Geologic units in Fulton county, Illinois

Carbondale Formation (Pennsylvanian (Moscovian to Kasimovian)) at surface, covers 56 % of this area

Carbondale Formation.

Tradewater Formation (Pennsylvanian (Bashkirian to Moscovian)) at surface, covers 34 % of this area

Tradewater Formation

Shelburn-Patoka Formations undivided (Pennsylvanian (Kasimovian)) at surface, covers 7 % of this area

Shelburn-Patoka Formations undivided.

St. Louis Limestone (Mississippian (Visean)) at surface, covers 2 % of this area

St. Louis Limestone.

Warsaw Formation and Salem Limestone (Mississippian (Visean)) at surface, covers 0.8 % of this area

Warsaw Formation and Salem Limestone in western Illinois.