• In this weeks lessons we will be investigating Glaciers and how they erode, transport and deposit material.

• By the end of today's lesson you will be able to describe how corries are created.

• Complete worksheet 19.1 from The New Wider World Resource Booklet.

How is a corrie formed?

Snow collects in a natural hollow on the side of a mountain. Over time, further snow collects in the hollow. This extra weight compresses the snow underneath, turning it into ice.

The hollow is deepened and widened by the corrie glacier through the processes of abrasion and plucking.

rock lip

This overdeepening leads to an ‘armchair’ shape characteristic of a corrie and causes a ‘rock lip’ to be formed.

Corrie formation

Diagram of a corrie

Explain the formation of a corrie

tarn

bowl-shaped corrie

steep backwall

Example of a corrie: Cwm Idwal

Drawing a fieldsketch of Cwm Idwal

Fieldsketch of Cwm Idwal looking south-west

tarn

steep backwall

fence

shattered rock

• Copy diagram D on p235 Foundation The New Wider World.

• Complete question 3 p248