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Coastal Processes. (Erosion (Cavitation (The collapse of bubbles that have…

- - - - Crystal Growth
        
        Crystals (magnesium sulphate and calcium carbonate are examples) grow in spaces within rock.
        
        Growing crystals, often resulting from the evaporation of saline water, prise the rock apart.
        
        This process is also known as salt weathering and s common in semi-arid areas.
      - Carbonation
        
        Calcium bicarbonate is soluble in water.
        
        Carbon dioxide reacts with water to produce a weak carbonic acid (NB rainwater is naturally weakly acidic).
        
        Carbonuc acid reacts with calcium carbonate (limestone), producing calcium bicarbonate.
      - Hydration
        
        Rocks absorb water
        
        Anhydrite (a form of calcium sulphate) absorbs water and becomes gypsum, a very weak rock.
        
        Rock swells and is easier to break down.
      - Hydrolosis
        
        Rocks, such as granite, containing feldspar, are commonly affected
        
        Water ions combine with ions from the rock, causing it to disintegrate.
        
        Carbonic acid releases hydrogen in the water, which reacts to minerals in the rock.
      - Solution
        
        No chemical reaction is required
        
        Certain minerals in rock, such as rock salt (halite), dissolve in water.
        
        This process is commonly associated with carbonation.
    - - Roots exert a destructive force on rock as they grow.
      - Tree roots prise apart rock.
      - Burrowing animals may remove soil and expose rock to other forms of weathering
    - - Freeze Thaw
        
        Water enters areas of weakness and freezes
        
        Fragments of rock break off, producing scree or talus
        
        Ice occupies more space than water, exerting pressure on the rock.
      - Heating and Cooling
        
        Rocks are heated to extreme temperatures during the day and then cool at night.
        
        Temperature change causes stresses in the rock to be set up and this causes it to disintergrate
        
        This process is sometimes known as insolation weathering
      - Wetting and Drying
        
        Rocks expand when wet and contract when dry
        
        Stresses induced by this cycle of wet and dry conditions causes the rock to crumble
        
        This is also known as slaking and may occur in inter-tidal areas