Example of corries are Upper and Lower Lough Bray, Co. Wicklow, Coomshingaun, Co. Waterford and the Devils Punchbowl, Co. Kerry.


Corries are features of glacial erosion found in upland areas, usually on north or north-east facing slopes.   They are amphitheatre-shaped hollows consisting of three steep sides, including a high back wall, with a low-lying ‘lip’ facing down valley. Corries usually contain a lake called a tarn or corrie lake. Corries formed when snow gathered in a hollow on a mountain.  As the snow remained on the ground throughout the year, snow patch erosion occurred and caused the hollow to deepen.


Snow continued to gather in the hollow and compression caused it to turn into glacial ice called firn ice.  Over time, a deep, semi-circular glacier, called a cirque glacier, developed.  As snow continued to fall on the glacier, the added weight increased pressure at the rear of the glacier.  This pressure increased fiction at the base of the glacier and caused partial melting producing a thin film of water.  Rotational slip occurred causing the glacier to rotate out of the hollow.  A large crevasse, called a bergschrund, opened at the rear of the glacier as the ice tore away from the backwall.


Further snow falls caused the glacier to extend down valley.  Freeze-thaw action weathered material from the slopes surrounding the glacier. Plucking and abrasion continued to deepen the hollow.  Plucking is a glacial erosion process whereby rocks are plucked from the ground by the passing glacier.  Friction cracks form on the ground.  Meltwater pours into the cracks and freezes, thereby sticking to the base of the glacier.  As the glacier moves off, the rock is plucked out of the ground.  Abrasion occurs when the rocks imbedded in the glacier scrape the landscape, wearing it away in a sandpaper-like fashion.  Eventually the ice age ended and the glacier melted.  A large circular lake, drained by a small stream, was left in the hollow.