OSADY PLEJSTOCENU GLACJALNEGO W OKOLICY NOWEGO TOMYŚLA (ZACHODNIA POLSKA)

Abstract

DEPOSITS OF THE PLEISTOCENE NEAR NOWY TOMYŚL (WESTERN POLAND)Abstract. Fluvial sediments has been recorded in three boreholes near Nowy Tomyśl, western Poland (Wola Jabłońska, Cicha Góra, Laski). Wola Jabłońska profile contains organie and fluvial deposits. This series has been formally named the Laski Formation. The fluvial sediments fill deep palaeovalley (40-50 m). They overlie the Dopiewiec till (Early Saalian, Odranian) and are overlain by three late Saalian (Wartanian) tills: Karolewo, Kopaszewko and Ujście. The fluvial suite was deposited mainly in periglacial environment, with strongly developed aeolian processes in the valley. However, during the optimal part of the period the aeolian processe almost completely ceased. The uppermost part of the suite exhibit suggests that deposition took place at the front of an advancing ice-sheet (high aggradation rate, admixtures of glacial derived material). The Laski Formation deposits may represent a fragment of pre-Warta/ Prosna palaeovalley. The organic sediments from Wola Jabłońska represent the climatic optimum of the inteiglacial and the early stages of the succeeding cold period. The picture of vegetation is characterized by spruce-pine forest with common alder and small admixtures of deciduous trees at the climatic optimum. Among local aquatic vegetation, the most characteristic is the occurrence of pollen and seeds of Trapa natam; a species hither noticed only in the inteiglacial successions. Climatic conditions that time were temperate and humid. The flora of Wola Jabłońska have features that resemble the forest communities at Bełchatów profiles in central Poland which was determined as the Pilica Interstadiał, currently named as the Lublinian Inteiglacial. However, the profile from Wola Jabłońska cannot be unequivocally ascribed to this inteiglacial period, since the palynostratigraphic and geologic position of its vegetation succession is difficult to determine.