GEOCHEMISTRY OF HOLOCENE CLAYS OF THE RHINE AND MEUSE RIVERS IN THE CENTRAL-EASTERN NETHERLANDS

Major and minor element geochemical analysis of Holocene clays from fi ve borings in the Rhine and Meuse floodplains shows that Rhine deposit s have less SiO2, MnO, Nb and Zr and more CaO, MgO, Na2O, P2O5, Rb and Sr than Meuse deposits. Geochemical differences between old and young floodplain clays of the Rhine are due to different granulometry and d epositional regime. Multivariate statistics show that more than 70% of variance in the deposits is related to provenance and sorting during transport and deposition. Pb and Zn concentrations are correlated with organic matter content, and vegetation horizons in old floodplain dep osits are naturally enriched in these heavy metals. Pb and Zn, therefo re, are potential paleoclimatic indicators. Increased contents of Pb, Zn, Cr, Ba and V in young floodplain sediments dating from the last ce ntury are due to industrial pollution.