LUMINESCENCE DATING OF CLIMATE-SENSITIVE SEDIMENTS IN YUKON

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In the Canadian North, the most economically and socially threatening impact of Global Warming in centuries to come will be the degradation of permafrost. Yukon is known to host sedimentary archives that could be used to interpret past sensitivity of physical environments to climate change. Among those, fossil ice wedges are probably the most spectacular witnesses of past climate conditions. Loess, glaciers as well as glacial deposits indicators of former ice limits are part of a continuum of paleoclimate proxies that are unique to Yukon. Past climate processes are nonetheless obscured by the poorly constrained geological age of these features. This research proposal is focused on the development of a universal luminescence dating method for feldspar minerals. The objectives and methodology herein require a large part of this research would benefit from being carried out in Yukon. Luminescence phenomenology will be tested on modern sediments, as those found in the St. Elias Mountains Ice Field Ranges of Southern Yukon, more specifically near the marginal environments of two waning glaciers (Kaskawulsh and Lowell). Research will also be conducted on the dating of detrital debris in fossil ice wedges in order to test ideas about the ages of some of these periglacial features. Finally, dating loess at former ice limits will contribute to better understand the glacial and paleoclimate history of Yukon. This research program should contribute to evaluate the stability of permafrost across the Quaternary. The integration of research and Traditional Knowledge is key to elaborate better solutions to secure health and social serenity in a world that will never be the same.