©Geol. Bundesanstalt, Wien; download unter www.geologie.ac.at
Berichte der Geologischen Bundesanstalt, ISSN 1017- 8880, Band 74, Wien 2008 - 41 - ______
EARLY CRETACEOUS CEPHALOPOD AND CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY OF
THE BERSEK QUARRY (GERECSE MTS, TRANSDANUBIAN RANGE, HUNGARY)
István FŐZY, Attila FOGARASI, Nico M.M. JANSSEN
An integrated biostratigraphic subdivision, Zones are documented by rich fossil on the basis of macrofossils (ammonites assemblages. Beds above yielded a and belemnites) and microfossils (mainly diverse fauna characteristic for the calcareous nannofossils), is proposed for Toxancyloceras vandenheckii ammonite the Lower Cretaceous siliciclastic Zone, indicating the base of the Upper succession of the Bersek Quarry (Gerecse Barremian. The topmost part of the Mts, Hungary). A thick succession of Early sampled succession in the quarry yielded Valanginian strata that crop out in the lower poorly preserved fossils only, hampering part of the quarry yielded no cephalopods, the recognition of any higher Upper hampering detailed zonation. Above it, a Barremian zones. On the basis of the rich rich ammonite fauna permit recognition of belemnite fauna an Upper Valanginian to many of the recently established lowermost Hauterivian, a Lower Mediterranean ammonite zones. The upper, Hauterivian, an Upper Hauterivian to fossiliferous part of the Bersek Marl lowermost Barremian, and a "Mid" Formation starts with the Upper Valanginian Barremian associations were distinguished. Varlhedeites peregrinus and Criosarasinella The biostratigraphic and paleobiogeographic furcillata ammonite Zones. This is overlain interpretations of the belemnite assemblages by a moderately condensed Hauterivian agree well with those based on ammonite succession, reduced in thickness especially studies. The late Valanginian to early late in its upper part, in which the Barremian cephalopod succession of the Acanthodiscus radiatus?, Crioceratites loryi, Bersek Quarry has a pronounced Lyticoceras nodosoplicatum ?, Subsaynella Mediterranean affinity, showing significant sayni, Plesiospitidiscus ligatus, similarities with ammonite assemblages Crioceratites balearis and from the Subbetic Domain of south-east Pseudothurmannia ohmi ammonite Zones Spain. The detailed cephalopod are recognised. These Hauterivian are in stratigraphy was correlated with the turn overlain by the Lábatlan Sandstone calcareous nannofossil zonation and Formation, the lower part of which is Lower events. The Lower Cretaceous deposits of Barremian. A complete succession of the the Bersek Quarry serve as useful Taveraidiscus hugii, Nicklesia pulchella, reference section in the Mediterranean Subpulchellia compressissima and Realm. Moutoniceras moutonianum ammonite
1st International Meeting on Correlation of Cretaceous Micro- and Macrofossils Vienna 16th – 18th April, 2008
©Geol. Bundesanstalt, Wien; download unter www.geologie.ac.at
- 42 - Berichte der Geologischen Bundesanstalt, ISSN 1017- 8880, Band 74, Wien 2008 ______
Istvan FÖZY Nico M.M. JANSSEN Hungarian Natural History Museum Geertekerkhof 14bis Department of Palaeontology 3511 XC Utrecht 1431 Budapest, Pf. 137 The Netherlands Budapest e-mail: [email protected] Hungary e-mail: [email protected]
Attila FOGARASI MOL Rt. Budapest, 1039 Batthyány u. 45 Hungary e-mail: [email protected]
1st International Meeting on Correlation of Cretaceous Micro- and Macrofossils Vienna 16th – 18th April, 2008