دورية أكاديمية
The redox state of arc mantle using Zn/Fe systematics
| العنوان: | The redox state of arc mantle using Zn/Fe systematics |
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| المؤلفون: | Lee, Cin-Ty Aeolus, Luffi, Peter, Le Roux, V., Dasgupta, R., Albarède, Francis, Leeman, William P. |
| المساهمون: | Department of Earth Science Houston, Rice University Houston, Department of Earth Sciences Houston, Laboratoire de Sciences de la Terre (LST), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Div Earth Sciences, National Science Foundation Arlington (NSF), Geological Society of America |
| المصدر: | ISSN: 0028-0836. |
| بيانات النشر: | HAL CCSD Nature Publishing Group |
| سنة النشر: | 2010 |
| المجموعة: | HAL Lyon 1 (University Claude Bernard Lyon 1) |
| مصطلحات موضوعية: | OXIDATION-STATE, OXYGEN FUGACITY, SOURCE REGIONS, EARTHS MANTLE, DIFFERENTIATION, PERIDOTITES, INSIGHTS, BASALTS, MAGMAS, METASOMATISM, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
| الوصف: | International audience ; Many arc lavas are more oxidized than mid-ocean-ridge basalts and subduction introduces oxidized components into the mantle(1-4). As a consequence, the sub-arc mantle wedge is widely believed to be oxidized(3,5). The Fe oxidation state of sub-arc mantle is, however, difficult to determine directly, and debate persists as to whether this oxidation is intrinsic to the mantle source(6,7). Here we show that Zn/Fe-T (where Fe-T = Fe2+ + Fe3+) is redox-sensitive and retains a memory of the valence state of Fe in primary arc basalts and their mantle sources. During melting of mantle peridotite, Fe2+ and Zn behave similarly, but because Fe3+ is more incompatible than Fe2+, melts generated in oxidized environments have low Zn/Fe-T. Primitive arc magmas have identical Zn/Fe-T to mid-ocean-ridge basalts, suggesting that primary mantle melts in arcs and ridges have similar Fe oxidation states. The constancy of Zn/Fe-T during early differentiation involving olivine requires that Fe3+/Fe-T remains low in the magma. Only after progressive fractionation does Fe3+/Fe-T increase and stabilize magnetite as a fractionating phase. These results suggest that subduction of oxidized crustal material may not significantly alter the redox state of the mantle wedge. Thus, the higher oxidation states of arc lavas must be in part a consequence of shallow-level differentiation processes, though such processes remain poorly understood. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| العلاقة: | hal-00598741; https://hal.science/hal-00598741Test |
| DOI: | 10.1038/nature09617 |
| الإتاحة: | https://doi.org/10.1038/nature09617Test https://hal.science/hal-00598741Test |
| رقم الانضمام: | edsbas.7E617035 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1038/nature09617 |
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