Papers by Chrystele Sanloup
Goldschmidt2021 abstracts, 2021
Earth and Planetary Science Letters, 2019
Iodine (I) and xenon (Xe) are two key elements that trace Earth's differentiation (e.g. atmospher... more 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 129 I that produced 129 Xe, 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 enveloppes, 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, 129 Xe 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.
Chemical Geology, 2018
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Geochemical perspectives letters, Apr 1, 2024
Xenon (Xe) behaviour in petrological processes, albeit essential to constrain mantle ingassing an... more Xenon (Xe) behaviour in petrological processes, albeit essential to constrain mantle ingassing and degassing models, is elusive due to its volatile nature, and lack of direct investigation at the pressures (P) and temperatures (T) relevant to magma formation and crystallisation at depth. Xenon stands out amongst noble gases due to its unique reactivity with silicates of the lower crust and upper mantle, which could at least partially explain that published mineral/melt partitioning coefficients span up to six orders of magnitude. We report partition coefficients of Xe using in situ X-ray fluorescence at high P and T, and mass spectrometry analyses. Xenon is found to be moderately incompatible in anorthite-clinopyroxene mix in equilibrium with basalt (partition coefficient value of 0.16 ± 0.06), and compatible in olivine in equilibrium with basalt (partition coefficients in the range 88 ± 22 to 302 ± 46). While Xe is, thus, concentrated in basaltic melts coexisting with crystallising pyroxenes and feldspars, it is strongly retained in olivine at depth. Consequently, Xe originally contained in solid Earth has been preferentially retained at depth throughout Earth's history, from the magma ocean stages to present day partial mantle melting processes.
Fostered by third-generation synchrotron sources, experimental studies of physical and chemical p... more Fostered by third-generation synchrotron sources, experimental studies of physical and chemical properties of liquids at high pressure and temperatures are constantly pushed towards more and more extreme conditions, with applications ranging from Earth and planetary science, to material science, to fundamental physics.In the last 20 years, many efforts have been dedicated to the development of a method to obtain structural information from the X-ray diffuse scattering signal of a liquid [1], allowing, for instance, to improve our understanding of the structure and evolution of deep planetary interiors. However, while data collection protocols are by now quite advanced and overall comparable across beamlines worldwide, data analysis largely differs depending on user and employed codes. To answer to the need of a unified data analysis tool for liquids and amorphous systems, we developed Amorpheus [2].Amorpheus is an open-source, versatile, free and easy-to-use software for the analysi...
A 2011 NASA study [1] of moonquakes, based on seismometer measurements made during the Apollo mis... more A 2011 NASA study [1] of moonquakes, based on seismometer measurements made during the Apollo missions, revealed a surprising new view of the lunar interior: the deepest parts of the rocky mantle of the Moon, at depths between 1200 and ~1350 km, appear to contain large amounts of molten rock (magma). In fact, up to 30 per cent of this deep layer may be molten. On Earth, such melt percentages would be accompanied by the formation of volcanoes, because magma formed in the interior of the Earth is less dense than the rock it originates from. This density difference provides a driving force for upward transport, leading to volcanic eruptions at the surface. However, despite the presence of large amounts of magma in its interior, the Moon has no active volcanoes. We have found an explanation for this apparent discrepancy by subjecting synthetic Moon rocks to extreme pressures and temperatures and measuring the density of the resulting magma using in situ techniques at beamline ID27.
We present the first results of in situ density measurements on lunar primitive picritic glass co... more We present the first results of in situ density measurements on lunar primitive picritic glass compositions at superliquidus conditions in the pressure (P) range ~0.5-5.0 GPa and temperature (T) range 1800 and 2200 K using synchrotron X-ray absorption measurements. Experiments were conducted on synthetic equivalents of Apollo 15C “green” glass (low titanium content of 0.23 wt% TiO2) and Apollo 14 “black” glass (high titanium content of 16.4 wt% TiO2) during two measurement sessions at the European Synchrotron Radiation Facility using a Paris-Edinburgh press. Although at first glance, experiments performed during the first session appeared successful, post-experiment analysis of run products showed significant sample contamination by surrounding boron and carbon assembly materials. In an attempt to closely monitor the sample melting process using X-ray diffraction slow heating rates had been applied. These slow rates led to crystallisation of mineral phases at intermediate temperatur...
Frontiers in Earth Science, 2019
Frontiers in Earth Science, 2019
Our understanding of the deep carbon cycle has witnessed amazing advances in the last decade, inc... more Our understanding of the deep carbon cycle has witnessed amazing advances in the last decade, including the discovery of tetrahedrally coordinated high pressure (P) carbonate phases. However, little is known about the physical properties of their molten counterpart at moderate depths, while their properties at lower mantle conditions remain unexplored. Here, we report the structure and density of FeCO 3 melts and glasses from 44 to 110 GPa by means of in situ x-ray synchrotron diffraction, and ex situ Raman and x-ray Raman spectroscopies. Carbon is fully transformed to 4-fold coordination, a bond change recoverable at ambient P. While low P melts react with silica, resulting in the formation of silico-carbonate glasses, high P melts are not contaminated but still quench as glasses. Carbonate melts are therefore polymerized, highly viscous and poorly reacting with silicates in the lower mantle, in stark opposition with their low P properties.
