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Chien YH, Marzotto E, Tsao YC, Hsieh WP. Anisotropic thermal conductivity of antigorite along slab subduction impacts seismicity of intermediate-depth earthquakes. Nat Commun 2024; 15:5198. [PMID: 38890301 PMCID: PMC11189502 DOI: 10.1038/s41467-024-49418-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 06/05/2024] [Indexed: 06/20/2024] Open
Abstract
Double seismic zones (DSZs) are a feature of some subducting slabs, where intermediate-depth earthquakes (~70-300 km) align along two separate planes. The upper seismic plane is generally attributed to dehydration embrittlement, whereas mechanisms forming the lower seismic plane are still debated. Thermal conductivity of slab minerals is expected to control the temperature evolution of subducting slabs, and therefore their seismicity. However, effects of the potential anisotropic thermal conductivity of layered serpentine minerals with crystal preferred orientation on slab's thermal evolution remain poorly understood. Here we measure the lattice thermal conductivity of antigorite, a hydrous serpentine mineral, along its crystallographic b- and c-axis at relevant high pressure-temperature conditions of subduction. We find that antigorite's thermal conductivity along the c-axis is ~3-4 folds smaller than the b-axis. Our numerical models further reveal that when the low-thermal-conductivity c-axis is aligned normal to the slab dip, antigorite's strongly anisotropic thermal conductivity enables heating at the top portion of the slab, facilitating dehydration embrittlement that causes the seismicity in the upper plane of DSZs. Potentially, the antigorite's thermal insulating effect also hinders the dissipation of frictional heat inside shear zones, promoting thermal runaway along serpentinized faults that could trigger intermediate-depth earthquakes.
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Affiliation(s)
- Yu-Hsiang Chien
- Earth System Science Program, Taiwan International Graduate Program (TIGP), Academia Sinica and National Central University, Taipei, Taiwan, ROC
- Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, ROC
- College of Earth Sciences, National Central University, Taoyuan, Taiwan, ROC
| | - Enrico Marzotto
- Helmholtz Center Potsdam, GeoForschungsZentrum (GFZ), Potsdam, Germany.
- Institute of Geosciences, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476, Potsdam, Germany.
| | - Yi-Chi Tsao
- Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, ROC
| | - Wen-Pin Hsieh
- Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, ROC.
- Department of Geosciences, National Taiwan University, Taipei, Taiwan, ROC.
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2
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Kotsyurbenko OR, Kompanichenko VN, Brouchkov AV, Khrunyk YY, Karlov SP, Sorokin VV, Skladnev DA. Different Scenarios for the Origin and the Subsequent Succession of a Hypothetical Microbial Community in the Cloud Layer of Venus. ASTROBIOLOGY 2024; 24:423-441. [PMID: 38563825 DOI: 10.1089/ast.2022.0117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The possible existence of a microbial community in the venusian clouds is one of the most intriguing hypotheses in modern astrobiology. Such a community must be characterized by a high survivability potential under severe environmental conditions, the most extreme of which are very low pH levels and water activity. Considering different scenarios for the origin of life and geological history of our planet, a few of these scenarios are discussed in the context of the origin of hypothetical microbial life within the venusian cloud layer. The existence of liquid water on the surface of ancient Venus is one of the key outstanding questions influencing this possibility. We link the inherent attributes of microbial life as we know it that favor the persistence of life in such an environment and review the possible scenarios of life's origin and its evolution under a strong greenhouse effect and loss of water on Venus. We also propose a roadmap and describe a novel methodological approach for astrobiological research in the framework of future missions to Venus with the intent to reveal whether life exists today on the planet.
