Landform change – the Dorset coastline
Dorset is located in the south of England. Its coastline has examples of large scale landforms. For example:
- Swanage is an example of a A high area of land that extends out into the sea. and A low-lying inlet of land on the coast.
- Old Harry Rocks is an example of A pillar of rock left standing in the sea when the top of an arch has collapsed.
How does the geology affect the rates of landform change?
The area around Swanage is made up of bands of hard and soft rock. This is called a A discordant coastline is a coastline where the geology alternates between strata (or bands) of hard rock and soft rock. A concordant coastline has the same type of rock along its length. Concordant coastlines tend to have fewer bays and headlands..
The soft rock is made of clay and sands, and the hard rock is chalk and limestone. As erosion processes take place, the clay erodes away quicker than the limestone and chalk. This forms headlands and bays, creating Swanage Bay and two headlands - Ballard Point and Durlston Head.
Old Harry Rocks
Old Harry Rocks are located on the headland between Swanage and Studland Bay. The headland is made out of chalk, a hard rock. The headland juts out into the sea, so it is more vulnerable to high-energy waves. This caused the formation of Old Harry, a stack. Over time Old Harry will collapse to form a stump.