Bitesize has changed! We're updating subjects as fast as we can. Visit our new site to find Bitesize guides and clips - and tell us what you think!


Processes affecting rock types


  1. 1
  2. 2
  1. Next

When rock is exposed to weather conditions it becomes subject to processes, such as freeze-thaw weathering, that cause it to change and break down.

Freeze-thaw weathering

The freeze-thaw weathering process is also known as frost shattering.

Mount Snowdon

Mount Snowdon in Snowdonia, Wales

  1. Water - eg from rainfall or melting snow and ice - becomes trapped in a crack or joint in the rock.
  2. If the air temperature drops below freezing, the water will freeze and expand by 9-10 per cent putting pressure on the rock.
  3. The ice will melt when the temperature rises above freezing.
  4. If this process happens repeatedly, the rock will weaken and eventually shatter into angular fragments.
  5. The fragments may then be deposited as scree at the foot of a slope.
  6. It is most effective where the temperature fluctuates around 0°C, eg on north-facing high altitude slopes in Snowdonia.


  1. 1
  2. 2
  1. Next

Back to Rock landscapes and processes index

BBC navigation

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.