Nature
Our understanding of atmosphere formation essentially relies on noble gases and their isotopes, x... more Our understanding of atmosphere formation essentially relies on noble gases and their isotopes, xenon (Xe) being a key tracer of the early planetary stages. A long standing issue however is the origin of atmospheric depletion in Xe 1 and its light isotopes for the Earth 2 and Mars 3. Here, we report that feldspar and olivine samples confined at high pressures (P) and high temperatures (T) with diluted Xe and krypton (Kr) in air or nitrogen are enriched in heavy Xe isotopes by +0.8 to +2.3‰ per a.m.u., and strongly enriched in Xe over Kr. The upper +2.3‰ per a.m.u. value is a minimum since quantitative trapping of unreacted Xe either in bubbles or adsorbed on the samples is likely. In the light of these results, we propose a scenario solving the missing Xe problem involving multiple events of magma ocean stage at the proto-planetary stage combined with atmospheric loss. Each of these events results in trapping Xe at depth and preferential retention of its heavy isotopes. In the case of the Earth, the heavy Xe fraction was later added to the secondary CI chondritic atmosphere through continental erosion and/or recycling of an Hadean felsic crust. Atmospheric Xe is elementally depleted by a factor of 24 relative to Kr in CI chondrites (Table 1), and isotopically depleted by 35 ‰ per a.m.u., which is known as the missing Xe problem 1. The loss of elemental Xe occurred very early on 4 (<100 My). Its isotopic fractionation in the terrestrial atmosphere is recorded continuously throughout the Archean 5 , a situation settled before 4 Gy for
Magmas Under Pressure, 2018
This chapter describes how X-ray structural measurements can be done on molten silicates under hi... more This chapter describes how X-ray structural measurements can be done on molten silicates under high pressures, using either large volume presses or diamond-anvil cells, the latter combined with resistive heating or laser heating techniques. A brief summary of the data obtained so far is given, followed by a description of both energy-dispersive and angle-dispersive techniques, including challenges and how they may be overcome. Three areas of research are then highlighted: 1) structural measurements at extreme pressure conditions up to 100 GPa, 2) tracking the structural environment of minor/trace elements in magmas, and 3) the different ways to obtain the density of melts from X-ray diffraction data. Finally, some future prospects are discussed.
Goldschmidt Abstracts, 2020
Acta Crystallographica Section A Foundations and Advances, 2019
Xenon (Xe) is the most reactive amongst noble gases, with over hundred compounds synthesised at a... more Xenon (Xe) is the most reactive amongst noble gases, with over hundred compounds synthesised at ambient pressure. Increasing pressure is an efficient way to induce Xe reactivity, especially with oxides, resulting in the formation of covalent Xe-O bonds. Some examples will be given, ranging from stoechiometric compounds to silicate minerals doped in Xe at the % level, the latter being stable at remarkably low P conditions. Xe reactivity with silicates extends to compressed magmas, molten materials that were also shown to react with krypton. The search for noble gases compounds has for long been fuelled for their high energy storage capacity, but implications in Earth's sciences are also large as the latter rely on noble gases to trace key planetary processes such as atmospheric formation or underground nuclear tests. Therefore, we will finally discuss the implications of heavy noble gases reactivity under P, i.e. at the conditions of planetary interiors, on isotopic fractionation.
Geochemistry, Geophysics, Geosystems, 2019
The Xe-SiO2 system is studied by in situ high pressure and temperature experiments and ab initio ... more The Xe-SiO2 system is studied by in situ high pressure and temperature experiments and ab initio calculations. • Xe is incorporated in quartz and a new (Xe,Si)O2 phase is identified. 1 • These findings emphasize the need to consider Xe storage in crust minerals in the framework of the 'missing xenon' issue.
Journal of Physics: Condensed Matter, 2018
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Geophysical Research Letters, 2017
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Earth and Planetary Science Letters, 2017
The structure of two Lu doped (4000 ppm) model end member silicate liquids, a highly polymerised ... more The structure of two Lu doped (4000 ppm) model end member silicate liquids, a highly polymerised haplogranite (Si-Al-Na-K-O) and a less polymerised anorthite-diopside (Si-Al-Mg-Ca-O), have been studied up to 8 GPa using in situ x-ray diffraction techniques. The results are the first to identify trace rare Earth element incorporation in silicate melts at high pressure. At pressures below 5 GPa, the bonding environment of Lu-O was found to be dependent on composition with coordination number CN Lu−O = 8 and bond distance r Lu−O = 2.36Å in the haplogranite melt, decreasing to CN Lu−O = 6 and r Lu−O = 2.29Å in the anorthite-diopside melt. This compositional variance in coordination number at low pressure is consistent with observations made for Y-O in glasses at ambient conditions and is coincident with a dramatic increase in the partition coefficients previously observed for rare Earth elements with increasing melt polymerisation. With increasing pressure we find that CN Lu−O and r Lu−O remain constant in the haplogranite melt. However, an abrupt change in both Lu-O coordination and bond distance is observed at 5 GPa in the anorthite-diopside melt, with CN Lu−O increasing from 6 to 8-fold and r Lu−O from 2.29 to 2.39Å. This occurs over a similar pressure range where a change in the P-dependence in the reported rare Earth element partition coefficients is observed for garnet-, clinopyroxene-, and olivine-melt systems. This work shows that standard models for predicting trace elements at depth must incorporate the effect of pressure-induced structural transformations in the melt in order to realistically predict partitioning behaviour.
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Papers by Chrystele Sanloup