Glacial morphogenesis of uplands of the Warta Glaciation in Poland as a control on heavy metal distribution in deposits

Abstract

The investigations were carried out to determine the relationship between Cr, Co, Cd, Cu, Zn and Pb content and glacial morphogenesis that implies the geomorphological position of outcrops of Quaternary deposits. The analysis deals with parts of two glacial uplands whose relief developed during deglaciation of the Warta ice sheet and which are characterized by similar relief and lithology of surface deposits. These are the Nidzica Upland near Grzebsk and the Bielsk Plain near Bielsk Podlaski. These areas show distinct regularity in pattern of geomorphological units, proving their areal deglaciation. Melt-out depressions, side valleys, ablation covers, kame terraces and kames as well as glaciofluvial plains are observed. The typical geomorphological element is isolated morainic hills (mesas). The investigations enabled determinations of regularity in the distribution of chemical elements in the soil environment of the geomorphological units. Among mineral sediments, clay interlayers observed within kame terrace and kame deposits were the most susceptible to concentrations of heavy metals, regardless of the region and the element to be determined. Lower Cd, Cu, Co, Pb, Zn and Cr contents were associated with morainic mesa and ablation cover deposits. The lowest contents of heavy minerals were measured in glaciofluvial plain, kame and kame terrace sands. Among landforms filled with organic deposits, the highest abilities to fix Cr, Co, Cu and Zn were shown by ice-dammed basins within upland deposits (Nidzica Upland) and side valley deposits (Bielsk Plain). Peats and muds of melt-out depressions were found to be most active in retaining Cd and Pb.