Geologic units in Muskegon county, Michigan

Marshall Sandstone (Mississippian) at surface, covers 59 % of this area

Marshall Sandstone

Michigan Formation (Mississippian) at surface, covers 35 % of this area

Michigan Formation

Coldwater Shale (Mississippian) at surface, covers 3 % of this area

Coldwater Shale

Bayport Limestone (Mississippian) at surface, covers 3 % of this area

Bayport Limestone