High resolution correlations between South Indian Ocean cores and Antarctic EPICA ice record

New high resolution records of bulk magnetic parameters (ARM, IRM, and low field susceptibility) of cores taken in the South Indian Ocean, northeast of the Kerguelen plateau document a coherent signature during the last glacial epoch and the previous interglacial, with marked variations at a millennial scale. We interpret this signal as tracing past changes in the deep-sea currents which erode the Kerguelen plateau and transport material to the studied sites. These profiles can be precisely correlated with the dust record obtained from Vostok and Epica (Petit et al., 1999, Delmonte et al, submitted). This suggests coherence at the millennial scale between eolian activity which transports dust to east Antarctica site and marine current activity in the southwestern sector of the Indian ocean. With this correlation, the Laschamp geomagnetic event recorded in the MD94-103 marine core is recorded below the position of the 10Be peak (Yiou et al., 1985) deduced from correlation with Vostok and EPICA ice core (Schwander et al., 2001). Two different causes may explain this difference. It may indicate that the climatic variations recorded in the ice around 41 kyr B.P. lead those recorded in the sedimentary cores by 500 to 750 years. Alternatively, it may indicate a non-zero lock-in depth, of about 10-15 cm, for the Natural Remanent Magnetization (NRM) signal recorded in core MD94-103. This second hypothesis would imply that the age model of core MD94-103, which was deduced from a geomagnetic correlation to Napis-75 in the 30-50 kyr B.P. interval (Mazaud et al., 2002), has to be shifted towards older ages by approximately 500 to 750 years. Implications of both scenarios on phasing with climatic records from the North hemisphere will be also discussed.