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Affiliation(s)
- Oleg R Kotsyurbenko
- Higher School of Ecology, Yugra State University, Khanty-Mansiysk, Russia
- Network of Researchers on the Chemical Evolution of Life, Leeds, United Kingdom
| | - Vladimir N Kompanichenko
- Network of Researchers on the Chemical Evolution of Life, Leeds, United Kingdom
- Institute for Complex Analysis of Regional Problems RAS, Birobidzhan, Russia
| | | | - Yuliya Y Khrunyk
- Department of Heat Treatment and Physics of Metal, Ural Federal University, Ekaterinburg, Russia
| | - Sergey P Karlov
- Faculty of Mechanical Engineering, Moscow Polytechnic University, Moscow, Russia
| | - Vladimir V Sorokin
- Research Center of Biotechnology of the Russian Academy of Sciences, Winogradsky Institute of Microbiology, Moscow, Russia
| | - Dmitry A Skladnev
- Network of Researchers on the Chemical Evolution of Life, Leeds, United Kingdom
- Research Center of Biotechnology of the Russian Academy of Sciences, Winogradsky Institute of Microbiology, Moscow, Russia
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3
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Dobrosavljevic VV, Zhang D, Sturhahn W, Chariton S, Prakapenka VB, Zhao J, Toellner TS, Pardo OS, Jackson JM. Melting and defect transitions in FeO up to pressures of Earth's core-mantle boundary. Nat Commun 2023; 14:7336. [PMID: 37957142 PMCID: PMC10643405 DOI: 10.1038/s41467-023-43154-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
The high-pressure melting curve of FeO controls key aspects of Earth's deep interior and the evolution of rocky planets more broadly. However, existing melting studies on wüstite were conducted across a limited pressure range and exhibit substantial disagreement. Here we use an in-situ dual-technique approach that combines a suite of >1000 x-ray diffraction and synchrotron Mössbauer measurements to report the melting curve for Fe1-xO wüstite to pressures of Earth's lowermost mantle. We further observe features in the data suggesting an order-disorder transition in the iron defect structure several hundred kelvin below melting. This solid-solid transition, suggested by decades of ambient pressure research, is detected across the full pressure range of the study (30 to 140 GPa). At 136 GPa, our results constrain a relatively high melting temperature of 4140 ± 110 K, which falls above recent temperature estimates for Earth's present-day core-mantle boundary and supports the viability of solid FeO-rich structures at the roots of mantle plumes. The coincidence of the defect order-disorder transition with pressure-temperature conditions of Earth's mantle base raises broad questions about its possible influence on key physical properties of the region, including rheology and conductivity.
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Affiliation(s)
- Vasilije V Dobrosavljevic
- Seismological Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
- Now at Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, USA.
| | - Dongzhou Zhang
- Hawai'i Institute of Geophysics and Planetology, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Wolfgang Sturhahn
- Seismological Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Stella Chariton
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL, USA
| | - Vitali B Prakapenka
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL, USA
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory, Chicago, IL, USA
| | - Thomas S Toellner
- Advanced Photon Source, Argonne National Laboratory, Chicago, IL, USA
| | - Olivia S Pardo
- Seismological Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
- Now at Physics Division, Physical & Life Sciences Directorate, Livermore, CA, USA
| | - Jennifer M Jackson
- Seismological Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
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4
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He Y, Kim DY, Struzhkin VV, Geballe ZM, Prakapenka V, Mao HK. The stability of FeH x and hydrogen transport at Earth's core mantle boundary. Sci Bull (Beijing) 2023:S2095-9273(23)00382-1. [PMID: 37355390 DOI: 10.1016/j.scib.2023.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 05/29/2023] [Accepted: 05/31/2023] [Indexed: 06/26/2023]
Abstract
Iron hydride in Earth's interior can be formed by the reaction between hydrous minerals (water) and iron. Studying iron hydride improves our understanding of hydrogen transportation in Earth's interior. Our high-pressure experiments found that face-centered cubic (fcc) FeHx (x ≤ 1) is stable up to 165 GPa, and our ab initio molecular dynamics simulations predicted that fcc FeHx transforms to a superionic state under lower mantle conditions. In the superionic state, H-ions in fcc FeH become highly diffusive-like fluids with a high diffusion coefficient of ∼3.7 × 10-4 cm2 s-1, which is comparable to that in the liquid Fe-H phase. The densities and melting temperatures of fcc FeHx were systematically calculated. Similar to superionic ice, the extra entropy of diffusive H-ions increases the melting temperature of fcc FeH. The wide stability field of fcc FeH enables hydrogen transport into the outer core to create a potential hydrogen reservoir in Earth's interior, leaving oxygen-rich patches (ORP) above the core mantle boundary (CMB).
