Processes of glacial deposition - Deformation

Question 1

When does deformation occur?

Answer 1

Deformation occurs when material beneath or in front of a glacier is unable to resist the glacier’s force.

Question 2

How is weak rock or pre-existing till deformed?

Answer 2

Weak rock or pre-existing till is deformed by the pressures exerted by moving ice and incorporated within the basal layer and then released from the ice.

Question 3

Give some of the deformation structures which the tills exhibit?

Answer 3

The tills exhibit various deformation structures such as folds and shears (these are called glaciotectonic structures).