engleski

Loess/palaeosol section in [arengrad, Croatia – The correlation of the geochemical and magnetic susceptibility data

The Šarengrad loess section is located on the south bank of the Danube River in the easternmost part of Croatia. The published lithostratigraphical results including grain size, total organic content, calcium carbonate content and luminescence dating results (Galović et al., 2009 ; submitted) were complemented by geochemical (content of major elements and trace elements and acidity) (Figs. 1 & 2) andmagnetic susceptibility (ê) studies (Fig. 3). Throughout the section, four palaeosols are intercalated in the loess. The oldest, hydromorphic one is covered by laminated alluvial sediments and loess. The second palaeosol is a well-developed dark brown soil, and the other two palaeosols are brownish, less developed and intercalated in loess. Geochemical characteristics of investigated palaeosols explained both the main characteristics and degree of pedogenesis. Major and trace element content is higher in palaeosol than in loess horizons. Palaeosol horizons could be clearly extracted based on weathering coefficients, such as Ba/Sr, and (CaO+Na2O+MgO+K2O)/Al2O3 (Fig. 2). An IRSL age of 86.6±8.6 and 55.3±5.5 ka indicates that most of the middle pleniglacial, pleniglacial and late glacial records are missing at the Šarengrad section (Fig. 3). Earlier research work done on loess chronostratigraphy by means of a luminescence dating approach highlighted the main characteristics of palaeosols and degrees of their pedogenesis in several sections in Eastern Croatia (Galović et al., 2009). However, in this study the focus is shifted to a single loess/palaeosol section in order to provide sedimentological and pedological support to previously investigated archives of Quaternary environmental and climate change on the narrower scale (Galović et al., 2010). Correlation of the geochemical and magnetic susceptibility data and distribution of trace elements with depth in particular, showed that these parameters are primarily the function of pedogenesis. Abundance of investigated trace elements increases with degree of pedogenetic development giving rise to their accumulation in palaeosols rather than in BC- and loess horizons. The highest concentrations are related to argillic and hydromorphic palaeosol horizons.

loess; palaeosol; geochemistry; magnetic susceptibility; Croatia

nije evidentirano