CGRG Bibliography of Canadian Geomorphology
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Author : Bruneau, H.C.
Date : 1984.
Title : L'evolution post-glaciaire du secteur aval de la riviere Coppermine, Territoires du Nord-Ouest
Publication : Unpublished M.A. thesis. University of Ottawa, Ottawa, Ont.
Issue :
Page(s) : 201 p.
Abstract
The study of the nature and distribution of surficial deposits in the lower course of the Coppermine River elucidates the relationship between the resumption of northward flow of the Coppermine River and a postglacial sea level at 170 m a.s.1. Systematic mapping of the surficial deposits at a scale of 1:100,000 and the lithostratigraphic analysis of sections found mainly along the Coppermine River have made it possible to delimit a series of generally coarse-grained deltas which interfinger with glacial and fluvioglacial deposits in the southern part of the area and with marine nearshore and offshore deposits in the northern part of the area. These deltas trace the postglacial sea regression from a maximum of 170 m a.s.l. The coarsening-upward sequence observed in the sections is typical of an offlap marine phase. The C14 dates suggest a minimum age of 10,200 B.P. for the postglacial marine transgression. Isostatic rebound, responsible forthe marine regression, is also the triggering mechanism responsible for the unpaired terraces formed by the downcutting and laterally eroding Coppermine River. The influence of permafrost on the progressively emerging lands is mainly marked by the abundance of solifluction lobes and the presence of numerous thermokarst lakes. The study of the surficial deposits then pieces together the postglacial history of the area and underlines the important role played by the ice retreat, the marine incursion and isostatic rebound on the distribution of these deposits. This thesis contributes significantly to our understanding of a little-studied area, the north central District of Mackenzie, in the Northwest Territories.(
Bibliography of Canadian Geomorphology