CGRG Bibliography of Canadian Geomorphology
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Author : Barendregt, R.W.; Duk-Rodkin, A.; Enkin, R.E.; Baker, J.; Christiansen, E.;Naeser, N.D.; and Westgate, J.
Date : 2007.
Title : New Magnetostratigraphic Data from Central Saskatchewan and the Horton Plateau, Mackenzie District, NWT, Canada: evidence for Matuyama Chron glaciations in the Interior Plains of Canada.
Publication : Quaternary International
Issue : 167-168. Supplement 1 - INQUA 2007 Abstracts.
Page(s) : 23-24.
Abstract
Recent paleomagnetic measurements from oriented borecores and outcrops in the Saskatoon and Wascana Creek areas of Central Saskatchewan, and from outcrops in the Horton Plateau region of the Northwest Territories provide evidence for late Pliocene and Early Pleistocene (pre-Illinoian) continental glaciations. Evidence for pre-Brunhes (>0.78 Ma) glaciations in the southern Interior Plains of Canada has not been found. Earlier work in southern Alberta, southern Saskatchewan, and Northern Manitoba identified only normally magnetized (Brunhes Chron) glacial and Interglacial sediments. The Saskatchewan borecore data reveal two reversely magnetized lower tills (Mennon and Dundurn Formation) overlain by a sequence of 5 normally magnetized tills. Low carbonate content and elemental analyses suggest that the reversely magnetized tills were laid down by ice which moved predominantly from the north. Several outcrops of glacial sediments on the Horton Plateau northwest of Great Bear Lake were sampled for paleomagnetic analysis and provide the first evidence of reversely magnetized tills on the mainland of the northernmost Interior Plains. Four reversed tills overlain by two normal tills allow for a preliminary correlation with the Mackenzie Delta borecores, and taken together, these records indicate that continental ice was present in the northwestern Interior Plains in the early Matuyama, in contrast to the central Interior Plains of Canada where continental ice first appeared in the late Matuyama, and to the south where it was apparently absent entirely during the Matuyama. The early glaciations in the Horton Plateau region appear to have been locally sourced, as the tills do not contain Canadian Shield erratics. This, and the evidence for northern sources of ice for the earliest glaciations in the Saskatoon area suggest that continental ice sources were perhaps very different during the Matuyama, as compared to those of the Brunhes Chron. New data from both northern and central localities within the Interior Plains suggest that the timing, extent, and source of continental ice sheets varied considerably in the Interior Plains of Canada during the Quaternary.
Bibliography of Canadian Geomorphology