Kerguelen Plateau Drift Deposits: outstanding high-resolution chronicle of Cenozoic climatic and oceanographic changes in the southern Indian Ocean
Cruise Leg SO272 with RV SONNE, leaving Port Louis, Mauritius, on January 11 2020, returning to Cape Town, South Africa, on March 4 2020, comprised seismic reflection studies and geological sampling of the Kerguelen Plateau in the southern part of the Indian Ocean. The Kerguelen Plateau rises up 2000 m above the surrounding seafloor and hence forms an obstacle for the flow of the Antarctic Circumpolar Current (ACC) and the Antarctic Bottomwater (AABW). The ACC is strongly deviated in its flow towards the north. A branch of the AABW flows northwards along the eastern flank of the plateau thereby shaping sediment drifts. A detailed study and analysis of the structure of the Labuan Basin and the central Kerguelen Plateau via seismic data and a correlation with results from DSP Leg 120 Sites 748, 750, and 751 was needed to supply information on the Cretaceous and Tertiary development of the AABW and its influence on the path of the Antarctic Circumpolar Current, This in turn will allow conclusions on the development of the East Antarctic Ice Sheet. Seismic profiles were gathered, which capture the structure of the Labuan Basin and the Kerguelen Plateau to basement and image sediment drifts. In total ~4000 km of high resolution seismic reflection data were recorded. Bathymetric and Parasound data were recorded parallel to the seismic profiling. To complement the seismic studies and provide ages of the outcropping sediment geological samples were retrieved at 11 locations using a gravity corer and multi-corer. Both datasets will form the base for an IODP proposal.