TRACE-METAL REMOVAL TO SEDIMENTS ON THE EASTERN ATLANTIC CONTINENTAL MARGINS

Th-230 and Pa-231 activities have been determined in trapped particulate matter and superficial sediments at three sites in the tropical Atlantic. The evaluation of radionuclide F/P ratios (particulate flux/production in the overlying water column) shows that eastern Atlantic continental margins constitute an important sink for Pa-231. The removal of this radionuclide is greatly dependent on the total mass flux, while it is not the case for Th-230. These results strongly indicate that large amounts of trace metals may be stored in these continental margins.