The mineralogy of Quaternary deposits in the Kennet Valley, Berkshire

Abstract

The sedimentary characteristics, composition and mineralogy of a sequence of Quaternary river terraces is described. An exotic suite of heavy minerals is found in the silt fraction of topsoil deposits on the higher terraces and throughout the lowest terrace and floodplain. Mineralogical analyses of local Tertiary deposits indicate that this heavy mineral suite was derived from outside the catchment. The most probable source of the exotic silts was the North Sea Basin during the Late Devensian period. The gravels, coarser sand fractions and majority of the clay minerals in the terrace deposits indicate derivation from Cretaceous, Tertiary and early Pleistocene deposits within the Kennet Catchment.