Stable carbon and oxygen carbonate isotope ratios of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

A total of 152 samples (8 cm average sample spacing) were analysed for carbonate d13C in order to identify the two characteristic positive excursions associated with the Lower and Upper Kellwasser Events. Measurements on powdered samples weighing 120-150 μg were carried out on a ThermoScientific Delta V Plus mass spectrometer at the University of Münster, using an in-house standard (Kabonat-1; δ13C = 1.46‰, δ18O = -1.19‰) for calibration and an external standard (NBS-19; δ13C = 1.95‰, δ18O = -2.20‰) for long-term performance monitoring.