The onset of the first sustained Antarctic glaciation at the Eocene-Oligocene Transition (~34 Ma; EOT) was marked by several changes in calcareous nannofossils coinciding with long-term cooling and modifications in the sea-surface water structure. Here, we combined a high-resolution calcareous nannofossil assemblage data (%) with bulk geochemical data from IODP Site U1509 (New Caledonia Trough, Tasman Sea) in order to give an overview of the paleoclimatic and palaeoceanographic evolution of the study area.