ZAPIS IZOTOPÓW TLENU I WĘGLA W KOPALNYCH OSADACH JEZIORNYCH STANOWISK SUCHA WIEŚ (POJEZIERZE EŁCKIE) I CZARNUCHA (RÓWNINA AUGUSTOWSKA), PÓŁNOCNO-WSCHODNIA POLSKA

Abstract

THE ISOTOPIC RECORD IN ANCIENT LACUSTRINE DEPOSITS OF THE SUCHA WIEŚ (EŁK LAKELAND) AND CZARNUCHA SITES (AUGUSTÓW PLAIN), NORTHEASTERN POLANDAbstract. Investigations of the O/C ratio in ancient deposits of the Augustovian complex of the Sucha Wieś and Czarnucha sites, northern Poland, indicate a complicated image of climate changes with at least two warmings.Detrital calcite, found in the ancient lacustrine deposits, makes it difficult to interpret the isotope ratio. An increase in content of marine calcite derived from older formations is characteristic of cool periods of the Augustovian when the vegetation was sparse, favouring washout of the particles, as evidenced by high δ values. If there is a predominance of autochthonous calcite deposited in the Quaternary basin, then the δ values are lower. The presence of saline-water diatoms in all the sections can indicate a periodic drying up of the lakes when heavier isotopes were being concentrated resulting in high δ values.