Geography

• Denudation


  Processes that wear down rocks on the earth's surface
• Main processes in denudation

  • Weathering
  • Erosion
• Weathering


  Physical, chemical or biological process that changes solid rock into smaller pieces or sediments
• Erosion


  Process that breaks down and moves the sediments away from their original positions
• Mechanical weathering


  1. Physical breaking down of rocks into smaller pieces

  2. Freeze-thaw action
• Chemical weathering


  1. Caused by chemical changes, when rock is dissolved or decays

  2. Carbonation
• Carbonation


  Chemical weathering process where rainwater dissolves carbon dioxide to form weak carbonic acid, which then dissolves limestone
• Karst landscapes


  • Areas of land made up of limestone where the effects of carbonation are best seen
• Karst region in Ireland

  • The Burren in County Clare
• Limestone pavement


  Bare, rocky karst surface made up of clints and grikes
• Clints


  Slabs of rock on the surface that separate the grikes
• Grikes


  Deep grooves in the limestone pavement that become weathered, widened and deepened by carbonation
• Swallow hole


  Big vertical holes formed when rivers enter a karst landscape and disappear underground through enlarged grikes
• Underground features formed by weathering

  1. Limestone caves

  2. Passages

  3. Stalactites

  4. Stalagmites

  5. Pillars
• Stalactites


  sometimes water seeps through the roof of the cave. This water contains dissolved limestone. Evaporation takes place on the roof of the cave leaving deposits of calcium carbonate behind. These deposits attach themselves to the roof of the cave and grow downwards forming stalactites.
• Stalagmites


  the water seeps through the roof of a cave and may fall to the floor of the cave. Evaporation takes place on the floor of the cave leaving deposits of calcium carbonate behind. These deposits build up and form stalagmites.
• Pillars


  Formed when a stalactite and stalagmite meet and join
• Biological weathering


  Weathering caused by animals, plants and living organisms, e.g. roots growing in cracks and breaking apart rock
• The weathering of limestone in the Burren has created a unique landscape that has attracted tourists from all over the world
• Tourism can give a great economic boost to an area, but it is also important to protect the natural landscape
• A proposed car park in the Burren National Park has sparked controversy, with concerns about the impact on the local environment