Fauna oligoceńska z otworu wiertniczego Izbica Kujawska

Abstract

OLIGOCENE FAUNA FROM THE BORE HOLE IZBICA KUJAWSKA (KUJAWY AREA)

Summary

The article presents a section of the Lower Oligocene encountered in the bore hole Izbica Kujawska K-67. The Oligocene consists here of 33,20 m thick bed of grey muscovite clays, yellow silts with glauconite, and light-grey clays that rest on a weathered surface of Jurrassic dolomites and are overlain by the Miocene and Quaternary overburden deposits, 120 metres in thickness. The species of the fauna occurring in the deposits under consideration are known from the Oligocene of Germany, Netherlands, Belgium, Denmark, France, Great Britain and Ukraine, a fact proving a connection of the Polish Lower Oligocene basin with the Oligocene seas of these countries. The assemblage here discussed lacks certain forms characteristic of the Middle and Upper Oligocene. On the other hand it contains even 7 species typical of the Lower Oligocene, this constituting almost one third of all 22 species documented. Such an assemblage of fauna proves the Lower Oligocene age of the deposits. A fact that almost all these species are found in the Lattorfian near Magdeburg allows to accept here Lattorfian age. Since much of these species pass into the Middle and Upper Oligocene we may assume that the deposits under discussion are of Upper Lattorfian age.