Conodonts from the Cape Clay Formation (Lower Ordovician), southern Devon Island, Arctic Archipelago

Abstract

As part of a program involving the Ordovician conodont faunas of southern Devon Island, Northwest Territories, 22 samples were processed from the Cape Clay Formation and lowest Nadlo Point Formation near Dundas Harbour. The Cape Clay Formation is 85 m thick and composed of bluff-forming mottled limestone and dolomitic limestone. A small but diverse conodont fauna of 229 elements was recovered in which 23 form and multielement species are represented. Several new taxa are described in open nomenclature, and multielement Utahconus? bassleri (Furnish) is discussed. The fauna is considered to represent Fauna C of the North American Midcontinent Faunal Province and is indicative of a late Tremadocian age. This fauna, in a unit with few macrofossils, indicates correlation of the Cape Clay Formation near Dundas Harbour with the upper Turner Cliffs Formation of the Foxe Basin, with the upper Copes Bay and (or) lower Baumann Fiord formations of Cornwallis, northwest Devon, and Ellesmere Islands of the Canadian Arctic, and with some portion of Ross–Hintze trilobite Zones A – lower D of the Great Basin.