'Cliff profiles are created by many complex factors'-Discuss

Essay by Saiful October 2004

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Cliff profiles owe their form to the geology (Lithology and structure), sub-aerial processes and wave energy along a given stretch of coastline. It takes thousands of years for the cliffs profile to form from complex processes, there are many complicated processes taking place on coasts that affect the profile of a cliff.

Wave action causes three erosional processes, abrasion, hydraulic action and corrosion. These processes are most effective when high energy waves, associated with storm conditions strike coast profiles made of less resistant rocks. Concentrated wave action on cliff leads to undercutting. The three types of wave erosion processes play an important part in forming cliff profile. A wave also trims the front of a cliff. These erosional processes take a long time and are very complex.

Lithology describes the mechanical and chemical properties of rocks. Rocks are a major factor that affects the profile of a cliff. Weathering and mass movement takes place on the rocks in the cliff.

Strong rocks (coherent rocks) support steep angled slopes while weaker rocks (incoherent rocks) support low angled slopes. This is because coherent rocks have few lines of weakness, and resist erosion whilst incoherent erodes easily and is often undercut by wave action leading to slumping.

Structure is a very important factor in forming the profiles of a cliff. The angle of dip of sedimentary rocks is one element of rock structure which has an important effect on cliff profiles. There are three types of strata's that affect the profile of a cliff, horizontally bedded strata, seaward-dipping strata and landward-dipping strata. Horizontally bedded sedimentary rocks are undercut by waves causing the collapse and retreat of the cliffs affecting its profile. Seaward-dipping strata have blocks of rocks that are weakened by erosion and weathering that slide into the sea while landward -dipping strata...