Ventifacts in the Mecsek region (SW Hungary) - Climatic interpretation and tectonic implications

摘要

The paper examines aeolian erosion in the SW Pannonian Basin, in the southern part of the European Pleistocene periglacial belt. In contrast to more northerly regions, where ventifacts and wind-sculpted landforms abound, only scarce signs of wind erosion have been reported here so far and this has been explained by the wind shadow effect of the Eastern Alps. Ventifacts mapped recently at numerous sites in the southern foreland of the Mecsek Mts. challenge this view. Together with some wind-blown sands they prove that conditions necessary for aeolian erosional processes were present in the Pleistocene and refer to areally widespread wind erosion. Multiple ventifact levels in the stratigraphic column and weakly developed ventifact morphologies indicate recurring but short wind erosion periods. The geometry of a reconstructed ventifact horizon indicates increasing elevation difference between the mountains and the foreland as well as intensifying valley incision in the late Quaternary, referring to ongoing vertical tectonic movements. The low number of ventifacts found does not necessarily prove a lack of aeolian erosion, it can also result from the inappropriateness of lithologies for ventifaction as well as from continuous erosion and burial due to tectonically induced increase in relief.