physical weathering Flashcards
1
Q
freeze thaw
A
water becomes trapped in fissures freezes and expands (9%), exerting pressure which may lead to rock breakdown
2
Q
salt crystal growth
A
saline water enters cracks, leaving behind salt which expands up to 300%. most effective at temps of 27 degrees
3
Q
thermal expansion
A
heating and cooling of a rock causes it to expand and contract, weakening the rock. limestone is not a good conductor so heats and cools quickly,and breaks down faster
4
Q
vegetation
A
growth of roots in cracks and crevices exploits them
5
Q
pressure release
A
reduction of pressure on rock by surface unloading means the rock is able to expand. leads to fracturing of rock
