Geography: Types of weathering

• freeze-thaw weathering

  1. rain water goes into cracks of rocks
  2. the water freezes over night
  3. the water expands becuase it turns into ice
  4. the rock expands with it
  5. the ice melts
  6. the process repeats
• Onion-skin weathering

  1. the rocks surface expands during the hot day
  2. the surface contracts during the cool night
  3. the surface fractures due to repeated expansion and contraction
  4. outer layers shatter and pieces of rock peel off
• Chemical weathering

  1. there is carbon dioxide in the air
  2. the carbon dioxide dissolves in rainwater
  3. the result is a solution called carbonic acid
  4. carbonic acid can dissolve some types of rock
• Biological weathering

  Biological weathering is where rocks are worn away by animals plants and living organisms
• Be able to draw and label diagrams of weathering