Multivariate statistical approach to identify metal sources in Litija area (Slovenia)

• Sampling and chemical analyses of topsoil and subsoil
• Chemistry varies significantly between both sampled soil layers.
• Identified two geogenic and two anthropogenic geochemical associations
• Geochemical maps of identified groups

A detailed soil geochemical survey has been performed in the abandoned polymetallic (Hg, Pb, Ag, Zn, Ba) mining and smelting region of Litija, central Slovenia. In an area of 30 km2 the soil was systematically sampled using a 500 × 500 m grid (120 sampling sites). Two soil horizons (0–5 cm and 15–30 cm) were sampled in order to distinguish between geogenic and anthropogenic metal sources. A metal dispersion halo has been mapped in a wide circle around Litija. This paper discusses its extension and characteristics, which were established on the basis of metal contents in soil. Data treatment included multivariate statistical approaches (multivariate cluster and R-mode factor analysis), which allowed the identification of two geogenic and two anthropogenic geochemical associations. The main geogenic group of element includes Ce, Cr, Fe, Hf, Nb, La, Th, Ti, Ta, U, V, W and Zr; high contents of these elements are associated with the sand fraction of the Würm terraces. The second geogenic group includes Al, Ba, K, Li, Rb, and Sc; high concentrations of these elements are related to the alluvial sediments of the Sava tributaries. The third geochemical group is partly geogenic and anthropogenic, linking typical elements (Ca, Mg, Sr) of alluvial sediments of the river Sava and some metals (Cd, Co, Cu, Ni, Mn and Zn); the source of these metals is most probably the ferrous metallurgy in the upper part of the Sava valley. The fourth and also the most important anthropogenic geochemical association (As, Mo, Hg, Pb, Sb and Sn) is typical for the areas affected by past mining and smelting activities.