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| Registros recuperados: 61 | |
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| Bayon, Germain; Pierre, C; Etoubleau, Joel; Voisset, Michel; Cauquil, E; Marsset, Tania; Sultan, Nabil; Le Drezen, Eliane; Fouquet, Yves. |
| We report on a reconnaissance analysis of the geochemical composition of authigenic carbonates and sediment samples collected from various seepage sites on the Niger deep-sea fan. Our aim has been to investigate whether evidence for the presence of authigenic carbonates and gas hydrates within sediments is discernible from solid-phase sediment geochemistry. We show that sedimentary Sr/Ca and Mg/Ca ratios can be used to infer the presence of authigenic aragonite (Sr-rich) and Mg-rich carbonate phases (high-Mg calcite, dolomite) in cold seep settings. Using Sr/Ca and Mg/Ca ratios, the proportion (wt.%) of authigenic carbonates in Niger Fan sediments can be calculated from a mixing model between sediment fractions of terrigenous material, biogenic calcite,... |
| Tipo: Text |
Palavras-chave: Niger Delta; Gas hydrates; Cold seeps; Mg/Ca; Sr/Ca; Authigenic carbonates. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2696.pdf |
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| Ondreas, Helene; Cannat, M.; Fouquet, Yves; Normand, Alain; Sarradin, Pierre-marie; Sarrazin, Jozee. |
| We present new high-resolution bathymetry and backscatter data acquired in 2006 with the ROV Victor 6000 over the Lucky Strike hydrothermal field, Mid-Atlantic Ridge. As long-term monitoring of the Lucky Strike area (MoMAR project) is being implemented, these new high-resolution data offer an unprecedented view of the distribution of hydrothermal edifices, eruptive facies, and small-scale tectonic features in the Lucky Strike vent field. We show that vents located in the NW and NE correspond with wide expanses of lumpy seafloor which we interpret as primarily made of broken chimneys and sulfide edifices. They are found above scarps with relief > 50 m or on associated mass wasting deposits. By contrast, the SE and SW vents correspond with small expanses... |
| Tipo: Text |
Palavras-chave: Hydrothermalism; Lava lake; Lucky Strike; Mid Atlantic Ridge. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6161.pdf |
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| Fouquet, Yves; Barriga, F; Charlou, Jean-luc; Elderfield, H; German, C.r; Ondreas, Helene; Parson, L; Radford-knoery, Joel; Relvas, J; Ribeiro, A; Schultz, A; Apprioual, R; Cambon, P; Costa, I; Donval, Jean-pierre; Douville, E; Landure, Jy; Normand, A; Pelle, H; Ponsevera, E. |
| Tipo: Text |
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| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00070/18133/15681.pdf |
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| Auzende, Jean-marie; Ishibashi, J; Beaudouin, Y; Charlou, Jean-luc; Delteil, J; Donval, Jean-pierre; Fouquet, Yves; Gouillou, Jp; Ildefonse, B; Kimura, H; Nishio, Y; Knoery, Joel; Ruollan, E. |
| In 1995, a joint French‐Japanese cruise (ManusFlux) explored the Manus Spreading Center and some sites of the South Eastern Rift in the Manus Basin off the coast of Papua New Guinea (Figure 1) with the Japanese submersible [Auzende et al., 1996; Gamo et al., 1997]. In the framework of this joint project, called New STARMER, the French and Japanese teams completed the Manaute cruise with the R/V LAtalante and the Ifremer submersible Nautile in April and May 2000. The Manaute cruise explored and sampled volcanic and hydrothermal sites in the eastern part of Manus Basin and on the spreading axis of the Western Ridge (WR). The eastern part of the Manus Basin (Figure 2) was interpreted as a stretched‐back arc basin crust showing alternatively elongated ridges... |
| Tipo: Text |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00069/18055/15597.pdf |
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| Lartaud, Franck; Little, Crispin T. S.; De Rafelis, Marc; Bayon, Germain; Dyment, Jerome; Ildefonse, Benoit; Gressier, Vincent; Fouquet, Yves; Gaill, Francoise; Le Bris, Nadine. |
| Among the deep-sea hydrothermal vent sites discovered in the past 30 years, Lost City on the Mid-Atlantic Ridge (MAR) is remarkable both for its alkaline fluids derived from mantle rock serpentinization and the spectacular seafloor carbonate chimneys precipitated from these fluids. Despite high concentrations of reduced chemicals in the fluids, this unique example of a serpentinite-hosted hydrothermal system currently lacks chemosynthetic assemblages dominated by large animals typical of high-temperature vent sites. Here we report abundant specimens of chemosymbiotic mussels, associated with gastropods and chemosymbiotic clams, in approximately 100 kyr old Lost City-like carbonates from the MAR close to the Rainbow site (36 degrees N). Our finding shows... |
