Depositional Features and Landforms
What is Deposition?
Once the sea has eroded the coastline and transported the material eroded from the cliffs and from the beach, deposition is the process whereby material is then dumped; deposited elswhere on the land. Longshore drift the process of transportation will carry material until it reaches an area where the water is sheltered for example in a bay or behind a headland. At this point waves lack energy and the material is able to settle.
Beaches
Beaches are the most common feature by which material is transported along and deposited elsewhere along the beach. Its futhest point is the point reached by storm waves at the highest tide. It begins where the lowest spring tide level reaches.
A beach is a geological formation consisting of loose rock particles such as sand, gravel, shingle, pebbles, cobble or even shell along the shoreline and sea.
Beaches form due to the transportation of material and deposition from constructibe waves. As cliffs are eroded a wave cut platform is formed gradually creating an overhang which eventially collapses and adds beach material to the beach. Waves then break down this material due to the action of waves and it is transported by longshore drift.
The rock type and wave energy determines whether the beach is sand, shingle or pebbles.
Beaches vary in steepness. Constructive and destructive waves will affect the steepness of the beach. Constructive waves transport material and this builds up the beach.
Quiz
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Beach Profile diagram
The beach profile of the right shows that the largest material is found at the top. During storms destructive waves throw larger cobbles to the top of the beach.
The other two material collections or ridges are known as burms. This material is deposited at high tide.
The bottom berm consists of the smallest material and this is the material that is within the active shoreline.