Mid-Wisconsinan eolian deposits of the Kittigazuit Formation, Tuktoyaktuk Coastlands, Northwest Territories, Canada

Abstract

The Kittigazuit Formation is a late Quaternary sand unit commonly observed throughout the Tuktoyaktuk Coastlands and in subbottom sediments of the southern Beaufort Shelf. Stratigraphic and sedimentology data, including sedimentary structures, grain-surface characteristics, and heavy and light mineralogy, assist in characterizing the deposit and indicate that it is eolian in origin. Plant and arthropod macrofossils suggest that, although the summer climate during deposition was as warm or slightly warmer than today, conditions were likely more arid. Permafrost is interpreted as being widespread during deposition. Accelerator mass spectrometry radiocarbon dates indicate that the Kittigazuit Formation was deposited between 37 and 33 ka BP. The unit is therefore interpreted as a Mid-Wisconsinan eolian dune deposit, formed by reworking of underlying alluvial sediments of the Kidluit Formation under nonglacial conditions. Glaciogenic sediments overlying the Kittigazuit Formation indicate that glacial ice covered the Tuktoyaktuk Peninsula, Richards Island, and parts of the Beaufort Shelf sometime after 33 ka BP, whereas several terrestrial dates indicate that the area may have been ice free by about 20 ka BP.