| Tipo: Text |
Palavras-chave: Bathymodiolus; Ghost City; Ultramafic-hosted; Mid-ocean ridge; Ecogeochemistry. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00036/14748/15832.pdf |
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| Cherkashov, G.; Poroshina, I.; Stepanova, T.; Ivanov, V.; Bel'Tenev, V.; Lazareva, L.; Rozhdestvenskaya, I.; Samovarov, M.; Shilov, V.; Glasby, G. P.; Fouquet, Yves; Kuznetsov, V.. |
| In addition to the two new hydrothermal fields Krasnov (l6 degrees 38' N) and Ashadze (13 degrees N) discovered in 2003-2004, some later discoveries were made in the Northern Equatorial segment of the Mid-Atlantic Ridge (MAR). Two new major seafloor massive sulfide (SMS) deposits: Semyenov (13 degrees 31' N) and Zenith-Victory (20 degrees 08' N), as well as the now extended Puy des Folles hydrothermal field (20 degrees 30.5' N), provide enough data to make conclusions about the general characteristics of SMS deposits in the northern equatorial MAR environment. Parameters of SMS deposits, such as their distribution, geological setting, morphology, composition and age, are discussed in this paper. A majority of studied SMS deposits (Ashadze, Logatchev,... |
| Tipo: Text |
Palavras-chave: Hydrothermal systems; Mid-atlantic ridge; Seafloor massive sulfides. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12413/9800.pdf |
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| Zeng, Xiang; Birrien, Jean-louis; Fouquet, Yves; Cherkashov, Georgy; Jebbar, Mohamed; Querellou, Joel; Oger, Philippe; Cambon-bonavita, Marie-anne; Xiao, Xiang; Prieur, Daniel. |
| A novel hydrothermal site was discovered in March 2007, on the mid-Atlantic ridge during the cruise 'Serpentine'. At a depth of 4100 m, the site 'Ashadze' is the deepest vent field known so far. Smoker samples were collected with the ROV 'Victor 6000' and processed in the laboratory for the enrichment of anaerobic heterotrophic microorganisms under high-temperature and high-hydrostatic pressure conditions. Strain CH1 was successfully isolated and assigned to the genus Pyrococcus, within the Euryarchaeota lineage within the Archaea domain. This organism grows within a temperature range of 80 to 108 degrees C and a pressure range of 20 to 120 MPa, with optima for 98 degrees C and 52 MPa respectively. Pyrococcus CH1 represents the first obligate piezophilic... |
| Tipo: Text |
Palavras-chave: Thermococcales; Extremophile; Deep sea hydrothermal vent; High hydrostatic pressure; Archaea. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6812.pdf |
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| Josso, P.; Pelleter, Ewan; Pourret, O.; Fouquet, Yves; Etoubleau, Joel; Cheron, Sandrine; Bollinger, C.. |
| Ferromanganese (Fe-Mn) deposits constitute a ubiquitous mineral type in oceanic settings, with metal (Cu, Ni, Zn, Co, Pt) and rare earth elements (REE) enrichments of potential economic interest. Routine analysis of trace elements by ICP-MS has advanced our understanding of the impact of hydrogenetic, diagenetic and hydrothermal processes on the mobility and interaction of high field strength elements (HFSE: Zr, Ti) and REE and yttrium (REY) with Fe-Mn oxyhydroxides. Recent discoveries in the French exclusive economic zone (EEZ) of Wallis and Futuna (southwest Pacific Ocean) have brought new insight to the formation of low temperature (LT) hydrothermal Mn deposits and lead us to reconsider the classification and discrimination diagrams for of Fe-Mn... |
| Tipo: Text |
Palavras-chave: Ferromanganese mineralization; Hydrogenetic crusts; Nodules; Hydrothermal deposits; Rare earth elements; High field strength elements; Classification. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00350/46156/45854.pdf |
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| Szitkar, Florent; Dyment, Jérôme; Fouquet, Yves. |
| Near-seafloor bathymetric and magnetic data have been collected by Autonomous Underwater Vehicle (AUV) and manned submersible (DSS) over a volcanically active area southeast of Futuna Island, French Territory of Wallis-and-Futuna, in the Southwestern Pacific Ocean. Located at the edge of the Lau and North Fiji basins, at the convergence of the Pacific and Australian plates, this area is characterized by intense volcanic and tectonic activity. Direct observation by submersible reveals that the seafloor is covered by recent lava flows, volcanoes and large, active or inactive calderas filled by smooth lava flows and eventually hosting hydrothermal sites. We investigate the volcanic chronology by combining a Bayesian inversion of the AUV-gridded magnetic data... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00651/76273/77225.pdf |
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| Szitkar, Florent; Dyment, Jerome; Fouquet, Yves; Choi, Yujin; Honsho, Chie. |
