Geologic units in Ohio county, Indiana

Dillsboro Formation (Ordovician) at surface, covers 74 % of this area

Skeletal limestone and calcareous shale

Kope Formation (Ordovician) at surface, covers 26 % of this area

Shale and thin skeletal limestone

Garrard Siltstone and Kope and Clays Ferry Formations, undivided (Ordovician) at surface, covers < 0.1 % of this area

Garrard Siltstone and Kope and Clays Ferry Formations, undivided