PRELIM REVISION

• explanation of a corrie

  A Corrie is an arm-chair shaped hollow in a mountain

  Formed when snow compresses into ice then a glacier

  By abrasion when rocks frozen into the base of the glacier grind at the valley floor as the glacier moves

  By plucking when ice sticks onto rocks at the sides of the valley and rips them out as it moves. 

  Rotational movement of the glacier over deepens the hollow
• Explanation of an arête 


  An arête is a ridge between 2 corries

  Formed by snow compressing into ice then a glacier

  By abrasion when rocks frozen into the base of the glacier it grinds the valley floor and rips them out as it moves

  By plucking when ice sticks onto rocks at the sides of the valley and rips them out as it moves. 

  Freeze-thaw weathering makes ridge more narrow& scree slopes