In this study, we create a new age model for the high-latitude South Pacific during the late Paleocene to early Eocene (50.5 to 57.5 Ma). We present a bulk sediment δ13C and δ18O record, measured on sediment cores of IODP Expedition 378 at Site U1553 on the Southern Campbell Plateau, south of New Zealand. This new dataset together with the age model enables further studies about high-latitude climate change during high temperature and high CO2 conditions of earth's past. The biostratigraphic data highlights a diachroneity of calcareous nannofossil events between Site U1553 and referenced calcareous nannofossil datums, which were defined at low- to mid-latitude regions (Agnini et al., 2007; Agnini et al., 2014).