Geologic units in Cumberland county, Illinois

Mattoon Formation (Pennsylvanian (Kasimovian)) at surface, covers 91 % of this area

Mattoon Formation.

Bond Formation (Pennsylvanian (Kasimovian)) at surface, covers 7 % of this area

Bond Formation

Shelburn-Patoka Formations undivided (Pennsylvanian (Kasimovian)) at surface, covers 2 % of this area

Shelburn-Patoka Formations undivided.