CGRG Bibliography of Canadian Geomorphology
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Author : Ford, D.C.; Thompson, P.; and Schwarcz, H.P
Date : 1972
Title : Dating cave calcite deposits by the uranium disequilibrium method: some preliminary results from Crowsnest Pass, Alberta
Publication : Research Methods in Pleistocene Geomorphology; Proceedings of 2nd Symposium on Geomorphology; Summer 1971, Guelph, Ontario, Canada: Guelph University Publication
Issue :
Page(s) : 247-255
Abstract
Uranium trapped within a calcite deposit is a potential clock, recording the time elapsed since precipitation by measurable radioactive decay. Specimens of ancient or recent calcite were taken from eight caves in the Canadian Rockies and the modern uranium ion concentrations were measured in underground stream and percolation waters. The calcite specimens were deposited in phreatic cave sites which were air-filled when net deposition began. Dating and hydrogeological interpretation of the dates suggest that at least 2,600 feet (or 63%) of the present relief existed 275,000 years ago; 90% of the relief existed at 200,000 years b.p., before the onset of the penultimate glacial. Since that time the valleys have been lowered by no more than 400 feet. The mean rate of lowering for the past 200,000 years is 2 feet per thousand years or somewhat less
Bibliography of Canadian Geomorphology