corrie

Scottish term for a steep-sided armchair-shaped hollow in the mountainside of a glaciated area. The weight and movement of the ice has ground out the bottom and worn back the sides. A corrie is open at the front, and its sides and back are formed of arêtes. There may be a small lake in the bottom, called a tarn.

A corrie is formed as follows: (1) snow accumulates in a hillside hollow (enlarging the hollow by nivation), and turns to ice; (2) the hollow is deepened by abrasion and plucking; (3) the ice in the corrie moves under the influence of gravity, deepening the hollow still further; (4) since the ice is at the foot of the hollow and moves more slowly, a rock lip (a ridge of solid rock) forms; (5) when the ice melts, a lake or tarn may be formed in the corrie. The steep back wall may be severely weathered by freeze–thaw weathering, providing material for further abrasion.