Malacological sequence of Weichselian (MIS 5-2) loess series from a profile in Grodzisko Dolne (southern Poland) and its palaeogeographic significance

Abundant and diverse molluscan assemblages have been identified in a loess site in Grodzisko Dolne. The profile is located in south-eastern Poland within a loess belt covering the Kolbuszowa Plateau. In the exposed sequence, which is 9 m thick, two loess covers underlain and divided by initial soil sequences have been distinguished. Numerous molluscan remnants were found throughout the entire profile. The malacological analysis enabled four faunal assemblages to be distinguished: Pupilla fauna, Succinella fauna, Arianta fauna and Mixed fauna. Their sequence in the vertical profile is indicative of environmental changes, especially concerning climate and substrate humidity. The occurrence of malacofauna within the loess and soil sequence which corresponds to the Early Glacial and Early Pleniglacial (MIS 5 and 4) is particularly interesting. The presence of molluscan shells in loesses of this age has been noted in few sites in Europe. The faunal studies and analyses performed in the Grodzisko Dolne site indicate the major importance of this profile in the research of regional differences in Weichselian loess covers in Europe.