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| Chu, N; Johnson, C; Beard, B; German, C; Nesbitt, R; Frank, M; Bohn, Marcel; Kubik, P; Usui, A; Graham, I. |
| Temporal variations in Fe isotope compositions at three locations in the Pacific Ocean over the last 10 Ma are inferred from high-resolution analyses of three hydrogenetic ferromanganese crusts. Iron pathways to the central deep Pacific Ocean appear to have remained constant over the past 10 Ma, reflected by a remarkably constant Fe isotope composition, despite large changes in the Fe delivery rates to the surface ocean via dust. These results suggest that the Fe cycle in the deep ocean is decoupled from that in surface waters. By contrast, one ferromanganese crust from the Izu-Bonin (IB) back-arc/marginal basin of the W. Pacific exhibits large delta Fe-56 variations. In that crust, decreases in delta Fe-56 values correlate with increases in Mn, Mg, Ni,... |
| Tipo: Text |
Palavras-chave: Pacific Ocean; Izu Bonin; Hydrothen nal; Ferromanganese crusts; Fe isotopes. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3700.pdf |
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| Lotfi-kalahroodi, Elaheh; Pierson-wickmann, Anne-catherine; Guénet, Hélène; Rouxel, Olivier; Ponzevera, Emmanuel; Bouhnik-lecoz, Martine; Vantelon, Delphine; Dia, Aliou; Davranche, Mélanie. |
| Colloids have been recognized as key vectors of pollutants in aqueous environment. Amongst them, those formed by iron (Fe) and organic matter (OM) are of major importance due to their ubiquity in the surface environment and strong affinity for metals. In the recent years, Fe stable isotopes have been increasingly used to elucidate the sources and biogeochemical cycling of Fe in Earth's surface environments. In this study, we aim to elucidate (i) the possible Fe isotopic signature resulting from the Fe/OM colloid formation and (ii) the mechanisms involved in the development of such isotopic signature. For this purpose, Fe-OM associations were synthesized through binding and titration experiments. Various pH levels were used in order to study the isotope... |
| Tipo: Text |
Palavras-chave: Filtration; Size fractionation; Isotope fractionation; Colloidal; Dissolved; Fe isotopes. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00480/59174/61811.pdf |
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