Geochemistry of Quaternary fluvial and eolian sediments in the southeastern Netherlands

Abstract

Bulk chemical analyses of Quaternary sediments in the southeastern Netherlands show that sands from the middle terraces of the Meuse in South Limburg are significantly lower in SiO2 and higher in almost all other analysed major and minor elements than mixed Meuse and Rhine sediments in North Limburg and adjacent areas. Within individual formations in North Limburg the Sterksel and Urk formation are charactenzed by relatively high Al, Fe, Mg, K and Rb and low Zr contents, the Kreftenheije Formation and Nuenen Group by low Rb and high Zr contents, whereas the Veghel Formation has both low Rb and low Zr contents. Principal component analysis is used to assign well-correlated element groups to individual minerals. Factor 1 (65% of the total variance) is composed of Fe, Al, Mg, K, As, Sc, Cs, Rb, Th and the LREE and is interpreted as a muscovite/goethite factor. Factor 2 (13% of the total variance), is dominated by Na, Ca, Al, Mg, K, Th and Sr and is interpreted as a feldspar factor. Factor 3 (7% of the total variance), is composed of Zr, Nb, Cr, Ti, V and Lu, elements concentrated in some stable heavy minerals. High levels of Factor 1 elements in South-Limburg sands are interpreted to be due to admixture of large amounts of shale fragments, muscovite and goethite particles. Depletion of Rb in eolian sands is interpreted to differential winnowing of micas during deflation. The concentration of many elements is also strongly grain-size dependent. Geochemical analysis is shown to provide much additional information not normally detected in routine petrographic analysis.