In situ building of dunes since the Sub Boreal (3600 BP): evidence of chronological continuity on the northern coast of Brittany. An example in Anse du Verger (Ille-et-Vilaine)
Résumé
A series of storms, from 1990 to 1995, has revealed new cross-sections on the Northern Coast of Brittany, more specifically close to St-Malo, in the Anse du Verger (Verger cove). They have also allowed the effects of storms surges on coastal features to be followed. An anthropogenic shell layer, discovered in a dune and dated from 3640 (conventional BP) is covered by a storms surge deposit, dated from 2460, conventional BP. A comparison between present and sub-boreal surges is attempted. Then a chronology for dune building is proposed, in relation with sea level rise and surges. The possibility of an accumulation feature rising itself instead of retreating before an increasing sea level is proposed.