Details of the Researcher

PHOTO

Ryosuke Oyanagi
Section
Graduate School of Environmental Studies
Job title
Assistant Professor
Degree

  • Ph.D. (Tohoku University)

e-Rad No.
90835729

Research History 6

  • 2026/06 - Present
    Japan Agency for Marine-Earth Science and Technology　Research Institute of Marine Geodynamics　External Researcher

  • 2026/04 - Present
    Tohoku University　Department of Environmental Studies for Advanced Society, Graduate School of Environmental Studies　Assistant Professor

  • 2021/04 - 2026/03
    Japan Agency for Marine-Earth Science and Technology (JAMSTEC)　Research Institute for Marine Geodynamics　External Researcher

  • 2021/04 - 2026/03
    Kokushikan University　School of Science and Engineering　Lecturer

  • 2018/04 - 2021/03
    Japan Agency for Marine-Earth Science and Technology (JAMSTEC)　JSPS Research Fellow (PD)

  • 2016/04 - 2018/03
    Tohoku University　Graduate school of environmental studies　JSPS Research Fellow (DC2)

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Education 4

  • Tohoku University　Graduate school of environmental studies　Department of Environmental Studies for Advanced Society

    2015/04 - 2018/03

  • Tohoku University　Graduate school of environmental studies

    2013/04 - 2015/03

  • Tohoku University　School of Engineering　Department of Mechanical and Aerospace Engineering

    2009/04 - 2013/03

  • 青森県立青森東高等学校

    2006/04 - 2009/03

Committee Memberships 2

  • 一般社団法人日本地質学会　代議員

    2026/06 - Present

  • 一般社団法人日本地質学会　岩石部会 庶務委員

    2023/09 - Present

Professional Memberships 3

  • Japan Association of Mineralogical Sciences

    2015 - Present

  • THE GEOLOGICAL SOCIETY OF JAPAN

    2014 - Present

  • JAPAN GEOSCIENCE UNION

    2013 - Present

Research Interests 9

  • CO2 mineralization

  • Natural hydrogen

  • Data-driven Science

  • Petrology

  • Geochemistry

  • Mineral carbonation

  • Carbon cycle

  • Fluid-rock interaction

  • Serpentinization

Research Areas 2

  • Energy / Earth resource engineering, energy science /

  • Natural sciences / Solid earth science /

Awards 8

  1. 令和７年度学術研究奨励賞

    2026/03　国士舘大学

  2. 2024年度日本鉱物科学会研究奨励賞

    2025/09　日本鉱物科学会

  3. Most downloaded paper award 2025

    2025/05　Progress in Earth and Planetary Science

  4. 令和５年度学術研究奨励賞

    2024/03　国士舘大学

  5. Sakuyama Masanori Award

    2023/09　The geological society of Japan

  6. 若手奨励賞

    2019/05　日本地球惑星科学連合 固体地球科学セクション ハードロック掘削科学フォーカスグループ

  7. President Award

    2018/03　Tohoku University

  8. Outstanding Student Presentation Award

    2016/05　Japan Geoscience Union

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Papers 37

  1. Carbonation of diverse ultramafic rocks: implications for Ca-rich protolith from the Setogawa Group, Central Japan International-journal Peer-reviewed

    Tatsuya Hattori, Ryosuke Oyanagi, Tomoyuki Mizukami, Yumiko Harigane, Mayuko Fukuyama, Asuka Yamaguchi, Tomoaki Morishita

    Contributions to Mineralogy and Petrology　181　(9)　2026/08/25

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s00410-026-02359-0 　

    ISSN： 0010-7999

    eISSN： 1432-0967

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    Abstract Ophicarbonate/listvenite and ultramafic rocks are distributed in various tectonic blocks in the western Izu Peninsula. These ultramafic rocks are likely of upper mantle origin, influenced by magmatic activity associated with the formation of the Izu-Bonin-Mariana intra-arc and back-arc basins within the Philippine Sea Plate. Carbonation of ultramafic rocks plays a fundamental role in fluid-rock interaction processes in subduction zone environments, yet the controls on carbonation pathways remain incompletely understood. In particular, the influence of protolith composition on reaction progress and mineral assemblage development has not been fully constrained. This study focuses on representative ophicarbonate/listvenite from the Setogawa Group, a Paleogene accretionary complex. The Setogawa Group contains diverse ultramafic rocks such as dunite, harzburgite, lherzolite and clinopyroxenite and is highly suitable for discussing carbonation of ultramafic rocks due to differences in original rock. Based on petrographic observations and whole-rock chemical compositions, the rocks are classified as Serpentine-Talc-Magnesite rock, Dolomite-Talc-Quartz rock, and listvenite. Thermodynamic modeling further reveals that clinopyroxene-rich ultramafic rocks undergo distinct reaction pathways compared to olivine-rich compositions, with earlier talc formation and different fluid-rock ratios required for listvenitization. These findings demonstrate that the bulk composition of the protolith, particularly Ca content, controls carbonation pathways, mineral assemblages, and the evolution of physical properties during fluid-rock interaction. Our results provide a unified framework for understanding variability in listvenite formation and highlight the importance of protolith heterogeneity in controlling carbonation processes in subduction zone environments.

  2. Rodingite diversity as a record of complex geological evolution during oceanic plateau accretion: insights from the Mikabu Unit, southwest Japan International-journal Peer-reviewed

    Hikaru Sawada, Ryosuke Oyanagi, Mitsuhiro Nagata, Sota Niki, Shuhei Sakata, Takafumi Hirata

    Journal of Asian Earth Sciences　107197-107197　2026/06

    Publisher: Elsevier BV

    DOI： 10.1016/j.jseaes.2026.107197 　

    ISSN： 1367-9120

  3. Melt-poor spreading in the Shikoku back-arc basin: widespread occurrence of oceanic core complexes and associated features International-journal International-coauthorship Peer-reviewed

    Yasuhiko Ohara, Kyoko Okino, Norikatsu Akizawa, Valentin Basch, Marco Cuffaro, Masakazu Fujii, Yumiko Harigane, Ken-ichi Hirauchi, So Inoue, Osamu Ishizuka, Shiki Machida, Katsuyoshi Michibayashi, Takaaki Moriguchi, Kohei Nimura, Ryosuke Oyanagi, Alessio Sanfilippo, Camilla Sani, Atlanta Sen, Jonathan E. Snow, Kenichiro Tani, Hiroyuki Yamashita

    Progress in Earth and Planetary Science　13　(1)　2026/05/21

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1186/s40645-026-00818-7 　

    eISSN： 2197-4284

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    Abstract The Shikoku Basin, a Miocene back-arc basin in the Philippine Sea, hosts numerous oceanic core complexes (OCCs) that reflect melt-poor lithospheric extension. Based on bathymetric mapping, gravity and magnetic surveys, dredging, and submersible dives conducted between 2007 and 2023, we identified multiple OCCs in its southern part, including the Mado, Sui-Shin, Tosa, Sanuki, and Awa Megamullions. These OCCs expose mantle and lower crustal rocks and are associated with high mantle Bouguer anomalies, indicating thin crust. Geochemical and geochronological data from the Sui-Shin Megamullion suggest its formation immediately after rifting of the proto-Izu-Bonin arc (~24 Ma). The Tosa Megamullion, dominated by plagioclase-peridotites with only minor gabbros, exemplifies melt-poor lithospheric conditions and may represent Hess-type oceanic crust. The spatial and temporal distribution of OCCs, including the triplet OCCs (Tosa, Sanuki, and Awa), implies multiple ridge jumps during basin evolution. These findings suggest that a significant portion of the Shikoku Basin formed largely through amagmatic or melt-poor processes, contrasting with typical mid-ocean ridge settings. The OCCs serve as tectonic windows into back-arc lithosphere evolution and provide a framework for future investigations into the role of melt supply and slab-derived fluids in shaping oceanic crustal architecture.

