Molybdenum isotope systematics in subduction zones
This study presents Mo isotope data for arc lavas from different subduction zones that range between δ98/95Mo=−0.72 and +0.07‰. Heaviest isotope values are observed for the most slab fluid dominated samples. Isotopically lighter signatures are related to increasing relevance of terrigenous sediment...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/414671 |
| Acceso en línea: | http://hdl.handle.net/10261/414671 https://doi.org/10.1016/j.epsl.2016.04.033 |
| Access Level: | acceso abierto |
| Palabra clave: | Mo isotopes Molybdenum Subduction Arc Slab fluid Sediments |
| Sumario: | This study presents Mo isotope data for arc lavas from different subduction zones that range between δ98/95Mo=−0.72 and +0.07‰. Heaviest isotope values are observed for the most slab fluid dominated samples. Isotopically lighter signatures are related to increasing relevance of terrigenous sediment subduction and sediment melt components. Our observation complements previous conclusions that an isotopically heavy Mo fluid flux likely mirrors selective incorporation of isotopically light Mo in secondary minerals within the subducting slab. Analogue to this interpretation, low δ98/95Mo flux that coincides with terrigenous sediment subduction and sediment melting cannot be simply related to a recycled input signature. Instead, breakdown of the controlling secondary minerals during sediment melting may release the light component and lead to decreasing δ98/95Mo influx into subarc mantle sources. The natural range between slab dehydration and hydrous sediment melting may thus cause a large spread of δ98/95Mo in global subduction zone magmas. |
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