Geologic units in Benzie county, Michigan

Ellsworth Shale (Late Devonian) at surface, covers 39 % of this area

Ellsworth Shale

Antrim Shale (Late Devonian) at surface, covers 31 % of this area

Antrim Shale

Traverse Group (Middle Devonian) at surface, covers 30 % of this area

Traverse Group

Coldwater Shale (Mississippian) at surface, covers 0.4 % of this area

Coldwater Shale