The latest Cenomanian to Santonian sedimentary record recovered at IODP Site U1513 in the Mentelle Basin (SE Indian Ocean, paleolatitude about 60°S at 85 Ma) is studied to interpret the paleoceanographic evolution in the Southern Hemisphere. Here we present the planktonic and benthic foraminifera distribution and absolute abundances, calcareous nannofossils distribution, bulk carbonate and foraminifera carbon and oxygen stable isotope data from IODP Holes 1513A, 1513B, and 1513D. The data presented here document an interval in the Santonian during which the rate of southern high latitude cooling increased. Both surface and bottom waters were affected, although the cooling signal is more evident in the data for surface waters. This pattern of cooling ascribes the deterioration of the Late Cretaceous climate to decreased CO2 in the atmosphere and changes in the oceanic circulation correlated with enhanced meridional circulation.