Geologic units in Presque Isle county, Michigan

Traverse Group (Middle Devonian) at surface, covers 66 % of this area

Traverse Group

Dundee Limestone (Middle Devonian) at surface, covers 22 % of this area

Dundee Limestone

Detroit River Group (Middle Devonian) at surface, covers 11 % of this area

Detroit River Group

Antrim Shale (Late Devonian) at surface, covers 0.2 % of this area

Antrim Shale

Bell Shale (Middle Devonian) at surface, covers < 0.1 % of this area

Bell Shale