Weathering

Question 1

Define weathering.

Answer 1

Weathering describes breakdown or dissolution of rocks and minerals in situ on Earth’s surface.

Question 2

List some agents of weathering.

Answer 2

Water, ice, salts, plants, animals, temperature changes.

Question 3

Describe freeze-thaw weathering (aka frost shattering).

Answer 3

Water freezes then thaws in cracks and holes in rocks. This occurs wherever water is plentiful and temperature fluctuated between above and below freezing.

Question 4

Describe thermal expansion (aka exfoliation).

Answer 4

Often occurring in hot deserts (high temperature fluctuation), only the outer part of rock responds to massive temperature fluctuations as rock is a poor heat conductor. After day expansion due to heat and night contraction due to cold cycles, the outer layer peels off. Water presence weakens the rock, increasing flaking vulnerability.

Question 5

Describe solution.

Answer 5

Dissolution of rocks and minerals by rainwater. It can be a means of transport as well. Rock salt, alongside table salt, dissolves in water so is vulnerable to solution.

Question 6

Describe tree weathering (aka biological weathering).

Answer 6

Action by flora and fauna. Plant roots expand into cracks in rocks, rabbits burrow into weak rocks.