 On the Manitoulin Island, the formation is dominated by limestone and dolomite.The formation is devoid of fossils in the uppermost shaly layers and is poorly fossiliferous throughout other parts, particularly, the bioclastic beds, where brachiopods, bryozoans, ostracodes, pelecypods, gastropods, tabulate corals and trilobites ("Acernaspis") are found.Ichnofossils are more common, represented by "Diplocraterion", "Skolithos" and "Chondrites".