1. Weathering Processes

2. Freeze-Thaw
Occurs in areas where the temperature regularly drops below 0°C.
Water enters cracks in the rock during the day. Overnight the temperature drops and the water freezes.
As it freezes, it expands.
The expanded ice places pressure on the rocks around it.
Over time this constant pressuring of the rock causes it to crack and split.

3. Freeze-Thaw Example

4. Exfoliation/Onion Skin
Occurs in hot, dry climates.
The outer layer of the rock is heated by the sun during the day, causing it to expand, during the night, as the temperature drops, the rock contracts.
This constant expanding and contracting eventually leads to the outer layers of the rock pealing away, leaving behind them rounded rocks and dome shaped outcrops.

5. Exfoliation/Onion Skin

6. Hydrolosis
Attacks rocks, which include feldspar crystals, the most common example being granite.
The feldspar reacts with acidic rainwater and dissolves to form kaolin (china clay).
The remainder of the rock breaks up into its individual crystals overtime.

7. Hydrolosis

8. Carbonation And Solution
Occurs on rocks containing calcium carbonate, such as limestone and chalk.
Rainwater and dissolved carbon dioxide mix to form a weak carbonic acid.
Calcium carbonate in the rocks reacts with the acidic water and dissolves leaving behind calcium bicarbonate.
This compound is soluble and is easily washed away by running water.

9. Carbonation And Solution