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1. Examination of Water Quantification and Incorporation in Transition Zone Minerals: Wadsleyite, Ringwoodite and Phase D Using ERDA (Elastic Recoil Detection Analysis)

Author

Nathalie Bolfan-Casanova, Federica Schiavi, Davide Novella, Hélène Bureau, Caroline Raepsaet, Hicham Khodja, and Sylvie Demouchy

Subjects
wadsleyite, ringwoodite, water incorporation, tarnsition zone, deep water cycle, Science
Abstract

Hydrous wadsleyite, ringwoodite, and phase D have been synthesized in the MgO-SiO2-H2O and MgO-FeO-SiO2-H2O systems at mantle transition zone conditions (15–21 GPa and 1,100–1,700°C) to investigate their water incorporation using Elastic Recoil Detection Analysis (ERDA), which is an absolute quantitative method. Wadsleyite and ringwoodite water contents vary from 0.1 to 3.2 wt% H2O and for ringwoodite containing up to 1.16 wt% H2O we observe that the (Mg+Fe)/Si ratio vs. water content follows the same trend as for wadsleyite, indicating that H is substituting for Mg as for wadsleyite. We also measured, for the first time, the water content of phase D and observed that it varies from 6.7 to 11.2 wt% H2O, up to twice less than estimated from electron microprobe analysis totals. Using these experiments, we were able to determine the absorptivity coefficient for OH infrared absorption bands in four wadsleyite and five ringwoodite samples. The average for the two iron-free wadsleyite samples leads to an absorptivity of 69,000 ± 7,000 L/moles H2O/cm2, in very good agreement with previous determinations. The wadsleyite with 8 mole% Fe displays an absorptivity of 67,000 ± 5,000 L/moles H2O/cm2. The absorptivity values vary from 118,500 ± 5,000 for Fe-free ringwoodite to ±135,000 ± 9,000 for Fe-bearing ringwoodite (10% mole Fe). Our results show that absorptivity coefficient for OH infrared absorption of ringwoodite do not drastically change with Fe content and that the frequency-based calibration of Paterson (1982) under-estimates its water determinations by 50%. This is very important to know when comparing data from different studies where different extinction coefficients have been used.

Published
2018
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2. Experimental and Observational Constraints on Halogen Behavior at Depth

Author

Bastian Joachim-Mrosko, Tatsuhiko Kawamoto, Hélène Bureau, Universität Innsbruck [Innsbruck], University of Shizuoka, Minéralogie, Pétrologie et physique planétaire [IMPMC] (IMPMC_MP3), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), and Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
volatiles, fluid inclusions, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), degassing, element partitioning, subduction, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

Halogens are volatile elements present in trace amounts in the Earth’s crust, mantle, and core. They show volatile behavior and tend to be incompatible except for fluorine, which makes them key tracers of fluid-mediated and/or melt-mediated chemical transport processes. Even small quantities of halogens can profoundly affect many physicochemical processes such as melt viscosity, the temperature stability of mineral phases, the behavior of trace elements in aqueous fluids, or the composition of the atmosphere through magma degassing. Experiments allow us to simulate deep-Earth conditions. A comparison of experimental results with natural rocks helps us to unravel the role and behavior of halogens in the Earth’s interior.

Published
2022

4. From the lithosphere to the lower mantle: An aqueous-rich metal-bearing growth environment to form type IIb blue diamonds

Author

Lucille Daver, Hélène Bureau, Églantine Boulard, Éloïse Gaillou, Pierre Cartigny, Daniele L. Pinti, Oulfa Belhadj, Nicolas Guignot, Eddy Foy, Imène Estève, Benoit Baptiste, Centre de recherche sur la dynamique du système Terre (GEOTOP), École Polytechnique de Montréal (EPM)-McGill University = Université McGill [Montréal, Canada]-Université de Montréal (UdeM)-Université du Québec en Abitibi-Témiscamingue (UQAT)-Université du Québec à Rimouski (UQAR)-Concordia University [Montreal]-Université du Québec à Montréal = University of Québec in Montréal (UQAM), Minéralogie, Pétrologie et physique planétaire [IMPMC] (IMPMC_MP3), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL), Musée de Minéralogie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Centre de Recherche sur la Conservation (CRC ), Muséum national d'Histoire naturelle (MNHN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire Archéomatériaux et Prévision de l'Altération (LAPA - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)

Subjects
Lithosphere, Aqueous fluids, Geochemistry and Petrology, Nitrogen, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Mineral inclusions, Fe-Ni alloys, Geology, Type IIb diamonds, Blue diamonds, Boron
Abstract

International audience; A study of five diamonds containing mineral and fluid inclusions, selected among forty-nine specimens from the Cullinan Mine, South Africa, was carried out to better document the origin and formation of N-absent B-poor (type IIb) diamonds. The combination of several in-situ non-destructive techniques was used to identify the mineralogy and the chemical composition of primary and secondary inclusions. These include breyite, larnite, graphite, Fe-Ni-Cu native metallic alloys, sulfides of the pyrrhotite group, Ni-rich oxide and potential hydrous ferric sulfates. A common and abundant hydrous fluid containing H2O + CH4 was also identified. From the various observations, we suggest that these type IIb diamonds grew in an aqueous oxidized fluid reacting with a reduced mantle characterized by low oxygen fugacity. Remnant pressures recorded in primary breyite by Raman shifts and XRD measurements enabled the calculation of minimal entrapment pressures of inclusions using elastic geothermobarometry. Applying pressure corrections caused by elastic relaxation, minimum trapping pressures from 4.9 GPa to 5.6 GPa were calculated, suggesting lithospheric depths consistent with the occurrence of numerous graphite inclusions. The association of breyite and larnite, which is often considered as an indicator of sublithospheric origin, also occurs at pressures of 6 GPa or lower in a H2O-rich and carbonate/Ca-rich environment. The B-poor and N-absent features of type IIb diamonds do not require the classic subduction-related model of their formation. Whereas high-pressure minerals would host boron in cold subducting slabs, slabs are also important carriers of nitrogen into the deep mantle, with this latter element mostly absent in these diamonds. In our alternative model, the mantle is proposed as an alternative source of boron, whereby metallic alloys or N speciation between fluid and melt would still prevent the incorporation of nitrogen, leading to the expression of the blue, boron-related and N-absent features of type IIb diamonds. The observed mineralogical assemblage neither proves sublithospheric origin nor does it exclude lithospheric depths of formation for these diamonds. Hence, we propose that type IIb diamonds form in a mantle continuum, from sublithospheric to lithospheric depths.

Published
2022

5. Coupled hydrogen and fluorine incorporation in garnet: New constraints from FTIR, ERDA, SIMS, and EPMA

Author

Jed L. Mosenfelder, Anette von der Handt, Anthony C. Withers, Hélène Bureau, Caroline Raepsaet, George R. Rossman, University of Minnesota [Twin Cities] (UMN), University of Minnesota System, Bayerisches Geoinstitut (BGI), Universität Bayreuth, Minéralogie, Pétrologie et physique planétaire [IMPMC] (IMPMC_MP3), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Division of Geological and Planetary Sciences [Pasadena], and California Institute of Technology (CALTECH)

Subjects
Geophysics, Geochemistry and Petrology, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

It is well known that some garnet compositions can incorporate hydrogen and/or fluorine at levels up to several wt%. However, accurate measurement of these elements can be difficult at trace to minor concentration levels, so they are frequently ignored in routine chemical analysis. Furthermore, the mechanisms of H incorporation are still under debate, and only one mechanism for F substitution is commonly considered. We employed infrared spectroscopy (FTIR), elastic recoil detection analysis (ERDA), secondary ion mass spectrometry (SIMS), and electron probe microanalysis (EPMA) to measure H and F concentrations and constrain incorporation mechanisms in ten grossular garnets. We also present SIMS data for 11 spessartine and two andradite garnets. Three grossular garnets were measured with ERDA to obtain an infrared integral molar absorption coefficient (εi) for H2O of 13 470 L/(mol·cm2). Grossular H2O and F concentrations range from 0.017 to 0.133 wt% and 0.012 to 0.248 wt%, respectively. Correlations between 16OH and 19F and interpretation of FTIR spectra prompt us to consider various coupled substitutions of H and F for Si, which can explain some high-frequency IR absorption bands that have been attributed previously to “hydrogrossular clusters” (variably sized clusters in which 4H substitute for Si) or to inclusions of hydrous minerals. A strong correlation between 16OH and 19F in spessartine and similar high-frequency IR bands implies a similar role for H-F substitution. Coupled H-F substitution is also probably relevant to some andradite-rich garnets, rare pyrope from the Dora Maira massif, and some synthetic garnets. Improvements in analytical methods for trace to minor H and F open up more possibilities for using these elements to calculate the activities of H2O and F-species in fluids that were in equilibrium with garnet-bearing phase assemblages, as well as constraining the recycling of these elements into the mantle via study of xenoliths.