  4. Depth variations in multi-stage hydrogen generation associated with serpentinization in the lower crust and mantle sections of the Oman Ophiolite International-journal Peer-reviewed

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Masakazu Fujii, Kenta K. Yoshida, Yasuhiro Niwa, Yasuo Takeichi, Masao Kimura

    Geochimica et Cosmochimica Acta　418　1-22　2026/04/01

    Publisher: Elsevier BV

    DOI： 10.1016/j.gca.2026.01.055 　

    ISSN： 0016-7037

  5. Reactive-transport processes at lithological boundaries: insights from experiments, natural samples, and numerical modeling

    Ryosuke Oyanagi

    Japanese Magazine of Mineralogical and Petrological Sciences　26　(1)　260108　2026/03/23

    Publisher: Japan Association of Mineralogical Sciences

    DOI： 10.2465/gkk.260108 　

    ISSN： 1345-630X

    eISSN： 1349-7979

  6. Amagmatic Mylonitic Deformation of Mantle Peridotites from the Tosa Megamullion in the Shikoku Basin, Philippine Sea International-journal International-coauthorship Peer-reviewed

    Katsuyoshi Michibayashi, So Inoue, Valentin Basch, Marco Cuffaro, Yumiko Harigane, Seira Katagiri, Takaaki Moriguchi, Itsuki Natsume, Kohei Nimura, Kyoko Okino, Takeo Okuwaki, Ryosuke Oyanagi, Alessio Sanfilippo, Jonathan E. Snow, Hiroyuki Yamashita, Yasuhiko Ohara

    Minerals　16　(2)　154-154　2026/01/29

    Publisher: MDPI AG

    DOI： 10.3390/min16020154 　

    eISSN： 2075-163X

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    Mylonitic mantle peridotites exposed at the Tosa Megamullion in the Shikoku Basin, Philippine Sea, provide direct evidence for amagmatic ductile shear deformation of the upper mantle beneath a back-arc spreading center. Oceanic core complexes (OCCs), or megamullions, are dome-shaped structures formed by detachment faulting and occur locally along slow-spreading mid-ocean ridges and back-arc basins, where they expose fault rocks derived from ductile shear zones in the lower crust and upper mantle. The Shikoku Basin hosts several OCCs, including the Tosa Megamullion, which formed during the early stage of back-arc spreading. In this study, nine ultramafic rocks were collected from the Tosa Megamullion using the submersible Shinkai6500 during cruise YK23-05S. Although all samples were highly serpentinized, several preserved primary peridotitic textures were composed mainly of olivine, orthopyroxene, with subordinate clinopyroxene, plagioclase, and spinel. Seven samples exhibit well-developed foliation and porphyroclastic textures dominated by orthopyroxene porphyroclasts, ranging from rounded to strongly elongated forms, commonly showing microkinks and undulose extinction. Crystallographic preferred orientations (CPOs) of three representative samples, analyzed using SEM-EBSD, reveal E-type-dominant olivine fabrics characterized by the (001)[100] slip system, with a subordinate contribution from C-type (100)[001] slip. These CPOs suggest deformation under non-dry conditions involving moderate hydration and/or elevated differential stress. These results indicate that the ultramafic rocks from the Tosa Megamullion represent mantle-derived mylonitic peridotites formed by ductile shear beneath the spreading axis and subsequently exhumed under strongly magma-poor, amagmatic conditions. The Tosa Megamullion thus represents an amagmatic end-member of the OCC formation in back-arc basins, dominated by tectonic strain localization rather than by magmatic accretion.

  7. Reactions, element transfer, and fracturing at ultramafic rock–sediment contacts: insights from reaction experiments at 500 °C and 1 GPa International-journal Peer-reviewed

    Shunya Okino, Atsushi Okamoto, Ryosuke Oyanagi, Yukiko Kita, Sando Sawa, Jun Muto

    Contributions to Mineralogy and Petrology　181　7　2026/01

    Publisher: Springer Nature

    DOI： 10.1007/s00410-025-02283-9 　

  8. Carbonation of oceanic serpentinite related to extensive intraplate magmatism International-journal Peer-reviewed

    Ryosuke Oyanagi, Hikaru Sawada, Qing Chang, Kenta Yoshida, Madhusoodhan Satish-Kumar

    Geological Society of America Bulletin　138　(1-2)　791-808　2026/01/01

    Publisher: Geological Society of America

    DOI： 10.1130/b38019.1 　 10.51094/jxiv.1533 　

    ISSN： 0016-7606

    eISSN： 1943-2674

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    Abstract Extensive intraplate magmatism that forms oceanic plateaux involves significant carbon outflux and perturbation of the global carbon cycle, potentially linking to climate change, oceanic anoxia, and mass extinction events. Hydrothermal alteration related to such magmatism can modify the major-element composition of the oceanic lithosphere around the hydrothermal system. However, the relationship between carbon mass transfer and hydrothermal systems associated with intraplate magmatism remains unclear. This study investigated carbonated serpentinites occurring along with mafic metavolcanic rocks, which were part of an oceanic plateau in the Late Jurassic Paleo-Pacific Ocean. Carbonate minerals (calcite and dolomite) occur as cement in the serpentinite breccias and as discrete veins in the serpentinite. C-O-Sr isotopic compositions and rare earth element data for the carbonates suggest the calcite cements in the serpentinite breccias formed in an oceanic setting by the mixing of seawater and hydrothermal fluids before subduction. The strontium isotopic compositions of the seawater-derived carbonates suggest that carbonation most likely occurred concurrently with the formation of an oceanic plateau, suggesting intraplate magmatism plays an important role as a carbon sink by inducing alteration and carbonation during associated hydrothermal activity. Moreover, our results suggest the calcite and dolomites formed in a subduction zone from CO2-rich fluids sourced by the devolatilization of metasediments, after the accretion of an oceanic plateau. These results may indicate that the life cycle of oceanic plateaux can cause perturbations in carbon influx and outflux, and that the interplay among oceanic plateau emplacement, subsequent alteration, and carbon uptake may have modulated atmospheric CO2 and Earth's surface environments.

  9. Extreme maldistribution of high field strength elements along subduction zones revealed by baddeleyite aggregates in serpentinite International-journal Peer-reviewed

    Hikaru Sawada, Ryosuke Oyanagi, Sota Niki, Takafumi Hirata, Kazuki Yoshida, Mitsuhiro Nagata, Atsushi Okamoto

    Scientific Reports　15　(1)　2025/07/04

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41598-025-07698-9 　

    eISSN： 2045-2322

  10. Estimating the iron oxidation state of serpentinite using X-ray absorption fine structure spectroscopy International-journal Peer-reviewed

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Yasuhiro Niwa, Masao Kimura

    American Mineralogist　110　(5)　757-766　2025/05/01

    Publisher: Mineralogical Society of America

    DOI： 10.2138/am-2024-9571 　

    ISSN： 0003-004X

    eISSN： 1945-3027

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    Abstract Iron can exist in serpentinite in various oxidation states. Changes in the oxidation state of Fe play a crucial role in geological processes, including supporting diverse biological systems on the ocean floor and the redox states of aqueous fluids released in subduction zones. Synchrotron X-ray absorption near-edge structure (XANES) spectroscopy has been used to measure the oxidation state of Fe in serpentine minerals; however, a general scheme for estimating the oxidation state of Fe in serpentinite composed of several Fe-bearing minerals has not been established. We evaluated the accuracy of using XANES spectra to estimate the Fe3+/ΣFe ratio (molar ratio of Fe3+ to total Fe) of physical olivine-magnetite mixtures and serpentinites. Two approaches were tested: (1) linear combination fitting (LCF) and (2) pre-edge peak analysis of XANES spectra. Estimating Fe3+/ΣFe using analysis of the pre-edge peaks was not always suitable when magnetite was included. Using LCF, XANES spectra are well fitted by the optimal combination of Fe-bearing minerals, even for mixtures of magnetite and Fe-bearing silicate minerals (i.e., serpentine and olivine). The Fe3+/ΣFe ratios of the serpentinites were estimated with a root mean squared error (RMSE) of 0.14 with LCF. These results demonstrate that LCF of XANES spectra is useful for estimating the oxidation state of Fe in serpentinites.

  11. Alteration processes of mantle peridotite in the Samail ophiolite inferred from independent component analysis of rock physical properties International-journal Peer-reviewed

    Yuya Akamatsu, Tatsu Kuwatani, Ryosuke Oyanagi

    Lithos　496-497　107946-107946　2025/03

    Publisher: Elsevier BV

    DOI： 10.1016/j.lithos.2025.107946 　

    ISSN： 0024-4937

  12. Subducted carbon weakens the forearc mantle wedge in a warm subduction zone International-journal Peer-reviewed

    Ryosuke Oyanagi, Atsushi Okamoto

    Nature Communications　15　(7159)　2024/08/26

    Publisher: Springer Nature

    DOI： 10.1038/s41467-024-51476-6 　

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    Subducting oceanic plates carry large amounts of carbon into the Earth’s interior. The subducted carbon is mobilized by fluid and encounters ultramafic rocks in the mantle wedge, resulting in changes to the mineral assemblage and mechanical properties of the mantle. Here, we use thermodynamic modeling of interactions between carbon-bearing multi-component fluids and mantle rocks to investigate the down-dip variation in mineral assemblage in the forearc mantle along subduction megathrusts. We found that fluids rich in aqueous carbon are preferentially generated in a warm subduction zone (e.g., Nankai, SW Japan), causing a change in mineral assemblage from serpentine-rich at the mantle wedge corner to talc + carbonate-rich at greater depths. The transition caused by the infiltration of aqueous carbon may influence the depth of the boundary between the seismogenic and aseismic zones, and the down-dip limit of episodic tremor and slip.

