Carbon-oxygen stable isotope stratigraphy of the Cretaceous-Tertiary boundary interval; data from the Biarritz section (SW France)

Abstract

The patterns displayed by the ratios of stable Carbon and Oxygen isotopes of calcareous nannofossil assemblages from the Cretaceous-Tertiary boundary interval in a section near Biarritz closely match those from the same interval in the Gredero section (SE Spain). The data give additional support to the occurrence of a catastrophic event at the end of the Cretaceous that was probably coupled with a drastic increase in temperature and a decrease in marine phytoplankton productivity.