Published
2022

6. Nanoscale Secondary Ion Mass Spectrometry determination of the water content of staurolite

Author

Samantha Azevedo‐Vannson, Laurent Remusat, Hélène Bureau, Keevin Béneut, Bernardo Cesare, Hicham Khodja, María Jiménez‐Mejías, and Mathieu Roskosz

Subjects
Minerals, Organic Chemistry, Spectroscopy, Fourier Transform Infrared, Spectrometry, Mass, Secondary Ion, Water, Spectroscopy, Analytical Chemistry
Abstract

Staurolite is an important mineral that can reveal much about metamorphic processes. For instance, it dominates the Fe-Mg exchange reactions in amphibolite-facies rocks between about 550 and 700°C, and can be also found at suprasolidus conditions. Staurolite contains a variable amount of OH in its structure, whose determination is a key petrological parameter. However, staurolite is often compositionally zoned, fine-grained, and may contain abundant inclusions. This makes conventional water analysis (e.g., Fourier transform infrared (FTIR) spectroscopy or by chemical titration) unsuitable. With its high sensitivity at high spatial resolution, Nanoscale Secondary Ion Mass Spectrometry (NanoSIMS) is potentially a valuable tool for determining water contents in staurolite. However a calibration with relevant standards covering a large range of water content is required to obtain accurate and reliable analyses, because matrix effects typically prevent direct quantification of water content by SIMS techniques.In this study, a calibration for NanoSIMS analyses of water content by using minerals with crystallographic structures comparable to that of staurolite (i.e., amphibole and kyanite, an inosilicate and a nesosilicate, respectively) has been developed.Water measurements in an inclusion-free crystal from Pizzo Forno, Ticino, Switzerland, by FTIR spectroscopy (1.56 ± 0.14 wt% HThis implies that our approach can accurately account for NanoSIMS matrix effects in the case of staurolite. With this calibration, it is now possible to investigate variations in water content at the microscale in metamorphic minerals exhibiting high spatial variability and/or very small size (few micrometers).

Published
2022

7. Elastic Recoil Detection Analysis of Hydrogen content in diamonds

Author

Pierre Cartigny, Hélène Bureau, Imène Esteve, Matthieu Charrondière-Lewis, Eloïse Gaillou, Keevin Béneut, Hicham Khodja, Sylvie Demouchy, and Jean-Claude Boulliard

Subjects
Elastic recoil detection, Materials science, Hydrogen content, Molecular physics
Published
2021

9. Hydrogen in an early magma ocean: Implications for Earth’s core composition

Author

Geeth Manthilake, Hélène Bureau, Federica Schiavi, Hicham Khodja, Ali Bouhifd, Rémi Delon, Denis Andrault, Nathalie Bolfan-Casanova, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), and Jouhannel, Sylvaine

Subjects
Core (optical fiber), Hydrogen, chemistry, Magma ocean, [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography, chemistry.chemical_element, [SDU.STU.PE] Sciences of the Universe [physics]/Earth Sciences/Petrography, Petrology, Geology, Earth (classical element), ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2021

10. Xenon high pressure crystal-chemistry, partitioning, and isotopic fractionation: what does that tell us about atmosphere formation on Earth and Mars

Author

E. Gilabert, Chrystèle Sanloup, Igor Rzeplinski, Robert Farla, Denis Horlait, Konstantin Glazyrin, Guoyin Shen, Hélène Bureau, and Qi Chen

Subjects
Atmosphere, Materials science, Xenon, chemistry, Crystal chemistry, High pressure, chemistry.chemical_element, Mars Exploration Program, Fractionation, Earth (classical element), Astrobiology
Published
2021

11. Xenon behavior in deep crust

Author

Qi Chen, Robert Farla, Hélène Bureau, Chrystèle Sanloup, and Konstantin Glazyrin

Subjects
Xenon, chemistry, chemistry.chemical_element, Crust, Petrology, Geology
Published
2021

14. Deep Earth carbon reactions through time and space

Author

Elizabeth Cottrell, Catherine McCammon, Susannah M. Dorfman, Chrystèle Sanloup, Hélène Bureau, Alberto Vitale Brovarone, Yves Moussallam, James H. Cleaves, Louise H. Kellogg, Sami Mikhail, Andrew Thomson, Jie Li, Bayerisches Geoinstitut (BGI), Universität Bayreuth, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], South China University of Technology [Guangzhou] (SCUT), Department of Geography [Cambridge, UK], University of Cambridge [UK] (CAM), McCammon, C., Bureau, H., Ii, H.J.C., Cottrell, E., Dorfman, S.M., Kellogg, L.H., Li, J., Mikhail, S., Moussallam, Y., Sanloup, C., Thomson, A.R., and Vitale Brovarone, A.

Subjects
010504 meteorology & atmospheric sciences, fluids and melts, chemistry.chemical_element, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, 01 natural sciences, 7. Clean energy, Mantle (geology), Astrobiology, redox freezing and melting, carbonate, freezing and melting, diamond, Geochemistry and Petrology, Planet, Mineral redox buffer, metal-silicate partitioning, 0105 earth and related environmental sciences, carbon-rich fluids and melts, Accretion (meteorology), Earth in Five Reactions: A Deep Carbon Perspective, Inner core, oxygen fugacity, Inner core, geodynamo, subduction, diamond, carbonate, carbon-rich fluids and melts, oxygen fugacity, metal-silicate partitioning, redox freezing and melting, Geophysics, carbon-rich, A Deep Carbon Perspective [Earth in Five Reactions], chemistry, 13. Climate action, [SDU]Sciences of the Universe [physics], redox, geodynamo, Dynamo theory, Environmental science, Earth (chemistry), Carbon, subduction
Abstract

Reactions involving carbon in the deep Earth have limited manifestations on Earth's surface, yet they have played a critical role in the evolution of our planet. The metal-silicate partitioning reaction promoted carbon capture during Earth's accretion and may have sequestered substantial carbon in Earth's core. The freezing reaction involving iron-carbon liquid could have contributed to the growth of Earth's inner core and the geodynamo. The redox melting/freezing reaction largely controls the movement of carbon in the modern mantle, and reactions between carbonates and silicates in the deep mantle also promote carbon mobility. The 10-year activity of the Deep Carbon Observatory has made important contributions to our knowledge of how these reactions are involved in the cycling of carbon throughout our planet, both past and present, and has helped to identify gaps in our understanding that motivate and give direction to future studies. © 2020 Walter de Gruyter GmbH, Berlin/Boston 2020.

Published
2020

15. Diamonds and the Mantle Geodynamics of Carbon

Author

Sami Mikhail, Richard A. Stern, Steven D. Jacobsen, Emilie Thomassot, Karen V. Smit, Hélène Bureau, Antony D. Burnham, Oded Navon, Steven B. Shirey, Erik H. Hauri, Fabrizio Nestola, Vincenzo Stagno, Y. Weiss, Frank E. Brenker, Sonja Aulbach, Robert W. Luth, Andrew Steele, Michael J. Walter, Thomas Chacko, Thomas Stachel, Dorrit E. Jacob, M. Palot, D. Graham Pearson, Andrew Thomson, Simon C. Kohn, Paolo Nimis, Evan M. Smith, Daniel J. Frost, and Pierre Cartigny

Subjects
Earth history, 010504 meteorology & atmospheric sciences, Diamond, Geodynamics, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), Astrobiology, Carbon cycle, Transition zone, engineering, Kimberlite, Geology, 0105 earth and related environmental sciences
Abstract

The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.

Published
2019

16. Deep Carbon

Author

D. Graham Pearson, Erik H. Hauri, Steven B. Shirey, Robert W. Luth, Thomas Chacko, Fabrizio Nestola, Daniel J. Frost, Pierre Cartigny, Emilie Thomassot, Frank E. Brenker, Karen V. Smit, Oded Navon, Evan M. Smith, Andrew Steele, Paolo Nimis, Sonja Aulbach, Michael J. Walter, Vincenzo Stagno, Simon C. Kohn, Richard A. Stern, Steven D. Jacobsen, Antony D. Burnham, Dorrit E. Jacob, M. Palot, Hélène Bureau, Thomas Stachel, Y. Weiss, Sami Mikhail, and Andrew Thomson

Subjects
Subduction, Earth science, Transition zone, engineering, Diamond, Crust, engineering.material, Geodynamics, Kimberlite, Geology, Mantle (geology), Metallogeny
Abstract

SBS and EHH for support from the US National Science Foundation (EAR-104992); FN and PN for support from the European Research Council Starting Grant (#307322); Wuyi Wang and Tom Moses of the Gemological Institute of America (GIA) for the support of the research projects undertaken by KVS and EMS; and SCK for the support of De Beers Technologies. This is contribution 1168 from the ARC Centre of Excellence for Core to Crust Fluid Systems (www.ccfs.mq.edu.au) and 1130 in the Geochemical Evolution and Metallogeny of the Continents Key Centre (www.gemoc.mq.edu.au).

Published
2019

17. NanoSIMS imaging of D/H ratios on FIB sections

Author

Hélène Bureau, Hicham Khodja, Alice Aléon-Toppani, Adriana Gonzalez-Cano, Daniel Lévy, Rémi Duhamel, David Troadec, Jérôme Aléon, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Centrale de Micro Nano Fabrication - IEMN (CMNF-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Museum National d'Histoire Naturelle, CNRS-INSU PNP national planetology program, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centrale de Micro Nano Fabrication - IEMN (CMNF - IEMN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Mineral hydration, 010504 meteorology & atmospheric sciences, Chemistry, [SDU]Sciences of the Universe [physics], Analytical chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 010502 geochemistry & geophysics, Nanoscale secondary ion mass spectrometry, 01 natural sciences, Focused ion beam, 0105 earth and related environmental sciences, Analytical Chemistry
Abstract

International audience; The D/H ratio imaging of weakly hydrated minerals prepared as Focused Ion Beam (FIB) sections is developed in order to combine isotopic imaging by Nanoscale Secondary Ion Mass Spectrometry (NanoSIMS) of micrometer-sized grains with other nanoscale imaging techniques, such as Transmission Electron Microscopy. In order to maximize the accuracy, sensitivity, precision and reproducibility of D/H ratios at the micrometer-size, while minimizing the surface contamination at the same time, we explored all instrumental parameters known to influence the measurement of D/H ratios in situ. Optimal conditions were found to be obtained with the use of (i) a Cs$^+$ ion source and detection of H$^-$ and D$^-$at low mass resolving power, (ii) a primary beam intensity of 100 pA, and (iii) raster sizes in the range 8-15 $\mu$m. Nominally anhydrous minerals were used to evaluate the detection limits and indicate a surface contamination level of about 200 ppm equivalent H$_2$O in these conditions. With the high primary intensity used here, the dwell time is not a parameter as critical as found in previous studies and a dwell time of 1 ms/px is used to minimize dynamic contamination during analysis. Analysis of FIB sections was found to reduce significantly static contamination due to sample preparation and improved accuracy compared to using polished sections embedded not only in epoxy but in indium as well. On amphiboles, the typical overall uncertainty including reproducibility is about 20 ‰ on bulk FIB sections and about 50 ‰ at the 1.5 $\mu$m scale using image processing (1$\sigma$).

