Example of periglacial landforms of the Łódź Plateau

Abstract

Article in French.

ORIGINAL TITLE: Exemple du modelé périglaciaire du plateau de Łódź

A detailed map of a fragment of the margin zone of the Łódź Plateau is presented as an example of periglacial landforms in Central Poland. On a substratum composed of Pleistocene sands, gravels, and clays, a series of traces of periglacial morphogenesis have been identified, including in situ debris covers, frost wedges and veins, as well as congelifluction structures. In several locations, truncation of glacial deposits caused by periglacial mass movements has also been observed. The periglacial morphogenesis associated with the South-Posnań stadial of the Wartanian II glaciation led to the development of a specific type of relief. A characteristic feature of this relief is the presence of landforms shaped by denudational processes. On the map, periglacial morphogenetic forms are marked in black. Particularly striking is the abundance of inactive forms such as denudational dells and dry valleys. These dells and dry valleys are connected to fluvial valleys that probably formed during the interglacial period. The meridionally oriented valleys display slope asymmetry related to the periglacial environment. As a result of periglacial denudation that incised into the slopes of the Plateau, its edge retreated southward. In the foreland of the Plateau, north of the escarpment, three levels of slope flattening have been distinguished (only the two uppermost are shown on the map). It is possible that these levels are related to climatic oscillations during the last glaciation. However, based on the analysis of such a small area, it is difficult to draw conclusions regarding the scale of these oscillations.