CGRG Bibliography of Canadian Geomorphology
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Author : Day, D.L.
Date : 1971
Title : The glacial geomorphology of the Trout Creek area, Porcupine Hills, Alberta
Publication : Unpublished M.Sc. thesis, University of Calgary, Calgary
Issue :
Page(s) : 158 p
Abstract
This study is an examination of the glacial geomorphology of the Trout Creek drainage basin of the Porcupine Hills, west of Claresholm, Alberta. There is evidence for two Laurentide ice advances into the area based on the distribution of tills and erratics, and the results of field and laboratory analyses. During the retreat of the latest ice sheet, lacustrine sediments were deposited in the valley of Trout Creek between 4,200 and 4,300 feet a.s.l., and along the eastern edge of the Porcupine Hills. Till and lacustrine sediments have been largely dissected or reworked during the postglacial. The earlier glaciation reached a minimum elevation of 5,700 feet a.s.l., and till deposited by this ice sheet is a westerly extension of the Basal till, reported by Horberg (1952a) to have terminated near Lethbridge, Alberta. Radiocarbon dates reported by Stalker (in Dyck, Fylesand Blake, 1965) indicate that this advance predated the Classical Wisconsin. Til1 deposited during the more recent advance is found to 4,820 feet a.s.l., and is correlated with the Lower till mapped by Horberg (1952a) to the southeast of the study area. No absolute age has been determined for this advance, although Stalker reported an age of 9,260±260 years B.P. (Dyck,Fyles and Blake, 1965) for postglacial mollusca near Stavely, Alberta. The tills can be differentiated on the basis of results of field and laboratory analyses,These included analysis of the pebble orientations, dry colour, grain size distributions, carbonate contents, pebble lithohogies, and heavy mineral contents of till samples.The initial ground moraine surface of the more recent till has been subsequently modified by the combined effects of fluvial and slope erosion. Prior to the incision of the streams into deposits of till and lacustrine sediments, a series of laterally heterogeneous silts were deposited in the valleys. A description of these silts parallels that given by Horberg(1952a) for the Lenzie silts. Erosional terraces along Trout, Lyndon and Cripple Creeks maybe related to the levels of proglacial lakes subsequently trapped between the Porcupine Hillsand the receding ice sheet. Colluviation has been the major factor in slope reduction sincethe retreat of the ice sheets from the study area.
Bibliography of Canadian Geomorphology