Published
2019

18. Xenon and iodine behaviour in magmas

Author

Hicham Khodja, C. Leroy, P. Munsch, Caroline Raepsaet, Chrystèle Sanloup, K. Glazirin, Gaëlle Prouteau, Hélène Bureau, M. Harmand, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre de Paris (iSTeP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Deutsches Elektronen-Synchrotron [Hamburg] (DESY), Institut de Recherche sur les CERamiques (IRCER), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 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)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Magma - UMR7327, PSL Research University (PSL)-PSL Research University (PSL)-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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-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)-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)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), 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), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Chimie du CNRS (INC)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (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), and PSL Research University (PSL)-PSL Research University (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)

Subjects
010504 meteorology & atmospheric sciences, silicate mel, Analytical chemistry, chemistry.chemical_element, silicate melt, 010502 geochemistry & geophysics, 01 natural sciences, Diamond anvil cell, chemistry.chemical_compound, symbols.namesake, Xenon, Geochemistry and Petrology, Chondrite, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, ddc:550, Earth and Planetary Sciences (miscellaneous), tsolubility, Solubility, 0105 earth and related environmental sciences, iodine, solubility, Silicate, xenon, Elastic recoil detection, Geophysics, chemistry, speciation, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], symbols, Raman spectroscopy, volcanic degassing, Earth (classical element), Geology
Abstract

International audience; Iodine (I) and xenon (Xe) are two key elements that trace Earth's differentiation (e.g. atmosphere formation) and dynamics (e.g. volcanism and recycling at subduction zones). Iodine and Xe abundances are linked through the decay of the extinct 129I that produced 129Xe, which is today depleted in the Earth's atmosphere compared to the composition of the solar system (i.e. chondrites). Iodine and Xe cycles and storage in the deep Earth are almost unknown, which is in large part due to the fact that their behaviour in magmas and fluids, key agents of mass transfer through planetary envelopes, are poorly known. Here, the solubility of Xe and I in melts is measured under high pressure (P) and temperature (T) conditions using large volume presses, and Xe and I behaviour in melts and fluids is monitored in situ under high P-T conditions using resistive heating diamond anvil cells combined with synchrotron x-ray fluorescence (XRF) and Raman spectroscopy. Xenon, I and H (H2O) contents were measured in quenched glasses by particle x-ray Emission (PIXE) and Elastic Recoil Detection Analysis (ERDA). Solubility, speciation and degassing processes are investigated for two different compositions: haplogranitic melt (HPG analogue for crustal melts) and basaltic melts (MORB and IAB). Experimentally measured solubilities for both elements are much higher than their natural abundances in terrestrial magmas. Xenon solubility at 3.5 GPa reaches 4.00 wt.% in HPG and 0.40 wt.% in basalts. Iodine solubility is 0.46 wt.% at 0.4 GPa on average in HPG, and reaches 1.42 wt.% in basalts at 2 GPa. The in situ Raman spectroscopic study shows that I forms I-I bonds in hydrous high P fluids/melts unlike Xe that was previously shown to oxidize in high P melts. The XRF monitoring of I and Xe partitioning between aqueous fluids and silicate melts during decompression (i.e. water degassing) shows that Xe degassing is strongly P-T dependent and can be retained in the melt at deep crust conditions, while I is totally washed out from the silicate melt by the aqueous phase. Xenon and I degassing processes are based on different mechanisms, which implies that the atmospheric isotopic signature of Xe cannot be inherited from a process involving volcanic water degassing. Instead, 129Xe depletion may originate from a separation of both elements at depth, by deep fluids, a proposition that agrees with a deep storage of Xe in minerals

Published
2019

19. Diamonds and the Mantle Geodynamics of Carbon

Author

Shirey, Steven B., Smit, Karen V., Graham Pearson, D., Walter, Michael J., Sonja Aulbach, Brenker, Frank E., Hélène Bureau, Burnham, Antony D., Pierre Cartigny, Thomas Chacko, Frost, Daniel J., Hauri, Erik H., Jacob, Dorrit E., Jacobsen, Steven D., Kohn, Simon C., Luth, Robert W., Sami Mikhail, Oded Navon, Fabrizio Nestola, Paolo Nimis, Mederic Palot, Smith, Evan M., Thomas Stachel, Vincenzo Stagno, Andrew Steele, Stern, Richard A., Emilie Thomassot, Thomson, Andrew R., Yaakov Weiss, Carnegie Institution for Science [Washington], University of Alberta, Goethe-Universität Frankfurt am Main, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Australian National University (ANU), Institut de Physique du Globe de Paris (IPGP), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Universität Bayreuth, Macquarie University, Northwestern University [Evanston], University of Bristol [Bristol], University of St Andrews [Scotland], The Hebrew University of Jerusalem (HUJ), Universita degli Studi di Padova, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), University College of London [London] (UCL), Beth N. Orcutt, Isabelle Daniel, Rajdeep Dasgupta, Carnegie Institution for Science, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Padova = University of Padua (Unipd), and Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA)

Subjects
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
Abstract

International audience; The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.

Published
2019

20. Experimental constraints on the fate of H and C during planetary core-mantle differentiation. Implications for the Earth

Author

Chloé Fourdrin, Hicham Khodja, Svyatoslav Shcheka, Caroline Raepsaet, Suzy Surblé, Damien Deldicque, Mélissa Poncet, Fabrice Gaillard, Valérie Malavergne, David Sifré, Hélène Bureau, Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 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), Magma - 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), Bayerrisches Geoinstitut (BGI), Universität Bayreuth, Laboratoire de géologie de l'ENS (LGENS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris)

Subjects
010504 meteorology & atmospheric sciences, Hydrogen, Analytical chemistry, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], chemistry.chemical_element, 01 natural sciences, 7. Clean energy, Redox, Mantle (geology), Planet, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Chemistry, Planetary core, Core segregation, Astronomy and Astrophysics, Primitive Earth, Carbon, Planetary differentiation, 13. Climate action, Space and Planetary Science, High pressure, Order of magnitude
Abstract

International audience; Hydrogen (H) and carbon (C) have probably been delivered to the Earth mainly during accretion processes at High Temperature (HT) and High Pressure (HP) and at variable redox conditions. We performed HP (1 – 15 GPa) and HT (1600 – 2300°C) experiments, combined with state-of-the-art analytical techniques to better understand the behavior of H and C during planetary differentiation processes. We show that increasing pressure makes H slightly siderophile and slightly decreases the highly siderophile nature of C. This implies that the capacity of a growing core to retain significant amounts of H or C is mainly controlled by the size of the planet: small planetary bodies may retain C in their cores while H may have rather been lost in space; larger bodies may store both H and C in their cores. During the Earth's differentiation, both C and H might be sequestrated in the core. However, the H content of the core would remain one or two orders of magnitude lower than that of C since the (H/C)core ratio might range between 0.04 and 0.27.

Published
2019

21. Micron-scale δ13C determination by NanoSIMS in a Juina diamond with a carbonate inclusion

Author

Daniele L. Pinti, Hélène Bureau, Pierre Cartigny, Naoto Takahata, Yuji Sano, and Akizumi Ishida

Subjects
010504 meteorology & atmospheric sciences, Geochemistry, Mineralogy, Diamond, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, chemistry.chemical_compound, Geophysics, chemistry, Geochemistry and Petrology, Micron scale, engineering, Carbonate, Inclusion (mineral), Geology, 0105 earth and related environmental sciences
Published
2016

22. Modern and past volcanic degassing of iodine

Author

Anne-Line Auzende, Denis Testemale, Hélène Bureau, Guillaume Fiquet, S. Kubsky, M. Marocchi, P. Munsch, M. Carriere, Caroline Raepsaet, Mohamed Mezouar, A. Ricolleau, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Matériaux, Rayonnements, Structure (MRS), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), European Synchrotron Radiation Facility (ESRF), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire Lésions des Acides Nucléiques (LAN), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut Nanosciences et Cryogénie (INAC), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Matériaux, Rayonnements, Structure (NEEL - MRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Ozone, 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mineralogy, chemistry.chemical_element, 010502 geochemistry & geophysics, Early Earth, 01 natural sciences, Silicate, chemistry.chemical_compound, chemistry, 13. Climate action, Geochemistry and Petrology, Halogen, Magma, Fluorine, Water vapor, Earth (classical element), Geology, 0105 earth and related environmental sciences
Abstract

International audience; We have monitored iodine degassing from a melt to a water vapor during decompression (i.e. magma ascent). Experimentshave been performed by combining diamond anvil cells experiments with synchrotron X-rays fluorescence analysis. Partitioncoefficients DIfluid/melt measured for a pressure and temperature range of 0.1–1.8 GPa and 500–900 C, range from 41 to 1.92,values for room conditions DIfluid/glass (quenched samples) are equal to or higher than 350. We show that iodine degassing withwater is earlier and much more efficient than for lighter halogen elements, Cl and Br. Iodine is totally degassed from the silicatemelt at room conditions. By applying these results to modern volcanology, we calculate an annual iodine flux for subductionrelated volcanism of 0.16–2.4 kt yr1. We suggest that the natural iodine degassing may be underestimated, havingpossible consequences on the Earth’s ozone destruction cycle. By applying this results to the Early Earth, we propose a processthat may explain the contrasted signature of I, Br and Cl, strongly depleted in the bulk silicate Earth, the most depletedbeing iodine, whereas fluorine is almost enriched. The Earth may have lost heavy halogen elements during an early waterdegassing process from the magma ocean.

