Postglacial morpholineaments as an indicator of ice sheet dynamics during the Saale Glaciation in the Białystok Plateau and Sokółka Hills (NE Poland)

The palaeogeographical reconstruction of the deglaciation process in NE Poland during the Odranian Glaciation Wartanian Stadial (Saale MIS 6) is based mainly on the analysis of glacial morpholineaments, performed using the GIS programs that provide us with better understanding of the glacial landscape evolution, spatial reconstruction of glacial processes, and postglacial landscape development. Analysis of postglacial morpholineaments was carried out based on the Digital Elevation Model (DEM) as well as geological, geomorphological and topographic maps. It resulted in the delimitation of visible linear postglacial landforms, their identification and classification, and the determination of their genetic and chronological relations. Directions of the lineaments were determined through quantitative analysis. Qualitative analysis was applied to determine the spatial and temporal sequence of events, directions of ice movement and its range. Two glacial lobes, Biebrza and Neman, existed in the north-western part of the Białystok Plateau and Sokółka Hills during the last glacial advance. The lobed nature of the ice sheet can be confirmed by field data collected from, e.g., sites in Knyszewicze, and by topographic analysis of Quaternary sediments, combined with their thickness and genesis. The obtained reconstruction of the last glacial advance and retreat in the study area can be used in further regional discussions on the character and dynamics of the last glaciation in this region.