Geologic units in Simpson county, Kentucky

Ste. Genevieve and St. Louis Limestones, undivided (Mississippian) at surface, covers 92 % of this area

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

Salem, Warsaw, and Harrodsburg Limestones, undivided (Mississippian) at surface, covers 4 % of this area

Salem, Warsaw, and Harrodsburg Limestones, undivided

Rocks of Chesterian age, lower part (Upper Mississippian) at surface, covers 2 % of this area

Rocks of Chesterian age, lower part

Alluvium (Pleistocene to Holocene) at surface, covers 2 % of this area

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

St. Louis Limestone and Warsaw Limestone (Mississippian) at surface, covers < 0.1 % of this area

St. Louis Limestone - Fine-grained, brownish-gray limestone, dolomitic and cherty. Thickness 100 to 280 feet; and Warsaw Limestone - Coarse-grained, gray, crossbedded limestone; somewhat shaly in the northeast. Thickness 40 to 150 feet.