Stable oxygen and carbon isotope analysis was done on the benthic foraminifera Uvigerina peregrina (>125 µm size fraction) from the IODP core 375-U1526B in the Southwest Pacific. The core was drilled at 2888 m below sea level on the western flank of the Tūranganui Knoll Seamount, along the Hikurangi Subduction Margin, offshore the North Island of New Zealand. The stable oxygen isotope data was used primarily to date the core. In total, 142 samples were analysed over 0.1-26.16 m (CSF-A), dated from 1-1304 ka. A light microscope (Olympus Ltd, SZX10 [x400 magnification]) was used for identifying the Uvigerina peregrina.