THE SUBSURFACE HOLOCENE MIDDLE SANDS OF DUNGENESS

Recently released deep borehole information from the site of the Dunge ness Power Station prove a 40 m succession informally subdivided into Basal gravels, Middle sands and Top gravels. The post-3270 BP (3100 ca librated years sp) Middle sands unit reaches a maximum thickness of 29 m and comprises mainly fine to very fine grained sand, laid down in a lower shoreface-offshore apron. The texture and mineralogy indicates derivation mainly from nearby subaerial and submarine outcrops, includ ing reworked Pleistocene materials. Grain surface textures imply bath simple and complex histories in which some of the silt grains appear t o have passed through episodes of windblown periglacial activity and s ubaerial weathering. The dominance and relative abundance of detrital high potash glauconite, indicating early Cretaceous sources, and the n ature of the clay mineral and heavy mineral assemblages substantiate t he prominence of local sources for the sediment. The mixed molluscan f auna carry representatives of both intertidal and subtidal habitats. F ive new radiocarbon dates indicate that the emplacement of the Middle sands beneath and to the immediate west of Dungeness must have commenc ed by 1600 sp (1150 calibrated years sp) at the latest and continued t hrough to at least 1000 BP (560 calibrated years BP).