Internal Structure of a relict rock glacier, Ślęża Massif, Southwest Poland

Abstract The sediments of a large accumulation landform, interpreted as one of six Pleistocene rock glaciers occurring in the Ślęża Massif, southwest Poland, are described. The sediments have been subject to strong compression and the main deformation mechanism is that of shearing. The similar angle of shear in sediments of extremely different lithology is inferred from the geometry of failure surfaces and indicates that ice was necessary for the debris transport. Because the geomorphological setting excludes a glacigenic origin, the sediments are interpreted to result from the creep of permafrost, i.e. the landform is a relict rock glacier. The movement of the rock glacier, at least in its terminal stage, is associated with a dense pattern of shear planes and would have occurred even in the presence of a small amount of interstitial ice. Copyright © 2002 John Wiley & Sons, Ltd.