Sedimentological and mineralogical characteristics of the Pleistocene loess/paleosol sections in the Eastern Croatia

Abstract

Abstract In the Eastern Croatia impressive loess–paleosol successions up to 30 m thick are exposed. In the Zmajevac I section three paleosols are intercalated in loess while in the Zmajevac, Erdut and Sarengrad sections there are four paleosols are intercalated in loess. IRSL age estimates of 17.8 ± 1.9 and 217 ± 22 ka. In all investigated sections, alluvial sediments are intercalated in the loess deposits, indicating periods of fluvial activity. Strongly abraded typical aeolian spherical grains characterized by pitted well-rounded surface that was developed during transportation have original crystal surface almost destroyed. Surface of quartz grains preserves micro textures characteristic for all transport medias that it has been exposed to. However, muscovite grain surface enable successful distinguishing if the last transport was by wind or by aquatic media. Characteristic of all horizons with muscovite as a dominant mineral is recent settling of organisms. Beside the Danube, Drava and Sava River flood plains, part of the analyzed sediments also originates from regional Tertiary sediments which are rich in granite (as a muscovite-bearing rock), indicating the local influence. Enrichment of pyroxenes in the Sarengrad section points to the Dinaride Ophiolite Zone as its source of origin eroded by the Sava River southern tributaries. Sarengrad section is the southernmost among the analyzed sections and the southern edge of the Carpathian Basin. Thus, beside the Alpine region, the mineral composition is influenced by minerals from the Dinaride Ophiolite Zone in Bosnia. Warming periods are not represented just by paleosols, but also with laminated alluvial sediments.