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The Whitemud Formation is a geologic formation of Late Cretaceous (Maastrichtian) age in the Western Canada Sedimentary Basin. Named by N.B. Davis in 1918,〔 it is present through the plains of southern Saskatchewan, southeastern Alberta and south-central Alberta. The formation is characterized by white kaolinitic clay and is a source of high-quality refractory clay.〔〔Lerbekmo, J.F. 1985. Magnetostratigraphic and biostratigraphic correlations of Maastrichtian to early Paleocene strata between south-central Alberta and southwestern Saskatchewan. Bulletin of Canadian Petroleum Geology, vol. 33, no. 2, p. 213-266.〕 The type locality has been designated as Dempster's clay pit northwest of Eastend, Saskatchewan.〔Kupsch, W.O. 1956. The Frenchman Formation of the eastern Cypress Hills, Saskatchewan. Geological Society of America Bulletin, vol. 6a, p. 413-420.〕 Although fossils are generally lacking in the Whitemud Formation, in southern Saskatchewan it contains coprolites (fossilized feces) and fossilized intestines of fish.〔 ==Lithology== In most areas the formation can be subdivided into three units: * Lower: Medium-grained arkosic and kaolinitic sandstones with trough cross-bedding. * Middle: Brown fissile carbonaceous shales and siltstones, with thin lignite beds. * Upper: Clays and siltstones, with some thinner, tabular units of simple and planar cross-bedded kaolinitic sandstones.〔〔Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. ISBN 0-920230-23-7.〕 In southwestern Alberta around the Red Deer and Oldman Rivers, the middle carbonaceous shale unit is absent and the formation consists of white-weathering, cross-bedded kaolinitic sandstones, interbedded with white- to cream-weathering silty and sandy clay.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Whitemud Formation」の詳細全文を読む スポンサード リンク
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