Published
2016

23. New method for initial composition determination of crystallized silicate melt inclusions

Author

Gerardo Carrasco-Núñez, Hélène Bureau, Laura Créon, Laurent Remusat, Gilles Levresse, Centro de Geociencias [Queretaro], Universidad Nacional Autónoma de México (UNAM), Investigacion Ciencias de la Terra, Instituto de Geologia, Centro de Geociencias, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Bubble, Analytical chemistry, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Geology, Electron microprobe, Trapping, 010502 geochemistry & geophysics, 01 natural sciences, Silicate, law.invention, Petrography, chemistry.chemical_compound, chemistry, 13. Climate action, Geochemistry and Petrology, law, [SDU]Sciences of the Universe [physics], Crystallization, Glass transition, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Melt inclusions
Abstract

Silicate melt inclusions (SMI) trapped in minerals and carried up to the surface by volcanism are routinely studied in order to determine the pre-eruptive volatile budgets of volcanic systems. The volatile contents of SMI that are affected by post-entrapment processes, such as crystallization (PEC) and/or bubble nucleation during cooling, are generally difficult to interpret. Therefore, there is a general preference to select the melt inclusions that experienced minimal post-entrapment effects. Conversely, SMI can be homogenized at high temperature and quickly quenched. This method is controversial because heating may induce leakage of water from the silicate melt during experiments in addition to loss by diffusion. Here, we propose a new multi-disciplinary method to study crystallized SMI. This method involves the following processes: (1) X-ray microtomography for measuring phase proportions; (2) NanoSIMS for measuring C and H concentrations in glass as a proxy for CO2 and H2O; (3) EPMA (electron probe microanalyzer) for major and volatile element concentrations in all phases; and (4) thermodynamical modeling using Rhyolite-MELTS for volatile saturation determination. To test this approach, we studied the Los Humeros (East Trans Mexican Volcanic Belt) volcanic complex SMI. Three-dimensional (3D) petrographic observations of the studied SMI demonstrate that minerals inside the SMI were crystallized from the trapped silicate melt and were not trapped with the silicate melt (protogenetic). Accordingly, the mathematical reconstruction of the SMI is performed with the following equation: XSMI = Σ[VMineral(i) ∗ XMineral(i)] + [VGlass ∗ XGlass] + [VBubble ∗ XBubble]. Bubbles are associated with a heterogeneous trapping of a melt + fluid mixed phase. The PEC of large minerals inside SMI is consistent with slow cooling rates of the SMI, meaning that exsolved volatiles diffused toward the bubble in equilibrium with the melt before the glass transition. The volatile pressure determined in XSMI and using Rhyolite-MELTS is therefore equal to the pressure of the bubble. The volatile mass in the bubble is determined and added to the bulk volatiles of the silicate melt. This method can be used for a wide range of samples and may significantly improve our knowledge of volatile degassing processes.

Published
2018

24. The growth of lithospheric diamonds

Author

Hélène, Bureau, Laurent, Remusat, Imène, Esteve, Daniele L, Pinti, and Pierre, Cartigny

Subjects
body regions, congenital, hereditary, and neonatal diseases and abnormalities, hemic and lymphatic diseases, parasitic diseases, SciAdv r-articles, Geology, Research Articles, Research Article
Abstract

The different habits of lithospheric diamonds are formed from the same fluids, from redox reactions at isotopic equilibrium., Natural diamonds contain mineral and fluid inclusions that record diamond growth conditions. Replicating the growth of inclusion-bearing diamonds in a laboratory is therefore a novel diagnostic tool to constrain the conditions of diamond formation in Earth’s lithosphere. By determining the carbon isotopic fractionation during diamond growth in fluids or melts, our laboratory experiments revealed that lithospheric monocrystalline and fibrous and coated diamonds grow similarly from redox reactions at isotopic equilibrium in water and carbonate-rich fluids or melts, and not from native carbon. These new results explain why most of the lithospheric diamonds are characterized by a common carbon isotopic fingerprint, inherited from their common parent fluids and not from the mantle assemblage.

Published
2018

25. Iodine

Author

Hélène Bureau

Subjects
010504 meteorology & atmospheric sciences, 010502 geochemistry & geophysics, 01 natural sciences, 0105 earth and related environmental sciences
Published
2018

26. Bromine

Author

Hélène Bureau

Published
2018

27. Bonding of xenon to oxygen in magmas at depth

Author

Chrystèle Sanloup, Hélène Bureau, Caroline Raepsaet, Burkhard C. Schmidt, C. Leroy, Zuzana Konôpková, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pétrologie, géochimie, minéralogie magmatiques (PGM2), Institut des Sciences de la Terre de Paris (iSTeP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), University of Göttingen - Georg-August-Universität Göttingen, Photone Sciences, Deutsches Elektronen-Synchrotron (DESY), Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), ANR-11-IDEX-0004,SUPER,Sorbonne Universités à Paris pour l'Enseignement et la Recherche(2011), European Project: 312284,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2012-1,CALIPSO(2012), European Project: 259649,EC:FP7:ERC,ERC-2010-StG_20091028,MAD-ESEC(2011), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Georg-August-University = Georg-August-Universität Göttingen, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Coordination number, chemistry.chemical_element, Electron microprobe, 010402 general chemistry, 01 natural sciences, Diamond anvil cell, law.invention, chemistry.chemical_compound, Xenon, Geochemistry and Petrology, law, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Earth and Planetary Sciences (miscellaneous), ddc:550, 0105 earth and related environmental sciences, Isotope, [CHIM.MATE]Chemical Sciences/Material chemistry, Synchrotron, Silicate, 0104 chemical sciences, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, Chemical physics, Geology, Order of magnitude
Abstract

International audience; The field of noble gases chemistry has witnessed amazing advances in the last decade with over 100 compounds reported including Xe oxides and Xe–Fe alloys stable at the pressure-temperature conditions of planetary interiors. The chemistry of Xe with planetary materials is nonetheless still mostly ignored, while Xe isotopes are used to trace a variety of key planetary processes from atmosphere formation to underground nuclear tests. It is indeed difficult to incorporate the possibility of Xe reactivity at depth in isotopic geochemical models without a precise knowledge of its chemical environment. The structure of Xe doped hydrous silica-rich melts is investigated by in situ high energy synchrotron X-ray diffraction using resistive heating diamond anvil cells. Obtained pair distribution functions reveal the oxidation of Xe between 0.2 GPa and 4 GPa at high T up to 1000 K. In addition to the usual interatomic distances, a contribution at 2.05 ± 0.05 Å is observed. This contribution is not observed in the undoped melt, and is interpreted as the Xe–O bond, with a coordination number of about 12 consistent with Xe insertion in rings of the melt structure. Xe solubility measurements by electron microprobe and particle induced X-rays emission analysis confirm that Xe and Ar have similar solubility values in wt% in silicate melts. These values are nonetheless an order of magnitude higher than those theoretically calculated for Xe. The formation of Xe–O bonds explains the enhanced solubility of Xe in deep continental crust magmas, revealing a mechanism that could store Xe and fractionate its isotopes. Xenon is indeed atypical among noble gases, the atmosphere being notably depleted in elemental Xe, and very strongly depleted in Xe light isotopes. These observations are known as the ‘missing’ Xe paradox, and could be solved by the present findings.

Published
2017

28. The use of 13C diamond as pressure and temperature sensor for diamond-anvil-cell experiments

Author

Hicham Khodja, Alexander M. Zaitsev, Hélène Bureau, P. Munsch, Marouan El Yakoubi, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Raman scattering, 010504 meteorology & atmospheric sciences, Analytical chemistry, Mineralogy, Frequency shift, engineering.material, 010502 geochemistry & geophysics, diamond-anvil cell, 01 natural sciences, Hydrothermal circulation, Diamond anvil cell, Mantle (geology), pressure, chemistry.chemical_compound, symbols.namesake, Geochemistry and Petrology, Raman band, 0105 earth and related environmental sciences, temperature, Diamond, [CHIM.MATE]Chemical Sciences/Material chemistry, calibration, Silicate, silicate melts, chemistry, engineering, symbols, geological fluids, 13C diamond, Geology
Abstract

International audience; This study aims at providing an accurate method to determine in situ the pressure in the sample chamber during a diamond-anvil-cell experiment. We report the calibration of the frequency shift with pressure of the Raman band of a 98.3 at.% 13C diamond against ruby and SrB4O7:Sm2+. This method is suitable for the study of geological fluids during hydrothermal experiments performed at pressures up to 16 GPa and temperature up to 800°C, particularly for subduction-zone processes involving fluids or/and silicate melts. Experiments were carried out in a new hydrothermal diamond-anvil cell (HDAC) designed for the study of geological fluids at crustal and mantle pressures.

