The town of Litija and the surrounding area have been strongly influenced by mining throughout history. The Sitarjevec mine is classified as a polymetallic mine. In order to characterise the geochemical and mineral composition and to determine the levels of potentially toxic elements (PTE) in the environment, stream sediment samples were collected from eight sites in the vicinity of the Sitarjevec Mine. Stream sediment is a good indicator of the geology and human activities in the catchment area.
The geochemical and mineral composition of the samples were determined by X-ray fluorescence spectroscopy (XRF), X-ray powder diffraction (XRD) and in-line electron microscopy combined with energy dispersive X-ray spectroscopy (SEM/EDS). The geochemical results show that the SiO2 content is above 47% in most of the samples. The two samples at Li-8 stand out with a lower content of SiO2 (less than 35%) and the highest content of CaO. Most of the samples have elevated contents, mainly of Ba, Pb and Zn. Based on the results of the parametric t-test and the non-parametric Mann-Whitney test, as well as the ranges of values of individual oxides and elements, we found that there are no significant differences in geochemical composition between the two fractions (2-0.063 mm and < 0.063 mm). XRD identified quartz, muscovite/illite, clay minerals and feldspars in all of the samples and dolomite in four of the samples. SEM/EDS analysis confirmed the presence of barite, galena, zircon, ilmenite, TiO2 (probably rutile), various iron oxides/hydroxides, monazite group minerals, xenotime group minerals and pyrite. The correlation coefficients of the individual elements confirm the mineral composition.
All samples exceed the target, alert or intervention values for at least one PTE. Intervention values were exceeded for As (one sample), Ba (13 samples), Pb (four samples) and Zn (four samples). Warning values were also exceeded for As (two samples), Pb (eight samples) and Zn (five samples). Cr, Cu and Mo values exceeded the limit values in individual samples.
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