Early Vistulian climate oscillations in the light of pollen analysis of deposits from Dziadowa Kłoda (Silesian Lowland, Poland)

The stratigraphy and palaeogeography of Quaternary deposits under lying the Oleoenica Plain were investigated during mapping of the Syców sheet of the De tailed Geo logical Map of Poland on the scale of 1:50 000. The Oleoenica Plain is part of the southern foreland of the Trzebnica Ridge, the latter representing a frontal moraine of the South and Middle Polish Glaciations. Neopleistocene deposits found at the Dziadowa Kłoda site were analyzed for their pollen content. These lacus trine to swamp deposits represent a continuous and undisturbed sequence spanning the Eemian Interglacial to Brörup Interstadial interval. The Early Vistulian deposits have been the subject of detailed palynological investigations. The reconstructed pattern of vegetation changes has allowed a precise determination of the upper boundary of the last interglacial as well as the recognition of stadial-interstadial horizons. Three climatic oscillations have been noted, corresponding to the Herning and Rederstallstadials and the Brörup Interstadial. In the climatic optimum of the interstadial, dense boreal pine-birch forests accompanied by a minor admixture of alder and spruce were predominant. Cold stadials were dominated by open vegetation with tundra and steppe elements.The pollen sequence from Dziadowa Kłoda is the first site on the Silesian Lowland that shows the first fully developed Early Vistulian warm oscillation that correlates with the Brörup Interstadial. A distinctive feature of this site is a long, continuous pollen sequence of the Eemian passing into deposits of the Vistulian Glaciation in the same profile.