CGRG Bibliography of Canadian Geomorphology
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Author : Duk-Rodkin, A.; and Huntley, D.
Date : 2007.
Title : -Late Quaternary glacial history of the southern Mackenzie region, Canada.
Publication : CANQUA Ottawa 2007. Canadian Quaternary Association Conference, June 4-8, 2007. Carleton University, Ottawa, Ontario, Canada.
Issue :
Page(s) :
Abstract
The southern Mackenzie Mountains region has a complex glacial history within the Canadian Cordillera. It is in this region where ice masses from several different sources coalesce: the Laurentide Ice Sheet, the Cordilleran Ice Sheet and local montane ice caps. The continental ice sheet (Laurentide) advanced over the foothills and up major valleys before mountain glaciers reached their maximum, or during their initial stages of development (ca. 30 ka). Stratigraphic and geomorphic evidence indicates that Laurentide ice advanced west and northwest over the foothills and up major valleys ahead of any local montane or Cordilleran ice. Large ice-dammed lakes formed in valleys such as the South Nahanni River; and Canadian Shield-derived erratic boulders, deposited by Laurentide ice, are found over 100 km west of the mountain front. Coalescence of the two ice sheets and montane glaciers led to buttressing and thickening of the regional ice cover up to 1820 m elevation in the south-eastern Mackenzie Mountains. Stratigraphic evidence indicates that Cordilleran and montane ice advanced short distances eastward overtopping continental glacial deposits. Ice-dammed lakes once again re-formed in valleys between the retreating ice masses. This pattern of glaciation is similarly reflected in late Pleistocene stratigraphic records from the northern Mackenzie Mountains. However, while areas north of the 64th parallel have an excellent pre-Late and Late Pleistocene records, southern areas only preserve widespread geomorphic and stratigraphic evidence of the last glaciation. Evidence of older glaciations is scant and locally preserved, in montane valleys in the North Nahanni and Root River watersheds; and in old cirques in the Dahadinni Range, that were later infilled with continental sediments during the last glaciation.
Bibliography of Canadian Geomorphology