ABSTRACT: Summary of Quaternary stratigraphy and history, western Canada

CGRG Bibliography of Canadian Geomorphology
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Abstract

Five major Quaternary events on the Canadian Prairies are of early or middle Pleistocene age - PW event, Wellsch Nongiacial Interval, Wascana Nonglacial Interval, Redcliff Nonglacial Interval, and Dunmore Glaciation - and four are of late Pleistocene age - Osler Nonglacial Interval, Burke L ake Glaciation, Watino Nonglacial Interval, and Lostwood Glaciation. The PW Event during which one or more early Pleistocene Laurentide glaciation(s) occurred that were responsible for transporting south the Precambrian stones found in the nonglacial sediment at Wellsch valley, was followed by the Wellsch Nonglacial Interval. Both events occurred during the Matuyama Reversed Magnetic Epoch and the nonglacial interval probably occurred at least in part during the Olduvai Event. The glaciation following the Wellsch Nonglacial Interval possibly was responsible for deposition of one or more tills of the Floral Formation and Sutherland Group. A lack of lithostratigraphic data at the Wellsch Valley site makes correlation between these units tentative. The Wascana nonglacial of Aftonian age is about 600+40 ka, based on fission track dating of volcanic ash. During the Redcliff Nonglcial Interval, which is late Kansan to Yarmouthian, the lower group of sediments in the Medicine Hat area were deposited. During the Dunmore Glaciation of Illinoian(?) age, two or more tills were deposited in the Miedicine Hat area. This was the most extensive glaciation to affect the Prairies with one advance extending to the eastern slopes of the Rocky Miountains in southwestern Alberta.The Osler Nonglacial Interval of Sangamonian age, Burke Lake Glaciation of Early Wisconsinan age, and Watino Nonglacial Interval of Middle Wisconsinan age have all been recognized at a number of places on the Prairies. Lostwood Glaciation of Late Wisconsinan age followed, resulting in ice covering most of the Prairies. The chronology for pre-Watino events is derived from correlation with events outside the Prairies, fission track age dates, or speculation. The chronology for younger events is based on radiocarbon dates. Watino Nonglacial Interval started before 43.5 ka. and perhaps before 52 ka. and ended after 23.7 ka. The succeeding Lostwood Glaciation reached its maximum between about 20 and 18 ka ago and ice had completely retreated from the Prairiesby about 10 ka.

Bibliography of Canadian Geomorphology