Many of the sediments have been reworked by erosion cycles associated with varying sea levels and are exposed as palimpsest (relict) pavements along the mid and outer shelves, exposed to the action of fringing shelf-edge currents such as the Agulhas Current (Green and MacKay in press). These may be interspersed with submerged shorelines of varying ages which have added small, in situ quantities of rubble and bioclastic debris to the shelf system (Green and MacKay in press). Along the east coast of South Africa, the relict sediment is thinly overlain by a sheet of Holocene aged material, on average no more than 10 m thick with a few localised depocentres up to 30 m thick, usually associated with the localised convergence of littoral and geostrophic currents.