Mineralogiczno-petrograficzne podstawy wydzieleń kompleksów osadów trzeciorzędowych

Abstract

MINERALOGICAL AND PETROGRAPHIC BASIS FOR DISTINGUISHING COMPLEXES OF TERTIARY AND "PREGLACIAL" DEPOSITS AT HIPOLITOWSummaryFive different complexes were distinguished in Tertiary and “preglacial” deposits from the Hipolitów borehole, nearWarsaw, on the basis of granulation, rounding of quartz grains (Fig. 1), and the mineral-petrographic composition (Fig. 2).The oldest complex I, extending, to a depth of234.4 m, was assigned to the Palaeocene by J. Nowak and T. Uberna (19"76). Complex II is characterized by the occurrence of feldspars (labrador) and considerable, though varied, quantities of topaz and andalusite, in addition to the predominating tourmaline-zircon group. This complex was compared with analogically developed deposits from the area ofWarsawand Otwock, so far assigned to the Eocene(?) – Oligocene (M. D. Baraniecka, in press; G. Kociszewska-Musiał, B. Kosmowska-Ceranowicz, in press). An attempt to compare these deposits with the Dipper Eocene series from Siemień (a sample from a borehole in Antonin was examined) has brought negative results so far, but this does not exclude the possibility that the uppermost beds of complex II may be assigned to another member of the Eocene (?).Complex III is distinctly tripartite, with a very characteristic middle series, marked by a large amount of disthene, the lack of garnet, an almost monomineral composition (quartz), and a very good rounding of quartz grains. A similar series was described from the vicinity ofGdansk(B. Kosmowska Ceranowicz, T. Hanczke, G. Kociszewska-Musiał, 1974). These are Miocene sands, interbedded with coals.The lower boundary of complex IV, a silty-clayey one, with typical variegated clays of the Pliocene, has not been definitely established. Feldspar-quartz fragments, which are most characteristic of this complex and of the overlying complex V, appeal already in the upper series of complex III.Deposits of complex V are characterized by the predominance of garnets, a considerable amount of feldspars and feldspar-quartz fragments, and poorly rounded quartz grains (Fig. 1). They belong to the typical preg1adal that has already been described from many localities.