COMPARATIVE INVESTIGATIONS ON THE BASAL FOSSILIFEROUS LAYERS AT THE OPENCAST MINE OBERDORF (KOFLACH-VOITSBERG LIGNITE DEPOSIT, STYRIA, AUSTRIA - EARLY MIOCENE)

Two fossil plant assemblages from the base of the lignite-bearing sequ ence of the opencast mine Oberdorf are investigated. Leaf, pollen, and diaspore records are studied. This method - integrating the results o btained for the different plant organs - provides more far-reaching co nclusions than the study of the fossil remains of only individual plan t organs. The different disciplines complement one another. 'Castanops is' bavarica, Poliothyrsis eurorimosa, Distylium cf. uralense, Lanroph yllum markvarticense, Laurophyllum pseudovillense, Eomastixia are repo rted for the first time from Austria. The analysed assemblages prove t he existence of a vegetation which may be best characterized as of the 'Younger Mastixioid' type (sensu Mai, 1964). It existed in the Koflac h-Voitsberg surroundings adjacent to the wetlands during the depositio nal phase of the lignite-bearing sequence (Early Miocene, Ottnangian/K arpatian). The results constitute the first proof of a species-rich Yo unger Mastixioid assemblage from Austria.