Geologic units in Rush county, Indiana

Louisville Limestone through Brassfield Limestone (Silurian) at surface, covers 50 % of this area

Sexton Creek Limestone at base in Kentland area and on cross-section

Muscatatuck Group (Devonian) at surface, covers 35 % of this area

Limestone and dolomite

Whitewater Formation (Ordovician) at surface, covers 11 % of this area

Skeletal limestone and calcareous shale; dolomitic mudstone (S, Saluda Member) at base

Dillsboro Formation (Ordovician) at surface, covers 2 % of this area

Skeletal limestone and calcareous shale

Pleasant Mills Formation (Silurian) at surface, covers 2 % of this area

Dolomite, limestone, and argillaceous dolomite