Samples for carbon and oxygen isotopic analysis were micromilled at 3.0 and 0.2 mm increments along the main growth axis. Approximately 3000 samples were measured using a semi-automated gas preparation and introduction system (Gasbench II) linked to a Delta V Plus isotope ratio mass spectrometer (both ThermoFisher) at the University of Innsbruck, following the methods of Spötl and Vennemann (2003). Isotope values are reported relative to the Vienna Pee Dee Belemnite (VPDB) reference. Long-term analytical precision is better than 0.1‰ (1σ) for both δ13C and δ18O.