Cape Storm Formation -- A New Silurian Unit in the Canadian Arctic

Abstract

ABSTRACT Cape Storm Formation is a new unit of limestone and dolomite that had earlier been included with the underlying Allen Bay Formation, or with an overlying formation -- either the Read Bay or the Douro. The type section is 8 mi east of Cape Storm on the south coast of Ellesmere Island, where the formation is 645 ft thick. The Cape Storm Formation is of Silurian age, late Llandoverian, Wenlockian, and early Ludlovian. At and near the type section, the Cape Storm Formation contains two members. The lower member is cliff-forming limestone, partly dolomitized; it is thickest along the south coast of Ellesmere Island, thinning and disappearing to the north. The upper member is thin-bedded dolomite and silty dolomite, grading upward to interbedded dolomite and limestone. The Cape Storm Formation has been mapped on southern Ellesmere Island, northwest Devon Island including Grinnell Peninsula, Cornwallis Island, and Griffith Island. The upper and lower contacts of the formation are conformable in all these areas, except for a narrow strip along western Grinnell Peninsula where the formation is unconformable on the Allen Bay Formation and Cornwallis Group.