Describe and Explain the Formation of a Spit, and any Modifications it may Experience?

A spit is a depositional landform that is a long, narrow beach of sand or shingle attached to the mainland at one end, and possibly across an estuary. The landform is formed by longshore drift in the dominant wind direction, which carries material eroded from the proximal end of the spit to deposit it at the distal end of the landform. Longshore drift transports beach sediment along the coastline following the direction of prevailing winds as swash. If a change in the coastline occurs, material continues to be transported following the direction of LSD rather than the coastline and so material is transported and the distal end of the spit will extend across the sea. Deposition of sediment occurs when there is a decrease in the water’s velocity, commonly at estuaries as the flow of water into the sea is stronger than the drift and sediment is forcefully deposited, causing the build up of sediment and therefore the growth of the spit. Modifications can occur during the formation of the spit effecting the spits overall form. Changes in the direction of prevailing winds will coincide with the direction of fetch and wave direction; therefore, the direction of transported material and the development of a re-curved distal end. Short changes in wind direction during the formation of a spit will form laterals. Wave refraction can also cause the spit to form a re-curved end as material is carried to more sheltered areas, leading to the modification of the original landform. These sheltered areas allow for the development of additional depositional landform's including mudflats and salt marshes on the leeward side. Further modifications of spits can occur due to the erosive powers of both wave and wind energy. In the event of a storm, the shape of a spit may change over short periods of time as erosion will exceed deposition and the removal of material from the spit is greater than the supply of sediment at that given time. finally the spits formation can be halted by fast river currents which carry deposited sediment from the spit seawards.The diagram above shows visually what a salt marsh would look like, however as this diagram has no laterals it suggests the wind direction hasn't changed yet.