Size shape and origin of the sands of the East Frisian Islands (North Sea, Germany)

Abstract

Beach and dune quartz sands of the East Frisian Islands (Germany) demonstrate an irregular tendency of coarsening eastwards. The sands contain flint, feldspar and igneous fragments. The sediments of the offshore probably determine grain-size of the sands: the coarse fractions are derived from reworked Pleistocene sands at Borkum Rough and Wangerooge Ground. On each island the dune sands form one population in size and shape. By means of rollability analyses it appears that the dune sands are more angular than their source, the beach sands.