  13. Si- versus Mg-metasomatism at the crust–mantle interface: insights from experiments, natural observations and geochemical modeling International-journal Invited Peer-reviewed

    Atsushi Okamoto, Ryosuke Oyanagi

    Progress in Earth and Planetary Science　10　(1)　2023/07/18

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1186/s40645-023-00568-w 　

    eISSN： 2197-4284

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    Abstract The slab–mantle interface in subduction zones is one of the geological boundaries with the most significant chemical potential gradients, which leads to fluid-mediated metasomatic reactions and chemical transport. As subducting sediment and basaltic crust often contain silica in various forms, the Si-metasomatism of mantle rocks is thought to occur along the subduction zone interface. However, growing evidence from the geochemistry of altered rocks and thermodynamic modelling has revealed the presence of multi-component fluids at the slab interface. Here, we review the laboratory experiments, geochemical models, and natural observations that improve our understanding of mass transport and metasomatic reactions at the crust–mantle interface, focusing on the relative mobility of Mg and Si. Hydrothermal experiments using analogues for the boundary between mantle (olivine) and crust (quartz or plagioclase) under vapor-saturated pressures indicate that Si is preferentially transported from crust to mantle, whereas Mg is immobile. This result is consistent with the distribution of talc rocks in oceanic lithosphere. On the other hand, at the contact between ultramafic (e.g., serpentinite) and crustal (pelitic schist or basaltic rocks) rocks in high-pressure metamorphic terranes, a large volume of chlorite rocks form in the crustal rocks, and the volume of chlorite often exceeds talc in serpentinites. Geochemical modeling reveals that in the shallow part of a subduction zone, the dissolved Si content of fluids in equilibrium with pelitic schist (CSi,crust) is significantly higher than the dissolved Mg content of fluids in equilibrium with mantle peridotite (CMg,mantle); however, CMg,mantle becomes dominant at depth, resulting in the Mg-metasomatism of crustal rocks to form chlorite rocks. This Mg-metasomatism is more widespread in warmer subduction zones (e.g., the Nankai and Cascadia subduction zones) than in colder subduction zones (e.g., in Northeast Japan). In addition, the infiltration of CO2-bearing fluid can form talc (along with carbonates) in ultramafic rocks without Si-metasomatism. Variations in the relative mobility of Si and Mg at the subduction zone interface produce variations in the overall solid volume change of mantle (expansion or contraction), the types of sheet silicates (talc versus chlorite), and the fluid budget (dehydration or hydration) during metasomatic reactions, which affects the pore fluid pressure, frictional strength of the subduction megathrust, and the location of seismicity around the mantle wedge corner.

  14. Metasomatism at a metapelite–ultramafic rock contact at the subduction interface: Insights into mass transfer and fluid flow at the mantle wedge corner International-journal Peer-reviewed

    Ryosuke Oyanagi, Masaoki Uno, Atsushi Okamoto

    Contributions to Mineralogy and Petrology　178　(5)　2023/04/14

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s00410-023-02011-1 　 10.51094/jxiv.1562 　

    ISSN： 0010-7999

    eISSN： 1432-0967

  15. Geological records of transient fluid drainage into the shallow mantle wedge International-journal International-coauthorship Peer-reviewed

    Kazuki Yoshida, Ryosuke Oyanagi, Masao Kimura, Oliver Plümper, Mayuko Fukuyama, Atsushi Okamoto

    Science Advances　9　(14)　2023/04/05

    Publisher: American Association for the Advancement of Science (AAAS)

    DOI： 10.1126/sciadv.ade6674 　

    eISSN： 2375-2548

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    Pore fluid pressure on subduction zone megathrusts is lowered by fluid drainage into the overlying plate, affecting subduction zone seismicity. However, the spatial and temporal scales of fluid flow through suprasubduction zones are poorly understood. We constrain the duration and velocity of fluid flow through a shallow mantle wedge based on the analyses of vein networks consisting of high-temperature serpentine in hydrated ultramafic rocks from the Oman ophiolite. On the basis of a diffusion model and the time-integrated fluid flux, we show that the channelized fluid flow was short-lived (2.1 × 10 −1 to 1.1 × 10 1  years) and had a high fluid velocity (2.7 × 10 −3 to 4.9 × 10 −2  meters second −1 ), which is close to the propagation velocities of seismic events in present-day subduction zones. Our results suggest that the drainage of fluid into the overlying plate occurs as episodic pulses, which may influence the recurrence of megathrust earthquakes.

  16. High-temperature silicified zones as potential caprocks of supercritical geothermal reservoirs Peer-reviewed

    Fajar Febiani Amanda, Noriyoshi Tsuchiya, Vani Novita Alviani, Masaoki Uno, Ryoichi Yamada, Shota Shimizu, Ryosuke Oyanagi

    Geothermics　105　102475-102475　2022/11

    Publisher: Elsevier BV

    DOI： 10.1016/j.geothermics.2022.102475 　

    ISSN： 0375-6505

  17. Decoupling of U–Pb ages and compositional zoning of garnet in a high–pressure marble from the eastern Iratsu body, Sanbagawa metamorphic terrane, Japan Peer-reviewed

    Sota Niki, Kenta Yoshida, Hikaru Sawada, Ryosuke Oyanagi, Takafumi Hirata

    Journal of Mineralogical and Petrological Sciences　117　(1)　n/a-n/a　2022/05

    Publisher: Japan Association of Mineralogical Sciences

    DOI： 10.2465/jmps.210814 　

    ISSN： 1345-6296

    eISSN： 1349-3825

  18. Dynamics of coupled olivine dissolution and serpentine precipitation revealed by hydrothermal flow-through experiments at 260 °C–300 °C Peer-reviewed

    Ryosuke Oyanagi, Tatsu Kuwatani, Katsuhiko Suzuki

    Chemical Geology　600　120869-120869　2022/04

    Publisher: Elsevier BV

    DOI： 10.1016/j.chemgeo.2022.120869 　

    ISSN： 0009-2541

  19. Hadal aragonite records venting of stagnant paleoseawater in the hydrated forearc mantle International-journal Peer-reviewed

    Ryosuke Oyanagi, Atsushi Okamoto, Madhusoodhan Satish-Kumar, Masayo Minami, Yumiko Harigane, Katsuyoshi Michibayashi

    Communications Earth & Environment　2　(1)　2021/12

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s43247-021-00317-1 　

    eISSN： 2662-4435

  20. Cataclastic and crystal-plastic deformation in shallow mantle-wedge serpentinite controlled by cyclic changes in pore fluid pressures International-journal Peer-reviewed

    Ken-ichi Hirauchi, Yurina Nagata, Kengo Kataoka, Ryosuke Oyanagi, Atsushi Okamoto, Katsuyoshi Michibayashi

    Earth and Planetary Science Letters　576　117232-117232　2021/12

    Publisher: Elsevier BV

    DOI： 10.1016/j.epsl.2021.117232 　

    ISSN： 0012-821X

  21. Rupture of wet mantle wedge by self-promoting carbonation International-journal Peer-reviewed

    Atsushi Okamoto, Ryosuke Oyanagi, Kazuki Yoshida, Masaoki Uno, Hiroyuki Shimizu, Madhusoodhan Satish-Kumar

    Communications Earth & Environment　2　(1)　2021/12

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s43247-021-00224-5 　

    eISSN： 2662-4435

  22. Discovery of the Early Jurassic high-temperature pre-Sanbagawa metamorphism recorded in titanite Peer-reviewed

    Kenta Yoshida, Sota Niki, Hikaru Sawada, Ryosuke Oyanagi, Takafumi Hirata, Kenji Asakura, Takao Hirajima

    Lithos　398　106349-106349　2021/07

    DOI： 10.1016/j.lithos.2021.106349 　

    ISSN： 0024-4937

    eISSN： 1872-6143

  23. Albite–K-feldspar–quartz equilibria in hydrothermal fluids at 400, 420°C and 20–35 MPa: Experimental measurements and thermodynamic calculations Peer-reviewed

    Atsushi Okamoto, Hajime Ishii, Ryosuke Oyanagi, Noriyoshi Tsuchiya

    Geothermics　94　102109-102109　2021/07

    Publisher: Elsevier BV

    DOI： 10.1016/j.geothermics.2021.102109 　

    ISSN： 0375-6505

  24. Data-Driven Analysis of Nonlinear Heterogeneous Reactions through Sparse Modeling and Bayesian Statistical Approaches Peer-reviewed

    Masaki Ito, Tatsu Kuwatani, Ryosuke Oyanagi, Toshiaki Omori

    Entropy　23　(7)　824-824　2021/06/28

    Publisher: MDPI AG

    DOI： 10.3390/e23070824 　

    eISSN： 1099-4300

  25. Exploration of nonlinear parallel heterogeneous reaction pathways through Bayesian variable selection International-journal Peer-reviewed