Published
2015

29. Bromine speciation in hydrous silicate melts at high pressure

Author

C. Leroy, Innokenty Kantor, Chrystèle Sanloup, Hélène Bureau, B. Cochain, Céline Crépisson, Tetsuo Irifune, C. de Grouchy, Institut des Sciences de la Terre de Paris (iSTeP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), University of Edinburgh, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), GRC, Ehime University [Matsuyama], Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), and Ehime University [Matsuyama, Japon]

Subjects
high-pressure, Absorption spectroscopy, Inorganic chemistry, chemistry.chemical_element, 010502 geochemistry & geophysics, 01 natural sciences, X-ray absorption, Ion, chemistry.chemical_compound, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Geochemistry and Petrology, 0103 physical sciences, halogens, structure, 010306 general physics, 0105 earth and related environmental sciences, X-ray absorption spectroscopy, Bromine, Extended X-ray absorption fine structure, Geology, Alkali metal, Silicate, EXAFS, speciation, silicate melts, chemistry, Halogen
Abstract

International audience; Br speciation in hydrous silicate melts at high pressure has been investigated up to 7.6 GPa using X-ray Absorption Spectroscopy (XAS) at the Br K-edge in a Paris-Edinburgh press. Br in silicate melts is surrounded by an average of 6 Na cations, a number slightly increasing with pressure (5.8 to 6.6), with a Br-Na distance increasing from 3.49 to 3.72 Å. Two oxygens, either from a water, an –OH molecule or from the tetrahedral silicate network, with an average Br-O distance of 1.80 Å, form the closest coordination shell around Br ions. The persistence of an alkali shell around Br, in a structure similar to crystalline NaBr, throughout the pressure range investigated shows that Br can be retained in the melt structure at relatively high pressure and supports the idea of its deep recycling. Finally, our results confirm that Br could be efficiently degassed with water at low pressures and that Br may also have been efficiently degassed along with water during the early stages of an oxidized magma ocean.

Published
2015

30. Low hydrogen contents in the cores of terrestrial planets

Author

Vincent, Clesi, Mohamed Ali, Bouhifd, Nathalie, Bolfan-Casanova, Geeth, Manthilake, Federica, Schiavi, Caroline, Raepsaet, Hélène, Bureau, Hicham, Khodja, and Denis, Andrault

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Physics::Space Physics, Physical Sciences, Astrophysics::Solar and Stellar Astrophysics, SciAdv r-articles, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Research Articles, Planetary Science, Research Article
Abstract

During planetary accretion, hydrogen behaves as a lithophile element and is unlikely to be a major element in planetary cores., Hydrogen has been thought to be an important light element in Earth’s core due to possible siderophile behavior during core-mantle segregation. We reproduced planetary differentiation conditions using hydrogen contents of 450 to 1500 parts per million (ppm) in the silicate phase, pressures of 5 to 20 GPa, oxygen fugacity varying within IW-3.7 and IW-0.2 (0.2 to 3.7 log units lower than iron-wüstite buffer), and Fe alloys typical of planetary cores. We report hydrogen metal-silicate partition coefficients of ~2 × 10−1, up to two orders of magnitude lower than reported previously, and indicative of lithophile behavior. Our results imply H contents of ~60 ppm in the Earth and Martian cores. A simple water budget suggests that 90% of the water initially present in planetary building blocks was lost during planetary accretion. The retained water segregated preferentially into planetary mantles.

Published
2017

31. Chlorine in wadsleyite and ringwoodite: An experimental study

Author

Nathalie Bolfan-Casanova, Hicham Khodja, Guillaume Fiquet, Suzy Surblé, Hélène Bureau, Mathilde Roberge, Caroline Raepsaet, Patrick Cordier, Anne-Line Auzende, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Analytical chemistry, Mineralogy, chemistry.chemical_element, Pyroxene, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, experimental study, Geochemistry and Petrology, Transition zone, Earth and Planetary Sciences (miscellaneous), Chlorine, [CHIM]Chemical Sciences, 0105 earth and related environmental sciences, Olivine, Wadsleyite, Elastic recoil detection, Ringwoodite, Geophysics, volatiles, chemistry, Space and Planetary Science, chlorine, transition zone, engineering, Anhydrous, Geology
Abstract

International audience; We report concentrations of Chlorine (Cl) in synthetic wadsleyite (Wd) and ringwoodite (Rw) in the system NaCl–(Mg, Fe)2SiO4 under hydrous and anhydrous conditions. Multi-anvil press experiments were performed under pressures (14–22 GPa) and temperatures (1100–1400 °C) relevant to the transition zone (TZ: 410–670 km depth). Cl and H contents were measured using Particle Induced X-ray Emission (PIXE) and Elastic Recoil Detection Analysis (ERDA) respectively. Results show that Cl content in Rw and Wd is significantly higher than in other nominally anhydrous minerals from the upper mantle (olivine, pyroxene, garnet), with up to 490 ppm Cl in anhydrous Rw, and from 174 to 200 ppm Cl in hydrous Wd and up to 113 ppm Cl in hydrous Rw.

Published
2017

32. Reactivity of heavy noble gases under high pressure

Author

Chrystele Sanloup, C. Leroy, Hélène Bureau, Laurent Cormier, Céline Crépisson, and Marc Blanchard

Subjects
Inorganic Chemistry, Structural Biology, Chemistry, High pressure, Inorganic chemistry, General Materials Science, Reactivity (chemistry), Physical and Theoretical Chemistry, Condensed Matter Physics, Biochemistry
Published
2019

33. Diamond growth in mantle fluids

Author

Hélène Bureau, Nathalie Bolfan-Casanova, C. Leroy, Daniel J. Frost, Patrick Cordier, Imène Esteve, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Bayerisches Geoinstitut (BGI), Universität Bayreuth, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC), Bayerisches GeoInstitut, Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC)

Subjects
010504 meteorology & atmospheric sciences, Geochemistry, Carbonates, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), chemistry.chemical_compound, Geochemistry and Petrology, [CHIM]Chemical Sciences, Graphite, Geothermal gradient, 0105 earth and related environmental sciences, Diamonds, Aqueous solution, Diamond, Water, Geology, Silicate, chemistry, Carbon dioxide, Inclusions, engineering, Carbonate, Chlorine
Abstract

International audience; In the upper mantle, diamonds can potentially grow from various forms of media (solid, gas, fluid) with a range of compositions (e.g. graphite, C–O–H fluids, silicate or carbonate melts). Inclusions trapped in diamonds are one of the few diagnostic tools that can constrain diamond growth conditions in the Earth's mantle. In this study, inclusion-bearing diamonds have been synthesized to understand the growth conditions of natural diamonds in the upper mantle. Diamonds containing syngenetic inclusions were synthesized in multi-anvil presses employing starting mixtures of carbonates, and silicate compositions in the presence of pure water and saline fluids (H2O–NaCl). Experiments were performed at conditions compatible with the Earth's geotherm (7 GPa, 1300–1400 °C). Results show that within the timescale of the experiments (6 to 30 h) diamond growth occurs if water and carbonates are present in the fluid phase. Water promotes faster diamond growth (up to 14 mm/year at 1400 °C, 7 GPa, 10 g/l NaCl), which is favorable to the inclusion trapping process. At 7 GPa, temperature and fluid composition are the main factors controlling diamond growth. In these experiments, diamonds grew in the presence of two fluids: an aqueous fluid and a hydrous silicate melt. The carbon source for diamond growth must be carbonate (CO32) dissolved in the melt or carbon dioxide species in the aqueous fluid (CO2aq). The presence of NaCl affects the growth kinetics but is not a prerequisite for inclusion-bearing diamond formation. The presence of small discrete or isolated volumes of water-rich fluids is necessary to grow inclusion-bearing peridotitic, eclogitic, fibrous, cloudy and coated diamonds, and may also be involved in the growth of ultradeep, ultrahigh-pressure metamorphic diamonds.

Published
2016

34. Iodine

Author

Hélène Bureau

Published
2016

35. Bromine

Author

Hélène Bureau

Subjects
010504 meteorology & atmospheric sciences, 010502 geochemistry & geophysics, 01 natural sciences, 0105 earth and related environmental sciences
Published
2016

36. The growth of fibrous, cloudy and polycrystalline diamonds

Author

Julien Siebert, Hélène Bureau, Daniel J. Frost, Imène Esteve, Falko Langenhorst, Anne-Line Auzende, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Bayerisches Geoinstitut (BGI), Universität Bayreuth, and Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
congenital, hereditary, and neonatal diseases and abnormalities, Materials science, 010504 meteorology & atmospheric sciences, chemistry.chemical_element, Mineralogy, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Miscibility, Monocrystalline silicon, chemistry.chemical_compound, Geochemistry and Petrology, hemic and lymphatic diseases, parasitic diseases, 0105 earth and related environmental sciences, Aqueous solution, Diamond, Silicate, Supercritical fluid, body regions, chemistry, Chemical engineering, engineering, Crystallite, Carbon, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

International audience; We have performed an experimental study designed to reproduce the growth of fibrous/coated, cloudy and polycrystalline diamonds in hydrous silica-carbonate-rich fluids. Multi-anvil experiments have been conducted at pressures between 7 and 9 GPa and temperatures between 1200 and 1675 C, with run durations ranging from a few hours to a few days. Significant diamond growth was observed in all experiments. The growth was either homogeneous, with new diamond crystals growing spontaneously in the fluid, or heterogeneous, by rim overgrowth on pre-existing diamond seeds. A wide range of the morphology observed in nature has been reproduced and identified in the run products (aggregates, fibrous, and monocrystalline areas). For the first time, multi-phase inclusions, closely mimicking those found in natural samples, have been experimentally produced during diamond growth. These arise either from a mixture of coexisting liquids (hydrous silicate melt and aqueous fluid) or from a unique supercritical fluid resulting from the total miscibility of the two fluids, which occurs at high pressure and temperature. These results strengthen the hypothesis that diamonds grow from carbon and water-rich fluids and support models proposing episodic growth from successive fluids. The results raise the possibility that natural inclusions with different compositions found in a single diamond may form through the trapping of immiscible liquids, which had locally unmixed prior to trapping. Finally, considering the composition of the diamond's parent fluids, a subduction origin is likely, at least for fibrous/coated, cloudy diamonds, and to some extent, for polycrystalline diamonds also.

