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Loess/Paleosols Sections in Eastern Croatia

The Pleistocene loess and Holocene alluvial sediments are dominant lithological members of Eastern Croatia. Impressive loess-palaeosol successions up to 30 m thick are exposed in Croatian part of Baranja (Zmajevac) and along the steep cliffs of the Danube River (Erdut and Šarengrad). The Croatian loess record provides an excellent high-resolution archive of climate and environmental change, providing evidence for the interaction between accumulation and erosion of aeolian and fluvial sediments during the Middle and Late Pleistocene. Sedimentological and pedological investigations were carried out on 110 samples collected from the loess sections at Zmajevac, Erdut and Šarengrad. Analyses include grain size analyses, XRF, microscopic analyses of light and heavy mineral fraction, chemical analyses of major and trace elements and REE, determination of carbonate content, pH, TOC and dating by infrared optically stimulated luminescence (IRSL) The age determination of the loess sediments between the palaeosols by IRSL provides a reliable basis for identification of the soil forming periods. Geochemical (content of major and trace elements, and REE, TOC, pH, CaCO3 content) and sedimentological (grain size, lamination, microscopic characteristic of carbonate concretions), characteristics of investigated palaeosols explained the main characteristics and degree of pedogenesis, while differences in composition of heavy and light mineral fraction emphasized differences in source material for the sediments under investigation. Presence of erosional discontinuities and infilling of crotovinas with soil material indicate that some of palaeosols are eroded and thus represent an incomplete record. Elementary statistics shows no significant difference in chemical composition between profiles. Loess horizons contain <0.1% of TOC, while palaeosol horizons contain between 0.1 and 0.5% of TOC. Based on TOC values, the sub-groups of samples selected according to the degree of soil development can be distinguished. The results of F- and t-tests show that weathering coefficient Ba/Sr fits the criteria of equality of variances and means in less developed palaeosols and palaeosols. Accordingly, possibility cannot be rejected that two subgroups of samples belong to the same population.

loess; palaeosols; porosity; statistical tests; Pannonian basin; Croatia

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