CGRG Bibliography of Canadian Geomorphology
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Author : Harris, S.A.
Date : 1987
Title : Early Holocene climate and palaeogeography, High Plains, Alberta
Publication : Man and the Mid-Holocene Climatic Optimum. Edited by: N.A. Mckinnon and G.S.L. Stuart. Proceedings of the Seventeenth Annual Conference of the Archaeological Association of the University of Calgary. Nov. 10-12, 1984
Issue :
Page(s) : 33-51
Abstract
At 11,000 B.P. three main ice masses were present in Western Canada. The Cordilleran ice still covered much of British Columbia while the Laurentide ice had retreated to northern Saskatchewan. Extensive areas of stagnant ice occurred between eastern Alberta and North Dakota. The Laurentide ice cap modified the local weather by being the locus of a high pressure call that caused increased frequencies of upslope weather conditions on the High Plains of Alberta, resulting in enhanced precipitation. This caused expansion of some of the extensive stagnant ice masses to produce the ice advances parallel to the contours across the drainage. As a result, a series of proglacial lakes were developed that lasted until about 8,000B.P., when the ice cap disintegrated as Hudson Bay opened up. Even then, a subsequent minor readvance occurred. The Hypsithermal interval on the High Plains of Alberta was warmer than now, but initially the precipitation was very much higher. This resulted in lakes in kettle holes being deeper than today in active alluvial fans at the foot of slopes where no streams presently occur, and in frequent major colluvial events, burying soils at the bases of the valley walls. The presence of Mazama ash in the sediments throughout the area aids in checking the evidence from radiocarbon dates. A single cold spell may have occurred at about 8,800 B.P.producing sorting of gravels as patterned ground at Calgary. Shortly after the deposition of the Mazama ash, the climate of the high plains became cooler and drier. These changes were much greater that the climatic fluctuations associated with Neoglacial events.
Bibliography of Canadian Geomorphology