Mantle-to-crust metal transfer by nanomelts
Abstract The transfer of chalcophile metals across the continental lithosphere has been traditionally modeled based on their chemical equilibrium partitioning in sulfide liquids and silicate magmas. Here, we report a suite of Ni-Fe-Cu sulfide droplets across a trans-lithospheric magmatic network lin...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-07-01
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| Series: | Communications Earth & Environment |
| Online Access: | https://doi.org/10.1038/s43247-023-00918-y |
| _version_ | 1797778696024621056 |
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| author | Erwin Schettino José María González-Jiménez Claudio Marchesi Francesco Palozza Idael F. Blanco-Quintero Fernando Gervilla Roberto Braga Carlos J. Garrido Marco Fiorentini |
| author_facet | Erwin Schettino José María González-Jiménez Claudio Marchesi Francesco Palozza Idael F. Blanco-Quintero Fernando Gervilla Roberto Braga Carlos J. Garrido Marco Fiorentini |
| author_sort | Erwin Schettino |
| collection | DOAJ |
| description | Abstract The transfer of chalcophile metals across the continental lithosphere has been traditionally modeled based on their chemical equilibrium partitioning in sulfide liquids and silicate magmas. Here, we report a suite of Ni-Fe-Cu sulfide droplets across a trans-lithospheric magmatic network linking the subcontinental lithospheric mantle to the overlying continental crust. Petrographic characteristics and numerical calculations both support that the sulfide droplets were mechanically scavenged from the mantle source during partial melting and transported upwards by alkaline magmas rising through the continental lithosphere. Nanoscale investigation by high-resolution transmission electron microscopy (HR-TEM) documents the presence of galena (PbS) nanoinclusions within the sulfide droplets that are involved in the mantle-to-crust magma route. The galena nanoinclusions show a range of microstructural features that are inconsistent with a derivation of PbS by exsolution from the solid products of the Ni-Fe-Cu sulfide liquid. It is argued that galena nanoinclusions crystallized from a precursor Pb(-Cu)-rich nanomelt, which was originally immiscible within the sulfide liquid even at Pb concentrations largely below those required for attaining galena saturation. We suggest that evidence of immiscibility between metal-rich nanomelts and sulfide liquids during magma transport would disrupt the classical way by which metal flux and ore genesis are interpreted, hinting for mechanical transfer of nanophases as a key mechanism for sourcing the amounts of mantle-derived metals that can be concentrated in the crust. |
| first_indexed | 2024-03-12T23:20:13Z |
| format | Article |
| id | doaj.art-5283039c9d2c4ad4925aa5b41d9ab21c |
| institution | Directory Open Access Journal |
| issn | 2662-4435 |
| language | English |
| last_indexed | 2024-03-12T23:20:13Z |
| publishDate | 2023-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Communications Earth & Environment |
| spelling | doaj.art-5283039c9d2c4ad4925aa5b41d9ab21c2023-07-16T11:29:11ZengNature PortfolioCommunications Earth & Environment2662-44352023-07-01411910.1038/s43247-023-00918-yMantle-to-crust metal transfer by nanomeltsErwin Schettino0José María González-Jiménez1Claudio Marchesi2Francesco Palozza3Idael F. Blanco-Quintero4Fernando Gervilla5Roberto Braga6Carlos J. Garrido7Marco Fiorentini8Instituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas-Universidad de GranadaInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas-Universidad de GranadaInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas-Universidad de GranadaDepartment of Biological, Geological and Environmental Sciences, Bologna UniversityDepartamento de Ciencias de la Tierra y del Medio Ambiente, Facultad de Ciencias, Universidad de AlicanteInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas-Universidad de GranadaDepartment of Biological, Geological and Environmental Sciences, Bologna UniversityInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas-Universidad de GranadaCentre for Exploration Targeting, School of Earth Sciences, ARC Centre of Excellence for Core to Crust Fluid Systems, University of Western AustraliaAbstract The transfer of chalcophile metals across the continental lithosphere has been traditionally modeled based on their chemical equilibrium partitioning in sulfide liquids and silicate magmas. Here, we report a suite of Ni-Fe-Cu sulfide droplets across a trans-lithospheric magmatic network linking the subcontinental lithospheric mantle to the overlying continental crust. Petrographic characteristics and numerical calculations both support that the sulfide droplets were mechanically scavenged from the mantle source during partial melting and transported upwards by alkaline magmas rising through the continental lithosphere. Nanoscale investigation by high-resolution transmission electron microscopy (HR-TEM) documents the presence of galena (PbS) nanoinclusions within the sulfide droplets that are involved in the mantle-to-crust magma route. The galena nanoinclusions show a range of microstructural features that are inconsistent with a derivation of PbS by exsolution from the solid products of the Ni-Fe-Cu sulfide liquid. It is argued that galena nanoinclusions crystallized from a precursor Pb(-Cu)-rich nanomelt, which was originally immiscible within the sulfide liquid even at Pb concentrations largely below those required for attaining galena saturation. We suggest that evidence of immiscibility between metal-rich nanomelts and sulfide liquids during magma transport would disrupt the classical way by which metal flux and ore genesis are interpreted, hinting for mechanical transfer of nanophases as a key mechanism for sourcing the amounts of mantle-derived metals that can be concentrated in the crust.https://doi.org/10.1038/s43247-023-00918-y |
| spellingShingle | Erwin Schettino José María González-Jiménez Claudio Marchesi Francesco Palozza Idael F. Blanco-Quintero Fernando Gervilla Roberto Braga Carlos J. Garrido Marco Fiorentini Mantle-to-crust metal transfer by nanomelts Communications Earth & Environment |
| title | Mantle-to-crust metal transfer by nanomelts |
| title_full | Mantle-to-crust metal transfer by nanomelts |
| title_fullStr | Mantle-to-crust metal transfer by nanomelts |
| title_full_unstemmed | Mantle-to-crust metal transfer by nanomelts |
| title_short | Mantle-to-crust metal transfer by nanomelts |
| title_sort | mantle to crust metal transfer by nanomelts |
| url | https://doi.org/10.1038/s43247-023-00918-y |
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