WEATHERED DIAMICTON BENEATH UPPER WEICHSELIAN SEDIMENTS AT SILVEREKE,SOUTHEASTERN SWEDEN

An at least 2 m thick, weathered, non-glacial diamicton, buried beneat h a 6 m thick Upper Weichselian glaciogenic sequence at Silvereke in S E Sweden, is composed of variously coloured angular/rhombohedral to ro unded clasts set in a red or reddish-brown matrix of clayey silty sand . The clasts (mainly local metavolcanic rock and Cambrian sandstone) a re generally thoroughly weathered and would hardly survive transport, suggesting weathering after deposition. XRD-analysis of the clay fract ion of individual argillized clasts reveals an assemblage dominated by kaolin minerals, probably including halloysite. The matrix has a more complex clay mineralogy, including vermiculite. The petrography and m ineralogy as well as the extensive argillization of the diamicton cont rast to the composition and texture of the overlying Upper Weichselian till. Apart from small amounts of pollen, mainly Pinus, Betula and NA P, the unit is almost devoid of organic matter. Since most pollen are well-preserved, they were probably added to the exposed, weathered sed iment. The pollen spectrum evidence a Quaternary age. It is suggested that the Silvereke diamicton was deposited between the Pliocene and th e beginning of the Eemian Interglacial, and that the Silvereke diamict on-Upper Weichselian till boundary represents a hiatus, or erosional u nconformity, of between 117,000 and some million years.