Coccolithophore assemblage and palaeoproductivity proxies at sediment cores PS75/076-2 and PS75/079-2

This work provides new insights into the productivity variations in the Pacific sector of the Southern Ocean. We present new data derived from three sediment cores that show glacial/interglacial coccolithophore variability across Marine Isotope Stage 11 (MIS 11).

The cores were retrieved during R/V Polarstern cruise PS75 from the Subantarctic and Polar Front Zones at the western flank of the East Pacific Rise and in the vicinity of the Antarctic-Pacific Ridge. Coccolithophore assemblages were overwhelmingly dominated by the species Gephyrocapsa caribbeanica and small Gephyrocapsa. Total numbers of coccoliths, coccolith accumulation rates, coccolith fraction (CF; <20 µm-fraction) Sr/Ca data and temperature-corrected CF Sr/Ca records consistently showed an increase in coccolithophore productivity during Termination V (MIS 12-11 boundary), highest productivity throughout MIS 11 (424-374 kyr), and a decrease during late MIS 11 in all the cores.