Corrie

Corrie Formation

Corries form when snow gathers in a small hole or hollow in the ground high up on a mountain. The snow does not melt but gets thicker and thicker each year and after hundreds of years it turns to ice. This is a glacier. The glacier will become too big for the hollow and will start to move down the hill. When this happens, it sticks to the back of the hollow and plucking takes place. This makes the back of the hollow very steep.

The rocks under the ice wear away the rocks on the bottom of the hollow. This is abrasion. This means that the hollow becomes deeper. When the ice melts, a very deep hollow with three steep sides is left.

Sometimes the hollow fills with water and makes a lake. This deep hollow is called a corrie, and the lake is called a tarn.

Formation of a corrie - simplified (you will need diagrams to accompany this note)

1. Snow gathers in a hollow and does not melt. This is the start of a glacier.
3. At the back of the hollow the ice sticks to the rocks and plucking occurs.
2. The glacier gets too big for the hollow and starts to move down the mountain.
4. At the bottom of the hollow the rocks in the ice rub against the rocks in the hollow. This is abrasion.
5. When the ice melts, a deep hollow called a corrie is left behind. It often fills with water and a tarn is made.

http://www.scalloway.org.uk/phyl13.htm - has good diagrams to show what a corrie looks like.

Type corrie into google images to see actual pictures.