Geologic units in Jackson county, Indiana

Borden Group (Mississippian) at surface, covers 76 % 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

New Albany Shale (Devonian-Mississippian) at surface, covers 20 % of this area

Black and greenish-gray shale

Sanders Group (Mississippian) at surface, covers 3 % of this area

Mostly skeletal limestone, cherty in lower part

Muscatatuck Group (Devonian) at surface, covers 1 % of this area

Limestone and dolomite