Metal partitioning after in situ filtration at deep-sea vents of the Lucky Strike hydrothermal field (EMSO-Azores, Mid-Atlantic Ridge, 37 degrees N)

• Published in: Deep Sea Research Part I: Oceanographic Research Papers
• Main Authors: Cotte, Laura, Chavagnac, V., Pelleter, E., Laes-Huon, A., Cathalot, C., Dulaquais, Gabriel, Riso, Ricardo, Sarradin, P.-M., Waeles, Matthieu
• Other Authors: Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Environnement Profond (LEP), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Unité de recherche Géosciences Marines (Ifremer) (GM), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), We are grateful to captains and crew of the R/V Pourquoi Pas?, R/V l'Atalante and the Victor 6000 ROV for their assistance at sea, Nicolas Gayet for help in collecting samples, Julie Tourolle for the bathymetric map, C.eline Liorzou, Marie-Laure Rouget and Bleuenn Gueguen (PSO) for ICP-AES and ICP-MS measurements. We are also grateful to Mathilde Cannat, Pierre-Marie Sarradin and J.erome Blandin coordinators of the projects and PI cruises (MomarSat 2014, doi.org: 10.17600/14000300; MomarSat 2015, doi.org: 10.17600/15000200; MomarSat 2016, doi. org: 10.17600/16001200). We acknowledge financial support from the French ANR Luckyscales project (ANR-14-CE02-0008-02), the EU project EMSO (http://www.emso-eu.org/) and the 'Laboratoire d'Excellence' LabexMER (ANR-10-LABX-19)., ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010), ANR-14-CE02-0008,LuckyScales,De la chambre magmatique aux micro-habitats: dynamique des écosystèmes hydrothermaux marins profonds(2014), European Project: 211816,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2007-1,EMSO(2008)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: plume; oxidation-kinetics; Precipitation; Mixing gradient; In-situ filtration; Deep-sea vents; rare-earth-elements; south atlantic; trace-metals; fe; particulate metals; distributions; dissolved iron; east pacific rise; Metal; Hydrothermal; ACL; geo; envir; Mid-Atlantic Ridge; Pacific; NADW; North Atlantic Deep Water; North Atlantic
• Online Access: https://doi.org/10.1016/j.dsr.2019.103204; https://hal.archives-ouvertes.fr/hal-02921204

WOS:000521509000009 International audience Metal partitioning between the dissolved and particulate phases is still poorly constrained within the early mixing of hydrothermal fluids and deep seawater. In this study, in situ filtration has been used to collect early buoyant plume fluids. This has provided the unique opportunity to reassess precisely metal partitioning along the mixing gradient by limiting chemical exchange processes between the dissolved (\textless0.45 mu m) and particulate (\textgreater0.45 mu m) phases during sampling. We report on the partitioning of three major metals (Fe, Cu, Zn) in the early buoyant plume of six black and clear smokers from the Lucky Strike hydrothermal field (37 degrees N, MAR; EMSO-Azores deep sea observatory). We show that chemical changes are limited in the warmest part of the plume [50-150 degrees C, dMn \textgreater 40 mu M; dilution factor (DF) of similar to 1-10 by NADW] as metal partitioning displays a chemical signature similar to the end-member one. However, as the dilution ratio between the hydrothermal fluid and North-Atlantic Deep-water (NADW) increases (4-50 degrees C, dMn \textless 40 mu M; DF of 10-100 by NADW), metal partitioning is affected by different precipitation and oxidation processes. Molar ratios normalized to Fe in the particles highlight the onset of Fe oxides formation, the precipitation of barite and the decreasing contribution of sulfide minerals (mainly Cu-Fe sulfides and sphalerite/wurtzite) along with fluid dilution.