Late Flandrian coastal change and tidal palaeochannel development at Hills Flats, Severn Estuary (SW Britain)

An eclectic range of stratigraphical, sedimentological, geochemical, archaeological and historical evidence relating to a tidal palaeochannel exposed at a deep erosional level in the modern intertidal zone on the Avon-Gloucestershire border demonstrates that tidal wetlands reclaimed during the Roman period ranged much further seaward than the modern coastline. Vigorous late medieval-early modern erosion, linked to the cool, disturbed conditions of the Little Ice Age, forced the coastline by the mid-seventeenth century to a location inland of its present line. A possible medieval landing place was destroyed and it was necessary to set back the flood defences. As the result of renewed mudflat-marsh growth, the coast at Hills Flats has built outward during modern times, but in three distinct stages and by no means as far seaward as its likely Roman position.