Mechanical weathering is the breakdown of rock without changing its chemical structure (composition).

Find out more about weathering.

Weathering is the breakdown of rock in situ by the action of rainwater, extremes of temperature, and biological activity.

Find out more about weathering.

Chemical weathering is the breakdown of rock through changing its chemical composition.

Find out more about weathering.

Salt weathering is when salt spray from the sea gets into a crack in a rock. It may evaporate and crystallise, putting pressure on the surrounding rock and weakening the structure.

Find out more about weathering.

When rainwater hits rock it decomposes it or eats it away. This is known as carbonation. This occurs when slightly acidic (carbonic) rain or seawater comes into contact with sedimentary rock, such as limestone or chalk, it causes it to dissolve. A chemical reaction occurs between the acidic water and the calcium carbonate and forms calcium bicarbonate. This is soluble and is carried away in solution. Carbonation weathering occurs in warm, wet conditions.

Find out more about weathering.