Mechanical weathering 3.2

Question 1

Factors affecting weathering

Answer 1

1-There are extreme weather conditions
2-There are less resistant rock types
3-Rock has been exposed for a long time

Question 2

Weathering types

Answer 2

Mechanical weathering is the fracture and breakdown of rocks into fragments.
Biological weathering is mechanical when there is a physical affect.

Question 3

Freeze-Thaw weathering
(scree formation)

Answer 3

Water enters cracks or joints, freezes and expands volume. This puts pressure and causes cracks to widen.
Material that breaks off can be collected on mountain slopes, called scree.
E.g regions with colder climate such as Iceland

Question 4

Thermal expansion(heating/cooling)

Answer 4

When rock is exposed to high temperature it expands, as it cools down it contracts.This causes rock to weaken and break into pieces or peel(onion peel).
E. g Desserts

Question 5

Pressure Release

Answer 5

Igneous rocks like granite are formed by solidification of magma under intense pressure. When these rocks are exposed to the surface, the intense pressure is released, developing cracks parallel to the surface or breaking away sheets of rock.

Question 6

Salt Crystal Growth

Answer 6

Evaporation occurs and leaves the salt in cracks and pores, as temperatures rise the crystals expand exerting pressure on the rocks. It can leave a honeycomb pattern.
e.g sea coast

Question 7

Vegetation root action

Answer 7

Roots break up the rocks.
Lichen and mosses can break down rocks-very slowly