Pollen analyses of tills from SE-Finland

Abstract

Various Quaternary till deposits in southeastern Finland were subjected to pollen analysis. Two profiles of varved clay were included for comparison. Betula is dominant in the majority of the arboreal pollen spectra whereas the uppermost part of the sections are often dominated by Pinns. Together with the arboreal pollen the NAP indicate the climatic conditions that prevailed during the continental glaciation. Winds from southern and southeastern Russia and southwestern Europe transported rather abundant pollen from the steppe regions onto the ice-sheet (e.g. Artemisia, Chenopodiaceae). Winds from the tundra region surrounding the icc sheet were responsible for the more northern species (e.g. Dryas, many Ericales, Gramineae and Cyperaceae species). Those pollen grains that could only be identified as to family or genus (e.g. Ranunculaceae, Rosaceae, Rumex and also many spores) may contain species that may just as well be typical of the tundra or the southern parts of Fenno-Scandinavia or even species with a widespread distribution. Even at its best the pollen spectra can only give a general view of the vegetational conditions that could have prevailed during the glaciation. The bulk of the pollen flora seems to reflect the climatic conditions during the Würm stage and especially during its latter part. The severely eroded pollen grains observed in the analyses might be referable to the last interglacial.