Geology means different kinds of rocks. The coast looks the way it does becuase some rocks are harder and more resistant than others. Limestone, chalk and granite are very resistant. Shale, clays and sands are much weaker.
Wind blows across the sea and friction creates waves. The size of the wave depend on:
- the strength of the wind
- how long the wind blows for
- how far the wave travels
There are two types of waves:
1) Destructive waves: these waves erode away beaches and coastlines. They create cliffs, bays, caves and stacks. They have a strong backwash, a weaker swash = a steeper beach.
2) Constructive waves: These waves make beaches and coastlines bigger. They create beaches and spits. They have a weak backwash and a stronger swash which means a shallow beach.
LANDFORMS OF DESTRUCTIVE COASTLINES
Cliffs: Rocks are eroded by the waves at sea level, creating a long notch along the coastline. This continues so the rocks above it are undercut forming a cliff overhang. The rocks of the cliff eventually collapse under their own weight. The collapsed rocks collect at the base of the cliff & get broken up by attrition. A flat rocky area forms at the base of the cliff. The cliffs get higher as the coastline erodes.
An example is the white cliffs of Dover, made form chalk
Headlands and Bays: waves eroding the coastline (through hydraulic action and corrosion) will erode less resistant rocks such as clay quicker than more resistant rocks like limestone. This will…