Geologic units in Lawrence county, Illinois

Modesto Formation (Pennsylvanian) at surface, covers 5 % of this area: Modesto Formation
Lithology: shale; sandstone; limestone; clay or mud; coal; black shale
Bond Formation (Pennsylvanian) at surface, covers < 0.1 % of this area: Bond Formation - Mostly shale and sandstone; also includes thin beds of limestone and coal
Lithology: shale; sandstone; limestone; coal
Patoka and Shelburn Formations (Pennsylvanian) at surface, covers < 0.1 % of this area: Patoka and Shelburn Formations - Mostly shale and sandstone; also includes thin beds of limestone and coal. WF, top of West Franklin member
Lithology: shale; sandstone; limestone; coal
Bond Formation (Pennsylvanian) at surface, covers 63 % of this area: Bond Formation
Lithology: limestone; shale; sandstone; clay or mud; coal; black shale
Mattoon Formation (Pennsylvanian) at surface, covers 32 % of this area: Mattoon Formation
Lithology: shale; sandstone; limestone; coal; black shale