International Geological Journal - Official Journal of the Carpathian-Balkan Geological Association

CALCAREOUS NANNOPLANKTON FROM THE EGGENBURGIAN STRATOTYPE AND FACIOSTRATOTYPES (LOWER MIOCENE, CENTRAL PARATETHYS)

Pages: 381 - 390

Authors: KATARINA HOLCOVA

Abstract: Calcareous nannoplankton was studied at the Eggenburgian holostratotype and faciostratotypes of Loibersdorf, Achberg, Brunnstube, "Judenfriedhof", Burgschleinitz, Fels am Walgram, Vadovce, Podkylava, Sverepec, Velka Causa and Lipovany. As sections with rich shallow-water molluscan fauna were chosen for Eggenburgian type sections, most of the samples are not favourable for the analysis of calcareous nannoplankton. Of 51 samples, 28 samples contain common to abundant calcareous nannoplankton which can be quantitatively analysed. Three bioevents were searched for in the type sections: FAD of Discoaster druggii (NN1/NN2 boundary), FAD of Helicosphaera ampliaperta (middle part of NN2 Zone, approximately Egerian/Eggenburgian boundary sensu Rögl 1998), FAD of Sphenolithus belemnos (NN2/NN3 boundary, upper part of the Eggenburgian). In areas with continuous sedimentation from the Egerian to Eggenburgian (the Outer Western Carpathians: Waschberg, Pouzdrany and Zdanice Units and the remnant flysch trough of the Skole-Skiba Zone; the Inner Western Carpathians: the Filakovo (Petervasara) Basin, all three events are successively observed while in areas with transgressive Eggenburgian sediments (Lower Austria, the Vienna Basin, the Danube Basin, the Vah River Valley and Horna Nitra Basin), sequences started with FAD of Helicosphaera ampliaperta. Two types of autochthonous assemblages were distinguished by multivariate statistical analysis (cluster and factor analysis): (1) abundant, dominated by Coccolithus pelagicus, (2) rare, dominated by reticulofenestrids. The third type of assemblage is dominated by reworked Cretaceous species.

Keywords: Eggenburgian, holostratotype and faciostratotypes, Central Paratethys, calcareous nannoplankton, quantitative analysis, biostratigraphy

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