Uwagi o plejstocenie w dolinie Pilicy na południe od Sulejowa

Krzysztof Grzybowski


Remarks on the Pleistocene in the Pilica Valley south of Sulejów

In the investigated area Pleistocene deposits are generally overlying Jurassic and Cretaceous rocks (Fig. 1). The thickness of Pleistocene deposits in the southern part of this region exceeds locally 80 m. The surface of Quaternary fundament is very diversified since its culminations are elevated by up to 130 m above the depressions of valley filled with Quaternary deposits. In the northern part of this region denivelations of the fundament surface do not exceed in general 30 m. Diversified morphology of fundament is connected first of all with erosion activity during the Great Interglacial period (Mindel/Riss) when nearly all the older Pleistocene deposits have been removed. Only locally some patches of washed out glacial clay of the Cracovian glaciation (Mindel) were preserved. In the southern part of the region it was possible to reconstruct a fragment of interglacial valley system (fig. 2), along which water were flowing westwards. In the environs of Aleksandrów and Janikowice there was a divide separating the above metioned and a system of ancient valleys occurring north of Sulejów. This divide was dissected at the end of the interglacial period. The interglacial valleys have been subsequently filled with fluvial sands containing intercalations of gravels and muds. Total thickness of these deposits amounts to 60 m. The latter have been covered with fluvioglacial sands and then with boulder 'day of the maximal stadial of the Middle Polish Glaciation (Riss). Recession of the continental ice-sheet of this stadial was accompanied by the formation of terminal morains. In the later Pleistocene periods the Scandinavian ice-isheet did not reach the region under examination.

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