engleski

Characteristics and provenance of loess in Baranja

Loess is terrestrial clastic sediment, composed dominantly of silt-sized particles formed by the accumulation of wind-blown dust. Small percentage of sand-sized particles are also present in loess deposits. Loess is usually inter-bedded with soil horizons forming loess-paleosol successions (LPS). Thickest LPS in Croatia are found in Baranja, region bounded with two big rivers, the Danube and the Drava. Two loess profiles on slopes of Bansko brdo were investigates. The results from grain-size, modal and SEM analyses provide information about source material and wind direction in different time periods during Pleistocene. Garnet, epidote and amphibole mineral group are most abundant heavy minerals in samples of the Danube River sediment. Comparing heavy mineral assemblage from studied LPS with that data, it is obvious that the main source area for loess in Baranja was the Danube alluvial plain and the main transport direction was from the North or North-West. However, the concentration of amphiboles higher in studied LPS (mean 26.3% in HMF) then in the Danube alluvial plain suggests additional source area. Western Carpathians with Neogene calc-alkaline volcanic rocks is a major source of that mineral in the Pannonian Basin. Alternatively, they could originate from locally exposed volcanic and metamorphic rocks. Hence, amphibolites are known from nearby Slavonian Mts. − Mt. Krndija and Mt. Papuk − adjoining the study area to the southwest. In that case, small amount of silty material of the Baranja loess would be transported by WSW winds. Except for that difference implying diversity and shifting of source area for Baranja loess during Late Pleistocene, the present results stay in good congruence with results from other LPS loess localities in the Pannonian Basin.

loess; Baranja; Pannonian Basin; silt

nije evidentirano