Shingle structures aggregate extraction involving deep excavation

The most widespread and damaging activity affecting shingle structures is the removal of gravel from within the body of the shingle structure itself. Deep excavations create a void which can rapidly become filled with water, creating gravel pits (see Figure below). Several large sites have been adversely affected in this way. Dungeness, the largest shingle structure in Great Britain and covering some 1600 ha of exposed surface, is the most disturbed site with some 420ha (20%) of its surface excavated to below the water table (Fuller 1985).

Figure Dungeness, Kent. Gravel extraction and the resulting gravel pit in the body of the shingle structure. Note the nuclear power stations in the background.

A similar story can be told for many other areas. For example, much of the surface shingle west of Rye Harbour, in southern England, has also been destroyed by gravel extraction. Pagham Harbour and the Crumbles again on the south coast of England have similarly been affected. Kingston shingle, which lies to the west of the River Spey in Scotland, is another important area where shingle extraction destroyed much of the ridge structure, probably during the 1940s. Though here shallower excavations were mainly above the water table. Less information is available for site in the rest of Europe, but it appears some French sites have been similarly affected. Cayeux sur Mer (Côte d'Opale), Sillon de Talbert (one of three locations on the north Brest peninsula) and two more to the south have also been degraded and diminished by gravel extraction (Géhu & Géhu-Franck 1979). At these and other sites shallower excavations has also resulted in a complete or partial loss of surface vegetation, though other terrestrial vegetation has become established.

References

Géhu, J.M. & Géhu-Franck, J. 1979. Sur la vegétátion nord-Allantiques et baltiques à Crambe maritima. Phytocoenologica, 6., 209-299.