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Affiliation(s)
- Yu He
- Key Laboratory of High-Temperature and High-Pressure Study of the Earth's Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Duck Young Kim
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China; Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea.
| | - Viktor V Struzhkin
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Zachary M Geballe
- Geophysical Laboratory, Carnegie Institution, Washington DC 20015, USA
| | - Vitali Prakapenka
- Center for Advanced Radiation Sources, University of Chicago, Chicago IL 60637, USA
| | - Ho-Kwang Mao
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
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5
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Zhang H, Egbert GD, Huang Q. A relatively dry mantle transition zone revealed by geomagnetic diurnal variations. SCIENCE ADVANCES 2022; 8:eabo3293. [PMID: 35921405 PMCID: PMC9348790 DOI: 10.1126/sciadv.abo3293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
The distribution of water within the mantle transition zone (MTZ) has important implications for the material circulation and partial melting of the mantle. Although solubility of hydrogen is very high, leading to speculations that the MTZ plays a key role in the deep-Earth water cycle, the actual water content remains an open question. Electrical conductivity of mantle minerals is very sensitive to water content, so reliable estimates of this physical parameter in the MTZ would provide valuable constraints. Here, we use recently developed joint inversion of geomagnetic diurnal variation for realistic source structure and one-dimensional mantle conductivity profile. Synthetic tests show that the resulting profile is a reasonable proxy for the electrical conductivity distribution of continental mantle over depths where model resolution is best (200 to 600 kilometer), even in the presence of lateral heterogeneity. The inferred water concentration in the MTZ is 0.03 weight %, one to two orders of magnitude below the solubility of wadsleyite and ringwoodite.
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Affiliation(s)
- Huiqian Zhang
- Department of Geophysics, School of Earth and Space Sciences, Peking University, Beijing, China
| | - Gary D. Egbert
- College of Earth, Ocean and Atmosphere, Oregon State University, Corvallis, OR, USA
| | - Qinghua Huang
- Department of Geophysics, School of Earth and Space Sciences, Peking University, Beijing, China
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6
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Calculated Elasticity of Al-Bearing Phase D. MINERALS 2022. [DOI: 10.3390/min12080922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Using first-principles calculations, this study evaluates the structure, equation of state, and elasticity of three compositions of phase D up to 75 GPa: (1) the magnesium endmember [MgSi2O4(OH)2], (2) the aluminum endmember [Al2SiO4(OH)2], and (3) phase D with 50% Al-substitution [AlMg0.5Si1.5O4(OH)2]. We find that the Mg-endmember undergoes hydrogen-bond symmetrization and that this symmetrization is linked to a 22% increase in the bulk modulus of phase D, in agreement with previous studies. Al2SiO4(OH)2 also undergoes hydrogen-bond symmetrization, but the concomitant increase in bulk modulus is only 13%—a a significant departure from the 22% increase of the Mg-end member. Additionally, Al-endmember phase D is denser (2%–6%), less compressible (6%–25%), and has faster compressional (6%–12%) and shear velocities (12%–15%) relative to its Mg-endmember counterpart. Finally, we investigated the properties of phase D with 50% Al-substitution [AlMg0.5Si1.5O4(OH)2], and found that the hydrogen-bond symmetrization, equation of state parameters, and elastic constants of this tie-line composition cannot be accurately modeled by interpolating the properties of the Mg- and Al-endmembers.
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7
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Li HF, Oganov AR, Cui H, Zhou XF, Dong X, Wang HT. Ultrahigh-Pressure Magnesium Hydrosilicates as Reservoirs of Water in Early Earth. PHYSICAL REVIEW LETTERS 2022; 128:035703. [PMID: 35119889 DOI: 10.1103/physrevlett.128.035703] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/03/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
The origin of water on the Earth is a long-standing mystery, requiring a comprehensive search for hydrous compounds, stable at conditions of the deep Earth and made of Earth-abundant elements. Previous studies usually focused on the current range of pressure-temperature conditions in the Earth's mantle and ignored a possible difference in the past, such as the stage of the core-mantle separation. Here, using ab initio evolutionary structure prediction, we find that only two magnesium hydrosilicate phases are stable at megabar pressures, α-Mg_{2}SiO_{5}H_{2} and β-Mg_{2}SiO_{5}H_{2}, stable at 262-338 GPa and >338 GPa, respectively (all these pressures now lie within the Earth's iron core). Both are superionic conductors with quasi-one-dimensional proton diffusion at relevant conditions. In the first 30 million years of Earth's history, before the Earth's core was formed, these must have existed in the Earth, hosting much of Earth's water. As dense iron alloys segregated to form the Earth's core, Mg_{2}SiO_{5}H_{2} phases decomposed and released water. Thus, now-extinct Mg_{2}SiO_{5}H_{2} phases have likely contributed in a major way to the evolution of our planet.
