Korelacja profilów plejstocenu w prawej krawędzi doliny Wisły (zachodnia część Kotliny Płockiej)

Abstract

 Opisano i skorelowano kilkanaście profilów osadów plejstoceńskich w krawędzi doliny Wisły okolic Dobrzynia i Włocławka. Wyróżniono nieznaną dotychczas warstwę gliny zwałowej pochodzącą przypuszczalnie ze zlodowacenia południowopolskiego. Postulowano opracowanie profilu podłużnego prawej krawędzi doliny Wisły miedzy Włocławkiem i Modlinem. CORRELATION OF PLEISTOCENE SECTIONS FROM RIGHT MARGIN OF THE VISTULA RIVER VALLEY (WESTERN PART OF THE PŁOCK BASIN) Over a dozen sections of Pleistocene deposits are described from right margin of the Vistula River valley in the Płock Basin, about 100 km WNW of Warsaw (Fig. 1). The deposits, 15–50 m thick, rest on trunctated glacitectonic structures built of Pliocene clays and Miocene sands with brown coal, which are the subject of a separate paper (M. Brykczynski, 1982). Five major lithostratigraphic horizons are distinguished: three till horizons, varved clay horizon separating the lower, hitherto unknown, and middle tills, and horizon of fluvioglacial sands and gravels, separating the middle and upper tills (Fig. 2).The middle till appears clearly bipartite (Fig. 3). A series of fluvioglacial gravels with boulders, over 30 m thick, was found to occur in some places at the base of the lowermost till (Fig. 2, section no. 1).With reference to stratigraphic subdivision of the Pleistocene of the Plock Basin, compiled by S. Skompski (1969), the tills were assigned to the South-Polish, Mid-Polish and Baltic Glaciations, respectively.The major lithological members of the Pleistocene appear to be continuous at relatively large distances along the margin which suggests the possibility to compile longitudinal geological section for the whole latitudinal fragment of the Middle Vistula River valley, where good exposures are fairly common. Such section may play the role of stratotype for the Pleistocene in central Poland.