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
- A 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 estuary prevents the build-up of sand.
- A 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 A shallow area of water separated from the sea by a bar or spit., salt marsh and finally dry land can develop in this sheltered area.