Geologic units in Benton county, Indiana

Borden Group (Mississippian) at surface, covers 81 % 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 18 % of this area

Black and greenish-gray shale

Raccoon Creek Group (Pennsylvanian) at surface, covers 0.5 % of this area

Mostly shale and sandstone; also includes thin beds of limestone, clay, and coal. B, Buffaloville Coal Member; LB, Lower Block Coal Member

Muscatatuck Group (Devonian) at surface, covers 0.3 % of this area

Limestone and dolomite

Borden Siltstone (Mississippian (Tourniaisian to Visean)) at surface, covers < 0.1 % of this area

Borden Siltstone, includes Chouteau Limestone in east-central Illinois.