| The analysis of high-resolution vector magnetic data acquired by deep-sea submersibles (DSSs) requires the development of specific approaches adapted to their uneven tracks. We present a method that takes advantage of (1) the varying altitude of the DSS above the seafloor and (2) high-resolution multibeam bathymetric data acquired separately, at higher altitude, by an Autonomous Underwater Vehicle, to estimate the absolute magnetization intensity and the magnetic polarity of the shallow subseafloor along the DSS path. We apply this method to data collected by DSS Nautile on a small active basalt-hosted hydrothermal site. The site is associated with a lack of magnetization, in agreement with previous findings at the same kind of sites: the contrast between... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00252/36300/34829.pdf |
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| Dekov, Vesselin M.; Rouxel, Olivier; Kouzmanov, Kalin; Bindi, Luca; Asael, Dan; Fouquet, Yves; Etoubleau, Joel; Burgaud, Gaetan; Walle, Markus. |
| Active and inactive hydrothermal chimneys composed almost entirely of enargite and luzonite, rare minerals in seafloor hydrothermal deposits, were found at the summits of two submarine volcanoes, North Su and Kaia Natai, in the Manus Back-Arc Basin. Detailed mineralogical and geochemical studies revealed that most probably these deposits precipitated at T = 200°–330 °C and high fS2. The negative δ34S values (− 8.58 to − 3.70‰) of the enargite-luzonite are best explained by disproportionation reactions of magmatic SO2 and suggest that the high fS2 is likely provided by direct magmatic input of SO2 into the hydrothermal system. Fractionation of Cu stable isotopes during the precipitation of enargite-luzonite (δ65Cu ranges from − 0.20 to + 0.35‰) is inferred... |
| Tipo: Text |
Palavras-chave: Enargite; Epithermal; Hydrothermal vent; Luzonite; S-Cu isotopes; Seafloor. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00337/44844/44432.pdf |
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| Fouquet, Yves; Pelleter, Ewan; Konn, Cecile; Chazot, Gilles; Dupre, Stephanie; Alix, Anne-sophie; Cheron, Sandrine; Donval, Jean-pierre; Guyader, Vivien; Etoubleau, Joel; Charlou, Jean-luc; Labanieh, Shasa; Scalabrin, Carla. |
| The study area is located at the transition between the northern end of the Tonga Trench and the North Fiji fracture zone, where tectonic movements are reputed to be the fastest in the world. To the southeast of Futuna Island, a broad area of volcanism occurs within a region characterized by a change in the tectonic fabric between a NE-SW oriented volcanic graben and the N-S oriented Alofi ridge. In 2010, the active volcano Kulo Lasi, which represents the most recent volcanic episode in the Futuna area, was discovered in the center of this extensive volcanic zone. Kulo Lasi is a 20 km diameter shield volcano that rises 400 m above the seafloor. It is composed of basaltic to trachy-andesitic lava with no obvious geochemical affinity with the Tonga... |
| Tipo: Text |
Palavras-chave: Subaqueous volcanism; Hydrothermal activity; Kulo Lasi caldera; Sulfides; SW Pacific. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55633/57279.pdf |
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| Langmuir, C; Charlou, Jean-luc; Colodner, D; Costa, I; Desbruyeres, Daniel; Desonie, D; Emerson, T; Fornari, D; Fouquet, Yves; Humphris, S; Fiala-medioni, A; Saldanha, L; Sours-page, R; Thatcher, M; Tivey, M.k; Van Dover, C; Von Damm, K; Wiese, K; Wilson, C. |
| Tipo: Text |
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| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00070/18096/15644.pdf |
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| Pierre, Catherine; Fouquet, Yves. |
| Submersible investigations with the ROV Victor 6000 of some pockmark structures on the seafloor of the Congo deep-sea fan have shown that they are active venting sites of methane-rich fluids, associated with abundant fauna and carbonate crusts. Moreover, methane hydrates have been observed both outcropping and deep in the sediments in the centre of the "Regab" giant pockmark. Authigenic carbonates, mostly calcite sometimes mixed with aragonite, are cementing the sedimentary matrix components and fauna; diatoms are abundant but only as moulds, indicating that biogenic silica dissolution occurred in situ synchronous with carbonate precipitation. The occurrence of diagenetic barite and pyrite in some carbonate crusts demonstrates that they can be formed... |
| Tipo: Text |
Palavras-chave: Oxygen isotopes; Carbon isotopes; Congo deep sea fan; Gas hydrate; Methane seep; Authigenic carbonate. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2608.pdf |
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| Registros recuperados: 61 | |
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