Persistence of Living Planktonic Foraminifera (Neogloboquadrina pachyderma) in Antarctic Sea-Ice Inferred from a Study of a Sediment Core (Ross Sea Continental Margin)

Abstract

This work attempts to constrain and discuss the persistence of living planktonic foraminifera Neogloboquadrina pachyderma (Ehrenberg, 1861) in Antarctic sea-ice (overwintering strategy) during the Last Glacial Maximum (LGM). Samples taken from Level 12 (2 16.5-238 em-depth) of a gravity sediment core ANTA95-89C (74° 29. 100'S-175° 34.059' W; 2058 m-depth) have radiocarbon date s of 28.2-17.2 yr BP. During the LGM , the Ross Sea Ice Shelf and associated sea ice extended far seaward of the position of this core. From 15 up to 60-80% of N. pachyderma were found in a three-layer interval referred as Level 12 and associated with up to 10.8-65.7 % of sand to gravel-sized Iceberg Rafted Debris (ffiRD). This suggests that foraminifera lived in wide areas of Ice Shelf/sea-ice during the LGM. Resul ts of such palaeoclimate/palaeoenvironmental investigation are integrated into an Astrobiology Roadmap science framework.