The litho- and biostratigraphy of a late Holocene tidal channel in Romney Marsh, southern England

Abstract

The evolution of tidal channels and, in particular, the sedimentological and biostratigraphic evidence for channel infilling, are areas of palaeoenvironmental research that have received relatively limited attention in stratigraphic studies aimed at landscape reconstruction. This paper details the results of a multidisciplinary investigation into the late Holocene evolution of the Wainway, a large tidal channel in Walland Marsh, East Sussex. Lithostratigraphic, microfossil and sedimentological data, as well as geomorphological and historical evidence detail the rapid infill of this channel between the tenth and sixteenth centuries. This infilling was associated with localized changes in coastal configuration caused by storm events. Our analyses suggest that the channel sediments provide a detailed insight into the dynamics of this important watercourse during the closure of the New Romney tidal inlet and the opening of a tidal inlet at Rye during this period. The final stages of sedimentation within the Wainway Channel record its progressive infilling and final inning at c . ad 1600. This is reflected in the sedimentological and micropalaeontological data by a progressive upward fining of the sediment sequence and the development of low energy mudflat and saltmarsh conditions. In this study we find significant differences in the usefulness of different microfossil groups for palaeoenvironmental interpretation. In particular, the foraminiferal data provide a more continuous and sensitive record of changing intertidal conditions compared with the diatom record.