Geologic units in Chippewa county, Michigan

Jacobsville Sandstone (Middle Proterozoic) at surface, covers 16 % of this area

Red, brown, and white quartzose sandstone, and minor siltstone, shale and conglomerate

Black River Limestone (Late Ordovician) at surface, covers 12 % of this area

Black River Limestone

Trenton Limestone (Late Ordovician) at surface, covers 9 % of this area

Trenton Limestone

Munising Formation (Late Cambrian) at surface, covers 9 % of this area

Munising Formation

Engadine Dolomite (Early Silurian) at surface, covers 8 % of this area

Engadine Dolomite

Stonington Formation (Late Ordovician) at surface, covers 8 % of this area

Stonington Formation

Utica Shale (Late Ordovician) at surface, covers 7 % of this area

Utica Shale

Prairie du Chien Group (Early Ordovician) at surface, covers 6 % of this area

Prairie du Chien Group

Manistique Formation (Early Silurian) at surface, covers 6 % of this area

Manistique Formation

Burnt Bluff Formation (Early Silurian) at surface, covers 5 % of this area

Burnt Bluff Formation

Big Hill Dolomite (Late Ordovician) at surface, covers 5 % of this area

Big Hill Dolomite

Queenston Shale (Late Ordovician) at surface, covers 4 % of this area

Queenston Shale

Cataract Formation (Early Silurian) at surface, covers 3 % of this area

Cataract Formation

Collingwood Limestone (Late Ordovician) at surface, covers 2 % of this area

Collingwood Limestone

Trempealeau Formation (Late Cambrian) at surface, covers < 0.1 % of this area

Trempealeau Formation

Menominee Group; Emperor Volcanic Complex (Early Proterozoic) at surface, covers < 0.1 % of this area

Metamorphosed intermediate to mafic pyroclastic and flow rocks in easternmost part of Gogebic Range