The role of magma degassing in sulphide melt mobility and metal enrichment
International audience A strong association between sulfide droplets and gas bubbles has been observed in both experimental and natural samples (e.g. the picrogabbrodolerites of the Norilsk-Talnakh ore-bearing intrusions), suggesting that the fluid phase may have a major control on the segregation a...
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HAL CCSD
2020
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Online Access: | https://hal-insu.archives-ouvertes.fr/insu-03442234 |
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ftunivnantes:oai:HAL:insu-03442234v1 |
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Université de Nantes: HAL-UNIV-NANTES |
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ftunivnantes |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography |
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[SDU]Sciences of the Universe [physics] [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography Iacono-Marziano, Giada Le Vaillant, Margaux Barnes, Stephen J. Arbaret, Laurent The role of magma degassing in sulphide melt mobility and metal enrichment |
topic_facet |
[SDU]Sciences of the Universe [physics] [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography |
description |
International audience A strong association between sulfide droplets and gas bubbles has been observed in both experimental and natural samples (e.g. the picrogabbrodolerites of the Norilsk-Talnakh ore-bearing intrusions), suggesting that the fluid phase may have a major control on the segregation and mobility of the sulfide melt. Here we show how the association between sulfide melt and gas bubbles during magma degassing can have consequences for the accumulation of the sulfide liquid but also for its metal enrichment. Two types of experiments are presented involving magma degassing in sulfide-bearing mafic magmas at 1200°C and variable pressure: experiments simulating the interaction of the magma with coal, and experiments simulating magma decompression. Despite a marked difference in the composition of the fluid phase of the two types of experiments, the sulfide melt and the fluid phase are always associated, with each gas bubble being generally connected to one or several sulfide droplets. By facilitating the coalesce of the sulfide droplets attached to the same gas bubble, the fluid phase therefore seems to play a crucial role on the accumulation of the sulfide liquid. Large sulfide blebs are produced by this process in experimental samples, suggesting that magma degassing can be a potentially critical mechanism for sulfide mobility and accumulation in magmas. Moreover, magma degassing can also play a role on metal content of the sulfide melt: metal enrichment of the sulfide droplets is observed in the degassed samples, due to the consumption of the sulfide melt consequent upon magma degassing. In experimental samples, limited degassing produces metal-enriched sulfide melts, while extensive degassing generates PGMs. The possible implication of this process in the formation of ore-deposits and particularly in those of Norilsk-Talnakh is discussed, with a particular attention to the disseminated sulfides in the picrogabbrodolerites and the S-poor, PGE-rich ores. |
author2 |
Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO) Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-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 Université Paris sciences et lettres (PSL)-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) Métallogénie - UMR7327 Université Paris sciences et lettres (PSL)-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) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC) CSIRO Mineral Ressources Kensington |
format |
Conference Object |
author |
Iacono-Marziano, Giada Le Vaillant, Margaux Barnes, Stephen J. Arbaret, Laurent |
author_facet |
Iacono-Marziano, Giada Le Vaillant, Margaux Barnes, Stephen J. Arbaret, Laurent |
author_sort |
Iacono-Marziano, Giada |
title |
The role of magma degassing in sulphide melt mobility and metal enrichment |
title_short |
The role of magma degassing in sulphide melt mobility and metal enrichment |
title_full |
The role of magma degassing in sulphide melt mobility and metal enrichment |
title_fullStr |
The role of magma degassing in sulphide melt mobility and metal enrichment |
title_full_unstemmed |
The role of magma degassing in sulphide melt mobility and metal enrichment |
title_sort |
role of magma degassing in sulphide melt mobility and metal enrichment |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://hal-insu.archives-ouvertes.fr/insu-03442234 |
op_coverage |
virtuel, Australia |
long_lat |
ENVELOPE(88.203,88.203,69.354,69.354) ENVELOPE(88.205,88.205,69.470,69.470) |
geographic |
Norilsk Talnakh |
geographic_facet |
Norilsk Talnakh |
genre |
norilsk |
genre_facet |
norilsk |
op_source |
14th International Ni-Cu-PGE and Naldrett Memoria Symposium https://hal-insu.archives-ouvertes.fr/insu-03442234 14th International Ni-Cu-PGE and Naldrett Memoria Symposium, Nov 2020, virtuel, Australia |
op_relation |
insu-03442234 https://hal-insu.archives-ouvertes.fr/insu-03442234 |
_version_ |
1766116327106281472 |
spelling |
ftunivnantes:oai:HAL:insu-03442234v1 2023-05-15T17:25:02+02:00 The role of magma degassing in sulphide melt mobility and metal enrichment Iacono-Marziano, Giada Le Vaillant, Margaux Barnes, Stephen J. Arbaret, Laurent Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO) Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-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 Université Paris sciences et lettres (PSL)-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) Métallogénie - UMR7327 Université Paris sciences et lettres (PSL)-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) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC) CSIRO Mineral Ressources Kensington virtuel, Australia 2020-11-10 https://hal-insu.archives-ouvertes.fr/insu-03442234 en eng HAL CCSD insu-03442234 https://hal-insu.archives-ouvertes.fr/insu-03442234 14th International Ni-Cu-PGE and Naldrett Memoria Symposium https://hal-insu.archives-ouvertes.fr/insu-03442234 14th International Ni-Cu-PGE and Naldrett Memoria Symposium, Nov 2020, virtuel, Australia [SDU]Sciences of the Universe [physics] [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography info:eu-repo/semantics/conferenceObject Conference papers 2020 ftunivnantes 2022-08-10T01:02:00Z International audience A strong association between sulfide droplets and gas bubbles has been observed in both experimental and natural samples (e.g. the picrogabbrodolerites of the Norilsk-Talnakh ore-bearing intrusions), suggesting that the fluid phase may have a major control on the segregation and mobility of the sulfide melt. Here we show how the association between sulfide melt and gas bubbles during magma degassing can have consequences for the accumulation of the sulfide liquid but also for its metal enrichment. Two types of experiments are presented involving magma degassing in sulfide-bearing mafic magmas at 1200°C and variable pressure: experiments simulating the interaction of the magma with coal, and experiments simulating magma decompression. Despite a marked difference in the composition of the fluid phase of the two types of experiments, the sulfide melt and the fluid phase are always associated, with each gas bubble being generally connected to one or several sulfide droplets. By facilitating the coalesce of the sulfide droplets attached to the same gas bubble, the fluid phase therefore seems to play a crucial role on the accumulation of the sulfide liquid. Large sulfide blebs are produced by this process in experimental samples, suggesting that magma degassing can be a potentially critical mechanism for sulfide mobility and accumulation in magmas. Moreover, magma degassing can also play a role on metal content of the sulfide melt: metal enrichment of the sulfide droplets is observed in the degassed samples, due to the consumption of the sulfide melt consequent upon magma degassing. In experimental samples, limited degassing produces metal-enriched sulfide melts, while extensive degassing generates PGMs. The possible implication of this process in the formation of ore-deposits and particularly in those of Norilsk-Talnakh is discussed, with a particular attention to the disseminated sulfides in the picrogabbrodolerites and the S-poor, PGE-rich ores. Conference Object norilsk Université de Nantes: HAL-UNIV-NANTES Norilsk ENVELOPE(88.203,88.203,69.354,69.354) Talnakh ENVELOPE(88.205,88.205,69.470,69.470) |