Geologic units in Barry county, Michigan

Michigan Formation (Mississippian) at surface, covers 47 % of this area

Michigan Formation

Marshall Sandstone (Mississippian) at surface, covers 36 % of this area

Marshall Sandstone

Coldwater Shale (Mississippian) at surface, covers 9 % of this area

Coldwater Shale

Bayport Limestone (Mississippian) at surface, covers 4 % of this area

Bayport Limestone

Saginaw Formation (Pennsylvanian) at surface, covers 3 % of this area

Saginaw Formation