Biostratygrafia i wiek izotopowy pogranicza kredy i trzeciorzędu w otworze wiertniczym Boryszew (Polska centralna)

Abstract

W otworze wiertniczym Boryszew na głębokości 193–207 m występują osady piaszczysto-margliste, bardzo silnie glaukonitowe z bogatymi szczątkami makro i mikrofauny, Wiek tych osadów oznaczono jako wczesnotrzeciorzędowy (danomont). Ostatnio dokonano rewizji tego wieku na podstawie otwornic (K. Pożaryska) oraz analizy glaukonitu metodą potasowo-argonową (H. Kreutzer) i określono go na wczesnopaleoceński.

BIOSTRATIGRAPHY AND ISOTOPIC AGE OF CRETACEOUS AND TERTIARY JUNCTION BEDS FROM: THE BORYSZEW BOREHOLE (CENTRAL POLAND)

Marly sands with a large admixture of glauconite and very rich in micro and macrofaunal remains were found at the depth of 193–207 m in the Boryszew borehole near Sochaczew, 60 km west of Warsaw. The deposits were studied by M. Różkowska, E. Voigt of FRG, A. Rosenkrantz of Denmark, R. Kongiel, K. Poąaryska and H. Pugaczewska, who identified several hundred species of corals, bryozoans, brachiopods, echinoids, foraminifers and serpulids. The deposits were assigned to the Lower Tertiary or Danian (A. Rosenkrantz, 1964; R. Kongiel, 1958), mixed, Dano-Montian (E. Voigt, 1964) or Montian (K. Pożaryska, 1964; M. Różkowska, 1955). The age of deposits from this borehole was subsequently reanalyzed by K. Pożaryska (1965) on the basis of rich foraminifer assemblage. Within the framework of the IGCP Project 124, the NW-European Tertiary Basin, K–Ar datings of glauconite from these deposits were made by H. Kreutzer of FRG.

According to these datings the deposits are 60.2 ± 0.9 · 10⁶ years old, that is they are of the Early Paleocene age.

On the basis of foraminifers, the deposits are correlated with those of GDR, USSR, Denmark, Belgium, Netherlands, England and USA.