Published
2012

37. In-situ monitoring of the formation of carbon compounds during the dissolution of iron(II) carbonate (siderite)

Author

Marta Marocchi, François Guyot, Guillaume Fiquet, and Hélène Bureau

Subjects
chemistry.chemical_classification, 010504 meteorology & atmospheric sciences, Thermal dissolution, Inorganic chemistry, chemistry.chemical_element, Geology, 010502 geochemistry & geophysics, 01 natural sciences, Ferrous, Siderite, chemistry.chemical_compound, chemistry, 13. Climate action, Geochemistry and Petrology, Carbonate, Compounds of carbon, Dissolution, Carbon, 0105 earth and related environmental sciences, Carbon monoxide
Abstract

Experiments of dissolution of siderite (FeCO 3 ) in pure water and in saline aqueous solution (“seawater” composition) have been performed at temperatures of up to 400 °C in a maximum pressure range of 720–1150 MPa, using an hydrothermal diamond anvil cell (HDAC). The reaction products were characterized in situ by Raman spectroscopy. At 250 °C, in pure water system, we document formation of formaldehyde (HCOH) near the surface of siderite. At 250 °C and above, formic acid (HCOOH) and carbon monoxide (CO) were detected in the bulk fluid. The reduction of oxidized carbon to HCOH and HCOOH is coupled to conversion of ferrous iron (Fe II ) from siderite to ferric iron (Fe III ). We thus provide experimental evidence of Fe II –CO 2 oxido-reductive coupling using a single mineral, siderite, in pure water and in saline solution. The presence of NaCl in the fluid enhances the kinetics of oxido-reductive dissolution of siderite, with formation of organic chlorinated molecules. The results suggest that in geological situations, especially in accretion prisms or active hydrothermal systems developing on ultrabasic rocks in which fluids may be transferred with relatively short residence times, formic acid and formaldehyde might be important metastable storage forms of hydrogen. Moreover, thermal dissolution of siderite may account for at least some of the reduced carbon observed in chondrites bearing traces of hydrothermal activity and in metasedimentary rocks from the early Earth.

Published
2011

38. Determination of hydrogen content in geological samples using elastic recoil detection analysis (ERDA)

Author

Caroline Raepsaet, Hicham Khodja, Hélène Bureau, Cyril Aubaud, and Anna Carraro

Subjects
Elastic recoil detection, Matrix (chemical analysis), Secondary ion mass spectrometry, Crystal, Hydrogen, Geochemistry and Petrology, Chemistry, Analytical chemistry, chemistry.chemical_element, Fourier transform infrared spectroscopy, Microanalysis, Quartz
Abstract

The present study illustrates the interest of using the elastic recoil detection analysis (ERDA) method to characterize any geological sample matrix with respect to hydrogen. ERDA is combined with Rutherford back scattering (RBS) and particle induced X-ray emission (PIXE), allowing the simultaneous characterization of the matrix with respect to major and trace elements ( Z > 15). Analyses are performed by mapping of a 4 × 16 μm 2 incident beam of 4 He + on large areas (50 × 200 μm 2 ). The method is almost not destructive and requires no calibration with respect to well known hydrous samples. Hydrous and nominally anhydrous phases in contact with each other in the same sample may both be characterized. The depth of the analyses is limited to several μm beneath the surface, allowing tiny samples to be investigated, provided their sizes are larger than the incident beam. Our setup has been improved in order to allow H determination on a micrometric scale with a 5–15% relative uncertainty and a detection limit of 94 wt ppm H 2 O. We present multi-elemental mappings on a large panel of samples: (1) natural and analogue synthetic glasses from Stromboli volcano (0.44–4.59 wt% H 2 O), natural rhyolitic glasses (1466–1616 wt ppm H 2 O); (2) magmatic rhyolitic melt inclusions from Guadeloupe Island (4.37–5.47 wt% H 2 O) and their quartz host crystal (2020 ± 230 wt ppm H 2 O); (3) nominally anhydrous natural (82–260 wt ppm H 2 O) and experimentally hydrated (240–790 wt ppm H 2 O) olivines; natural clinopyroxenes (159–716 wt ppm H 2 O); natural orthopyroxenes (201–452 wt ppm H 2 O); a natural garnet (90 wt ppm H 2 O). Results show that ERDA is a strong and accurate reference method that can be used to characterize geological sample from various matrix compositions from high to low water contents. It can be used to calibrate other methods of microanalysis such as Fourier Transform Infrared Spectroscopy (FTIR) or secondary ion mass spectrometry (SIMS).

Published
2009

39. μ-Erda developments in order to improve the water content determination in hydrous and nominally anhydrous mantle phases

Author

Cyril Aubaud, Hicham Khodja, Hélène Bureau, Caroline Raepsaet, and A. Carraro

Subjects
Nuclear and High Energy Physics, Microprobe, Olivine, 010504 meteorology & atmospheric sciences, Chemistry, Analytical chemistry, Mineralogy, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Elastic recoil detection, Anhydrous, engineering, Sample preparation, Surface layer, Fourier transform infrared spectroscopy, Instrumentation, Water content, 0105 earth and related environmental sciences
Abstract

The precise knowledge of the water content in geological samples such as mantle minerals, volcanic glasses and glassy inclusions proves to be crucial information for the Earth Sciences because water has a considerable influence on physical and chemical properties of Earth’s mantle and crust. Among the nuclear microbeam techniques, elastic recoil detection analysis (ERDA) has been used at the nuclear microprobe of the Pierre Sue Laboratory (LPS) with a very good reliability for a long time to determine the water content of various materials. Previous ERDA measurements gave the total H content at a micrometric scale in the bulk of hydrous geologic samples. However, it was more difficult to characterize nominally anhydrous phases. Recent efforts allowed us to significantly improve the different steps of the ERDA analysis, from the sample preparation to the determination of the uncertainties of the resulting H concentration. A large series of very different geological samples has been measured: volcanic glasses and glassy inclusions, synthetic and natural nominally anhydrous minerals. Our new sample preparation protocol limited the thickness of the surface layer of H-pollution, leading to an easier differentiation of the bulk contribution. Simultaneous PIXE and RBS measurements allow the precise location of the interesting areas and also give information on the chemical characterization of the investigated samples, with respect to the major and minor elements. The processing of the list-mode acquisition files is made using the RISMIN software, allowing among other interesting features to check the absence of water loss under the beam. We will present the results of the H-content measurements and show the good agreement between our present results and those obtained by Fourier transform infrared spectroscopy (FTIR) for the same set of samples. The detection limit was measured on a dehydrated natural San Carlos olivine ((Mg,Fe)2SiO4) equal to 130 wt ppm H2O (15 wt ppm H or 300 at ppm H) and the relative uncertainties on the water concentration range from 10% to 15%.

Published
2008

40. In situmapping of high-pressure fluids using hydrothermal diamond anvil cells

Author

Bénédicte Ménez, D. Massare, Andrea Somogyi, L. Daudin, Hélène Bureau, M. Bonnin-Mosbah, Alexandre Simionovici, Valérie Malavergne, Hicham Khodja, Jean-Paul Gallien, and Cliff S. J. Shaw

Subjects
Quenching, In situ, Materials science, Aqueous solution, Analytical chemistry, Synchrotron radiation, Mineralogy, Condensed Matter Physics, Diamond anvil cell, Synchrotron, Hydrothermal circulation, Silicate, law.invention, chemistry.chemical_compound, chemistry, law
Abstract

We present new results combining high pressures and temperatures attainable in a diamond anvil cell with in situ synchrotron radiation induced micro-X-ray fluorescence measurements. Hydrothermal diamond anvil cells experiments have been performed by measuring the partitioning of Pb between aqueous fluids (pure water or NaCl-enriched water) and hydrous silicate melts of haplogranite composition using synchrotron X-ray fluorescence. The in situ measurements were performed in the range 0.3–1.2 GPa and 730–850 °C both in the aqueous fluid and in the silicate melts being in equilibrium. Pb is strongly partitioned into high-pressure–temperature hydrous melts when Cl is present in either the hydrous melt or the aqueous fluid. Moreover, our comparisons of in situ results with post-mortem results show that significant changes take place during rapid quenching especially when samples are small (few hundred of microns in diameter). Water exsolution is induced by the quench in the silicate melt showing the high mobil...

Published
2007

41. New high-pressure and high-temperature metal/silicate partitioning of U and Pb: Implications for the cores of the Earth and Mars

Author

Hélène Bureau, Craig S. Schwandt, Valérie Malavergne, Martine Tarrida, R. Combes, and John H. Jones

Subjects
Partition coefficient, Martian, chemistry.chemical_compound, Valence (chemistry), chemistry, Geochemistry and Petrology, Mineral redox buffer, Analytical chemistry, Mineralogy, Fugacity, Mars Exploration Program, Silicate, Mantle (geology)
Abstract

In order to quantify possible fractionation of U and Pb into a metallic core, we have performed piston cylinder and multi-anvil press experiments at high pressure (up to 20 GPa) and high temperature (up to 2400 °C) and obtained the distribution coefficient Dmetal–silicate and the exchange partition coefficient Kmetal–silicate for these elements between metal and silicates (mineral or liquid). D Pb metal–silicate and D U metal–silicate depend strongly on the S content of the metallic phase, and also on the oxygen fugacity, in agreement with an effective valence state of 4 for U in silicates and 2 for Pb in silicates. K Pb d metal–silicate and K U d metal–silicate show no discernable pressure and temperature trend. U remains lithophile even at high pressure and high temperature but its lithophile nature decreases at very low oxygen fugacity. From our experimental data, it was possible to calculate the U and Pb contents of the cores of Mars and Earth under core-mantle equilibrium conditions at high pressure and high temperature. From the Dmetal–silicate of the present study, we obtained that: 0.008 ppm Our results suggest that the low concentration of Pb in the terrestrial mantle could not be explained by an early Pb sequestration in the Earth’s core even if S is the dominant light element of the core. If we assume a magma ocean scenario, U might produced a maximum value of 1.5% of the total heat budget of the core with a segregation occurring below ΔIW-3. The values found in the present study for U in the Martian core suggest that the magnetic field activity of Mars before ∼0.5 b.y. after its formation would be difficult to ascribe to the decay of U alone.

