Late Pleistocene (MIS-2-MIS-4) Mollusc Assemblages of the Loess-Palaeosol Sequence in Zalesie Near Przemyœl (southern Poland)

Lithological and malacological anal y sis was car ried out at the loess site in Zalesie near Przemysl. The pro file ex posed here com prises the last gla cial loess-palaeosol se quence L-1 and is cor re lated with the Pleniglacial (MIS-2-MIS-4) of the Weichselian gla ci ation. Three loess lay ers sep a rated by interstadial palaeosols are re cog nised here. Within the two youn ger loess lay ers, cor re spond ing to the youn ger mid dle loess (LMs) and the youn ger up per loess (LMg), and in the soil ho ri zon (Gi/LMs) sep a rat ing them, nu mer ous mol lusc shells were found. The di ver sity of the mol lusc as sem blages al lowed five types of fau nal as sem blages to be dis tin guished. The main fau nal com po nents in the youn ger mid dle loess were open-coun try spe cies typ i cal of dry sub arc tic steppe. The interstadial palaeosol ho ri zon de vel oped on this loess was dom i nated by hygrophilous taxa char ac ter is tic of the sub arc tic tun dra en vi ron ment. The molluscs of the youn gest part of the loess bed com prise mainly mesophilous snails, in di cat ing the pres ence of open but rel a tively hu mid biotopes. The pro file in Zalesie belongs to a tiny group of loess sites in Po land with a com plete malacological se quence pre served, en com pass ing both the youn ger up per and mid dle loesses and the palaeosol ho ri zon sep a rat ing them.