Weathering

Question 1

Mechanical Weathering

Answer 1

1. By day water is collected in the cracks in rocks.
2. At night the water freezes and expands.
3. Repeated freezes thaw action causes the rocks to shatter. It falls to the bottom of the slope as sree.

Question 2

Chemical Weathering

Answer 2

1. As rain water falls and passes through the air, it dissolves carbon dioxide.
2. Carbon dioxide mixes with the rain water to form a weak carbonic acid.
3. Limestone in the ground contains carbon. When the weak carbonic acid in the rainwater falls onto the limestone a chemical reaction takes place.
4. The calcium carbonate in the limestone begins to dissolve. This is known as carbonation.
5. Limestone is a permeable rock, which means that rainwater can easily pass through it. It has vertical cracks which are known as joints and horizontal bedding planes.

Question 3

Chemical Weathering: Karst Landscapes

Answer 3

The effects of carbonation are seen in karst landscapes.
The overlying plants have been removed and the limestone rock is exposed.
The Burren in County Clare is an example of a karst region.

Question 4

Burren: Surface Features

Answer 4

The bare, rocky karst surface is called a limestone pavement.
The pavement is made up of clings and grikes.

Question 5

Biological Weathering

Answer 5

Biological weathering is where rocks are worn away by animals, plants and living organisms.
Trees and plants can grow within the cracks in rocks.
As the roots grow they push open the cracks making them wider and bigger.