Vistulian periglacial and glacial environments in central Poland : an overview

Vistulian climatic changes are recorded in various sedimentary environments of central Poland, both in the extraglacial zone of the last glaciation and also in the area occupied by the last Scandinavian Ice Sheet, being reflected by palaeobotanical, palaeozoological, sedimentological and geochronological data. The most pronounced morphogenetic processes are linked to a glacial succession in the northern part of the study area, referred to the Upper Plenivistulian. For most of the study area, located in the extraglacial zone, the climatic changes are reconstructed from lake-bog, fluvial, slope and aeolian sedimentary successions. In central Poland, no site has been documented so far where there would be a continuous biogenic record through the whole Vistulian. Environmental changes recorded through the Vistulian include temperature, vegetation and the dynamics of morphogenetic processes, and sedimentary environments most useful for assessing changes occurring at that time may be indicated. The Early Vistulian is best recognized within biogenic deposits, as in the older part of Plenivistulian. The conditions in the earlier part of the Plenivistulian are best reported from fluvial and slope deposits with evidence of permafrost and of glacial conditions, though only in the northern part of the study area. Changing conditions of the Late Vistulian are expressed via well-documented morphogenetic processes occurring in all (except glacial) sedimentary environments, lake-bog and aeolian environments providing the most complete information about the nature of this period. Most of the Vistulian deposits reflect cold periods. There is a distinctive increase in periglacial impacts throughout the Plenivistulian with the apogee during the Upper Plenivistulian and interstadial warmings did not influence this trend. Each sedimentary environment provides significant data about the climate evolution, and processes playing a leading role vary according to the Vistulian stratigraphic unit. The consolidation of findings from regional research has provided new directions for further interdisciplinary studies.