O mikrofaunistycznej granicy eocenu i oligocenu na Kujawachm

Abstract

MICROFAUNISTIC BOUNDARY BETWEEN THE EOCENE AND OLIGOCENE IN THE KUJAWY AREASummaryThe present paper deals with the micropalaeontological stratigraphy of the older Tertiary encountered by the bore hole Augustynowo 1 situated in the Kujawy area (Polish Lowland). On the basis of an abundant foraminifer fauna revealing a predominance of Upper Eocene species such as Rotalia lithothamnica lithothamnica (Uhl.), Rotalia lithothamnica pinarensis (Cush. et Berm.), Asterigerina bimammata Gümb., and Asterigerina cyclops Dorreen, and on subordinately occurring Oligocene species, the deposits found in this bore hole at a depth from 123 to 207 metres have been determined as transitional between the Upper Eocene and Lower Oligocene. The present author compared the results of her examinations with those obtained by other authors investigating the microfauna from the Izbica Kujawska area, and established stratigraphical value of some species of foraminifers occurring in the bore hole discussed, and compared it with the observations of foreign authors (Table 1). The diagram attached to the text illustrates the vertical extent of more important foraminifer species found in the bore hole studied (Table 2). Summing up her observations the author pays attention to a necessity of continuation of micropalaeontological studies on the Tertiary of the region in study, mainly due to a low reconnaisance degree of the stratigraphy of the older Tertiary in the Polish Lowland area.