CGRG Bibliography of Canadian Geomorphology
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Author : Gilchrist, C.M.
Date : 1982
Title : The glacial geology of the southeastern area of the District of Keewatin, Northwest Territories, Canada
Publication : Unpublished Ph.D. thesis, University of Massachusetts, Boston
Issue :
Page(s) : 326 p
Abstract
The southeastern area of the District of Keewatin, Northwest Territories, Canada, was occupied by an early Wisconsin ice mass. Evidence for this conclusion (Shilts, Cunningham, and Kaszycki, 1979) includes the results of striation measurements, dispersal of interglacial sedimentary rocks and Paleozoic erratics from the Hudson Bay Basin, dispersal of erratics of Proterozoic Dubawnt Group 'Red Beds' from the Baker Lake area, and postulated rates of flows of ice masses. In later Wisconsin time, it was the site for the southeastern end of the Keewatin Ice Divide. Surficial geologic mapping of ice-flow features, glaciofluvial, glaciolacustrine, and glaciomarine deposits of NTS (Canada) map sheets 55D (Hyde Lake) and 65A (Edehon Lake) revealed that the southern end of the north-northeast-south-southwest-oriented Keewatin Ice Divide was oriented in an east-west direction redefined from Lee's (1959) initial Keewatin Ice Divide shape. This 'new' shape is attributed to calving generated by ice-dammed lakes and marine incursion of the Tyrrell Sea. Patterns of reticulate moraine laternate with ribbed moraine along the southern border of the Hyde Lake sheet. The latter describe the directions of ice flow and the former reflect till deposition in ice crevasses. The preservation of ribbed moraine and the presence of reticulate moraine indicate that the ice stagnated during the latter stages of Wisconsin glacial history in southeastern Keewatin. Overflow channels, spillways, meltwater channels, lacustrine raised beaches and deltas, and eskers indicate the positions occupied by former ice blocks. These erosional and depositional features are especially prominent in the south-central area and in the extreme west-central area of the Edehon Lake map sheet, and indicate that large fragments of the late-stage Keewatin Ice Divide were effective in damming lakes in these areas.
Bibliography of Canadian Geomorphology