CGRG Bibliography of Canadian Geomorphology
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Author : Berg, T.E.
Date : 1966.
Title : Pleistocene climatic conditions from fossil sand wedges at Edmonton, Alberta, Canada
Publication : Abstracts of the Program of the 79th Annual Meeting of the Geological Society of America
Issue :
Page(s) : p. 15
Abstract
Fossil wedges filled with clean, round, well-sorted quartz sand are exposed in a gravel pit 3 miles east of Edmonton. The wedges are at the top of 15-20 feet of dirty, stratified, fluvial quartz sands with interbedded quartzite gravels, preglacial in age, and overlain by 10 to 15 feet of till of classical Wisconsin age that is in turn overlain by 3 to 5 feet of lake sediments. The wedges are 40 to 100 cm wide and 80 to 160 cm high. The wedges appear to be true fossil ice wedge casts filled with sand because of: (1) the presence of vertical lineations in the sand filling; (2) numerous small veins filled with sand at the base of the wedge; (3) the absence of any till or slump structures in the sand fillings. Active sand wedges have been reported only from Victoria land, ntarctica. If similar growth rates and climate are assumed, then permafrost was present for 500 to 2000 years before the classical Wisconsin ice advanced into the area. Precipitation was similar to the present (15"/year) or less, and the average annual temperature was at least 3-5°C colder than now.
Bibliography of Canadian Geomorphology