Spatial prediction of the variability of Early Pleistocene subsurface sediments in the Netherlands - Part 1: Heavy minerals

We investigated the spatial variability of the heavy-mineral composition in the Early Pleistocene fluviatile Kedichem Formation in the Netherlands in order to meet the demand for more information about subsurface sediment com position. We first determined the spatial extension and thickness of the se diment body, then used Fuzzy clustering techniques on a database containing approx. 2000 heavy-mineral counts from the Kedichem Formation to map the s patial extension of the various sediment provenances within the formation. Three clusters could be discerned, one representing a combined Meuse-Scheld t source, the other two representing a mixed Rhine-Baltic source. We made s lice maps at several depths through the formation, and plotted the cluster memberships. The maps show an overall dominance of the Meuse-Scheldt source in the south of the Netherlands, whereas the Rhine-Baltic source occurs mainly in the c entral Netherlands. The methods employed show that it is possible to map an d study the 3-D variation in heavy-mineral composition and hence sediment p rovenance in the Dutch subsurface with the use of simple statistical and vi sualization techniques.