FN Archimer Export Format PT J TI Natural and anthropogenic trace metals in sediments of the Ligurian Sea (Northwestern Mediterranean) BT AF HEIMBUERGER, Lars-Eric COSSA, Daniel THIBODEAU, Benoit KHRIPOUNOFF, Alexis MAS, Virginie CHIFFOLEAU, Jean-Francois SCHMIDT, Sabine MIGON, Christophe AS 1:1,2,3;2:1;3:4;4:5;5:5;6:6;7:7;8:2,3; FF 1:PDG-DOP-LER-LERPAC;2:PDG-RBE-BE-LBCM;3:;4:PDG-REM-EEP-LEP;5:PDG-DOP-DCB-GM-LES;6:PDG-RBE-BE-LBCM;7:;8:; C1 IFREMER, Ctr Mediterranee, F-83507 La Seyne Sur Mer, France. Univ Paris 06, Observ Oceanol Villefranche sur Mer, UMR 7093, F-06234 Villefranche Sur Mer, France. CNRS INSU, UMR 7093, Lab Oceanog Villefranche, F-06234 Villefranche Sur Mer, France. Univ Quebec, Geotop, Montreal, PQ H3C 3P8, Canada. IFREMER,Ctr Brest, F-29280 Plouzane, France. IFREMER, Ctr Nantes, F-44311 Nantes, France. Univ Bordeaux, CNRS INSU, UMR 5805, F-33405 Talence, France. C2 IFREMER, FRANCE OBSERV OCEANOL VILLEFRANCHE, FRANCE CNRS, FRANCE UNIV QUEBEC (UQAM-UQAR), CANADA IFREMER, FRANCE IFREMER, FRANCE UNIV BORDEAUX, FRANCE UNIV PARIS 06, FRANCE SI TOULON BREST NANTES SE PDG-DOP-LER-LERPAC PDG-RBE-BE-LBCM PDG-REM-EEP-LEP PDG-DOP-DCB-GM-LES IN WOS Ifremer jusqu'en 2018 copubli-france copubli-univ-france copubli-int-hors-europe IF 3.15 TC 28 TU Centre national d'études spatiales Centre national de la recherche scientifique Institut de recherche pour le développement Institut national de la recherche agronomique Université Pierre et Marie Curie Université de Bordeaux Université de Toulouse III - Paul Sabatier École nationale de météorologie de Toulouse École pratique des hautes études UR https://archimer.ifremer.fr/doc/00073/18435/16125.pdf LA English DT Article CR DYFAMED 2007 ENVAR5 ENVAR6 MEDECO MOOSE (DYFAMED) MOOSE (DYFAMED) MOOSE-GE BO Unknown Téthys II DE ;Marine sediments;Sediment traps;Mercury;Trace metals;Lead isotopes;Geochronology AB The magnitude and the chronology of anthropogenic impregnation by Hg and other trace metals of environmental concern (V, Cr, Ni, Cu, Zn, Ag, Cd and Pb, including its stable isotopes) in the sediments are determined at the DYFAMED station, a site in the Ligurian Sea (Northwestern Mediterranean) chosen for its supposed open-sea characteristics. The DYFAMED site (VD) is located on the right levee of the Var Canyon turbidite system, at the end of the Middle Valley. In order to trace the influence of the gravity current coming from the canyon on trace metal distribution in the sediment, we studied an additional sediment core (VA) from a terrace of the Var Canyon, and material collected in sediment traps at the both sites at 20 m above sea bottom. The patterns of Hg and other trace element distribution profiles are interpreted using stable Pb isotope ratios as proxies for its sources, taking into account the sedimentary context (turbidites, redox conditions, and sedimentation rates). Major element distributions, coupled with the stratigraphic examination of the sediment cores point out the high heterogeneity of the deposits at VA, and major turbiditic events at both sites. At the DYFAMED site, we observed direct anthropogenic influence in the upper sediment layer (<2 cm), while on the Var Canyon site (VA), the anthropization concerns the whole sedimentary column sampled (19 cm). Turbiditic events superimpose their specific signature on trace metal distributions. According to the Pb-210(xs)-derived sedimentation rate at the DYFAMED site (0.4 mm yr(-1)), the Hg-enriched layer of the top core corresponds to the sediment accumulation of the last 50 years, which is the period of the highest increase in Hg deposition on a global scale. With the hypothesis of the absence of significant post-depositional redistribution of Hg, the Hg/C-org ratio changes between the surface and below are used to estimate the anthropogenic contribution to the Hg flux accumulated in the sediment. The Hg enrichment, from pre-industrial to the present time is calculated to be around 60%, consistent with estimations of global Hg models. However, based on the chemical composition of the trapped material collected in sediment traps, we calculated that epibenthic mobilization of Hg would reach 73%. Conversely, the Cd/C-org ratio decreases in the upper 5 cm, which may reflect the recent decrease of atmospheric Cd inputs or losses due to diagenetic processes. (C) 2011 Elsevier B.V. All rights reserved. PY 2012 PD JAN SO Chemical Geology SN 0009-2541 PU Elsevier Science Bv VL 291 UT 000300202300012 BP 141 EP 151 DI 10.1016/j.chemgeo.2011.10.011 ID 18435 ER EF