    Ryosuke X. Oyanagi, Tatsu Kuwatani, Toshiaki Omori

    The European Physical Journal B　94　(2)　2021/02

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1140/epjb/s10051-021-00053-7 　

    ISSN： 1434-6028

    eISSN： 1434-6036

  26. Discovery of datolite in a high–pressure marble from the Sanbagawa metamorphic belt: Indication of B–rich fluid activity

    Kenta Yoshida, Sota Niki, Hikaru Sawada, Ryosuke Oyanagi

    Journal of Mineralogical and Petrological Sciences　116　(1)　1-8　2021

    Publisher: Japan Association of Mineralogical Sciences

    DOI： 10.2465/jmps.200730 　

    ISSN： 1345-6296

    eISSN： 1349-3825

  27. Fluid Infiltration Through Oceanic Lower Crust in Response to Reaction‐induced Fracturing: Insights from Serpentinized Troctolite and Numerical Models Peer-reviewed

    Kazuki Yoshida, Atsushi Okamoto, Hiroyuki Shimizu, Ryosuke Oyanagi, Noriyoshi Tsuchiya, Oman Drilling Project Phase 2 Science Party

    Journal of Geophysical Research: Solid Earth　125　(11)　2020/10/30

    Publisher: American Geophysical Union (AGU)

    DOI： 10.1029/2020jb020268 　

    ISSN： 2169-9313

    eISSN： 2169-9356

  28. Crystallographic preferred orientation of talc determined by an improved EBSD procedure for sheet silicates: Implications for anisotropy at the slab–mantle interface due to Si-metasomatism Peer-reviewed

    Takayoshi Nagaya, Atsushi Okamoto, Ryosuke Oyanagi, Yusuke Seto, Akira Miyake, Masaoki Uno, Jun Muto, Simon R. Wallis

    American Mineralogist　105　(6)　873-893　2020/06/01

    Publisher: Mineralogical Society of America

    DOI： 10.2138/am-2020-7006 　

    ISSN： 0003-004X

    eISSN： 1945-3027

  29. Silica controls on hydration kinetics during serpentinization of olivine: Insights from hydrothermal experiments and a reactive transport model International-journal Peer-reviewed

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    Geochimica et Cosmochimica Acta　270　21-42　2020/02

    DOI： 10.1016/j.gca.2019.11.017 　

    ISSN： 0016-7037

    eISSN： 1872-9533

  30. Sparse isocon analysis: A data-driven approach for material transfer estimation Peer-reviewed

    Tatsu Kuwatani, Kenta Yoshida, Kenta Ueki, Ryosuke Oyanagi, Masaoki Uno, Shotaro Akaho

    Chemical Geology　532　2020/01/20

    DOI： 10.1016/j.chemgeo.2019.119345 　

    ISSN： 0009-2541

  31. Formation of secondary olivine after orthopyroxene during hydration of mantle wedge: evidence from the Khantaishir Ophiolite, western Mongolia Peer-reviewed

    Otgonbayar Dandar, Atsushi Okamoto, Masaoki Uno, Ryosuke Oyanagi, Takayoshi Nagaya, Ulziiburen Burenjargal, Tsuyoshi Miyamoto, Noriyoshi Tsuchiya

    Contributions to Mineralogy and Petrology　174　(11)　2019/11/01

    DOI： 10.1007/s00410-019-1623-1 　

    ISSN： 0010-7999

    eISSN： 1432-0967

  32. Sparse Modeling of Nonlinear Dynamics in Heterogeneous Reactions Peer-reviewed

    Masaki Ito, Tatsu Kuwatani, Ryosuke Oyanagi, Toshiaki Omori

    Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)　11954 LNCS　380-391　2019

    DOI： 10.1007/978-3-030-36711-4_32 　

    ISSN： 0302-9743

    eISSN： 1611-3349

  33. Multiple kinetic parameterization in a reactive transport model using the exchange Monte Carlo method Peer-reviewed

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    Minerals　8　(12)　2018/12

    DOI： 10.3390/min8120579 　

    eISSN： 2075-163X

  34. Al-Zoning of Serpentine Aggregates in Mesh Texture Induced by Metasomatic Replacement Reactions Peer-reviewed

    Ryosuke Oyanagi, Atsushi Okamoto, Yumiko Harigane, Noriyoshi Tsuchiya

    JOURNAL OF PETROLOGY　59　(4)　613-634　2018/04

    DOI： 10.1093/petrology/egy039 　

    ISSN： 0022-3530

    eISSN： 1460-2415

  35. アンケート調査による小・中学生対象の防災教育教材「減災アクションカードゲーム」の効果測定 Peer-reviewed

    富田史章, 大柳良介, 久松明史, 山田修司, 石橋信治, 渡邉俊介, 金子亮介, 安西瞳, 久利美和

    災害情報　15　(2)　207-220　2017

  36. Mechanisms of serpentinization utilizing olivine-plagioclase-H2O system under hydrothermal conditions Peer-reviewed

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    Procedia Earth and Planetary Science　17　686-689　2017

    DOI： 10.1016/j.proeps.2016.12.153 　

    ISSN： 1878-5220

  37. Competitive hydration and dehydration at olivine-quartz boundary revealed by hydrothermal experiments: Implications for silica metasomatism at the crust-mantle boundary International-journal Peer-reviewed

    Ryosuke Oyanagi, Atsushi Okamoto, Nobuo Hirano, Noriyoshi Tsuchiya

    Earth and Planetary Science Letters　425　44-54　2015/09/01

    DOI： 10.1016/j.epsl.2015.05.046 　

    ISSN： 0012-821X

Show all ︎Show first 5

Misc. 6

  1. JAMS Award for Young Scientists to Ryosuke Oyanagi

    Elements　21　(12)　445-445　2025/12

  2. Research topics from JAMS: New study finds subducted carbon may weaken subduction interfaces

    Elements　21　(2)　140-141　2025/04

  3. 全地球炭素循環におけるマントルの役割を流体−岩石平衡計算から解読する

    大柳 良介

    国士舘大学理工学部紀要　18　92-92　2025/03

    DOI： 10.18882/0002000767 　

  4. A study on learning motivation in "Artificial intelligence and Sciences"

    Naoki Ito, Rie Enomoto, Ryosuke Oyanagi, Motoo Sekiguchi, Yoshinori Honma, Yuko Murakami

    Kyoyo-ronshu Liberal arts review　48　(1)　101-111　2024/02/25

    Publisher: 國士舘大學教養学会

    ISSN： 0288-1500

  5. 地球内部でおこる反応輸送現象の理解に向けて

    大柳 良介

    日本地質学会News　26　(11)　27-27　2023/11

  6. 花崗岩若手の会in山口県青海島

    大柳 良介

    日本地質学会News　20　(2)　5-5　2017/02

Show all ︎Show first 5

Presentations 136

  1. Hydrothermal alteration of subducting oceanic mantle: Implications from the Kanasaki serpentinites, Kanto Mountains Invited

    Ryosuke Oyanagi, Hikaru Sawada, Qing Chang, Kenta K. Yoshida, Madhusoodhan Satish-Kumar

    Japan Geoscience Union Meeting 2025　2025/05/25

  2. Mass transfer at the slab-mantle interface: perspectives from the geological record and thermodynamic model Invited

    Ryosuke Oyanagi, Atsushi Okamoto

    The 131th annual meeting of the geological society of japan　2024/09/08

  3. Carbon cycling in the shallow forearc: insights from carbonated serpentinites International-presentation Invited

    Ryosuke Oyanagi

    17th International Symposium on Water-Rock Interaction and the 14th International Symposium on Applied Isotope Geochemistry　2023/08/22

  4. Fluid and carbon cycling in the shallow forearc mantle revealed by serpentinized peridotite from hadal seafloor Invited

    Ryosuke Oyanagi, Atsushi Okamoto, Madhusoodhan Satish-Kumar, Masayo Minami, Yumiko Harigane, Katsuyoshi Michibayashi

    Japan Geoscience Union Meeting 2022　2022/05

  5. Variable occurrences of magnetite and iron mobility during serpentinization: insights from samples from CM1A of Oman Drilling Project Invited

    Ryosuke Oyanagi, Kazuki Yoshida, Yasuhiro Niwa, Yasuo Takeichi, Masao Kimura, Kenta Yoshida, Atsushi Okamoto, Oman Drilling Project Phase 2 Science Party

    JpGU-AGU Joint Meeting 2020　2020/07

  6. Dynamic rate control changes during reactive-transport processes of serpentinization International-presentation Invited

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    Goldschmidt 2020　2020/06

