Features of coastal deposition
How deposition forms spits, sand bars and lagoons
Spits
There are different depositional features produced by longshore drift including beaches.
Formation of a sand spit
- spitA stretch of beach at one end of a coastline caused by waves depositing material. form where the coastline changes direction and longshore drift continues to move material along the beach.
- Longshore drift will deposit material in the sea after the coastline has changed direction.
- Over time the level of the sand deposited will build-up until it is above sea level.
- The spit cannot develop right across the bay as a river's estuaryThe open mouth of the river where it meets the sea. prevents the build-up of sand.
- sand spitA depositional feature connected to the coastline (also called a spit). often have a curved or hooked end. This is created when secondary wind and wave direction causes waves to strike from a different direction.
- The beach therefore appears to extend out into the sea and is known as a spit or sandspit.
- The spit creates an area of calmer water, sheltered by the spit. A lagoonA shallow area of water separated from the sea by a bar or spit., salt marshA coastal ecosystem located between land and open salt water that is often flooded by the sea. and finally dry land can develop in this sheltered area.