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Affiliation(s)
- Han-Fei Li
- Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China
| | - Artem R Oganov
- Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, Bolshoy Boulevard 30, Building 1, Moscow 121205, Russia
| | - Haixu Cui
- College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387, China
| | - Xiang-Feng Zhou
- Center for High Pressure Science, State Key Laboratory of Metastable Materials Science and Technology, School of Science, Yanshan University, Qinhuangdao 066004, China
| | - Xiao Dong
- Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, China
| | - Hui-Tian Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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8
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Park JO, Takahata N, Jamali Hondori E, Yamaguchi A, Kagoshima T, Tsuru T, Fujie G, Sun Y, Ashi J, Yamano M, Sano Y. Mantle-derived helium released through the Japan trench bend-faults. Sci Rep 2021; 11:12026. [PMID: 34127710 PMCID: PMC8203651 DOI: 10.1038/s41598-021-91523-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 05/25/2021] [Indexed: 11/14/2022] Open
Abstract
Plate bending-related normal faults (i.e. bend-faults) develop at the outer trench-slope of the oceanic plate incoming into the subduction zone. Numerous geophysical studies and numerical simulations suggest that bend-faults play a key role by providing pathways for seawater to flow into the oceanic crust and the upper mantle, thereby promoting hydration of the oceanic plate. However, deep penetration of seawater along bend-faults remains controversial because fluids that have percolated down into the mantle are difficult to detect. This report presents anomalously high helium isotope (3He/4He) ratios in sediment pore water and seismic reflection data which suggest fluid infiltration into the upper mantle and subsequent outflow through bend-faults across the outer slope of the Japan trench. The 3He/4He and 4He/20Ne ratios at sites near-trench bend-faults, which are close to the isotopic ratios of bottom seawater, are almost constant with depth, supporting local seawater inflow. Our findings provide the first reported evidence for a potentially large-scale active hydrothermal circulation system through bend-faults across the Moho (crust-mantle boundary) in and out of the oceanic lithospheric mantle.
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Affiliation(s)
- Jin-Oh Park
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan.
| | - Naoto Takahata
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
| | | | - Asuka Yamaguchi
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
| | - Takanori Kagoshima
- Department of Environmental Biology and Chemistry, University of Toyama, Toyama, Japan
| | - Tetsuro Tsuru
- Department of Marine Resources and Energy, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Gou Fujie
- Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
| | - Yue Sun
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
| | - Juichiro Ashi
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
| | - Makoto Yamano
- Earthquake Research Institute, University of Tokyo, Tokyo, Japan
| | - Yuji Sano
- Center for Advanced Marine Core Research, Kochi University, Nankoku, Japan
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9
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Ohira I, Jackson JM, Sturhahn W, Finkelstein GJ, Kawazoe T, Toellner TS, Suzuki A, Ohtani E. The influence of δ-(Al,Fe)OOH on seismic heterogeneities in Earth's lower mantle. Sci Rep 2021; 11:12036. [PMID: 34103572 PMCID: PMC8187711 DOI: 10.1038/s41598-021-91180-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 05/17/2021] [Indexed: 12/02/2022] Open
Abstract
The high-pressure phases of oxyhydroxides (δ-AlOOH, ε-FeOOH, and their solid solution), candidate components of subducted slabs, have wide stability fields, thus potentially influencing volatile circulation and dynamics in the Earth's lower mantle. Here, we report the elastic wave velocities of δ-(Al,Fe)OOH (Fe/(Al + Fe) = 0.13, δ-Fe13) to 79 GPa, determined by nuclear resonant inelastic X-ray scattering. At pressures below 20 GPa, a softening of the phonon spectra is observed. With increasing pressure up to the Fe3+ spin crossover (~ 45 GPa), the Debye sound velocity (vD) increases. At higher pressures, the low spin δ-Fe13 is characterized by a pressure-invariant vD. Using the equation of state for the same sample, the shear-, compressional-, and bulk-velocities (vS, vP, and vΦ) are calculated and extrapolated to deep mantle conditions. The obtained velocity data show that δ-(Al,Fe)OOH may cause low-vΦ and low-vP anomalies in the shallow lower mantle. At deeper depths, we find that this hydrous phase reproduces the anti-correlation between vS and vΦ reported for the large low seismic velocity provinces, thus serving as a potential seismic signature of hydrous circulation in the lower mantle.
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Affiliation(s)
- Itaru Ohira
- Department of Earth Science, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan.