  7. Ca and Si Transport and Fixation during Wollastonite Carbonation: Insights from Hydrothermal Experiments

    Han Shan, Atsushi Okamoto, Ryosuke Oyanagi, Dandar Otgonbayar

    2026 Annual Meeting and General Assembly of the Japan Association of Mineralogical Sciences (JAMS)　2026/09/25

  8. Carbonation of forearc mantle: Insights from rock physics modelling and Bayesian inversion

    Ryosuke Oyanagi, Yuya Akamatsu, Takayoshi Nagaya, Tatsu Kuwatani

    2026 Annual Meeting and General Assembly of the Japan Association of Mineralogical Sciences (JAMS)　2026/09/25

  9. Investigation of Thermoelectric Conversion Mechanisms Mediated by Sulfide Mineral Network Structures in Seafloor Hydrothermal Vents

    Kentaro Toda, Atsushi Okamoto, OTGONBAYAR DANDAR, Yoshinori Sato, Ryosuke Oyanagi

    2026 Annual Meeting and General Assembly of the Japan Association of Mineralogical Sciences (JAMS)　2026/09/25

  10. Multiscale Topological Characterization of Pore Structures in Mid-Ocean Ridge Basalts

    Masayoshi HOSHIDA, Ryosuke OYANAGI, Atsushi OKAMOTO

    The 133rd Annual Meeting of the Geological Society of Japan (2026 Kanazawa)　2026/09/15

  11. Unraveling the alteration processes of mantle peridotite based on rock physical properties Invited

    Yuya Akamatsu, Ryosuke Oyanagi, Yuto Miki, Tatsu Kuwatani

    The 133rd Annual Meeting of the Geological Society of Japan (2026 Kanazawa)　2026/09/15

  12. Evaluation of fluid pressure fluctuations in the updip limit of the seismogenic zone using oscillatory zoning of quartz veins in the Mugi mélange, Shimanto Belt

    Manato AKISHIBA, Otgonbayar DANDAR, Ryosuke OYANAGI, Asuka YAMAGUCHI, Yoshiro NISHIO, Andrew SMYE, Donald FISHER, Maureen FEINEMAN, Atsushi OKAMOTO

    The 133rd Annual Meeting of the Geological Society of Japan (2026 Kanazawa)　2026/09/14

  13. Fluid-rock reaction and fault weakening within a fault zone in a deep subduction zone: an example from the Sanbagawa metamorphic belt, Kanto mountains

    Tatsuru Fukuta, Kazuki Yoshida, Otgonbayar Dandar, Ryosuke Oyanagi, Atsushi Okamoto

    The 133rd Annual Meeting of the Geological Society of Japan (2026 Kanazawa)　2026/09/14

  14. Record of hydrogen generation during serpentinization in the lower crust to the upper mantle of the Oman Ophiolite Invited

    Kazuki YOSHIDA, Atsushi OKAMOTO, Ryosuke OYANAGI, Masakazu FUJII, Kenta YOSHIDA, Yasuhiro NIWA, Yasuo TAKEICHI, Masao KIMURA

    The 133rd Annual Meeting of the Geological Society of Japan (2026 Kanazawa)　2026/09/13

  15. Fluid-rock interaction and deep carbon cycling in the forearc mantle: insights from numerical models International-presentation Invited

    Ryosuke Oyanagi

    24th International Mineralogical Association General Meeting　2026/08/23

  16. 海洋リソスフェアや前弧マントルにおける岩石―水相互作用 Invited

    大柳 良介

    ハードロック掘削科学 学生・若手の勉強会2026　2026/06/06

  17. 超苦鉄質岩の CO2 固定化ポテンシャル評価について：自然の岩石および岩石熱力学シミュレーションからのアプローチ

    服部 達也, 大柳 良介, 森下 知晃

    石油技術協会 令和 8 年度 春季講演会　2026/06/03

  18. “Weak” paleomagnetic field intensity in the Cretaceous Normal Superchron measured from the drilling core basalts of the Central Kerguelen plateau Elan Bank and implications of thermal condition at the core-mantle boundary

    Yutaka Yoshimura, Masakazu Fujii, Chie Kato, Osamu Ishizuka, Kenji Shimizu, Ryosuke Oyanagi

    JpGU-AGU Joint Meeting 2026　2026/05/29

  19. Unraveling Fe oxidation state and H2 generation during serpentinization of the lower crust to the upper mantle using XANES analysis

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Masakazu Fujii, Kenta K Yoshida, Niwa Yasuhiro, Takeichi Yasuo, Masao Kimura

    JpGU-AGU Joint Meeting 2026　2026/05/28

  20. Variation of Carbonated-Ultramafic Rocks in the Setogawa Group, Central Japan: Implications from natural samples and thermodynamic modelling

    Tatsuya Hattori, Ryosuke Oyanagi, Tomoyuki Mizukami, Yumiko Harigane, Mayuko Fukuyama, Asuka Yamaguchi, Tomoaki Morishi

    JpGU-AGU Joint Meeting 2026　2026/05/28

  21. Drilling Multiple Oceanic Core Complexes in the Shikoku Basin: A Geodynamic Backarc Transect from Early Rifting to Basin Termination

    Yasuhiko Ohara, Valentin Basch, Marco Cuffaro, Masakazu Fujii, Yumiko Harigane, Osamu Ishizuka, Katsuyoshi Michibayashi, Kohei Nimura, Kyoko Okino, Ryosuke Oyanagi, Alessio Sanfilippo, Jonathan E. Snow, Kenichiro Tani, Hiroyuki Yamashi

    JpGU-AGU Joint Meeting 2026　2026/05/27

  22. Tectonic evolution of the Mikabu Greenstones: formation, alteration, and accretion of an oceanic plateau

    Hikaru Sawada, Ryosuke Oyanagi

    JpGU-AGU Joint Meeting 2026　2026/05/24

  23. The Jurassic preceding metamorphic stage of the Sanbagawa metamorphism recorded in high-pressure marble

    Kenta K Yoshida, Sota Niki, Hikaru Sawada, Takafumi Hirata, Takao Hirajima, Ryosuke Oyanagi

    JpGU-AGU Joint Meeting 2026　2026/05/24

  24. Reaction-induced fracturing and rheological effects of carbonation at the slab–mantle interface: Constraints from hydrostatic and shear experiments International-presentation

    Shunya Okino, Atsushi Okamoto, Ryosuke Oyanagi, Yukiko Kita, Sando Sawa, Jun Muto

    EGU General Assembly 2026　2026/05/06

  25. Fluid process in the forearc and the Hahajima seamount

    Ryosuke Oyanagi

    Hardrock Drilling Science Workshop Winter 2025 with special reference to Hahajima Seamount　2025/12/05

  26. Serpentinization of the peridotites from the Tosa Megamullion

    Ryosuke Oyanagi

    Mini-workshop on Godzilla Megamullion IODP3 drilling: Toward its implementation in near future　2025/11/27

  27. A preliminary report of weak paleointensity during the Cretaceous Normal Superchron estimated from the Kerguelen plateau basalts

    Yutaka Yoshimura, Masakazu Fujii, Chie Kato, Osamu Ishizuka, Kenji Shimizu, Ryosuke Oyanagi

    Society of Geomagnetism and Earth, Planetary and Space Sciences 2025 Fall meeting　2025/11/25

  28. Progress of hydrothermal alteration of ultramafic rocks in the Tosa Megamullion.

    Ryosuke Oyanagi, Yasuhiko Ohara

    The 132th Annual Meeting of the Geological Society of Japan　2025/09/15

  29. Timing of mantle wedge alteration events recorded by baddeleyite aggregates in the Higuchi serpentinite body, Sanbagawa belt

    Hikaru Sawada, Ryosuke Oyanagi, Sota Niki, Kazuki Yoshida, Mitsuhiro Nagata, Takafumi Hirata, Atsushi Okamoto

    The 132th Annual Meeting of the Geological Society of Japan　2025/09/15

  30. Structural and geochemical analysis of a metasomatized tectonic mélange in the Nomo metamorphic rocks, western Kyusyu, Japan.

