Glacial processes

Question 1

Abrasion

Answer 1

Material which rubs against the valley floor which acts like sandpaper which creates micro features such as striations

Question 2

Plucking

Answer 2

when meltwater penetrates into joints of rocks and freezes onto rock, then as the ice moves it exerts an immense pulling force onto attached rock - which may fracture + be plucked from its position

Question 3

fracture and traction

Answer 3

occur due to weight of moving ice passing over the rock and variations in pressures lead to freezing and thawing of the meltwater (basal melting) which aids plucking process.

Question 4

Dilation

Answer 4

Occurs as overlying material is moved causing fractures in the rock parallel to erosion surfaces as the bedrock adjusts to the unloading

Question 5

Meltwater erosion

Answer 5

mechanical - water under hydrostatic pressure, chemical - meltwater dissolves minerals and carries away the solutes espacially in limestone.