Glacial and neotectonic constraints on the Quaternary evolution of the Fore-Sudetic reach of the Nysa Kłodzka River

Abstract

This work shows influence of the Pleistocene ice sheets and neotectonic movements on palaeogeogrophic evolution of tile eastern part of the Sudetic Foreland during the Quaternary. Mutual relationships between glacial and fluvial series have been analysed. The preglacial fluvial deposits of the Nysa Kłodzka River are proved to have been much more widespread in the Sudetic Foreland compared with the extent that had been suggested before. A series of morphometric methods, using computer data analysis, have been applied in order to reconstruct influence of neotectonic movements on development of the river system. Influence of the Pleistocene ice sheets on palaeogeographic evolution of this region cannot be easily reconstructed in detail due to strong erosional transformations of glacial deposits. The Quaternary neotectonic movements influenced a river system stronger than it has been suggested before. They resulted in deformations of the oldest fluvial accumulation beds, being of the order of 40-50 m. Neotectonic movements are also proved by several meters high deformations at the lowest beds of river valleys.