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Chanyshev A, Ishii T, Bondar D, Bhat S, Kim EJ, Farla R, Nishida K, Liu Z, Wang L, Nakajima A, Yan B, Tang H, Chen Z, Higo Y, Tange Y, Katsura T. Depressed 660-km discontinuity caused by akimotoite-bridgmanite transition. Nature 2022; 601:69-73. [PMID: 34987213 PMCID: PMC8732283 DOI: 10.1038/s41586-021-04157-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 10/18/2021] [Indexed: 11/09/2022]
Abstract
The 660-kilometre seismic discontinuity is the boundary between the Earth’s lower mantle and transition zone and is commonly interpreted as being due to the dissociation of ringwoodite to bridgmanite plus ferropericlase (post-spinel transition)1–3. A distinct feature of the 660-kilometre discontinuity is its depression to 750 kilometres beneath subduction zones4–10. However, in situ X-ray diffraction studies using multi-anvil techniques have demonstrated negative but gentle Clapeyron slopes (that is, the ratio between pressure and temperature changes) of the post-spinel transition that do not allow a significant depression11–13. On the other hand, conventional high-pressure experiments face difficulties in accurate phase identification due to inevitable pressure changes during heating and the persistent presence of metastable phases1,3. Here we determine the post-spinel and akimotoite–bridgmanite transition boundaries by multi-anvil experiments using in situ X-ray diffraction, with the boundaries strictly based on the definition of phase equilibrium. The post-spinel boundary has almost no temperature dependence, whereas the akimotoite–bridgmanite transition has a very steep negative boundary slope at temperatures lower than ambient mantle geotherms. The large depressions of the 660-kilometre discontinuity in cold subduction zones are thus interpreted as the akimotoite–bridgmanite transition. The steep negative boundary of the akimotoite–bridgmanite transition will cause slab stagnation (a stalling of the slab’s descent) due to significant upward buoyancy14,15. X-ray diffraction experiments indicate that the depression of the Earth’s 660-kilometre seismic discontinuity beneath cold subduction zones is caused by a phase transition from akimotoite to bridgmanite, leading to slab stagnation.
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Affiliation(s)
- Artem Chanyshev
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany. .,Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany.
| | - Takayuki Ishii
- Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany. .,Center for High Pressure Science and Technology Advanced Research, Beijing, China.
| | - Dmitry Bondar
- Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany
| | - Shrikant Bhat
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Eun Jeong Kim
- Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany
| | - Robert Farla
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Keisuke Nishida
- Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany
| | - Zhaodong Liu
- Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany.,State Key Laboratory of Superhard Materials, Jilin University, Changchun, China
| | - Lin Wang
- Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany.,Earth and Planets Laboratory, Carnegie Institution, Washington, DC, USA
| | - Ayano Nakajima
- Department of Earth Sciences, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Bingmin Yan
- Center for High Pressure Science and Technology Advanced Research, Beijing, China
| | - Hu Tang
- Center for High Pressure Science and Technology Advanced Research, Beijing, China
| | - Zhen Chen
- Center for High Pressure Science and Technology Advanced Research, Beijing, China
| | - Yuji Higo
- Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Japan
| | - Yoshinori Tange
- Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Japan
| | - Tomoo Katsura
- Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany.,Center for High Pressure Science and Technology Advanced Research, Beijing, China
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Yu YG, Wentzcovitch RM, Vinograd VL, Angel RJ. Thermodynamic properties of MgSiO3majorite and phase transitions near 660 km depth in MgSiO3and Mg2SiO4: A first principles study. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jb007912] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Wang Y, Shen G, Rivers M, Sutton S. A Multi-Anvil High Pressure System with Synchrotron X-Ray Probe: New Opportunities for In-Situ Materials Research at Simultaneously High Pressure and Temperature. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-499-289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTWe describe the multi-anvil, large-volume, high-pressure facility that is being constructed at the GeoSoilEnviroCARS (Sector 13) at the Advanced Photon Source, Argonne National Laboratory. Various multi-anvil, high-pressure apparatus will be used to cover pressure and temperature conditions up to 40 GPa and 3000 °C, respectively, with milimeter to centimeter sized samples. This national facility is open to all users, providing excellent opportunities for high pressure, high temperature experiments.
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Abstract
Abstract
During the last 60 years, new high pressure techniques and their exploitation have permitted the extension of attainable pressure/volume conditions, increased versatility of the apparatus, and hydrostaticity of the attained pressure in a remarkable way. In preparative solid state chemistry, high-pressure/high-temperature synthesis always played a minor role due to technical difficulties and costs. Piston-cylinder and Belt-apparatus both were limited to the working range up to 3 and 10 GPa, respectively. New technical developments, which allow synthesis up to 25 GPa, open up an enormous field of sample synthesis in solid state chemistry. In the following, a short overview on the most important developments in multianvil-techniques is given with respect to their applications for solid state chemistry under high-pressure conditions.
