Discrimination Of Fluvial, Eolian And Neotectonic Features In A Low Hilly Landscape: A Dem-based Morphotectonic Analysis In The Central Pannonian Basin, Hungary

摘要

The Godollo Hills, a low-relief terrain within the Central Pannonian Basin in Hungary, is characterised by moderate tectonic deformation rates. Although typical tectonic landforms are not dearly recognisable in the study area, this paper succeeded in discriminating between tectonically controlled landforms and features shaped by fluvial erosion or deflation with no tectonic control. DEM-based morphometric parameters including elevation, slope and surface roughness, enabled the delineation of two NW-SE trending spearhead-shaped ridges separated by a wide rectilinear valley of the same strike. Although directional statistics suggested possible tectonic control of NW-SE striking landforms, precise morphometry completed with an analysis of subsurface structures rejected their tectonic preformation. Deflation plays a significant role in shaping the area, and the presence of two large-scale yardangs separated by a wind channel is proposed. In temperate-continental areas of Europe, no deflational landforms of such scale have been described so far, suggesting that Pleistocene wind power in periglacial areas was more significant than it was previously thought. Characteristic drainage patterns and longitudinal valley profiles enabled the recognition of areas probably affected by neotectonic deformation. A good agreement was observed between locations of Quaternary warping predicted by the morphometric study and subsurface structures revealed by the tectonic analysis. Zones of surface uplift and subsidence corresponded to anticlinal and synclinal hinges of fault-related folds. In low-relief and slowly-deforming areas, where exogenous forces may override tectonic deformation, only the integrated application of morphometric and subsurface-structural indications could assure correct interpretation of the origin of various landforms, while a morphometric study alone could have led to misinterpretation of some morphometric indices apparently suggesting tectonic preformation. On the other hand, the described morphological expression of subsurface structures could verify Quaternary age of the deformation.