Stratigraphy and genesis of Pleistocene deposits at Alphen (southern Netherlands)

Abstract

A detailed study was carried out on a large outcrop at Alphen in the southern Netherlands. At the base fluvial, gravel-bearing sands were found with a stable heavy-mineral association. These deposits, referred to as 'Alphen Sands', are of Early or Middle Pleistocene age. They are overlain by Eemian peat and Weichselian aeolian deposits. Besides loamy coversands, the latter comprise a compact aeolian loam layer, fine dune sands and superficially reworked coversands. During two separate periods the sediments have been subject to periglacial deformations under permafrost conditions. Furthermore they show two gravel pavements. Mineralogically they are characterized by an association of both stable and unstable heavy minerals, probably indicating a mixture of allochthonous Rhine-derived sediments and more or less local deposits.