Accumulations of major and trace elements in particle size fractions of soils on eight different parent materials

Abstract

The major (ME) and trace element (TE) contents of virgin soils are very important in areas with chances to be contaminated from anthropogenic activities. We determined the ME and TE composition of 21 soils developed on dacite, lamproite, andesite, basalt, diabase, mica schist, quartzite and colluvial deposits to elucidate elemental transfer from PGM to soils. We also studied the enrichment of ME and TE in various particle size fractions. In general, the highest content of Si was observed in sand fraction regardless of PGM and is attributed to the dominance of quartz (SiO 2) in this size fraction. Results showed that Pb, Cd, Cu and Zn are associated with Al- and/or Fe-containing minerals such as micas, pyroxenes, and amphiboles and exhibit preferential partitioning into fine particle size fractions in the soils studied. Cobalt, Ni, and Cr are associated with Mg-bearing minerals such as smectites and Ti is related to Na-bearing mineral such as plagioclases (e.g. albite and andesine). Significant correlations between elemental contents in soils and PGM confirm that rock types significantly control ME and TE contents in soils, although some variations are expected due to factors such as resistance of rock to weathering, formation of secondary Fe oxides, elemental fixation and other pedogenic processes. Our data can be used to as benchmark or background information for ME and TE contents to assess any elemental enrichment from anthropogenic activities.