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Dekov, Vesselin; Rouxel, Olivier; Asael, Dan; Halenius, Ulf; Munnik, Frans. |
Ocean drilling has revealed that, although a minor mineral phase, native Cu ubiquitously occurs in the oceanic crust. Cu isotope systematics for native Cu from a set of occurrences from volcanic basement and sediment cover of the oceanic crust drilled at several sites in the Pacific, Atlantic and Indian oceans constrains the sources of Cu and processes that produced Cu0. We propose that both hydrothermally-released Cu and seawater were the sources of Cu at these sites. Phase stability diagrams suggest that Cu0 precipitation is favored only under strictly anoxic, but not sulfidic conditions at circum-neutral pH even at low temperature. In the basaltic basement, dissolution of primary igneous and potentially hydrothermal Cu-sulfides leads to Cu0... |
Tipo: Text |
Palavras-chave: Cu-isotopes; Deep-Sea Drilling Project; Native Cu; Ocean Drilling Project; Oceanic crust alteration. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00158/26966/25117.pdf |
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Cuadros, Javier; Michalski, Joseph R.; Dekov, Vesselin; Bishop, Janice; Fiore, Saverio; Dyar, M. Darby. |
Seafloor hydrothermal sites generate abundant Mg- and Fe-rich clays. These clays are structurally and compositionally interesting because these environments are characterized by large, dynamic temperature and chemical gradients in their deposition environment, which promote the formation of chemically and structurally complex clays, including interstratified phases. The system is also interesting as a proxy for the study of the large Mg- and Fe-rich phyllosilicate deposits on Mars, which are broadly characterized as smectitic clay of hydrothermal, volcanic or sedimentary origin. Thirty submarine samples and four terrestrial ones, for comparison, were studied by means of X-ray diffraction (XRD), thermogravimetry (TG), mid-IR and Mössbauer spectroscopies and... |
Tipo: Text |
Palavras-chave: Interstratified clays; Martian clays; Submarine hydrothermal sites; Thermogravimetry; XRD. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00160/27131/25329.pdf |
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