CGRG Bibliography of Canadian Geomorphology
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Author : Fisher, T.G. and Spooner, I. S.
Date : 1994
Title : Subglacial and subaerial meltwater origins for drumlins near Morley, Alberta, Canada.
Publication : Sedimentary Geology
Issue : 91(1-4):
Page(s) : 285-298
Abstract
Drumlins in the Bow valley west of Calgary, Alberta, are interpreted as the product of subglacial and subaerial meltwater erosion. On the sides of the Bow valley highly elongated, streamlined, first-generation drumlins are aligned in an en-echelon fashion and are not significantly modified by post-glacial processes. In the valley bottom, scalloped, stubby, irregularly spaced second-generation drumlins are found in close association with valley fill. The drumlins are composed of bedrock and diamicton, and some are overlain by a thin gravel veneer. Stratified gravel is found on the leeward flanks of some second-generation drumlins. Meltwater erosional forms (s-forms) found on the limestone bedrock up-flow of the drumlins, and crescentic furrows around their proximal ends, indicate that subglacial meltwater beneath the Bow valley ice was probably the main erosive agent responsible for the shaping of the drumlins. The second-generation drumlins are believed to be the remnants of the first-generation drumlins that were dissected and reworked by postglacial, subaerial meltwater flow(s). Meltwater drainage from ice-dammed glacial Lake Kananaskis and possibly other glacially dammed tributary valley lakes, resulted in the deposition of megaripples (3.5 m high, 40 m wavelength) 8 km down-flow from the drumlins and reverse eddy deposits on the flanks of the drumlins. Post-glacial Bow River incision and terrace development has continued to further sculpt these forms.
Bibliography of Canadian Geomorphology