How important is the geology in determining the shape of the coastline?

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How important is the geology in determining the shape of the coastline?

The shape of the United Kingdom has changed over many years. Enerally, this essay will aim to show that the geology of an area is the main factor in determining the shape of the coastline. However, there are many other important factors which contribute to the shape of areas.

The geology of England is one of the most important reasons as the why the island is shaped as it is now. The geology of land, such as the type of rocks or the positioning of the rocks, can determine the shape of any coastline. The first example is Lulworth Cove on the south coast of England near Dorset. The cove was formed 100,000 years ago, when a glacier to the north of the original area was melting, causing a river to swell due to melt water, which flowed over the land to sea. The river cut a valley and breached the Portland stone, cutting the first notch in the cove. The rising sea level flooded into the valley and gouged out the cove. The sea exploited cracks and faults in the hard Portland rock and Purbeck limestone. However, after the two hard rocks, the rest of the land is made of soft rock. The sea quickly eroded the Weladen clay, Gualt clay and greensand by abrasion, hydraulic action and subaerial erosion. After the soft rock is a layer of chalk, which is hard and difficult to erode. Therefore the cove was eroded horizontally. Now, erosion has slowed leaving the cove in the shape it is now. The cove was only formed due to the geology of the land. Nevertheless, this is not the only area where Portland limestone has effected the coastline. Durdle Door is a famous archway on the heritage coast. The front section is made from Portland rock, which is extremely hard to erode. Therefore, this section is still standing. Behind Durdle Door is a layer of clay which is easily eroded and has somewhat withdraw from the Portland stone with the sediment from the clay forming a beach. However, the erosion has stopped as behind is a layer of chalk. The archway of Durdle Door has been eroded due to a large amount of joints in the Portland rock, causing the archway to form and expand from a single crack. This is another example as to why the geology is important. Single handedly, it has created the landform of Durdle Door due to the resistence of certain rocks. Portland’s shape has also been determined due to the geology of the area. It is a small area located on the south coast to the east of Durdle Door. The existence of Portland is solely due to the geology. The rock has resisted erosion, even from storms from the Atlantic Ocean. However, before the Portland rock is a lyaer of soft rock, leaving Portland being ‘T’ shaped, with only one road in and one road out due to the narrowness of the land leading back to the south coast being constantly eroded. All of these areas have been altered solely due to geology. Therefore, in these situations, geology has been the most important factor in determining the shape of the coastline.

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Regardless, this is not the only factor that determines the shape of a coastline. Climate change results in a change of seal level. This can alter the coastline significantly. Sea level is constantly changing, for example, in each ice age, the ocean is frozen, creating a dramatic fall in sea level. This causes the coastline to extend. For example, there used to be a peice of land that connected England and France dring the ice age, due to a fall in seal leavel, however, the seal level then rises at the end of each ice age, which causes the coastline ...

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