Danubian loess shows dominance of proximal sediment sources and negligible inputs from the Sahara

Abstract

The Pannonian Basin, especially areas in proximity to the Danube River, provides a record of long-term Quaternary dust (loess) deposition in central-eastern Europe. Here, Sr-Nd isotopic data from 47 samples (four profiles) from loess-palaeosol deposits spanning the last two-glacial-interglacial cycles is presented. This geochemical data is compared with a large number of bedrock and sedimentary samples from across the region to decipher the sources of sediment and transport pathways. The results counter the hypothesis that the Sahara was a major sediment contributor to loess in central-eastern Europe. Instead North African contributions are shown to have been negligible over the late Pleistocene, which suggests suppressed southerly wind direction and supports westerly and northwesterly wind systems. The isotopic results point to alluvial plains (which are themselves sourced from surrounding mountain belts) as an immediate geomorphic source of material and consequently relatively short distance transport.