Foreland basin

A foreland basin is a structural basin that develops adjacent and parallel to a mountain belt. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithosphere to bend, by a process known as lithospheric flexure. The width and depth of the foreland basin is determined by the flexural rigidity of the underlying lithosphere, and the characteristics of the mountain belt. The foreland basin receives sediment that is eroded off the adjacent mountain belt, filling with thick sedimentary successions that thin away from the mountain belt. Foreland basins represent an endmember basin type, the other being rift basins. Space for sediments, accommodation space, is provided by loading and downflexure to form foreland basins, in contrast to rift basins, where accommodation space is generated by lithospheric extension.

Types of foreland basin

Foreland basins can be divided into two categories:

Foreland

Foreland is the easternmost point of the Isle of Wight. It is located three miles (five kilometres) east of the town of Brading, and due south of the city of Portsmouth on the British mainland. It is characterised by a pub called the Crab and Lobster Inn and various beach huts plus a beach cafe and a coast guard lookout. In the sea are the reefs of Bembridge Ledge which is rich in edible crabs, lobsters and spider crabs and shoals of mackerel. In the Crab & Lobster Inn are photographs of the many shipwrecks, which included the submarine HMS Alliance, now a museum ship at Gosport and the First World War troopship the S.S. Mehndi carrying troops from South Africa, with great loss of life.

The channel through the interior of the Bembridge Ledges is known as "Dickie Dawes Gut" after a notorious local smuggler (and father of the courtesan Sophie Dawes) due to his feat of escaping the excise men by superior local navigational knowledge. There was a pill-box built in the Second World War, now subsumed in the sea defences. The beach is sandy with stones which contain Cretaceous fossils. The cliffs also feature Horsetails ferns.