    Matsutake Koumi, Ken-ichi Hirauchi, Ryosuke Oyanagi, Asuka Yamaguchi

    Japan Geoscience Union Meeting 2025　2025/05/30

  31. Contrasting evolution of the hydrogen generation between the lower crust gabbroic rocks and the mantle peridotite serpentinization

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Masakazu Fujii, Kenta K. Yoshida, Yasuhiro Niwa, Yasuo Takeichi, Masao Kimura

    Japan Geoscience Union Meeting 2025　2025/05/30

  32. The time-dependent contrasting slip behavior induced by H2O-CO2 fluid within slab-mantle interface and implication to slow earthquakes at shallow mantle wedge

    2025/05/28

  33. Relative significance of Si-, Mg- and CO2-metasomatism at shallow mantle wedge Invited

    Atsushi Okamoto, Ryosuke Oyanagi, Shunya Okino

    Japan Geoscience Union Meeting 2025　2025/05/28

  34. Petrological Characteristics of Serpentinite Blocks and Metamorphic Clasts from South Chamorro Seamount: Results from KM23-05 Drilling Expedition

    Hikaru Sawada, Ryosuke Oyanagi, Junichi Miyazaki, Masayuki Miyazaki, Hisanori Iwamoto, Ken Takai

    Japan Geoscience Union Meeting 2025　2025/05/28

  35. Complexity in zircon geochronology of serpentinite bodies

    Hikaru Sawada, Ryosuke Oyanagi, Mitsuhiro Nagata, Sota Niki, Takafumi Hirata

    Japan Geoscience Union Meeting 2025　2025/05/27

  36. Weakening of forearc mantle wedge at the subduction interface in a warm subduction zone: Insights from the phase equilibria modeling on the fluid-rock reaction

    Ryosuke Oyanagi, Atsushi Okamoto

    Japan Geoscience Union Meeting 2025　2025/05/27

  37. New frontiers in fluid-rock interaction process

    Ryosuke Oyanagi

    Japan Geoscience Union Meeting 2025　2025/05/26

  38. 沈み込み帯深部スラブ-マントル境界における物質移動とすべり挙動 -反応実験と摩擦実験による制約-

    沖野峻也, 岡本敦, 大柳良介, 喜多倖子, 澤燦道, 武藤潤

    変成岩などシンポジウム　2025/03/12

  39. Dynamic interplay of fluid-rock reactions, mass transport and fracturing at shallow mantle wedge International-presentation Invited

    Atsushi Okamoto, Kazuki Yoshida, Shunya Okino, Ryosuke Oyanagi

    5th serpentine days 2024　2024/09/25

  40. Zirconium minerals in ultramafic rocks Invited

    Hikaru Sawada, Ryosuke Oyanagi

    2024 Annual Meeting of Japan Association of Mineralogical Sciences　2024/09/14

  41. Petrogenesis and significance of ophicarbonate in the Kanasaki serpentinite body (Kanto Mountains, Central Japan)

    Ryosuke Oyanagi, Hikaru Sawada, Qing Chang, Madhusoodhan Satish-Kumar

    2024 Annual Meeting of Japan Association of Mineralogical Sciences　2024/09/12

  42. Multi-geochronology of metamorphism based on recent developments in laser ablation ICP mass spectrometry Invited

    Sota Niki, Kenta Yoshida, Hikaru Sawada, Ryosuke Oyanagi, Takafumi Hirata

    The 131th annual meeting of the geological society of japan　2024/09/09

  43. Alteration processes of mantle based on independent component analysis using physical properties of serpentinite from the Oman ophiolite

    Yuya Akamatsu, Ryosuke Oyanagi, Tatsu Kuwatani

    The 131th annual meeting of the geological society of japan　2024/09/08

  44. Geological and thermodynamic constraints on fluid-rock interaction and element cycling in the forearc mantle

    Ryosuke Oyanagi

    Hardrock Drilling Science Workshop Summer2024　2024/08/01

  45. Dynamic interplay of reaction-fracturing-mass transport at the crust-mantle boundary induced by CO2 fluids Invited

    Atsushi Okamoto, Ryosuke Oyanagi, Shunya Okino

    Japan Geoscience Union Meeting 2024　2024/05/31

  46. Large heterogeneity in a small rock body—U-Pb dating and trace element imaging of Zr and Th minerals in a serpentinite body of the Sanbagawa metamorphic belt

    Hikaru Sawada, Ryosuke Oyanagi, Sota Niki, Kazuki Yoshida, Mitsuhiro Nagata, Takafumi Hirata, Atsushi Okamoto

    Japan Geoscience Union Meeting 2024　2024/05/29

  47. Effect of lithology on hydrogen generation by serpentinization reaction in the oceanic lithosphere

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Masakazu Fujii, Yasuhiro Niwa, Yasuo Takeichi, Shuhei Tanaka, Masao Kimura

    Japan Geoscience Union Meeting 2024　2024/05/28

  48. Data-driven estimation of spatiotemporal nonlinear dynamics of heterogeneous reaction

    Takeshi Aibe, Tatsu Kuwatani, Ryosuke Oyanagi, Toshiaki Omori

    Japan Geoscience Union Meeting 2024　2024/05/27

  49. Data-driven approach for inverse problems in the petrology Invited

    Ryosuke Oyanagi

    59th Japanese Conference on Calorimetry and Thermal Analysis　2023/10/25

  50. Fluid flow and fluid-rock interactions at shallow mantle wedge International-presentation Invited

    Atsushi Okamoto, Kazuki Yoshida, Shunya Okino, Ryosuke Oyangi

    International Joint Workshop on Slow-to-Fast Earthquakes 2023　2023/09/14

  51. Spatial distribution of Fe(III) during serpentinization of the lower crust-upper mantle of the Oman ophiolite: Insights from multiscale observations

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Masakazu Fujii, Yasuhiro Niwa, Yasuo Takeichi, Masao Kimura

    The 130th annual meeting of the geological society of japan　2023/09/17

  52. Integrated analysis using rock magnetism and synchrotron radiation for magnetite within abyssal serpentinized peridotites International-presentation

    Masakazu Fujii, Kazuki Yoshida, Atsushi Okamoto, Kenta Yoshida, Ryosuke Oyanagi, Yasuhiro Niwa, Masao Kimura

    17th International Symposium on Water-Rock Interaction and the 14th International Symposium on Applied Isotope Geochemistry　2023/08/21

  53. Carbonation of serpentinite in the subduction zone: Insight from the Kanasaki ophicarbonate, Kanto Mountains, Japan. International-presentation

    Ryosuke Oyanagi, Hikaru Sawada, Qing Chang, Madhusoodhan Satish-Kumar

    17th International Symposium on Water-Rock Interaction and the 14th International Symposium on Applied Isotope Geochemistry　2023/08/21

  54. Redox state of iron during serpentinization of the crust-mantle transition zone to the upper mantle section of the Oman Ophiolite International-presentation

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Masakazu Fujii, Yasuhiro Niwa, Yasuo Takeichi, Shuhei Tanaka, Masao Kimura

    17th International Symposium on Water-Rock Interaction and the 14th International Symposium on Applied Isotope Geochemistry　2023/08/21

  55. Transient fluid flow in the subduction zone setting: Implications from the Oman Ophiolite International-presentation International-coauthorship

    Kazuki Yoshida, Ryosuke Oyanagi, Masao Kimura, Oliver Plümper, Mayuko Fukuyama, Atsushi Okamoto

    17th International Symposium on Water-Rock Interaction and the 14th International Symposium on Applied Isotope Geochemistry　2023/08/19

  56. Effects of fluid chemistry on metasomatic reactions at slab-mantle interfaces within the subduction zones: Significance of Si vs. Mg and CO2

    Atsushi Okamoto, Ryosuke Oyanagi, Shunya Okino

    Japan Geoscience Union Meeting 2023　2023/05/25

  57. Simultaneous P-T-t estimation using titanite from the Tonaru body of the Sanbagawa metamorphic belt, central Shikoku, revealed another locality of 200 Ma pre-Sanbagawa metamorphism

    Kenta Yoshida, Sota Niki, Hikaru Sawada, Ryosuke Oyanagi, Takafumi Hirata

    Japan Geoscience Union Meeting 2023　2023/05/25

  58. Hydrogen Production in the Oceanic Lithosphere: Implications from the Oman Ophiolite

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Masakazu Fujii, Yasuhiro Niwa, Yasuo Takeichi, Shuhei Tanaka, Masao Kimura

    Japan Geoscience Union Meeting 2023　2023/05/23

  59. Preliminary report of YK23-05S cruise: a Shinkai 6500 dive study on the oceanic core complexes in the West Philippine Basin

    Yasuhiko Ohara, Yumiko Harigane, Katsuyoshi Michibayashi, Kyoko Okino, Ryosuke Oyanagi, Alessio Sanfilippo Jonathan, E. Snow, Marco Cuffaro, Kohei Nimura, Takaaki Moriguchi

    Japan Geoscience Union Meeting 2023　2023/05/23

  60. Petrologic and geochemical investigation of the Kanasaki ophicarbonate, Kanto Mountains, Japan.

    Ryosuke Oyanagi, Hikaru Sawada, Qing Chang

    Japan Geoscience Union Meeting 2023　2023/05/21

  61. Baddeleyite in the Higuchi serpentinite body, the Sanbagawa metamorphic belt suggests dissolution and precipitation of high field strength elements due to low-T hydrothermal alteration along the plate subduction

    Hikaru Sawada, Ryosuke Oyanagi, Sota Niki Mitsuhiro Nagata, Takafumi Hirata

    Japan Geoscience Union Meeting 2023　2023/05/21

  62. Transient fluid flow recorded in the Crust-Mantle transition zone of the Oman Ophiolite International-presentation International-coauthorship

