Late Plenivistulian deglaciation and the expansion of the periglacial zone in NW Poland

Abstract

In NW Poland, in the area of the last Scandinavian icesheet, periglacial phenomena occur mostly in outwash plains, till plains and pradolina terraces, and sporadically also in alluvial fans and inland dunes. Some of them contain indications of former permafrost and can be used in palaeoenvironmental reconstructions of the Late Pleistocene deglaciation. They include epigenetic and syngenetic ice-wedge casts, fossil sand-wedge polygons, ice-vein network casts and oriented icing depressions. The cryostratigraphic record of permafrost indicators and their geomorphic distribution testify to the presence of continuous permafrost or at least vast permafrost patches in the deglaciated area in NW Poland during the Late Plenivistulian and during cold spells of the Late Vistulian.