Quaternary ice transport in the Canadian Arctic and extent of Late Wisconsinan Glaciation in the Queen Elizabeth Islands

Abstract

Most of the ice-rafted debris in channels off the Queen Elizabeth Islands, Nunavut, is of local origin, particularly in the inner part of the archipelago, but samples from the Arctic shelf contain as much as 40% grains from sources as far away as 2000 km, including the Siberian shelves. Particle transport by drifting sea ice from distant shelves is an important process on the Arctic continental shelf of the Queen Elizabeth Islands. In the interior of the Queen Elizabeth Islands and in the Viscount Melville and Lancaster sounds, particle transport is limited to distances of approximately 200 km. Mixing is more common among grains of coarse silt to fine sand than in the >250 µm fraction, but even the latter contains debris from sources far apart. During the Late Wisconsinan, the northern, southern, and eastern Queen Elizabeth Islands were covered by glaciers flowing radially from ice centers on the islands into the inter-island channels. Queens Channel was completely filled by ice, and a glacier lobe moved north from an ice divide northwest of Devon Island to Peary Channel. This lobe redistributed crystalline and carbonate erratics that are derived in part from a strongly weathered and degraded till that was deposited by a pre-Late Wisconsinan glaciation, and in part from glacial erratics that were deposited below the marine limit by icebergs during the Late Wisconsin deglaciation. Tills from eastern Bathurst Island are locally derived and devoid of erratics, but submarine tills west of Bathurst Island contain crystalline erratics that could be from either the Canadian Shield or Victoria Island.