Geologic units in Crawford county, Illinois

Bond Formation (Pennsylvanian (Kasimovian)) at surface, covers 51 % of this area

Bond Formation

Mattoon Formation (Pennsylvanian (Kasimovian)) at surface, covers 41 % of this area

Mattoon Formation.

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

Shelburn-Patoka Formations undivided.

Bond Formation (Pennsylvanian) at surface, covers 0.4 % of this area

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

Patoka and Shelburn Formations (Pennsylvanian) at surface, covers 0.2 % of this area

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