Global climatic changes affect polar regions, specifically the arctic,in disproportionately large ways, producing substantial variations inthe extent of terrestrial and marine ice sheets, of sea ice, and ofocean temperatures. These variations have not only occurred overgeologic time scales, but are thought to occur over much shorter timescales in response to the varying carbon dioxide content of theatmosphere, as an example. Understanding the responses of major ice sheets to the climaticchanges that have occurred is one of the primary objectives of marinepaleoenvironmental research. Such understanding is based on thedetailed study of the sedimentation history of the region, whichincludes the location of ancient and modern sediment pathways, theexamination of closely spaced samples from high quality sedimentcores, and the regional correlation of environmental events. This project will apply these techniques in a study of the extent andtiming of the decay of the northern hemisphere pleistocene ice sheet. The deglaciation of the high Canadian Arctic is quite speculative atthis time. Hypotheses that have been advanced range from the areabeing ice-free to being covered by the Innuitian Ice Sheet which hadmerged with the Greenland Ice Sheet to the east, and the LaurentideIce Sheet to the south. The key to resolving this question lies inidentifying a tracer that may be unambiguously related to advances andretreats of an actual ice sheet. This project will examine theoccurrences of high coarse-fraction abundance in selected sedimentsamples (indicative of general deglaciation) in conjunction withkaolinite-rich layers (indicative of a Queen Elizabeth Islands sourceregion). A detailed Carbon-14 analysis program will provide a precisetime scale.
