Geologic units in Wabash county, Illinois

Mattoon Formation (Pennsylvanian (Kasimovian)) at surface, covers 64 % of this area

Mattoon Formation.

Bond Formation (Pennsylvanian (Kasimovian)) at surface, covers 35 % of this area

Bond Formation

Bond Formation (Pennsylvanian) at surface, covers 0.3 % of this area

Mostly shale and sandstone; also includes thin beds of limestone and coal

Mattoon Formation (Pennsylvanian) at surface, covers 0.1 % of this area

Mostly shale and sandstone; also includes thin beds of coal

Patoka and Shelburn Formations (Pennsylvanian) at surface, covers < 0.1 % of this area

Mostly shale and sandstone; also includes thin beds of limestone and coal. WF, top of West Franklin member