Squaw Bay Limestone

Squaw Bay Limestone (referred to as the Traverse Formation in older literature) is a geologic formation in Michigan. It is a part of the Traverse Group, which preserves fossils dating to the Middle to Late Devonian. It is the uppermost formation in the group, overlying the Thunder Bay Limestone and underlying the Antrim shale. It preserves a marine environment in the last section of the area's transition from an oxygen-rich shallow carbonate platform to an oxygen-poor deep sea floor. Though most well known for the diversity of conodonts, the formation also contains fossils from other groups such as cephalopods and brachiopods.