- Department of Chemistry, Gakushuin University, 1-5-1, Mejiro, Toshima-ku, Tokyo, 171-8588, Japan.
| | - Jennifer M Jackson
- Seismological Laboratory, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Wolfgang Sturhahn
- Seismological Laboratory, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Gregory J Finkelstein
- Seismological Laboratory, California Institute of Technology, Pasadena, CA, 91125, USA
- Department of Geosciences, Princeton University, Princeton, NJ, 08544, USA
| | - Takaaki Kawazoe
- Bayerisches Geoinstitut, University of Bayreuth, 95440, Bayreuth, Germany
- Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, 739-8526, Japan
| | - Thomas S Toellner
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Akio Suzuki
- Department of Earth Science, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan
| | - Eiji Ohtani
- Department of Earth Science, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan
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10
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Hu Q, Liu J, Chen J, Yan B, Meng Y, Prakapenka VB, Mao WL, Mao HK. Mineralogy of the deep lower mantle in the presence of H 2O. Natl Sci Rev 2021; 8:nwaa098. [PMID: 34691606 PMCID: PMC8288427 DOI: 10.1093/nsr/nwaa098] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/08/2020] [Accepted: 05/11/2020] [Indexed: 11/12/2022] Open
Abstract
Understanding the mineralogy of the Earth's interior is a prerequisite for unravelling the evolution and dynamics of our planet. Here, we conducted high pressure-temperature experiments mimicking the conditions of the deep lower mantle (DLM, 1800-2890 km in depth) and observed surprising mineralogical transformations in the presence of water. Ferropericlase, (Mg, Fe)O, which is the most abundant oxide mineral in Earth, reacts with H2O to form a previously unknown (Mg, Fe)O2H x (x ≤ 1) phase. The (Mg, Fe)O2H x has a pyrite structure and it coexists with the dominant silicate phases, bridgmanite and post-perovskite. Depending on Mg content and geotherm temperatures, the transformation may occur at 1800 km for (Mg0.6Fe0.4)O or beyond 2300 km for (Mg0.7Fe0.3)O. The (Mg, Fe)O2H x is an oxygen excess phase that stores an excessive amount of oxygen beyond the charge balance of maximum cation valences (Mg2+, Fe3+ and H+). This important phase has a number of far-reaching implications including extreme redox inhomogeneity, deep-oxygen reservoirs in the DLM and an internal source for modulating oxygen in the atmosphere.
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Affiliation(s)
- Qingyang Hu
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
| | - Jin Liu
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
- Department of Geological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Jiuhua Chen
- Center for Study of Matter under Extreme Conditions, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33199, USA
| | - Bingmin Yan
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
| | - Yue Meng
- High Pressure Collaborative Access Team (HPCAT), X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Vitali B Prakapenka
- Center for Advanced Radiation Sources, University of Chicago, Chicago, IL 60437, USA
| | - Wendy L Mao
- Department of Geological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Ho-Kwang Mao
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
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11
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Liu J, Wang C, Lv C, Su X, Liu Y, Tang R, Chen J, Hu Q, Mao HK, Mao WL. Evidence for oxygenation of Fe-Mg oxides at mid-mantle conditions and the rise of deep oxygen. Natl Sci Rev 2021; 8:nwaa096. [PMID: 34691604 PMCID: PMC8288346 DOI: 10.1093/nsr/nwaa096] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/09/2020] [Accepted: 05/09/2020] [Indexed: 12/04/2022] Open
Abstract
As the reaction product of subducted water and the iron core, FeO2 with more oxygen than hematite (Fe2O3) has been recently recognized as an important component in the D" layer just above the Earth's core-mantle boundary. Here, we report a new oxygen-excess phase (Mg, Fe)2O3+ δ (0 < δ < 1, denoted as 'OE-phase'). It forms at pressures greater than 40 gigapascal when (Mg, Fe)-bearing hydrous materials are heated over 1500 kelvin. The OE-phase is fully recoverable to ambient conditions for ex situ investigation using transmission electron microscopy, which indicates that the OE-phase contains ferric iron (Fe3+) as in Fe2O3 but holds excess oxygen through interactions between oxygen atoms. The new OE-phase provides strong evidence that H2O has extraordinary oxidation power at high pressure. Unlike the formation of pyrite-type FeO2Hx which usually requires saturated water, the OE-phase can be formed with under-saturated water at mid-mantle conditions, and is expected to be more ubiquitous at depths greater than 1000 km in the Earth's mantle. The emergence of oxygen-excess reservoirs out of primordial or subducted (Mg, Fe)-bearing hydrous materials may revise our view on the deep-mantle redox chemistry.
