SEDIMENTARY RECORDS OF CLIMATIC AND OCEANOGRAPHIC CHANGES NORTHWEST OF KERGUELEN (SOUTHERN INDIAN-OCEAN) DURING THE LAST 620,000 YEARS

The comparison of carbonate and biogenic silica content with the past sea surface temperature estimated by the siliceous flora in a sediment core from the north-west of Kerguelen (located just southwards of the Subantarctic Front) during the Late Quaternary is presented. The inte rglacial stages correspond to the carbonate maxima and include a suban tarctic assemblage of siliceous phytoplankton, while the glacial stage s of biogenic silica maxima are caracterised by flora typical of the a rea south of the Antarctic Polar Front. By comparing this data, we can show that the Polar Front has migrated at least 4 degrees northwards during the glacial periods.