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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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| El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E.; Riboulleau, Armelle; Bard, Claire Rollion; Macchiarelli, Roberto; Pemba, Lauriss Ngombi; Hammarlund, Emma; Meunier, Alain; Mouele, Idalina Moubiya; Benzerara, Karim; Bernard, Sylvain; Boulvais, Philippe; Chaussidon, Marc; Cesari, Christian; Fontaine, Claude; Chi-fru, Ernest; Garcia Ruiz, Juan Manuel; Gauthier-lafaye, Francois; Mazurier, Arnaud; Pierson-wickmann, Anne Catherine; Rouxel, Olivier; Trentesaux, Alain; Vecoli, Marco; Versteegh, Gerard J. M.; White, Lee; Whitehouse, Martin; Bekker, Andrey. |
| The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations similar to 2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00202/31356/29754.pdf |
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