The Thames valley sediment conveyor: fluvial system development over the last two interglacial-glacial cycles [ Le " convoyeur sédimentaire " de la vallée de la Tamise

Abstract

The fluvial archive of the River Thames over the last two interglacial-glacial cycles is examined in terms of the spatial distribution of fluvial sediments across the basin and the temporal patterns of aggradation and incision. The spatial distnbution of fluvial sediments can be interpreted as a series of sedimentation zones and intervening sediment transfer zones. The factors that control the distnbution of fluvial sediments are considered. The notion of a "jerky conveyor" is utilised to develop a conceptual model of the Thames Valley Sediment Conveyor and the operation of this conveyor over the last two interglacial-glacial cycles is discussed. The model incorporates the sedimentation zones identified here and also the effects of the formation of a coastal pnsm dunng lnterglacial high-stands in sea level. The model is compared with the sedimentary record for the last interglacial-glacial cycle in the Lower Thames and its implications for understanding fluvial behaviour and the stratigraphie record are discussed.