engleski

Magnetic susceptibility and heavy metal pollution in the Lausitz area, Eastern Germany

A magnetic 'hot spot', which had been identified previously by magnetic proxy mapping within the EU-Project MAGPROX, was investigated using an integrated magnetic and geochemical approach. Detailed field mapping of top soil magnetic susceptibility (MS), based on 140 sampling points with an average grid density of about 1 km, using a Bartington MS2D loop and GPS equipment for geographic positioning, was performed. Soil profile cores and hand samples of different soil horizons were taken for further laboratory analysis. MS downhole profiles were measured in situ at each sampling site using the newly developed MAGPROX SM400 susceptibility meter for combined in situ sampling and MS profiling. In laboratory, MS profiles were obtained from all soil cores and discrete subsamples of the soil cores, using Bartington MS2C and KLY-2 kappabridge instruments. Magnetite like phases are indicated by IRM acquisition curves from bulk material and by thermomagnetic curves from magnetic extracts. SEM/EDX analyses from magnetic extracts frequently show spherule-shaped particles with high iron contents. Heavy metal (HM) concentrations of Fe, Mn, Pb, Zn, Cu, Cr, Ni, Co, and Cd along selected soil profile cores were determined using flame AAS . The resulting data set of MS and HM values from the same sampling points in a dense grid around presumed pollution sources gives a detailed picture of the MS and HM distributions in the area and within vertical soil profiles. Statistical analyses of the relationship of MS values to HM values are presented and discussed. Strong positive correlations between MS values and HM concentrations are found for Fe, Mn, Pb, Zn, Cu, and Cd within the studied soil profiles.

Magnetic proxies; Heavy metals; Soil pollution; Lausitz area; Germany

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