    Kazuki Yoshida, Ryosuke Oyanagi, Masao Kimura, Oliver Plümper, Mayuko Fukuyama, Atsushi Okamoto

    European Geosciences Union General Assembly 2023　2023/04/27

  63. 伊豆・小笠原海溝の前弧マントル岩石の変成作用

    大柳良介, 沢田輝, Qing Chang, 吉田健太, 針金由美子, 岡本敦, 道林克禎

    海と地球のシンポジウム2022　2023/03/16

  64. 伊豆・小笠原海溝の前弧マントル研究

    道林克禎, 柿畑優季, 斎藤涼, 針金由美子, 石塚治, 岡本敦, 大柳良介, 畠山航平, 片山郁夫, 二村康平, 夏目樹, 小野重明, 北里洋

    海と地球のシンポジウム2022　2023/03/16

  65. Chloritization and porosity generation at crust-mantle material boundary

    Atsushi Okamoto, Ryosuke Oyanagi, Kazuki Yoshida

    2022 Annual Meeting of Japan Association of Mineralogical Sciences　2022/09/17

  66. Transient fluid infiltration in the shallow mantle wedge recorded in the Oman Ophiolite International-presentation

    Kazuki Yoshida, Ryosuke Oyanagi, Masao Kimura, Oliver Plümper, Mayuko Fukuyama, Atsushi Okamoto

    International Joint Workshop on Slow-to-Fast Earthquakes 2022　2022/09/14

  67. マントルー地殻境界におけるマグネシウムとシリカの相対的移動度

    Atsushi Okamoto, Kazuki Yoshida, Ryosuke Oyanagi

    The 129th annual meeting of the geological society of japan

  68. Metasomatism and mass transfer at the slab-mantle interface in the subduction zone: Insights from serpentinite in the Tomisato area of the Sanbagawa belt (Central Shikoku, Japan).

    Ryosuke Oyanagi, Masaoki Uno, Atsushi Okamoto

    The 129th annual meeting of the geological society of japan

  69. Transient fluid migration recorded in antigorite veins formed by subduction-related fluids

    Kazuki Yoshida, Ryosuke Oyanagi, Masao Kimura Oliver Plümper, Mayuko Fukuyama, Atsushi Okamoto

    The 129th annual meeting of the geological society of japan

  70. Multiphase “former supercritical fluid” inclusion from the high-temperature pre-Sanbagawa metamorphism International-presentation

    Kenta Yoshida, Atsushi Okamoto, Yasuhiro Niwa, Masao Kimura, Ryosuke Oyanagi, Hikaru Sawada, Sota Niki, Kazuki Yoshida

    14th International Eclogite Conference

  71. Formation of brucite reaction zone with antigorite veins from the Oman ophiolite and its comparison with hydrothermal experiments. Invited

    Kazuki Yoshida, Ryosuke Oyanagi, Atsushi Okamoto

    Japan Geoscience Union Meeting 2022　2022/06/01

  72. 2-Myr metamorphic history of the Sanbagawa terrane deduced from the multimineral petrochronology Invited

    Kenta Yoshida, Sota Niki, Hikaru Sawada, Ryosuke Oyanagi, Takafumi Hirata, Kenji Asakura, Takao Hirajima

    Japan Geoscience Union Meeting 2022　2022/05/24

  73. Inversely depleted forearc mantle section records the subduction zone infancy: Umigame Seamount, Bonin Trench

    Katsuyoshi Michibayashi, Suzu Saito, Yuki Kakihata, Yumiko Harigane, Atsushi Okamoto, Ryosuke Oyanagi, Kohei Hatakeyama, Ikuo Katayama, Osamu Ishizuka, Shigeaki Ono

    Japan Geoscience Union Meeting 2022　2022/05

  74. Rupture of serpentinized mantle wedge by self-promoting carbonation: insights from Sanbagawa metamorphic belt International-presentation

    Atsushi Okamoto, Ryosuke Oyanagi, Kazuki Yoshida, Masaoki Uno, Hiroyuki Shimizu, Madhusoodhan Satish-Kumar

    EGU General Assembly 2022　2022/05

  75. Rapid fluid infiltration recorded in the brucite-rich reaction zone along the antigorite veins from the Oman ophiolite International-presentation

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Masao Kimura

    EGU General Assembly 2022　2022/05

  76. 海洋プレートの下部地殻ーマントルに海水が浸透したときの反応プロセス

    岡本敦, 大柳良介, 吉田一貴

    「海溝海側の過程に関する横断的研究：沈み込み帯インプットの実態解明を目指して」研究集会　2021/10/25

  77. オマーンオフィオライト地殻―マントル遷移帯 におけるアンチゴライト脈形成と流体流動

    吉田 一貴, 岡本敦, 大柳良介, 木村正雄

    日本鉱物科学会2021年年会　2021/09/16

  78. 三波川変成帯エクロジャイト岩体中のマーブルに見られた柘榴石中の溶解再析出反応と微小空隙

    吉田 健太, 沢田 輝, 仁木 創太, 大柳 良介

    日本鉱物科学会2021年年会　2021/09/16

  79. オマーンオフィオライトの蛇紋岩化した地殻―マントル境界におけるFe(III)の分布

    岡本 敦, 吉田 一貴, 大柳 良介, 藤井 昌和, 丹羽 尉博, 武市 泰男, 木村 正雄

    日本地質学会 第126年学術大会　2021/09/04

  80. 先三波川変成作用の高温場で形成された超臨界流体起源の多相包有物

    吉田 健太, 岡本 敦, 丹羽 尉博, 木村 正雄, 大柳 良介, 沢田 輝, 仁木 創太, 吉田 一貴

    日本地質学会 第126年学術大会　2021/09/06

  81. 高間隙流体圧下での古マントルウェッジ蛇紋岩体の破壊作用と深部スロー地震発生サイクルとの関連性

    平内 健一, 永田 有里奈, 大柳 良介, 岡本 敦, 道林 克禎

    日本地質学会第128年学術大会　2021/09/04

  82. Rupture of serpentinized mantle wedge by self-promoting carbonation International-presentation

    AtsushiOkamoto, Ryosuke Oyangi, Kazuki Yoshida, Masaoki Uno, Hiroyuki Shimizu, Madhusoodhan Satish-kumar

    the International Joint Workshop on Slow Earthquakes 2021　2021/09

  83. Simultaneous P-T-t estimation of ultrahigh-temperature high-pressure granulite facies metamorphism recorded in titanite International-presentation

    KENTA YOSHIDA, SOTA NIKI, HIKARU SAWADA, RYOSUKE OYANAGI, TAKAFUMI HIRATA, KENJI ASAKURA, TAKAO HIRAJIMA

    Goldschmidt 2021　2021/07

  84. Extension of log K of aqueous species to low-water density conditions and comparison with hydrothermal experiments on feldspar dissolution

    石井 肇, 岡本 敦, 大柳 良介, 土屋 範芳

    JpGU-AGU Joint Meeting 2020　2020/07

  85. Numerical prediction of effect of olivine content for proceeding of serpentinization

    吉田 一貴, 岡本 敦, 大柳 良介, 清水 浩之, 土屋 範芳, Oman Drilling Project Phase 2 Science Party

    JpGU-AGU Joint Meeting 2020　2020/07

  86. Bayesian Data-driven Approach for Extracting Nonlinear Dynamics of Heterogeneous Reactions

    伊藤 雅起, 桑谷 立, 大柳 良介, 大森 敏明

    JpGU-AGU Joint Meeting 2020　2020/07

  87. 四国中央部三波川変成帯東五良津岩体中のマーブルに見られるダトー石の形成条件とその意義

    吉田 健太, 仁木 創太, 沢田 輝, 大柳 良介

    JpGU-AGU Joint Meeting 2020　2020/07

  88. Formation of fracture network permeability enhancement during olivine hydration within oceanic lower crust International-presentation

    Kazuki Yoshida, Atsushi Okamoto, Ryosuke Oyanagi, Hiroyuki Shimizu, Noriyoshi Tsuchiya

    International Conference on Ophiolites and the Oceanic Lithosphere, Oman　2020/01

  89. Hydration and development of fracture network within oceanic lower crust: an evidence from CM1A of Oman Drilling Invited

    岡本敦, 吉田一貴, 大柳良介

    日本地球惑星科学連合2019年大会　2019/05

  90. スパースモデリングにより捉えた沈み込みスラブの発展的組成変化

    吉田健太, 桑谷立, 上木賢太, 大柳良介, 赤穗昭太郎

    日本地球惑星科学連合2019年大会.　2019/05

  91. 超臨界岩石–水相互作用のための溶存種の熱力学データ：溶解実験と密度を用いた外挿

    岡本敦, 石井肇, 大柳良介, 土屋範芳

    日本地球惑星科学連合2019年大会.　2019/05

  92. Specifying rate constants and reaction path on the water-rock chemical reaction based on exchange Monte Carlo method and sparse modeling

