Aluwialne wypełnienie doliny oraz stożek napływowy na terasie zalewowej Prosny w Kościelnej Wsi (koło Kalisza) : zmienność litofacjalna i antropogeniczne uwarunkowania

The sediment study of the alluvial bottom of Prosna river valley and of alluvial fan in the floodplain terrace, with the special attention paid to its origins, anthropogenic conditions at that time and also to lithofacial variability, enabled to draw the following conclusions. The fan was the result of erosion-denudation processes triggered after 6220š140 BP (Gd-4677) (about 4300 BC). The beginning of these processes can be associated with the Neolithic human beings activity, having taken into account conditions of the Holocene Climatic Optimum as well as presence of Neolithic cultures found in the investigated area. The lithofacial analysis of the sediments has revealed a simple fractionation sequence: D right arrow B right arrow C right arrow A for the alluvial filling of the river bottom. This indicates its accumulation as the result of meandering river activity. Cyclical lithofacies transitions for the alluvial fan sediments have been observed: A (sandy) into F (sandy-silty) and into E (silty)