Mineralogy, fluid inclusions and stable isotope study of epithermal Au-Ag-Bi-Te mineralization from the SE Afar Rift (Djibouti)
Type | Article | ||||||||||||
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Date | 2019-08 | ||||||||||||
Language | English | ||||||||||||
Author(s) | Moussa N.1, 2, 3, Boiron M.C-4, Grassineau N.V.5, Asael Dan6, Fouquet Yves2, Le Gall Bernard3, Rolet Joël3, Etoubleau Joel2, Delacourt Christophe3 | ||||||||||||
Affiliation(s) | 1 : IST, Centre d’Etudes et de Recherches de Djibouti, B.P. 486, Djibouti 2 : IFREMER, Centre de Brest, BP 70, 29280 Plouzané, France 3 : UMR/CNRS 6538 Géosciences Océan, UBO-IUEM, Place Nicolas Copernic, 29280, Plouzané, France 4 : GéoRessources, Université de Lorraine, CNRS, CREGU, Boulevard des Aiguillettes, B.P. 70239, F-54506, Vandœuvre-lès-Nancy, France 5 : Department of Earth Sciences, Royal Holloway University of London, EGHAM Surrey TW20 0EX, UK 6 : Department of Geology and Geophysics, Yale University, New Haven, CT 06520, USA |
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Source | Ore Geology Reviews (0169-1368) (Elsevier BV), 2019-08 , Vol. 111 , P. 102916 (14p.) | ||||||||||||
DOI | 10.1016/j.oregeorev.2019.05.002 | ||||||||||||
WOS© Times Cited | 6 | ||||||||||||
Keyword(s) | Fluid inclusions, Stable isotopes, Hydrothermal, Epithermal system, SE Afar Rift, Djibouti | ||||||||||||
Abstract | In this paper, the mineralogy, fluid inclusions and stable isotopes of hydrothermal veins from the SE part of the Afar Rift (Djibouti) were studied. Mineralization occurs as gold-silver in quartz/carbonate veins and is mainly associated with felsic volcanism. The morphologies and textures of quartz show crustiform colloform banding, massive and breccias. Microthermometric measurements were made on quartz-hosted two phases (liquid + vapor) inclusions. Mean homogenization temperature ranges from 150°C to 340°C and ice-melting temperatures range from -0.2°C to - 1.6°C indicating that inclusion solutions contain 0.35 to 2.7 eq. wt. % NaCl. Furthermore, δ18O and δ13C values from calcite range from 3.7 to 26.6 ‰ and -7.5 to 0.3 ‰, respectively. The presence of platy calcite and adularia are consistent with boiling conditions. Our study shows that the deposit of precious-metal deposition occurred at around 250°C and is linked to a fluid generated by the mixture of magmatic fluid, hydrothermal fluid and seawater. |
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