Integrated bio- and carbon-isotope stratigraphy of the Upper Cretaceous Gurpi Formation (Iran): A new reference for the eastern Tethys and its implications for large-scale correlation of stage boundaries

A high-resolution stratigraphic analysis of the Upper Cretaceous Gurpi Formation has been undertaken in
the Shahneshin section (Zagros Basin, Iran). New results on calcareous nannofossils, planktic foramini-
fers, dino
fl
agellate cysts and high-resolution carbon and oxygen stable isotopes form the basis of a
reference section for the eastern Tethys that spans the upper Coniacian to the late Danian. Carbon-
isotope correlation to Gubbio, Italy and the NW German chalk allows for the identi
fi
cation of many
isotopic events as well as for the de
fi
nition of new events in the Campanian and Maastrichtian. Our
results allow for a review of the accurate position of the Coniacian/Santonian, Santonian/Campanian, and
Campanian/Maastrichtian stage boundaries relative to carbon isotopes and plankton bioevents. The
reliability of Coniacian to Maastrichtian planktic foraminifer, dino
flagellate cysts and calcareous nannofossil biohorizons is assessed.