Academic Journal
Is Gold Solubility Subject to Pressure Variations in Ascending Arc Magmas?
| العنوان: | Is Gold Solubility Subject to Pressure Variations in Ascending Arc Magmas? |
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| المؤلفون: | Jégo, Sébastien, Nakamura, Michihiko, Kimura, Jun-Ichi, Iizuka, Yoshiyuki, Chang, Qing, Zellmer, Georg F. |
| المساهمون: | Institute of Earth Sciences Tapei (IES Sinica), Academia Sinica, Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Bureau de Recherches Géologiques et Minières (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Magma - UMR7327, Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Department of Earth Science, Tohoku University, Tohoku University Sendai, Institute for Research on Earth Evolution Yokosuka (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Soil and Earth Sciences Group, National Science Council of Taiwan (YI: NSC 99-2116-M-001-013), the Institute of Earth Sciences, Academia Sinica, Taipei (Taiwan) and the GCOE Program for Earth Sciences (Tohoku University, Japan) |
| المصدر: | ISSN: 0016-7037. |
| بيانات النشر: | CCSD Elsevier |
| سنة النشر: | 2016 |
| المجموعة: | Université d'Orléans: HAL |
| مصطلحات موضوعية: | Piston-cylinder experiments, Sulfur solubility, Sulfide-sulfate transition, Au-Cu-Mo deposits, Pressure, Gold solubility, fO2, Arc magmas, [SDU]Sciences of the Universe [physics] |
| الوصف: | International audience ; Magmas play a key role in the genesis of epithermal and porphyry ore deposits, notably by providing the bulk of ore metals to the hydrothermal fluid phase. It has been long shown that the formation of major deposits requires a multi-stage process, including the concentration of metals in silicate melts at depth and their transfer into the exsolved ore fluid in more superficial environments. Both aspects have been intensively studied for most of noble metals in subsurface conditions, whereas the effect of pressure on the concentration (i.e., solubility) of those metals in magmas ascending from the sublithospheric mantle to the shallow arc crust has been quite neglected. Here, we present new experimental data aiming to constrain the processes of gold (Au) dissolution in subduction-linked magmas along a range of depth. We have conducted hydrous melting experiments on two dacitic/adakitic magmas at 0.9 and 1.4 GPa and ∼1000°C in an end-loaded piston cylinder apparatus, under fO2 conditions close to NNO as measured by solid Co-Pd-O sensors. Experimental charges were carried out in pure Au containers, the latter serving as the source of gold, in presence of variable amounts of H2O and, for half of the charges, with elemental sulfur (S) so as to reach sulfide saturation. Au concentrations in melt quenched to glass were determined by LA-ICPMS. When compared to previous data obtained at lower pressures and variable redox conditions, our results show that in both S-free and sulfide-saturated systems pressure has no direct, detectable effect on melt Au solubility. Nevertheless, pressure has a strong, negative effect on sulfur solubility. Since gold dissolution is closely related to the behaviour of sulfur in reducing and moderately oxidizing conditions, pressure has therefore a significant but indirect effect on Au solubility. The present study confirms that Au dissolution is mainly controlled by fO2 in S-free melts and by a complex interplay of fO2 and melt S2- concentration in sulfide-saturated ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| DOI: | 10.1016/j.gca.2016.05.034 |
| الاتاحة: | https://insu.hal.science/insu-01323314 https://insu.hal.science/insu-01323314v1/document https://insu.hal.science/insu-01323314v1/file/1-s2.0-S0016703716302770-main.pdf https://doi.org/10.1016/j.gca.2016.05.034 |
| Rights: | http://creativecommons.org/licenses/by-nc-nd/ ; info:eu-repo/semantics/OpenAccess |
| رقم الانضمام: | edsbas.D3F4C942 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1016/j.gca.2016.05.034 |
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