Environmental and Oceanographic Conditions at the Continental Margin of the Central Basin, Northwestern Ross Sea (Antarctica) since Last Glacial Maximum

Over the last few decades, different researches have led to important advances in our understanding of late Quaternary Antarctic Ice Sheet (AIS) behavior. However, the continental shelf margin remains still poorly investigated. To address this issue, we aim to increase the knowledge of the last glacial/deglacial dynamics in the Central Basin (slope-basin system) using a multidisciplinary approach, including sedimentological, micropaleontological, and tephrochronological analyses performed on marine sediments cores. Based on grain size clustering and the sortable silt data, together with diatom, silicoflagellate and foraminifera assemblages, we recognize three stratigraphic units. Unit 1 (24-17 ka BP) documents the influence of the ice shelf calving zone vicinity, Unit 2 (17-10.2 ka BP) represents the progressive retreat of the ice shelf due to Circumpolar Deep Water inflow, and Unit 3 (10.2 ka BP-present) corresponds to the establishment of seasonal sea ice with a strengthening of bottom currents. The dominant and persistent process is the sedimentation controlled by contour currents, which tend to modulate intensity in time and space. The study also allowed us to document the presence of a primary volcanic ash layer dated 22 ka BP correlated with the explosive activity of Mount Rittmann. This study has been conducted in the framework of the STREAM Project (Late Quaternary evolution of the ocean-ice sheet interactions: the record from the Ross Sea continental margin, Antarctica) funded by the Italian Ministry of Foreign Affairs and International Cooperation and the National Research Foundation of Korea.