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Affiliation(s)
- Jin Liu
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
- Department of Geological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Chenxu Wang
- Department of Geological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Chaojia Lv
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
| | - Xiaowan Su
- School of Earth and Space Sciences, Peking University, Beijing 100871, China
| | - Yijin Liu
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Ruilian Tang
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
| | - Jiuhua Chen
- Center for Study of Matter at Extreme Conditions, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33199, USA
| | - Qingyang Hu
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
| | - Ho-Kwang Mao
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
| | - Wendy L Mao
- Department of Geological Sciences, Stanford University, Stanford, CA 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
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12
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Walter MJ. Water transport to the core-mantle boundary. Natl Sci Rev 2021; 8:nwab007. [PMID: 34691622 PMCID: PMC8288335 DOI: 10.1093/nsr/nwab007] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/20/2020] [Accepted: 01/10/2021] [Indexed: 11/14/2022] Open
Abstract
Water is transported to Earth's interior in lithospheric slabs at subduction zones. Shallow dehydration fuels hydrous island arc magmatism but some water is transported deeper in cool slab mantle. Further dehydration at ∼700 km may limit deeper transport but hydrated phases in slab crust have considerable capacity for transporting water to the core-mantle boundary. Quantifying how much remains the challenge.
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Patabendigedara S, Nowak D, Nancarrow MJB, Clark SM. Determining the water content of nominally anhydrous minerals at the nanometre scale. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:023103. [PMID: 33648053 DOI: 10.1063/5.0025570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
The amount and distribution of water in nominally anhydrous minerals (NAMs) are usually determined by Fourier-transform infrared spectroscopy. This method is limited by the spot size of the beam to the study of samples with dimensions greater than a few micrometers. Here, we demonstrate the potential of using photoinduced force microscopy for the measurement of water in NAMs with samples sizes down to the nanometer scale with a study of water concentration across grain boundaries in forsterite. This development will enable the study of water speciation and diffusion in small-grained rock matrixes and allow a determination of the influence of nanoscale heterogeneity on the incorporation of water to NAMs.
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Affiliation(s)
- Sarath Patabendigedara
- Department of Earth and Environmental Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Derek Nowak
- Molecular Vista, Inc. San Jose, California 95119, USA
| | - Mitchell J B Nancarrow
- Electron Microscopy Centre, University of Wollongong, Wollongong, New South Wales 2500, Australia
| | - Simon Martin Clark
- Department of Earth and Environmental Sciences, Macquarie University, Sydney, NSW 2109, Australia
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Lin Y, Hu Q, Meng Y, Walter M, Mao HK. Evidence for the stability of ultrahydrous stishovite in Earth's lower mantle. Proc Natl Acad Sci U S A 2020; 117:184-189. [PMID: 31843935 PMCID: PMC6955296 DOI: 10.1073/pnas.1914295117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The distribution and transportation of water in Earth's interior depends on the stability of water-bearing phases. The transition zone in Earth's mantle is generally accepted as an important potential water reservoir because its main constituents, wadsleyite and ringwoodite, can incorporate weight percent levels of H2O in their structures at mantle temperatures. The extent to which water can be transported beyond the transition zone deeper into the mantle depends on the water carrying capacity of minerals stable in subducted lithosphere. Stishovite is one of the major mineral components in subducting oceanic crust, yet the capacity of stishovite to incorporate water beyond at lower mantle conditions remains speculative. In this study, we combine in situ laser heating with synchrotron X-ray diffraction to show that the unit cell volume of stishovite synthesized under hydrous conditions is ∼2.3 to 5.0% greater than that of anhydrous stishovite at pressures of ∼27 to 58 GPa and temperatures of 1,240 to 1,835 K. Our results indicate that stishovite, even at temperatures along a mantle geotherm, can potentially incorporate weight percent levels of H2O in its crystal structure and has the potential to be a key phase for transporting and storing water in the lower mantle.
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Affiliation(s)
- Yanhao Lin
- Geophysical Laboratory, Carnegie Institution for Science, Washington, DC 20015;
| | - Qingyang Hu
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China;
| | - Yue Meng
- High-Pressure Collaborative Access Team (HPCAT), X-Ray Science Division, Argonne National Laboratory, Lemont, IL 60439
| | - Michael Walter
- Geophysical Laboratory, Carnegie Institution for Science, Washington, DC 20015
| | - Ho-Kwang Mao
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China;
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