Pleistocene wind system in eastern Austria and its impact on landscape evolution

Abstract

During cold periods in the Quaternary, the intracontinental Pannonian Basin was part of the European periglacial zone, and aeolian erosion had a profound effect in shaping the landscape. Geomorphologically most effective winds were channelled between the Alps and Carpathians and entered the Pannonian Basin from the NW. To assess the nature of meteorological conditions producing these winds, field studies were carried out in the foreland of the basin entrance, in eastern Austria.As a result, we report on the first bedrock ventifacts from Austria and aeolian sand occurrence in the Bohemian Massif. Through a compilation of published data and field work, the distribution of ventifacts was mapped and appears to be controlled primarily by available lithologies. Palaeo-wind directions were identified using mesoforms of bedrock ventifacts, especially flutes. The acquired air flow directions are accordant with the orientation of erosional landforms on soft sediments and form a coherent system, with westerly to north-westerly winds in the west, which turn towards the entrance of the Pannonian Basin in the east. There are no directions referring to the direct influence of katabatic winds produced on the ice sheet, instead, the wind system must have been driven by synoptic-scale patterns like the polar front. The narrow distribution of wind directions suggests that the low-altitude air flow system was relatively stable even without a funnelling topography as in the Pannonian Basin, though the Alps could have acted to deflect the winds. OSL data from the Bohemian Massif indicate aeolian sand movement during the Late Pleistocene. The results provide data for aeolian transport studies, among them for loess provenance analyses and can be used as input for climate models.