First-principles calculation of iron and silicon isotope fractionation between Fe-bearing minerals at magmatic temperatures: The importance of second atomic neighbors
| العنوان: | First-principles calculation of iron and silicon isotope fractionation between Fe-bearing minerals at magmatic temperatures: The importance of second atomic neighbors |
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| المؤلفون: | Michel Grégoire, S. Rabin, Carlos Pinilla, Franck Poitrasson, Marc Blanchard |
| المساهمون: | Analytical, Environmental & Geo-Chemistry, Chemistry, Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Universidad del Norte, Barranquilla, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD) |
| المصدر: | Geochimica et Cosmochimica Acta Geochimica et Cosmochimica Acta, 2021, 304, pp.101-118. ⟨10.1016/j.gca.2021.03.028⟩ Geochimica et Cosmochimica Acta, Elsevier, 2021, 304, pp.101-118. ⟨10.1016/j.gca.2021.03.028⟩ |
| بيانات النشر: | Elsevier Limited, 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Mineral, Fractional crystallization (geology), 010504 meteorology & atmospheric sciences, Chemistry, Stable isotope ratio, Analytical chemistry, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Equilibrium fractionation, Silicate, chemistry.chemical_compound, Isotope fractionation, 13. Climate action, Geochemistry and Petrology, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDU]Sciences of the Universe [physics], Silicate minerals, engineering, Hedenbergite, 0105 earth and related environmental sciences, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy |
| الوصف: | International audience; In order to elucidate the processes involved in iron and silicon isotopes partitioning during magmatic differentiation, it is essential to know the precise value of equilibrium fractionation factors between the main minerals present in the evolving silicic melts. In this study, we performed first-principles calculations based on the density functional theory to determine the equilibrium iron and silicon isotopes fractionation factors between eleven relevant silicate or oxide minerals in the context of magmatic differentiation, namely: aegirine, hedenbergite, augite, diopside, enstatite, fayalite, hortonolite, Fe-rich and Fe-free forsterites, magnetite and ulvospinel. Results show that Fe2+-bearing silicate minerals display significant differences in iron isotope fractionation factors that cannot be neglected, even at high temperature (1000 °C). Various physical and chemical parameters control the iron isotopic fractionation of silicate minerals. However, the main parameter, after temperature and the iron oxidation state, is the nature and number of iron second neighbors (i.e. the local chemical composition around Fe atoms). This conclusion is also valid for silicon isotopes. In the investigated nesosilicates and inosilicates, silicon isotope reduced partition function ratios (also called β-factors) show no correlation with the average Si-O bond length, which remains almost constant, but Si β-factors are correlated with the local chemical composition of the minerals. Fractional crystallization is one of the mechanisms, which could explain the evolution of iron isotopic compositions during magmatic differentiation. Using the present theoretical set of equilibrium fractionation factors allows us to assess the impact of inter-mineral isotopic fractionations, and shows that pyroxene appears to be the main mineral phase driving the isotopic evolution to a heavier signature in the most evolved lavas. |
| اللغة: | English |
| تدمد: | 0016-7037 |
| DOI: | 10.1016/j.gca.2021.03.028⟩ |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cae2ae65a8939678609c4b660699918a https://biblio.vub.ac.be/vubir/firstprinciples-calculation-of-iron-and-silicon-isotope-fractionation-between-febearing-minerals-at-magmatic-temperatures-the-importance-of-second-atomic-neighbors(4b6ffb20-0ae0-444e-9b5c-a98a2ae86a14).html |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....cae2ae65a8939678609c4b660699918a |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 00167037 |
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| DOI: | 10.1016/j.gca.2021.03.028⟩ |