Geologic units in Milwaukee county, Wisconsin

Additional scientific data in this geographic area

Silurian, undivided (Silurian) at surface, covers 82 % of this area

Dolomite, undivided; includes Cayugan, Niagaran, and Alexandrian series

Traverse Group (Middle Devonian) at surface, covers 18 % of this area

Traverse Group

Maquoketa Formation (Ordovician) at surface, covers 0.3 % of this area

Shale, dolomitic shale and dolomite; includes overlying Neda Formation (age uncertain) consisting of oolitic iron oxides and shale