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Mosenfelder JL, Asimow PD, Frost DJ, Rubie DC, Ahrens TJ. The MgSiO3system at high pressure: Thermodynamic properties of perovskite, postperovskite, and melt from global inversion of shock and static compression data. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jb005900] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jed L. Mosenfelder
- Division of Geological and Planetary Sciences; California Institute of Technology; Pasadena California USA
| | - Paul D. Asimow
- Division of Geological and Planetary Sciences; California Institute of Technology; Pasadena California USA
| | - Daniel J. Frost
- Bayerisches Geoinstitut; Universität Bayreuth; Bayreuth Germany
| | - David C. Rubie
- Bayerisches Geoinstitut; Universität Bayreuth; Bayreuth Germany
| | - Thomas J. Ahrens
- Division of Geological and Planetary Sciences; California Institute of Technology; Pasadena California USA
- Lindhurst Laboratory of Experimental Geophysics, Seismological Laboratory; California Institute of Technology; Pasadena California USA
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Kubo T, Ohtani E, Kondo T, Kato T, Toma M, Hosoya T, Sano A, Kikegawa T, Nagase T. Metastable garnet in oceanic crust at the top of the lower mantle. Nature 2002; 420:803-6. [PMID: 12490946 DOI: 10.1038/nature01281] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2002] [Accepted: 10/25/2002] [Indexed: 11/09/2022]
Abstract
As oceanic tectonic plates descend into the Earth's lower mantle, garnet (in the basaltic crust) and silicate spinel (in the underlying peridotite layer) each decompose to form silicate perovskite-the 'post-garnet' and 'post-spinel' transformations, respectively. Recent phase equilibrium studies have shown that the post-garnet transformation occurs in the shallow lower mantle in a cold slab, rather than at approximately 800 km depth as earlier studies indicated, with the implication that the subducted basaltic crust is unlikely to become buoyant enough to delaminate as it enters the lower mantle. But here we report results of a kinetic study of the post-garnet transformation, obtained from in situ X-ray observations using sintered diamond anvils, which show that the kinetics of the post-garnet transformation are significantly slower than for the post-spinel transformation. Although metastable spinel quickly breaks down at a temperature of 1,000 K, we estimate that metastable garnet should survive of the order of 10 Myr even at 1,600 K. Accordingly, the expectation of where the subducted oceanic crust would be buoyant spans a much wider depth range at the top of the lower mantle, when transformation kinetics are taken into account.
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Affiliation(s)
- Tomoaki Kubo
- Institute of Mineralogy, Petrology and Economic Geology, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
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Irifune T, Nishiyama N, Kuroda K, Inoue T, Isshiki M, Utsumi W, Funakoshi K, Urakawa S, Uchida T, Katsura T, Ohtaka O. The postspinel phase boundary in Mg2SiO4 determined by in situ X-ray diffraction. Science 1998; 279:1698-700. [PMID: 9497283 DOI: 10.1126/science.279.5357.1698] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The phase boundary between spinel (gamma phase) and MgSiO3 perovskite + MgO periclase in Mg2SiO4 was determined by in situ x-ray measurements by a combination of the synchrotron radiation source (SPring-8) and a large multianvil high-pressure apparatus. The boundary was determined at temperatures between 1400 degrees to 1800 degreesC, demonstrating that the postspinel phase boundary has a negative Clapeyron slope as estimated by quench experiments and thermodynamic analyses. The boundary was located at 21.1 (+/-0.2) gigapascals, at 1600 degreesC, which is approximately 2 gigapascals lower than earlier estimates based on other high-pressure studies.
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Affiliation(s)
- T Irifune
- T. Irifune, N. Nishiyama, K. Kuroda, T. Inoue, M. Isshiki, Department of Earth Sciences, Ehime University, Matsuyama 790, Japan. W. Utsumi, Japan Atomic Energy Research Institute, Kamigori, Ako-gun, Hyogo 678-12, Japan. K. Funakoshi, Ja
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Ohtani E, Suzuki A, Kato T. Flotation of olivine and diamond in mantle melt at high pressure: Implications for fractionation in the deep mantle and ultradeep origin of diamond. GEOPHYSICAL MONOGRAPH SERIES 1998. [DOI: 10.1029/gm101p0227] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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