Record of the Vistula ice lobe advances in the Late Weichselian glacial sequence in north-central Poland

During the Last Glacial Maximum (LGM), the Vistula ice lobe was one of the key morphological elements at the southern margin of the Scandinavian Ice Sheet in north-central Poland. The area of the Vistula ice lobe experienced two ice sheet advances of varied extent: the older one is correlated with the Leszno (Brandenburg) Phase and the younger one is correlated with the Poznań (Frankfurt) Phase.Sedimentological research and luminescence dating of the Late Weichselian glacial sequence in the Vistula ice lobe area was conducted. A new scenario of the Late Weichselian ice events in the area is presented. The limit of the Leszno Phase within the Vistula ice lobe was much smaller than had been accepted previously, and its age is estimated to be about 20,300 BP. Significant ice sheet retreat was followed by an ice re-advance during the Poznań Phase, overriding the extent of the Leszno Phase. The Poznań re-advance reached the maximum limit in the Vistula ice lobe area about 18,400 BP. The rapid ice sheet transgression, especially during the Poznań Phase (on average 400 m/a), was connected with the Vistula palaeo-ice stream.