Published
2007

42. Is the transition zone a deep reservoir for fluorine?

Author

Guillaume Fiquet, Daniel J. Frost, Hélène Bureau, Hicham Khodja, Suzy Surblé, Caroline Raepsaet, Mathilde Roberge, Anne-Line Auzende, Nathalie Bolfan-Casanova, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Laboratoire Magmas et Volcans (LMV), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Bayerisches Geoinstitut (BGI), Universität Bayreuth, Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)

Subjects
010504 meteorology & atmospheric sciences, water, Mineralogy, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), chemistry.chemical_compound, Geochemistry and Petrology, fluorine, Transition zone, Earth and Planetary Sciences (miscellaneous), ringwoodite, Volatiles, wadsleyite, 0105 earth and related environmental sciences, Basalt, solubility, Wadsleyite, Silicate, Ringwoodite, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], transition zone, engineering, Anhydrous, Geology
Abstract

International audience; It is now recognized that the transition zone (TZ) is a significant repository for water. This means that other volatile species may also be stored in this region such as halogen elements. We have measured the solubility of fluorine in wadsleyite (Wd) and ringwoodite (Rw) under hydrous and anhydrous conditions at different pressures and temperatures, relevant for the transition zone. F contents are similar in Wd (665 to 1045 ppm F, up to 956 ppm H2O) and in Rw (186 to 1235 ppm F, up to 1404 ppm H2O). This suggests that F may be incorporated in the same manner as water in the major nominally anhydrous minerals of the TZ: ringwoodite and wadsleyite and that the transition zone could be a major reservoir for fluorine. In the framework of the “water filter model” proposed by Bercovici and Karato (2003), the contrast of volatile element contents between a depleted upper mantle and an enriched transition zone could be maintained over geological time scales. Previous estimates of the fluorine content of the Bulk Silicate Earth (BSE), such as 25 ppm by mass (McDonough and Sun, 1995), have assumed a homogeneous mantle. Although we do not know whether the TZ is F saturated or not, we used our new experimental data and estimates of the lower mantle F content from ocean island basalts to estimate a maximum BSE fluorine content of 59 ppm by mass for a hydrous, F-saturated TZ. This upper bound on the range of possible BSE F content emphasizes the challenges when explaining the origin of volatile elements in the Earth from a carbonaceous chondrite late veneer.

Published
2015

44. The partitioning of barium and lead between silicate melts and aqueous fluids at high pressures and temperatures

Author

Nicole Métrich, L. Daudin, D. Massare, Jean-Paul Gallien, Hélène Bureau, Cliff S. J. Shaw, Hicham Khodja, and Bénédicte Ménez

Subjects
Nuclear and High Energy Physics, Aqueous solution, Analytical chemistry, Trace element, chemistry.chemical_element, Mineralogy, Barium, Fractionation, Hydrothermal circulation, Silicate, Partition coefficient, chemistry.chemical_compound, chemistry, Phase (matter), Instrumentation
Abstract

The origin of subduction-related magmas is still a matter of debate in the Earth Sciences. These magmas are characterised by their distinctive trace element compositions compared to magmas from other tectonic settings, e.g. mid-ocean ridges or rifts. The distinct trace element composition of these magmas is generally attributed to alteration of the source region by a contaminating agent: either a silicate melt or a hydrous fluid, possibly chlorine-enriched. In this study, we have used μPIXE (proton induced X-ray emission) to analyse synthetic samples obtained from a micro-experimental petrology study that aims to determine the partitioning behaviour of two key elements, Ba and Pb, between silicate melt and both pure water and saline fluids. Our experiments were performed at high-pressure (>0.34–1.53 GPa) and high-temperature (697–1082 °C) in a hydrothermal diamond anvil cell, that was used as a transparent rapid quench autoclave. We observed that at high pressure and temperature, in the presence of pure water, Ba and Pb are not strongly fractionated into one phase or the other. The partition coefficient of Pb is ranging from 0.46 to 1.28. Results from one experiment performed at 0.83 GPa and 847 °C, in the presence of a saline fluid indicate that the presence of Cl induces strong fractionation of Pb and moderate fractionation of Ba both into the silicate melt. In addition, our data indicate that Cl is strongly partitioned into the fluid phase.

Published
2003

45. Determination of the concentration of water dissolved in glasses and minerals using nuclear microprobe

Author

Sylvie Demouchy, Patrick Trocellier, Hélène Bureau, Cliff S. J. Shaw, Nathalie Bolfan-Casanova, and Hicham Khodja

Subjects
Elastic recoil detection, Secondary ion mass spectrometry, Nuclear and High Energy Physics, Microprobe, Chemistry, Extinction (optical mineralogy), Analytical chemistry, Mineralogy, Fourier transform infrared spectroscopy, Rutherford backscattering spectrometry, Spectroscopy, Instrumentation, Water content
Abstract

In Earth Sciences, the global water cycle is of fundamental importance. For this reason, the H2O content of volcanic glass and mantle minerals must be analysed: usually by micro-infrared spectroscopy (FTIR) or secondary ion mass spectrometry (SIMS). However, both of these methods require calibration using standards of known water content. To avoid matrix effects, the standards and unknowns must be otherwise identical in composition. In this study we have determined the water content of geological samples, in the range 10 ppm–5wt.%H2O, using an absolute analytical technique: a combination of elastic recoil detection analysis (ERDA) and Rutherford backscattering spectrometry (RBS). We compared the results obtained by this method to data obtained by FTIR on the same samples. We discuss the limitations of the method and use the results to calibrate IR extinction coefficients for FTIR spectroscopy.

Published
2003

46. Large-ion lithophile elements delivered by saline fluids to the sub-arc mantle

Author

Shigeaki Ono, Hélène Bureau, Tetsu Kogiso, Tatsuhiko Kawamoto, Cristian Mocuta, Dominique Thiaudière, Solenn Reguer, S. Kubsky, Kenji Mibe, Kyoto University, The University of Tokyo (UTokyo), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Research and Development Center for Ocean Drilling Scienc (JAMSTEC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kyoto University [Kyoto], and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Basalt, Aqueous solution, Brine, Mantle wedge, Analytical chemistry, Mineralogy, Water, Geology, Mantle (geology), Supercritical fluid, Partition coefficient, 13. Climate action, Space and Planetary Science, Oceanic crust, H 2 O, [SDE]Environmental Sciences, Trace element, Lithophile, Subduction zone magmatism, Chlorine
Abstract

International audience; Geochemical signatures of arc basalts can be explained by addition of aqueous fluids, melts, and/or supercritical fluids from the subducting slab to the sub-arc mantle. Partitioning of large-ion lithophile elements between aqueous fluids and melts is crucial as these two liquid phases are present in the sub-arc pressure-temperature conditions. Using a micro-focused synchrotron X-ray beam, in situ X-ray fluorescence (XRF) spectra were obtained from aqueous fluids and haplogranite or jadeite melts at 0.3 to 1.3 GPa and 730°C to 830°C under varied concentrations of (Na, K)Cl (0 to 25 wt.%). Partition coefficients between the aqueous fluids and melts were calculated for Pb, Rb, and Sr (D fluid=melt Pb; Rb; Sr). There was a positive correlation between D fluid=melt Pb; Rb; Sr values and pressure, as well as D fluid=melt Pb; Rb; Sr values and salinity. As compared to the saline fluids with 25 wt.% (Na, K)Cl, the Cl-free aqueous fluids can only dissolve one tenth (Pb, Rb) to one fifth (Sr) of the amount of large-ion lithophile elements when they coexist with the melts. In the systems with 13 to 25 wt.% (Na, K)Cl, D fluid=melt Pb; Rb values were greater than unity, which is indicative of the capacity of such highly saline fluids to effectively transfer Pb and Rb. Enrichment of large-ion lithophile elements such as Pb and Rb in arc basalts relative to mid-oceanic ridge basalts (MORB) has been attributed to mantle source fertilization by aqueous fluids from dehydrating oceanic plates. Such aqueous fluids are likely to contain Cl, although the amount remains to be quantified.

