Debris Flows and Snow Avalanche Landforms in the Lairig Ghru, Cairngorm Mountains, Scotland

ABSTRACT

Snow avalanche landforms are identified at 22 sites in the Lairig Ghru based on morphology and distinctive surface sediment sorting patterns. Avalanche boulder tongues intermediate between fan and roadbank tongues occur at the Pools of Dee and larger, inactive roadbank tongues are described from Glen Luibeg. Two major recent debris flow events are identified in the valley and dated to 1961 and 1978. Contemporary morphological activity by avalanches is mainly associated with the reworking of debris flow deposits. Levées from one of the 1961 flows were completely bevelled over a 20 year period. These observations indicate snow avalanches are locally significant geomorphic agents in the Scottish mountains although the morphological evidence may be masked by more obvious debris flow or alluvial cone deposits which originate from similar source areas.