Coastal shaping

Coastal shaping

1. Types of weathering

   • Chemical - when the minerals in the rocks are changed by a chemical process
   • Biological - when plants and animals cause the breakdown of rocks
   • Physical/mechanical - when the rocks are broken up by processes acting on the rocks making them move

2. Types of weathering

   • Onion skin - in hot areas during the day rocks heat up and expand, as temperatures drop at night the rock contracts again. This is repeated daily and the rock gets weaker and breaks off.
   • Freeze-thaw - when it rains water fills natural cracks in the rocks. At night when temperatures drop the water freezes and expands pushing the crack apart. this is repeated everyday and eventually pieces of rock break off. This is common in mountainous areas.
   • Chemical - rain water is naturally slightly acidic, when this comes into contact with certain rock types such as limestone, the chemicals react and change leading to the erosion of the rock
   • Biological - plant roots can fall into cracks in rocks and start to grow. As the plant develops the roots push cracks further apart which weathers them and they break up. Animals walking on rocks can also cause parts to break off.