Published
2014

47. How Mercury can be the most reduced terrestrial planet and still store iron in its mantle

Author

Kevin Righter, Roger H. Hewins, Thomas Smith, Suzy Surblé, Caroline Raepsaet, Hélène Bureau, Valérie Malavergne, Fabrice Brunet, Brigitte Zanda, Ahmed Addad, E. Charon, Patrick Cordier, Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée (UPEM), Laboratoire de géologie de l'ENS (LGENS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), NASA Johnson Space Center (JSC), NASA, Institut des Sciences de la Terre (ISTerre), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Planetary Sciences [Piscataway], Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers)-Rutgers University System (Rutgers), Service Interdisciplinaire sur les Systèmes Moléculaires et les Matériaux (ex SCM) (SIS2M UMR 3299), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Programme National de Planetologie of the Institut National des Sciences de l'Univers (INSU), Lunar and Planetary Institute, NASA Johnson Space Center (Houston, TX, USA), Conseil Regional du Nord-Pas de Calais, European Regional Development Fund (ERDF), INSU, CNRS, Laboratoire de géologie de l'ENS (LGE), École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), and Institut de Chimie du CNRS (INC)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)

Subjects
planetary differentiation, sulfides, Inorganic chemistry, Mineralogy, chemistry.chemical_element, Mercury, Mantle (geology), Outer core, Troilite, Silicate, Mercury (element), chemistry.chemical_compound, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Core–mantle boundary, Earth and Planetary Sciences (miscellaneous), enstatitechondrites, primitive mantle, Primitive mantle, Planetary differentiation, Geology, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

International audience; Mercury is notorious as the most reduced planet with the highest metal/silicate ratio, yet paradoxically data from the MESSENGER spacecraft show that its iron-poor crust is high in sulfur (up to ∼6 wt%, ∼80× Earth crust abundance) present mainly as Ca-rich sulfides on its surface. These particularities are simply impossible on the other terrestrial planets. In order to understand the role played by sulfur during the formation of Mercury, we investigated the phase relationships in Mercurian analogs of enstatite chondrite-like composition experimentally under conditions relevant to differentiation of Mercury (∼1 GPa and 1300–2000 °C). Our results show that Mg-rich and Ca-rich sulfides, which both contain Fe, crystallize successively from reduced silicate melts upon cooling below 1550 °C. As the iron concentration in the reduced silicates stays very low (≪1 wt%), these sulfides represent new host phases for both iron and sulfur in the run products. Extrapolated to Mercury, these results show that Mg-rich sulfide crystallization provides the first viable and fundamental means for retaining iron as well as sulfur in the mantle during differentiation, while sulfides richer in Ca would crystallize at shallower levels. The distribution of iron in the differentiating mantle of Mercury was mainly determined by its partitioning between metal (or troilite) and Mg–Fe–Ca-rich sulfides rather than by its partitioning between metal (or troilite) and silicates. Moreover, the primitive mantle might also be boosted in Fe by a reaction at the core mantle boundary (CMB) between Mg-rich sulfides of the mantle and FeS-rich outer core materials to produce (Fe, Mg)S. The stability of Mg–Fe–Ca-rich sulfides over a large range of depths up to the surface of Mercury would be consistent with sulfur, calcium and iron abundances measured by MESSENGER.

Published
2014

48. Clumped fluoride-hydroxyl defects in forsterite:Implications for the upper-mantle

Author

Anthony C. Withers, Hélène Bureau, Hicham Khodja, Céline Crépisson, P. Giura, Caroline Raepsaet, Marc Blanchard, Keevin Béneut, Chrystèle Sanloup, Etienne Balan, C. Leroy, Suzy Surblé, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre de Paris (iSTeP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), SUPA, Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Department of Earth Sciences [London, ON], University of Western Ontario (UWO), Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Analytical chemistry, Infrared spectroscopy, chemistry.chemical_element, Mineralogy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Crystal structure, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, chemistry.chemical_compound, Geochemistry and Petrology, fluorine, Earth and Planetary Sciences (miscellaneous), infrared spectroscopy, olivine, defects, 0105 earth and related environmental sciences, Olivine, ab initio calculations, OH, ion beam analysis, Forsterite, Geophysics, chemistry, Space and Planetary Science, engineering, Anhydrous, Fluorine, Density functional theory, Fluoride, Geology
Abstract

International audience; The mechanism and magnitude of fluorine incorporation in H-bearing forsterite were investigated through a combined experimental and theoretical approach. Forsterite samples were synthesized in a piston cylinder press at 2 and 4 GPa, in hydrous conditions, with or without fluorine. High fluorine solubilities of 1715 and 1308 ppm F were measured by particle induced gamma-ray emission (PIGE) in forsterites synthesized at 2 and 4 GPa, respectively. In addition, first-principles calculations based on density functional theory were performed in order to investigate the coupled incorporation mechanisms of fluorine and water in forsterite. Our results demonstrate the close association of fluoride, hydroxyl groups and Si vacancies. Comparison of experimental and theoretical infrared absorption spectra enables assignment of the nine OH stretching bands (3500-3700 cm-1) observed in F-rich synthetic forsterite to clumped fluoride-hydroxyl defects in the forsterite crystal structure. Noteworthily, similar bands were previously recorded on some natural olivine with Mg/(Mg+Fe) molar ratio down to 0.86. Fluorine and water cycles are therefore strongly coupled through the nominally anhydrous minerals and the mantle fluorine budget can be entirely accommodated by these mineral phases.

Published
2014

49. Theoretical infrared spectrum of partially protonated cationic vacancies in forsterite

Author

Céline Crépisson, Jannick Ingrin, Marc Blanchard, Hélène Bureau, Etienne Balan, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL), and Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA)

Subjects
010504 meteorology & atmospheric sciences, Infrared, Inorganic chemistry, Infrared spectroscopy, Protonation, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Electric charge, Condensed Matter::Materials Science, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Geochemistry and Petrology, Ab initio quantum chemistry methods, Physics::Atomic and Molecular Clusters, Astrophysics::Solar and Stellar Astrophysics, 0105 earth and related environmental sciences, Chemistry, ab initio calculations, Cationic polymerization, Forsterite, Crystallography, IR spectroscopy, engineering, forsterite, Absorption (chemistry), OH defects
Abstract

International audience; Hydroxyl defects in pure forsterite are usually ascribed to incorporation of protons fully compensating the electrostatic charge of cationic vacancies. However, partially compensated vacancies have been predicted from theoretical considerations. Here, we theoretically determine the structural, vibrational and infrared spectroscopic properties of partially protonated cationic vacancies in forsterite using a first-principles theoretical modeling approach. The results show that the partial protonation of Si vacancies strongly modifies their spectroscopic properties with respect to those of the fully protonated (4H)x Si defect, leading to a significant downshift of at least one of the OH-stretching absorption bands. Comparison with experimental observations shows that such defects are unlikely to significantly contribute to the speciation of OH groups in pure synthetic forsterite samples. A partial protonation of Mg vacancies has a weak effect on the spectroscopic properties of OH groups, compared with those of the fully protonated defect, making it difficult to assess their occurrence from spectroscopic observations only.

Published
2014

50. The distribution of H2O between silicate melt and nominally anhydrousperidotiteandtheonsetofhydrousmelting in thedeepuppermantle

Author

Hélène Bureau, Daniel J. Frost, Davide Novella, Erik H. Hauri, Caroline Raepsaet, Mathilde Roberge, Bayerisches Geoinstitut (BGI), Universität Bayreuth, Department of Terrestrial Magnetism [Carnegie Institution], Carnegie Institution for Science [Washington], Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes des Eléments Légers (LEEL - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Carnegie Institution for Science, and Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)

Subjects
Peridotite, upper mantle nominallyanhydrousminerals, Analytical chemistry, Mineralogy, seismic anisotropy, Mantle (geology), Silicate, chemistry.chemical_compound, Geophysics, chemistry, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Anhydrous, waterpartitioning, hydrousmelting, Geology, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

International audience; The partitioningofH2O betweenamantleperidotiteassemblageandlowdegreehydrousmelthas beeninvestigatedat6GPa(correspondingto ∼180kmdepth)atatemperatureof1400 ◦C. Peridotite mineralphaseswereanalysedfrom6meltingexperimentsperformedinanaturalchemicalsystem.The experimentscontained ∼80wt%ofalowdegreehydrousmeltthatwasobtainedthroughaseriesof experimentswherethemeltcompositionwasiterativelyadjusteduntilsaturationwiththeappropriate peridotiteassemblagewasachieved.Themeltisfluid-undersaturatedattheconditionsoftheexperiment. Ion microprobemeasurementsofthemineralphasesindicateolivineH2O concentrationsof434 ± 61 ppmwtandaverageclinopyroxene(cpx)concentrationsof1268 ± 173 ppmwtH2O. Orthopyroxene (opx) andgarnetcontain700 ± 46 ppmwtand347 ± 83 ppmwtH2O, respectively.TheH2O contentof the hydrousmeltswasdeterminedbymassbalancetobe11 ± 0.5 wt%H2O. H2O partitioncoefficients betweenmineralsandmelt(Dmin/melt H2O = Xmin H2O/Xmelt H2O ) are0.0040±0.0006 forolivine,0.0064±0.0004 for opx, 0.0115±0.0016 forcpxand0.0032±0.0008 forgarnet. Using thedeterminedH2O partitioncoefficientstheonsetandextentofmeltingatconditionsequivalent to180kmbelowmid-oceanridgeswasdeterminedasafunctionofmantleH2O content.Current estimatesfortheH2O contentofthedepletedmantle(50-200ppmwtH2O) areinsufficienttoinduce mantle meltingatthisdepth,whichrequires ∼700 ppmwtH2O toproduce0.1%meltingand1600 ppmwtH2O for1%melting,alonganadiabatwithapotentialtemperatureof1327 ◦C. Meltingcanoccur at theseconditionswithinthemantlesourceofoceanislandbasalts,whichareestimatedtocontainup to900ppmwtH2O. Ifadiabatictemperaturesare200 ◦C higherwithinsuchplumerelatedsources,then melt fractionsofover1%canbereachedat180kmdepth.Inaddition,amodelforthedistributionof H2O betweenperidotitemineralphasesasafunctionofdepthandatH2O-undersaturatedconditions is constructed.Themodelindicatesthatforafixedmantlecompositioncontaining150ppmwtH2O, the olivineH2O contentwillincreasewithdepthsolelyduetochangesininter-phasepartitioningand modal proportionsofminerals.ThechangeintheolivineH2O concentrationwithdepthcorrespondsto proposedchangesinthedominantolivineslipsystemfordeformationbydislocationcreep,thatmight provideanexplanationforthereductioninseismicanisotropyobservedatdepths >200 km.

Published
2014

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