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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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Little, Crispin T. S.; Johannessen, Karen C; Bengtson, Stefan; Chan, Clara S; Ivarsson, Magnus; Slack, John F; Broman, Curt; Thorseth, Ingunn H.; Grenne, Tor; Rouxel, Olivier; Bekker, Andrey. |
Modern marine hydrothermal vents occur in a wide variety of tectonic settings and are characterized by seafloor emission of fluids rich in dissolved chemicals and rapid mineral precipitation. Some hydrothermal systems vent only low‐temperature Fe‐rich fluids, which precipitate deposits dominated by iron oxyhydroxides, in places together with Mn‐oxyhydroxides and amorphous silica. While a proportion of this mineralization is abiogenic, most is the result of the metabolic activities of benthic, Fe‐oxidizing bacteria (FeOB), principally belonging to the Zetaproteobacteria. These micro‐organisms secrete micrometer‐scale stalks, sheaths, and tubes with a variety of morphologies, composed largely of ferrihydrite that act as sacrificial structures, preventing... |
Tipo: Text |
Palavras-chave: Arizona; Fe-oxidizing bacteria; Hydrothermal vents; Jasper; Late Paleoproterozoic; Verde mining district. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00680/79162/81674.pdf |
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