engleski

Loess/Palaeosol Sequences in Eastern Croatia- Accumulation vs. Erosion

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, 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) Presence of erosional discontinuities and infilling of crotovinas with soil material that is not present in overlaying sediments indicate that some of palaeosols are eroded and so represent an incomplete record. Presence of soil sediments indicate that within the loess sediment a hiatus can be detected consisting of eroded palaeosol(s), which is not documented by the presence of Cc-horizon. Assuming that intensive pedogenesis is required for forming Cc -horizon that is extremely resistant to erosion, one can infer that several Cc -horizons without interbedded palaeosols indicate that their palaeosols were eroded. Thus, the possibility is ruled out of marking palaeosols by “ counting from surface” and of using correlation method conversing similar outcrop sections in the region. The synthesis of investigated profiles would probably result with at least eight profiles. A-horizons are eroded from all palaeosols. The loess successions are intercalated by at least four palaeosols or pedocomplexes. Alluvial sediments are intercalated in the loess deposits, indicating periods of fluvial activity. Therefore, a higher sampling resolution is needed in the future for the quantitative reconstructing of accumulation and erosion rates as well as a more reliable regional and interregional correlation correlation combining luminescence dating with magnetic and malacological investigations.

loess; paleosoil; erosion; Slavonia; Crtoatia

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