194 STRATI 2002 -3ème Congrès français de Stratigraphie -Lyon, 8-10 juillet 2002
A NEW MULTISTRATIGRAPHIC ZONATION FOR THE UPPER-APTIAN AND ALBIAN OF THE VOCONTIAN BASIN (SE-FRANCE) AND NE-TEXAS, BASED ON PLANKTIC FORAMINIFERAS, CALCAREOUS NANNOFOSSILS, AMMONITES AND STABLE ISOTOPES
REICHELT K.(1), HERRLE J. O.(1), LEHMANN J.(2) & HEMLEBEN Ch.(1)
(1) Institut für Geologie und Paläontologie, Sigwartstrasse 10, 72076 Tübingen < kerstin. reichelt@ uni-tuebingen. de> (2) Fachbereich Geowissenschaften Universität Bremen, Klagenfurterstraße, 28359 Bremen
The classical biostratigraphical zonation of the Aptian and Albian is based on ammonites and planktic foraminifera. However, during the last decade calcareous nannofossils, geochemical and geophysical data, have become more important for stratigraphical zonations, although the resolution of the geochemical and geophysical methods, are still very limited to short intervals. Thus a combination of planktic foraminifera, calcareous nannofossils, ammonites and geochemical data became a powerful tool for mid-Cretaceous times. Using these methods we studied various sections from the Vocontian Basin (SE-France) and Middle-/ Upper-Albian sections in NE-Texas. Based on our data, we suggest a high-resolution multistratigraphic zonation for the Vocontian Basin and NE-Texas. Especially 13C data from SE-France and NE-Texas (Aptian and Albian) permit a correlation with sections in the Atlantic (DSDP Site 545 and 547, Mazagan Plateau ; ODP Site 171, Blake Nose Plateau), consequently, improving the stratigraphic correlations between western Tethys and Atlantic. For the first time, a direct comparison between boreal realm and the Tethys is possible by correlation of the 13C curves of SE-France and the borehole Kirchrode II. Finally, our results suggest that the combination of modern high resolution biostratigraphy and stable isotope stratigraphy is a reliable method for structuring Cretaceous deposits.
