Thunder Bay Limestone

Thunder Bay Limestone Stratigraphic range: Middle Devonian
Type	Formation
Unit of	Traverse Group
Sub-units	Partidge Point Member, Potter Farm Member, and Norway Point Member
Underlies	Kettle Point Formation and Squaw Bay Limestone
Overlies	Alpena Limestone
Location
Region	Michigan
Country	United States

The Thunder Bay Limestone is a geologic formation in Michigan. It preserves fossils dating back to the Devonian period.