Stratygrafia oligocenu Polski zachodniej na podstawie makrofauny

Abstract

THE STRATIGRAPHY OF THE OLIGOCENE OF WESTERN POLAND ON THE BASIS OF ITS MACROFAUNA

The interpretation of the macrofauna found in bore-holes Wschowa geo 6, Drawno geo 1 and Gorzów Wielkopolski IG 1 disclosed the occurrence of the Oligocene in the vicinity of Wschowa and of the Middle Oligocene in the region of Drawno and Gorzów Wielkopolski.

The faunal association from bore-hole Wschowa geo 6 contains, among its 23 mollusk species, 7 Lower Oligocene species, 2 species from the Eocene-Lower Oligocene, 3 species extending from the Eoecne to the Upper Oligocene, 1 species extending from Middle to Upper Oligocene, 5 species known from the entire Oligocene, 3 species appearing in the Oligocene and Miocene, and 2 species occurring in Middle and Upper Oligocene. Since in this association forms of positively Middle or Upper Oligocene are lacking, and 30% of the species show a Lower Oligocene character; it seems reasonable to assign the Tertiary sediments appearing in bore-hole Wschowa geo 8 in the range from 393,6 m. to 396.8 m.to the Lower Oligocene; although part of the Middle and Upper Oligocene forms imply the feasibility of assigning the sediments to the upper, part of the Lower Oligocene. The absence of stenohalic forms, like pectens and echinoderms indicates a brackish character of these deposits.