On the Pleistocene palaeoenvironmental evidence from the Amatola screes : research letter

Relict openwork scree deposits in the Amatola Mountains in the Eastern Cape, South Africa, have previously been attributed to frost action and nival activity predominating on south-facing slopes. The data have been used as representing the minimum snow-line for the area and hence as supporting evidence for constructing a Pleistocene periglacial gradient for the subcontinent. A geomorphological re-examination of the deposits, however, does not support an origin specifically associated with enhanced periglacial activity above a minimum altitude on south-facing slopes. The spatial distribution is attributed to lithological and topographical control and the openwork block deposits were found to be remnants of scree slopes, formed irrespective of slope aspect orientation, which were subsequently infilled by fines. Although block production appears concurrent with that found at other high-altitude sites in southern Africa during the colder Late Pleistocene, specific palaeoenvironmental conditions such as the presence of late-lying snow and enhanced frost action processes on south-facing slopes cannot be inferred.