Obserwacje mikropaleontologiczne utworów górnomioceńskich i plioceńskich z rejonu Ostrzeszowa i Kępna

Abstract

Przedstawiono wyniki badań mikropaleontologicznych osadów górnomioceńskich i plioceńskich. Materiał pochodził z wierceń: Dobrygość, Huby i Bierzów (fig. 1). W osadach pochodzących z dwóch pierwszych wierceń znaleziono tylko mikroszczątki makrofauny. W materiale uzyskanym z wiercenia Bierzów oznaczono 35 gatunków otwornic. Są to głównie gatunki górnotortońskie. Analiza ich stanu zachowania wykazała, iż gatunki te znajdują się na wtórnym złożu.MICROPALEONTOLOGICAL ANALYSIS OF UPPER MIOCENE AND PLIOCENE ROCKS FROM THE OSTRZESZóW AND KĘPNO REGIONThe paper presents the results of micropaleontological studies of Upper Miocene and Pliocene rocks from the Ostrzeszów and Kępno region, south-eastern part of the Fore-Sudetic Monocline. The studies were aimed at dating these rocks on the basis of foraminifers. They covered core material from three boreholes: Dobrygość, Huby and Bierzów (Fig. 1). The material from the first two boreholes yielded macrofaunal remains only (Fig. 2) whereas that from the Bierzów 99/10 borehole – foraminifers assigned to 35 species. The analysis of distribution of foraminifers in the borehole section showed that they are clearly confined to some depth intervals (Fig. 2).The recorded species are usually represented by single specimens only. They are characterized by very small, fragile and usually poorly preserved tests. Several species are represented by juvenile specimens. These foraminifers do not form any characteristic assemblage (Tables I - VI). Upper Tortonian (Badenian) species predominate here, being accompanied by some Lower Tortonian ones.The analysis of the mode of preservation indicates redeposition of these specimens. They were transported to that region from intensively eroded areas on the south. If this is really redeposited Tortonian microfauna, the rocks yielding it would be younger than the Tortonian, presumably Sarmatian or Pannonian in age.