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Publication . Article . Other literature type . 2015

Total dissolvable and dissolved iron isotopes in the water column of the Peru upwelling regime

F. Chever; Olivier Rouxel; Peter Croot; Emmanuel Ponzevera; Kathrin Wuttig; Maureen E. Auro;
Open Access
Published: 01 Aug 2015
Publisher: Pergamon-elsevier Science Ltd
Country: France

Vertical distributions of iron (Fe) concentrations and isotopes were determined in the total dissolvable and dissolved pools in the water column at three coastal stations located along the Peruvian margin, in the core of the Oxygen Minimum Zone (OMZ). The shallowest station 121 (161 m total water depth) was characterized by lithogenic input from the continental plateau, yielding concentrations as high as 456 nM in the total dissolvable pool. At the 2 other stations (stations 122 and 123), Fe concentrations of dissolved and total dissolvable pools exhibited maxima in both surface and deep layers. Fe isotopic composition (δ56Fe) showed a fractionation toward lighter values for both physical pools throughout the water column for all stations with minimum values observed for the surface layer (between -0.64 and -0.97‰ at 10-20 m depth) and deep layer (between -0.03 and -1.25‰ at 160-300 m depth). An Fe isotope budget was established to determine the isotopic composition of the particulate pool. We observed a range of δ56Fe values for particulate Fe from +0.02 to -0.87‰, with lightest values obtained at water depth above 50 m. Such light values in the both particulate and dissolved pools suggest sources other than atmospheric dust deposition in the surface ocean, including lateral transport of isotopically light Fe. Samples collected at station 122 closest to the sediment show the lightest isotope composition in the dissolved and the particulate pools (-1.25 and -0.53‰ respectively) and high Fe(II) concentrations (14.2 ± 2.1 nM) consistent with a major reductive benthic Fe sources that is transferred to the ocean water column. A simple isotopic model is proposed to link the extent of Fe(II) oxidation and the Fe isotope composition of both particulate and dissolved Fe pools. This study demonstrates that Fe isotopic composition in OMZ regions is not only affected by the relative contribution of reductive and non-reductive shelf sediment input but also by seawater-column processes during the transport and oxidation of Fe from the source region to open seawater.

Subjects by Vocabulary

Microsoft Academic Graph classification: Deposition (aerosol physics) Geology Water column Environmental chemistry Benthic zone Particulates Chemical oceanography Oxygen minimum zone Sediment Seawater


[SDU] Sciences of the Universe [physics], Geochemistry and Petrology

97 references, page 1 of 10

Anderson, M. and F. Morel (1980) Uptake of Fe (II) by a diatom in oxic culture medium. Mar. Biol. Lett 1, 263-268.

Balci, N., T. D. Bullen, K. Witte-Lien, W. C. Shanks, M. Motelica and K. W. Mandernack (2006) Iron isotope fractionation during microbially stimulated Fe(II) oxidation and Fe(III) precipitation. Geochimica Et Cosmochimica Acta 70, 622-639. [OpenAIRE]

Barbeau, K., E. L. Rue, K. W. Bruland and A. Butler (2001) Photochemical cycling of iron in the surface ocean mediated by microbial iron(III)-binding ligands. Nature 413, 409- 413.

Beard, B. L., C. M. Johnson, J. L. Skulan, K. H. Nealson, L. Cox and H. Sun (2003a) Application of Fe isotopes to tracing the geochemical and biological cycling of Fe. Chem. Geol. 195, 87-117.

Beard, B. L., C. M. Johnson, K. L. Von Damm and R. L. Poulson (2003b) Iron isotope constraints on Fe cycling and mass balance in oxygenated Earth oceans. Geology 31, 629-632.

Bennett, S. A., E. P. Achterberg, D. P. Connelly, P. J. Statham, G. R. Fones and C. R. German (2008) The distribution and stabilisation of dissolved Fe in deep-sea hydrothermal plumes. Earth Planet. Sci. Lett. 270, 157-167.

Bennett, S. A., O. Rouxel, K. Schmidt, D. Garbe-Schönberg, P. J. Statham and C. R. German (2009) Iron isotope fractionation in a buoyant hydrothermal plume, 5 S Mid-Atlantic Ridge. Geochim. Cosmochim. Acta 73, 5619-5634.

Bergquist, B. A. and E. A. Boyle (2006) Iron isotopes in the Amazon River system: Weathering and transport signatures. Earth Planet. Sci. Lett. 248, 54-68.

Blain, S., B. Queguiner, L. Armand, S. Belviso, B. Bombled, L. Bopp, A. Bowie, C. Brunet, C. Brussaard, F. Carlotti, U. Christaki, A. Corbiere, I. Durand, F. Ebersbach, J. L. Fuda, N. Garcia, L. Gerringa, B. Griffiths, C. Guigue, C. Guillerm, S. Jacquet, C. Jeandel, P. Laan, D. Lefevre, C. Lo Monaco, A. Malits, J. Mosseri, I. Obernosterer, Y. H. Park, M. Picheral, P. Pondaven, T. Remenyi, V. Sandroni, G. Sarthou, N. Savoye, L. Scouarnec, M. Souhaut, D. Thuiller, K. Timmermans, T. Trull, J. Uitz, P. van Beek, M. Veldhuis, D. Vincent, E. Viollier, L. Vong and T. Wagener (2007) Effect of natural iron fertilization on carbon sequestration in the Southern Ocean. Nature 446, 1070-U1071. [OpenAIRE]

Bowie, A. R., A. T. Townsend, D. Lannuzel, T. A. Remenyi and P. van der Merwe (2010) Modern sampling and analytical methods for the determination of trace elements in marine particulate material using magnetic sector inductively coupled plasma-mass spectrometry. Analytica Chimica Acta 676, 15-27.

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Funded by
Sources and Biogeochemical Cycling of Iron Isotopes in Marine Environments
  • Funder: European Commission (EC)
  • Project Code: 247837
  • Funding stream: FP7 | SP3 | PEOPLE
Related to Research communities
European Marine Science Marine Environmental Science : Sources and biogeochemical cycling of iron isotopes in marine environments
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