Summit of Lurcher's Crag, a glacially-disturbed block slope
Clach Choutsaich, Ben Avon. Tor and regolith.
Periglacial landforms of the plateau
At least three generations of periglacial feature exist on the Cairngorm plateau:
- features active today or earlier in the Holocene
- features formed under intensely cold conditions during the Loch Lomond Stadial and the early phases of deglaciation
- features inherited from phases of periglacial activity prior to the last ice sheet
Permafrost conditions are absent from the Cairngorm plateau today and the active forms reflect a prevailing environment of high wind speeds, heavy but now short-lived snowfalls, high ground moisture levels, except in high summer, and frequent freeze thaw cycles. The relict forms reflect, at least in part, more severe periglacial conditions when permafrost was widespread, if not continuous. The former presence of permafrost allowed heave processes to operate to the base of the former active layer, thereby allowing much bigger blocks to move than is currently possible.
regolith
solifluction
ploughing blocks
