Processes called erosion, mass movement and weathering break down and remove material from the coast. The material is moved along the coastline by the sea and deposited when there is energy loss.
Sediment is carried by the waves along the coastline. The movement of the material is known as longshore driftThe movement of material along a coastline due to the angled approach of waves.. Waves approach the coast at an angle because of the direction of the prevailing windThe wind direction that occurs most often throughout the year, or occurs most often at this time of year, in a certain geographical region.. The swashThe water flowing towards a beach when a wave breaks. will carry the material towards the beach at an angle. The backwashThe movement of water down the beach. then flows back to the sea, down the slope of the beach. The process repeats itself along the coast in the zigzag movement.
Beach material can be moved in four different ways. These are:
Solution - when minerals in rocks like chalk and limestone are dissolved in sea water and then carried in solution. The load is not visible.
Suspension - small particles such as silts and clays are suspended in the flow of the water.
Saltation - where small pieces of shingle or large sand grains are bounced along the sea bed.
Traction - where pebbles and larger material are rolled along the sea bed.