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Lessons  12-13
        2.  Cliffs


        Rocks are worn away by:-


              Waves trapping air in the rocks and forcing them to expand, breaking rocks apart.
              Rocks and stones being thrown up by the waves. These rocks crash into the cliffs and

                eventually break down piece by piece.
              Some rocks such as chalk and limestone dissolve slowly in the sea water.


        All of these three activities take place at Durdle Door in Dorset.





        In chalk and limestone areas the following features can appear: -





                                  A stack               A cave                             An arch











  HT


              stump    stack            arch               cave               blow hole          cave

  LT


               HT = high tide, LT = low tide





        Find out more about how coastlines are changed by looking in books or on the Internet.



















                                         (God's Amazing Landscapes)          51
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