We analyse the mineralogy and isotope (Nd, Pb) signatures of two sediments cores collected in Labrador Sea (MD99-2227, ODP646). Clay composition and their isotopic ratios bring information on the origin of particles driven by deep currents. Our aim is to monitor deep current variability over the last 10-100 kyr. We emphasize that sedimentary supply variations allow for reconstruct of deep circulation patterns in the North Atlantic. Such indirect approach is promising to indirectly follow past circulation. As the Arctic Ocean also plays a role in the global thermohaline circulation (see Fig. 1) it could be interesting to adapt such approach to characterise the Arctic sedimentary supplies and further precise main Arctic circulation pathways. Previous investigations (Haley et al. 2007) on authigenic fraction of sediments (i.e., Fe-Mn nodules) already evidence some variability in Arctic circulation over the last 15 Myr. However the low rate of nodule formation limits the temporal resolution. Therefore detrital sedimentary fraction could be an alternative material to track for circulation changes in the Arctic basins over the Holocene.
This manuscript summarizes more than 10 years of research made in close collaboration with the team of GEOTOP (C. Hillaire-Marcel, R. Stevenson, C. Hillaire-Marcel, M. Preda - UQAM, Canada) as well as with the support of DSTE (N. Mattielli). Interpretations have been improved by fruitful discussion with C. Innocent (presently at BRGM, France). Part of this work has been done within the framework of master thesis in Oceanology at the University of Liege (R. Brasseur, M. Humblet). On the Belgian side the research was partly funded by FNRS.
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