississippian) at surface, covers 1 % of this area

Sandstone, micritic and skeletal limestone, and shale

Glacial deposits, undifferentiated (Pleistocene to Holocene) at surface, covers < 0.1 % of this area

Glacial deposits, undifferentiated; shown locally

Ste. Genevieve and St. Louis Limestones, undivided (Mississippian) at surface, covers < 0.1 % of this area

Ste. Genevieve and St. Louis Limestones, undivided; includes Salem Limestone west of Christian County

Alluvium (Pleistocene to Holocene) at surface, covers < 0.1 % of this area

Alluvium; includes glacial deposits along the Ohio River and its tributaries west of Cannelton locks