MD-QDA characteristics of montane deposits and their confounding of the QDA-MD model for the discrimination of continental environments

Abstract

The Md-QDa domains of a range of continental deposits originating in a montane environment are derived. They indicate that the Buller-McManus model for environmental discrimination based on Md-QDa analysis lacks generality and is ambiguous to a large degree. This paper's conclusion that alluvial, colluvial and glacial materials are commonly indistinguishable on the basis of their Md-QDa associations cautions against the use of such methodology in the analysis of ancient sediments. Concentrations of the Md-QDa plots for gravel and silt beds about the diagonal of the Md-QDa space are interpreted as resulting from the peculiar nature of source materials for slope deposits in montane environments of the type studied and to the mass movement mode of transportation common to such regions.