Holocene sea-level changes and coastal sedimentation in Romney Marsh, southeast England, UK

Abstract

This paper describes the results of a litho-, bio- and chronostratigraphic survey of the Midley Church bank, Romney Marsh. These results are then combined with other previously published sea-level data from Romney Marsh to study the relationship between Holocene coastal sedimentation and (i) barrier development; (ii) time/altitude changes in sea-level in Romney Marsh and southeast England. Pollen data show that a peat bed which underlies the Midley Church bank accumulated under a gradual decrease and then increase in the proximity of marine conditions. Four 14 C dates indicate that peat accumulation at this site took place between c . 3700−2200 bp (4050−2200 calibrated years bp ). Peat accumulation was encouraged by a slow rate of regional sea-level change during this period, and by the probable existence of a shingle barrier to the southwest and southeast of the study site. The time/altitude distribution of sea-level index points from Romney Marsh is comparable with those from other sites in East Sussex, suggesting that the altitudes of these index points are the product of regional and not local processes. However, the age of peat formation in Romney Marsh is variable, and with the current dataset there is no support for synchronous local sea-level tendencies during the last 7000 calibrated years bp. It is argued that the nature of Holocene coastal sedimentation and the chronology of sea-level tendencies in Romney Marsh have been strongly influenced by local factors. These local factors appear to have operated during periods of both high and low rates of sea-level rise. The stratigraphie record of Romney Marsh therefore records evidence of both local and regional coastal processes.