Pliocene—pleistocene boundary in the Kleszczów Graben at Belchatów, central Poland

Abstract

The Pliocene-Pleistocene boundary, defined using pollen analysis, has been recorded in sections at the Betchat6w outcrop, Kleszczow Graben, central Poland. The boundary is located at the top of the green clay subunit of the Tertiary Clayey-sandy unit. A pollen flora of Reuverian C type, dominated by pine, 10-20% of 'Reuverian elements' and scarce thermophilous Tertiary trees, was found directly below this subunit. Cold stage floras of Praetiglian type were, in turn, recorded in the tekilisko Formation, lying directly on the green clays. The Pliocene-Pleistocene transition at Belchatow demonstrates the characteristic features of this boundary in western Europe, that is, the disappearance of Tertiary thermophilous tree pollen taxa, followed by a cooling to open-forest or forest-steppe conditions. Both pollen analysis and geological data suggest continuous sedimentation at least from the Upper Pliocene to the PraeTiglian, with no change of sediment sources and no marked hiatuses. The fluvial deposits of the Praetiglian Cekilisko Formation, although Pleistocene in age, mark a final period in the Tertiary evolution of the Kleszczow Graben. Later, there is a hiatus to the deposition of the first glacigenic sediments in the region possibly of Elsterian age. jourml of Quaternary Science

Evolution of Early Pleistocene fluvial systems in central Poland prior to the first ice sheet advance – a case study from the Bełchatów lignite mine

“…A palynological analysis of organic beds has revealed cool Pleistocene floras. Krzyszkowski & Szuchnik (1995) evidenced that the heavy-mineral spectrum was nearly the same as in Neogene deposits, only some increase of garnet frequency and sand-grain roundness was noted. They concluded that there was no hiatus between the Neogene Clayey-sandy Unauthenticated Download Date | 5/11/18 1:14 PM Complex and the Pleistocene Łękińsko Series.…”

“…These are so-called 'brown sands' which underlie Quaternary deposits at Bełchatów. Krzyszkowski & Szuchnik (1995) studied the organic beds in the top part of the Clayey-sandy Complex and noted that it was difficult to correlate the pollen assemblage from these beds with Pliocene spectra of other Polish sites. Those authors found some similarities to Late Pliocene (cool phase C of Reuverian, sensu Zagwijn) in northwest Europe.…”

“…In the eastern part of the Bełchatów mine Krzyszkowski & Szuchnik (1995) identified the lower Pleistocene alluvium as the Łękińsko Series, overlying the Neogene Clayey-sandy Complex. With ongoing exploitation, in the middle part of the mine, other fluvial deposits cropped out above the Neogene Clayey-sandy Complex.…”

“…In this zone Krzyszkowski & Szuchnik (1995) documented the Łękińsko Series (Figs. 1, 2), the base of which was found at an altitude of 152-155 m a.s.l.…”

“…Baraniecka & Sarnacka (1971) attempted to determine the preglacial units in the area. Studying the successions that cropped out at the mine, Krzyszkowski & Szuchnik (1995) subdivided the oldest Pleistocene deposits in the Kleszczów Graben into the Łękińsko Series. As a result of successive exploitation the next fluvial deposits above the Łękińsko Series were exposed (Fig.…”