Morphological and geochemical record of historical erosion on the example of small alluvial and deluvial fans accumulated on the Bug River terraces in the Neple area (Podlasie Lowland, eastern Poland)

Abstract

The gullies in the vicinity of Neple (Podlaska Lowland, eastern Poland) are relatively young and were created due to the land use and climate changes. The aim of the research was to determine the variability of selected alluvial-diluvial fans occurring in the Bug River valley and their age using interdisciplinary methods (e.g. absolute dating, geochemical analyzes, cartographic data). Geological mapping and several drillings (both within the fans, valleys or gullies bottoms and glacial or fluvioglacial plateaus) were done. Historical data dealing with the human economic activity in the region were analyzed. The obtained radiocarbon dating and geochemical features of sediments building the alluvial and diluvial fans proved that these forms are not older than some 500 years. Due to the lateral movement of the Bug River channel only some of the forms are preserved in the area under study. The rest of them disappeared due to the fluvial erosion.