How are sand spits formed?

Answer

Sand spits form after sudden changes in the shape of a coastline. This causes longshore drifts that deposit sediment in the direction of the drift, rather than along the coastline. Sand spits appear as fingers of land projecting from the coast.

Longshore drifts occur when prevailing winds blow at an angle to the coastline. The drifts carry sediment to the shore. When the shoreline suddenly changes direction the sediment continues to drift, eventually being deposited when currents become weaker. Wave refraction generates a hook in the shape of the spit. This hooked land area creates a shallow protected body of water. Salt marshes form within this protected body.

The continual erosion of sand spits combined with the continual deposition of sediment makes sand pits unstable land forms. Increased amounts of sediment may increase the rate of deposition behind the sand spit. When events such as storms create an imbalance between deposition and erosion, the shape of the sand pit can change dramatically. Sand pits that become large enough to completely block off a bay of water they are called bars. The water behind a bar is known as a lagoon. Many sand spits occur at the mouth of a river.

Q&A Related to "How are sand spits formed?"
Spits form as a result of deposition by longshore drift, which is the movement of sand along the coast by the waves. The spit is formed when any material that is being carried by
http://wiki.answers.com/Q/How_are_sand-spits_forme...
They form from the deposition of sediments by the longshore current. Sand spits elongate in the direction of the longshore current.
http://answers.yahoo.com/question/index?qid=200904...
Sand is formed by the process of erosion and weathering of rocks, most commonly by water! ChaCha for more!
http://www.chacha.com/question/how-does-sand-form
Sand is rock material that has been eroded into tiny grains. Sand starts as gravel. Text back soon!
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