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The Pannonian Basin was located in the southernmost, disputed limit of permafrost during the Last Glacial Maximum (LGM). In the western part of the basin, over an area of 1,200 km2, more than 150 sites with polygonal patterned ground were surveyed, and 72 sediment samples from forms identified as relict sand wedges were collected. Ten optically stimulated luminescence ages were obtained from the infills, while morphometric analyses were also carried out on satellite images. Our study revealed that the polygonal networks developed in several phases, from 15.01 ± 1.68 to 23.0 ± 1.7 ka. The polygons have an average diameter of 13–23 m and are mainly present on flat surfaces, intruding into the gravelly, alluvial host of the paleo‐Rába. Statistical analyses highlighted the short transportation period of the sandy infill and multiple sediment provenances. This study adds further data to assess the presence of permafrost or deep seasonal frost and to the interpretation of the LGM in the central European periglacial domain. [ABSTRACT FROM AUTHOR]

Wedge structures and involutions suggest that Late Pleistocene frozen ground, either permafrost or deep seasonal frost, extended at least as far south as latitude 47° N in central Europe (the Pannonian Basin). Optically stimulated luminescence dating of the sand infill from a number of wedges indicates that emplacement of the sand infill occurred during the Late Pleistocene (22.2-15.7 ka). This suggests that during this time the mean annual air temperature was depressed by at least ∼15° C relative to the present. Either continuous or discontinuous permafrost was probably present in the north and NW of the Pannonian Basin. The subsequent thaw of frozen ground is indicated by the widespread occurrence of deformed sediments. The presence of soil (ground) wedges suggests conditions of deep seasonal frost probably existed during the period when climate ameliorated following the Last Permafrost Maximum ( LPM). [ABSTRACT FROM AUTHOR]