Quaternary geology of part of the Kale Water catchment, Western Cheviot Hills, southern Scotland

Abstract

Synopsis This study reports on a survey of the middle part of the Kale Water, one of the western Cheviot catchments. Field mapping has revealed the presence of weathered andesite bedrock on many hillslopes. Conversely, evidence for glaciation is limited and restricted to a few exposures of till and meltwater channels suggesting that the last (Late Devensian) ice sheet in this area was cold-based, creating a frozen patch that lay to the east of a thermal boundary related to the Tweed ice stream. A well developed solifluction sheet is found on the lower valley slopes, indicating remobilization of former glacial sediments under periglacial conditions when head formed on the upper slopes. A particular feature is the presence of stratified fine gravels forming an upper lithofacies on many hillslopes which appear to be due to reworking of weathered material. Although there has been no dating of these sediments, it is suggested that the upper part of the sequence dates from Late Devensian deglaciation with the soliflucted sediments related to periglacial processes and paraglacial adjustment in association with permafrost degradation at the end of the Dimlington Stadial, and the stratified gravels related to fluvio-nivational processes associated with snowmelt during the subsequent Loch Lomond Stadial.