SEDYMENTOLOGICZNY I PALEOBOTANICZNY ZAPIS ZMIAN KLIMATU W PLIOCEŃSKICH OSADACH RZECZNYCH POŁUDNIOWO-WSCHODNIEJ CZĘŚCI NIZINY ŚLĄSKIEJ

Abstract

SEDIMENTOLOGICAL AND PALAEOBOTANICAL RECORDS OF CLIMATIC CHANGES WITHIN PLIOCENE FLUVIAL SEDIMENTS IN THE SOUTHEASTERN SILESIAN LOWLAND

Abstract. Neogene fluvial deposits of the Gozdnica Formation constitute a continuous cover in the southeastern part of the Silesian Lowland, in the Nysa Kłodzka and Odra interfluve. The 18 m thick succession of these deposits was studied in the Tułowice site on the Niemodlin Plain. Heavy mineral analysis indicates that deposits of the lower part of the succession were probably accumulated by the Nysa Kłodzka River, and those of the upper part — by the Odra River. Detailed sedimentological research was conducted in an excavation where the latter deposits are exposed. Four lithologic complexes were distinguished. It was found that three older complexes were formed mostly ha a meandering river system. The deposits of complex 4 represent alluvium of an anastomozing river system. Palaeobotanical analyses were made for silty-clayey deposits of complexes 1 and 2, and revealed plant cover variability indicating a climatic tendency for short-term oscillations of mean temperatures and humidity. Pollen spectra evidenced Pliocene age of the deposits under study. Both sedimentological and paleobotanical data indicate that the change of fluvial environment could have been associated with a progressive climatic change during the Late Pliocene, directly preceding the Early Pleistocene cooling.