Geologic units in Grayson county, Kentucky

Rocks of Chesterian age, lower part (Upper Mississippian) at surface, covers 38 % of this area

Rocks of Chesterian age, lower part

Caseyville Formation (Lower to Middle Pennsylvanian) at surface, covers 37 % of this area

Caseyville Formation

Rocks of Chesterian age, upper part (Upper Mississippian) at surface, covers 22 % of this area

Rocks of Chesterian age, upper part

Ste. Genevieve and St. Louis Limestones, undivided (Mississippian) at surface, covers 1 % of this area

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

Alluvium (Pleistocene to Holocene) at surface, covers 0.9 % of this area

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

Tradewater Formation (Middle Pennsylvanian) at surface, covers 0.2 % of this area

Tradewater Formation