Cuspate foreland

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Cuspate forelands are geographical features found on coastlines and created by long shore drift. Made out of sand and shingle, and later stabilised by vegetation, cuspate forelands are triangular-shaped accretions and extend seawards.

Contents 1 Formation 2 Succession 3 References 4 External links

[edit] Formation

Cuspate forelands develop mainly as a result of long shore drift that occurs in two directions, merging two spits into a triangular protrusion into the sea by converging the material onto one location.

In normal circumstances, spits are formed when long shore drift moves beach material down the beach until the coastline makes an abrupt change in direction, leading to the beach material 'spilling over' the corner to create a protrusion (for example: this normally occurs across a river mouth). In the case of a cuspate foreland, the prevailing wind and a powerful secondary wind in the opposite direction move shingle down the coastline from both directions to a place where the coastline changes, causing a foreland to develop^[1]. The majority of cuspate forelands are formed over a coastline that juts out into the sea at enough of an angle to allow the drifting beach material to 'spill over' as a result of long shore drift in both directions.

In a similar formation to that of salt marshes, the deposited matter is solidified by the encroachment of vegetation, which secures the material and develops the foreland into a feature of the coastline, and in time the more dominant wind will shift the cuspate foreland down the coast at a rate depending on how relatively strong the secondary wind. This as with other landforms by the coast puts anything built on the Cuspate foreland under threat from coastal erosion^[2].

Notable examples of cuspate forelands can be found in dungerness in Kent, and Cape Canaveral in Florida.

[edit] Succession

Main article: Ecological succession

After the formation of the cuspate foreland into its distinctive triangular shape, the cuspate foreland will be begun to be colonised by pioneer species, which are hardy and tough enough to survive in the environment. These pioneer species secure the cuspate foreland and allow a greater amount of sediment to further secure the dune. The pioneer species are replaced over time by species of plant which have less need to be resistant towards to elements, and tend to be larger than the pioneer species. Along with these new species of plant, animals being to colonise the dune, which include animals such as waders. These plants are slowly replaced by bigger species, along with other animals which colonise the area, which results in a climatic climax.

[edit] References

[edit] External links

• USGS Coastal Change
• Dungeness, a cuspate foreland