Stratified Slope Deposits of the Grèze-Litée Type in the Ardèche Region in the South of France

Abstract

In this article observations are made about the sedimentological and geomorphological character of a number of grèze-litée deposits in the Ardèche region in the south of France. There follows an interpretation of the way in which we think the sediments were deposited.The evidence points to an alternation of gelifluction, resulting in the deposition of layers with a well-developed matrix of material < 0.05 mm and sliding of coarse gelifracts over a snow cover or over some other low-resistance surface, leading to the formation of openwork layers. It has become clear to us that, contrary to the widely held view, slope wash or nivation can not have contributed much to the deposition of the grèzes litées, at least in the area of our research.Because it has been impossible to match these results fully with any of the existing hypotheses about grèze-litée formation, the article ends with a discussion in which our results are compared and contrasted with those of other authors.