CGRG Bibliography of Canadian Geomorphology
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Author : Bajc, A.F.
Date : 1992.
Title : Glacial and glaciolacustrine history of the Fort Frances-Rainy River area, Ontario, Canada.
Publication : Unpublished PhD dissertation. University of Waterloo, Waterloo.
Issue :
Page(s) :
Abstract
Quaternary deposits in the Fort Frances-Rainy River area were deposited by ice of both the Labradorean and Keewatin sectors of the Laurentide Ice Sheet. Up to 60 m of glacial drift, mainly of Late Wisconsinan age, overlies Cretaceous sediments and Archean supracrustal and granitic rocks. The remnants of Pre-Late Wisconsinan glacial advances from both Labradorean and Keewatin ice centres are represented by isolated occurrences of older, possibly weathered glacial till. Weathering probably occurred during a Sangamonian or Middle Wisconsinan non-glacial interval. Wood contained within Late-Wisconsinan, Labradorean-derived till (Whiteshell till) was radiocarbon dated at >47 410 years B.P. The wood was probably eroded from a Sangamonian Interglacial or a Middle Wisconsinan Interstadial deposit. Remnant deposits of older glacial lakes underlie Late Wisconsinan tills across the report area. These sediments were deposited in precursors to Glacial Lake Agassiz which fronted the advancing Late Wisconsinan ice sheets. Late Wisconsinan events began with an initial advance of Labradorean ice towards the southwest, and the deposition of stony, sandy Whiteshell till. Following the retreat of the Labradorean glacier to the Rainy Lake-Lake of the Woods Moraine, Keewatin ice advanced into the report area from the west and deposited stone-poor, clayey, Whitemouth Lake till. A late stage reactivation of the Keewatin glacier, following its retreat into the Lake Winnipeg basin, resulted in the deposition of the pebbly, sandy, Marchand till in the extreme southwestern corner of the report area. In low-lying areas, glaciolacustrine sedimentation accompanied and followed the deposition of these till sheets. Glaciolacustrine sediments were deposited during the Pre-Lockhart, Lockhart, and Emerson phases of Lake Agassiz; the latter two were separated by shallow water and terrestrial sedimentation of the Moorhead low-water phase. Surficial deposits of granular resources are restricted primarily to the Rainy Lake-Lake of the Woods Moraine. Buried deposits of Labradorean-derived ice-contact stratified drift and subaquatic fan deposits are concentrated within buried bedrock depressions in the area affected by the last Keewatin glaciation. Smaller reserves of low quality aggregates are found in isolated Keewatin-derived glaciofluvial deposits and littoral glaciolacustrine features throughout the area.
Bibliography of Canadian Geomorphology