engleski

The composition of soils developed on different lithological units of the Medvednica Mt.

Statement of the Problem: Six pedological profiles were analyzed overlying the five typical lithological units on the Medvednica Mountain to determine the effect of aeolian additions to the soil composition, as well as the possible influence of relief, vegetation cover, and anthropogenic input on the dynamics of pedogenesis. Methodology: Bedrock composition was defined using petrographic (thin sections) and chemical (major and trace element contents) analyses, whereas pedological, sedimentological and geochemical characteristics of six cross-sections were determined by chemical (major and trace element contents), mineralogical (modal analysis), and grain size analyses. Findings: Soils developed on sedimentary bedrock (Mollic Rendzic Leptosols (Calcaric) and Albic Luvisol (Sceletic)) mostly originate from weathering of siliciclastic detritus that was exposed to oxidization before diagenesis. Furthermore, soils on metasiltstone, marble and lithothamnium limestone exhibit similar modal and geochemical composition and element distribution across the soil profile. In contrast, soils developed on igneous bedrock originate mostly from weathering of minerals of the first weathering cycle and thus abound with chemically less resistant minerals and less mobile elements. However, all profiles contain higher concentrations of lead with respect to bedrock, indicating airborne contamination. Conclusion: Soils developed on the sedimentary rocks mostly originate from weathering of siliciclastic detritus that was exposed to oxidization before diagenesis of the bedrock. Thus, the soil was depleted in all chemical components that were unstable in subaerial conditions. After diagenesis, chemical composition of the soil did not alter substantially, or the changes were reversible. Therefore, soils on metasiltstone, marble and bioclastic calcarenite have similar modal and geochemical composition and element distribution in the soil profiles. As a contrast, soils developed on orthometamorphite bedrock originate mostly from the weathering of minerals of the first weathering cycle, which is why these contain chemically less resistant minerals and mobile elements.

Soil profile Geochemistry Mineralogy Parent material Eolian contribution

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