d18O of Globigerina bulloides from sediment core MD01-2444 on the Portuguese Margin, Marine Isotope Stage 3

Planktonic foraminifera (G. bulloides) oxygen isotopes: Measurements of foraminiferal stable isotopes were carried out in the Godwin Laboratory for Palaeoclimate Research (University of Cambridge), using a VG SIRA mass spectrometer. Analyses were made on samples consisting of 30 specimens of G. bulloides in the 300-355 mm size fraction, picked by M.J. Mleneck-Vautravers. Results are reported with reference to the international standard VPDB and the precision is better than ±0.08‰ for d18O. Age model: The age model was developed by aligning the abrupt transitions of d18O record of G. bulloides in core MD01-2444 to warming and cooling events in the NGRIP d18Oice record, presented on: (i) the GICC05 timescale [Svensson, A. et al. A 60,000 year Greenland stratigraphic ice core chronology. Clim. Past 4, 47–57 (2008)]; and (ii) the WD2014: modified timescale, whereby NGRIP GICC05 ice ages 31.2–67.2 ka are multiplied by 1.0063. [Buizert, C. et al. The WAIS Divide deep ice core WD2014 chronology – Part 1: Methane synchronization (68–31 ka BP) and the gas age–ice age difference. Clim. Past 11, 153-173 (2015)].