a frost-shattered upper headwall
b abraded lower part of headwall, with slabs and chocks
c scree/talus slope
d lochans set amid moraine ridges
e outer terminal moraine from the small Loch Lomond Stadial glacier
f disputed "protalus rampart"
Chock marks on slabs below the Fiacaill Buttress
Talus slopes below Aladdin's Buttress
Panoramic view with Aladdin's Buttress in the centre
Coire an t-Sneachda
Audio tour (1-5 Mb downloads)
Introduction
On the corrie floor
Reconstructing the glacier
Age of the
moraines
Below the Fiacaill Buttress
Postglacial change
Rockfall
This is a classic example of a glacial corrie or cirque. In Gaelic, Coire an t-Sneachda is the 'corrie of the snows' and it deserves its title. The hollow is north facing and shaded from the sun. It receives large volumes of snow blown from the plateau when the winds swing to the southwest.
The long profile of the corrie is close to being logarithmic in its curvature, as the sketch below shows.
The corrie shows many typical features. The headwall (a) is a cliff. The structure of the granite controls the detail of the cliff face, with buttresses in areas of widely-spaced joints and gulleys and chimneys between, a diversity that has created many challenging climbs. This diversity also reflects glacial and periglacial activity, with intense frost-riving above the latest corrie glacier and plucking of the backwall behind the glacier. In the lower parts of the headwall (b), evidence of abrasion is seen. Here there are large, steeply inclined slabs with chock marks. The scree slope (c) has formed since the last glacier filled the back of the corrie - it continues to accumulate today, as shown by the blocks resting on late-lying snow banks and the hazard to climbers of rockfalls. The lochans (d) are ponded behind low moraines from the last glacier to occupy Coire an t-Sneachda. These moraines are 1-3 m high and composed on large granite blocks, largely derived from the headwall and carried on the surface of the glacier. The last glacier occupied the corrie during the Loch Lomond Stadial, between 11 and 10 thousand radiocarbon years ago.