    大柳良介, 桑谷立, 大森敏明

    日本地球惑星科学連合2019年大会.　2019/05

  93. 超臨界条件の岩石̶水相互作用と斜長石の溶解・析出

    岡本敦, 天谷宇志, 大柳良介, Nurdiana Astin, 土屋 範芳

    日本地質学会第１２５年学術大会　2019/05

  94. Kinetics of silica metasomatism during serpentinization revealed by hydrothermal experiments on olivine-quartz-seawater system at 300 ∘C International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    EGU General Assembly 2019　2019/04/10

  95. Hydrothermal Alteration of the Crust-Mantle Transition and Upper Mantle in the Samail Ophiolite: Insights from the Oman Drilling Project International-presentation International-coauthorship

    Gretchen L. Früh-Green, Marta Grabowska, Ryosuke Oyanagi, Kosuke Kimura, Atsushi Okamoto, Tomoaki Morishita, Akihiro Tamura, Frieder Klein, Damon A, H. Teagle, Eiichi Takazawa, Judith A. Coggon, Jürg M. Matter, Peter B. Kelemen, OmanDP Phase 2 Science Party

    EGU General Assembly 2019　2019/04/09

  96. 蛇紋岩体中のドロマイトー滑石脈の形成と泥質片岩境界との反応帯：三波川帯関東山地長瀞の例

    岡本 敦, 大柳 良介, 吉田 一貴, サティシュ クマール, 宇野 正起

    日本地質学会 第126年学術大会　2019

  97. スパースモデリングによる沈み込み帯深部流体活動の定量的見積もり

    吉田 健太, 桑谷 立, 上木 賢太, 大柳 良介, 赤穂 昭太郎

    日本地質学会 第126年学術大会　2019

  98. スパースアイソコン解析：リファレンスフレームの自動決定

    桑谷 立, 吉田 健太, 上木 賢太, 大柳 良介, 宇野 正起, 赤穂 昭太郎

    日本地質学会 第126年学術大会　2019

  99. Hydrothermal experiments on olivine-quartz-seawater system at 300 °C: implication for the progress of silica-metasomatism during serpentinization at the crust-mantle boundary in the oceanic lithosphere International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    American Geophysical Union 2018 Fall meeting.　2018/12/12

  100. Hydrothermal Alteration of the Crust-Mantle Transition and Upper Mantle in the Samail Ophiolite: Insights from Holes CM1A and CM2B of the Oman Drilling Project International-presentation International-coauthorship

    Gretchen L. Frueh-Green, Marta Grabowska, Ryosuke Oyanagi, Kosuke Kimura, Tomoaki Morishita, Atsushi Okamoto, Frieder Klein, Akihiro Tamura, Damon A H Teagle, Eiichi Takazawa, Judith A. Coggon, Peter B Kelemer, Juerg Michael Matter, Oman DP Phase 2 Science Party

    American Geophysical Union 2018 Fall meeting　2018/12/10

  101. First geochemical and mineralogical results of Oman Crust-Mantle transition: holes CM1A and CM2B characterization aboard DV-Chikyu_ Oman Drilling Project, Phase 2 Leg3 International-presentation

    Kourim Fatna, Mathieu Rospabé, Manolis Giampouras, Sayantani Chatterjee, Keisuke Ishii, Akihiro Tamura, Nicholas Dyger, Ryosuke Oyanagi, Kuo-Lung Wang, Mathieu Benoi, Damon A H Teagle, Eiichi Takazawa, Peter B Kelemen, Jude Ann Coggon, Oman Drilling, Project Phase, Science Party

    American Geophysical Union 2018 Fall meeting　2018/12/10

  102. 海洋底蛇紋岩作用におけるSi 交代作用の律速過程」

    大柳良介, 岡本敦, 土屋範芳

    日本地質学会第１２５年学術大会　2018/09

  103. 玄武岩-水系における熱水変成作用によるザクロ石の合成

    根津勇介, 岡本敦, 宇野正起, 平野伸夫, 大柳良介, 土屋 範芳

    日本地球惑星科学連合2018年大会　2018/05

  104. 交換モンテカルロ法を用いた蛇紋岩化作用におけるSi交代作用メカニズムの解明

    大柳良介, 岡本敦, 土屋範芳

    日本地球惑星科学連合2018年大会　2018/05

  105. 海洋底の蛇紋岩化に伴う物質移動とメッシュ組織

    岡本敦, 大柳良介, 土屋範芳

    海洋リソスフェアの蛇紋岩化作用と物理・化学・生物プロセス- InterRidge Japan 研究集会　2017/11

  106. Model selection on chemical kinetics during water-rock interaction using exchange Monte Carlo method International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    International Meeting on “High-Dimensional Data-Driven Science” (HD3-2017)　2017/09

  107. 交換モンテカルロ法によるかんらん石の熱水変質速度の最適化

    大柳良介, 岡本敦, 土屋範芳

    2017/09

  108. 沈み込み帯プレート境界におけるSi流体交代作用によるTalc CPOの形成

    永冶 方敬, 岡本 敦, Simon Wallis, 大柳 良介, 武藤 潤, 宇野 正起

    日本鉱物科学会 2017年会.　2017/09

  109. Si-metasomatism during sea floor serpentinization and estimation of its kinetic parameters

    大柳良介, 岡本敦, 土屋範芳

    日本地球惑星科学連合2017年大会　2017/05

  110. Unraveling the oceanic serpentinization reaction from aluminum-zoning in mesh textures

    大柳良介, 岡本敦, 土屋範芳

    日本地球惑星科学連合2017年大会　2017/05

  111. Mass transfer and mineral replacement during serpentinization in Olivine–Plagioclase–H2O System International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    Water Dynamics-14 Ultimate Fluids for Metamorphism and Geothermal.　2017/03

  112. Bidirectional replacement zoning developed during serpentinization on olivine-plagioclase system International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    American Geophysical Union 2016 Fall meeting.　2016/12

  113. Serpentinization Utilizing Olivine–Plagioclase–H2O System under Hydrothermal Conditions International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    15th Water–Rock Interaction International Symposium　2016/10

  114. 水熱実験による蛇紋岩化反応とSi交代作用の速度論的研究

    大柳良介, 岡本敦, 土屋範芳

    日本鉱物科学会201６年年会　2016/09

  115. Bidirectional Replacement Zoning Developed in Metasomatic Reaction of Olivine during Serpentinization on Olivine-Plagioclase System International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    Goldschmidt2016　2016/07

  116. Significance of Silica Transport on Serpentinization: Insights from Hydrothermal Experiments International-presentation Invited

    Atsushi Okamoto, Ryosuke Oyanagi, Noriyoshi Tsuchiya

    Goldschmidt2016　2016/06

  117. 沈み込み帯における地殻―マントル物質境界の交代作用：四国中央部三波川帯富郷地域の蛇紋岩岩体における例

    大柳良介, 岡本敦, 宇野正起, 土屋範芳

    日本地球惑星科学連合2016年大会　2016/05

  118. かんらん石の交代作用時に発達する双方向の反応進行フロント：メッシュ組織形成過程への示唆

    大柳良介, 岡本敦, 土屋範芳

    日本地球惑星科学連合2016年大会　2016/05

  119. Bidirectional replacement zoning as a consequence from metasomatic reaction in olivine-plagioclase system International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    13th International Workshop on WATER DYNAMICS Hydrogen in the Earth and Fluid Behaviors　2016/03

  120. Mechanism of metasomatic replacement in olivine-plagioclase system under hydrothermal conditions International-presentation

    Ryosuke Oyanagi

    Metamorphic rocks and Metamorphism: Future Perspectives　2016/03

  121. 簡易アンケートによる小・中学生の防災意識の調査と「減災アクションカードゲーム」の効果測定

    大柳良介, 久松明史, 渡邉俊介, 石橋信治, 安西瞳, 金子亮介, 富田史章, 山田修司, 久利美和

    日本災害情報学会 第17回学会大会　2015/10

  122. 水熱実験によるかんらん石―斜長石系における熱水変質過程

    大柳良介, 岡本敦, 土屋範芳

    日本鉱物科学会2015年年会　2015/09

  123. 水熱実験による地殻マントル境界における交代作用

    大柳良介, 岡本敦, 土屋範芳

    日本地球惑星科学連合2015年大会　2015/05

  124. Metasomatic Processes on Crust-Mantle Boundary Deduced from Hydrothermal Experiments International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    12th International Workshop on WATER DYNAMICS Deep Carbon Cycle,　2015/03

  125. 地殻－マントル境界における熱水変質の時空間発展

    大柳良介

    変成岩などシンポジウム2015　2015/03

  126. 蛇紋岩から流体の化学的性質を読み取る岩石学的試み

    水上知行, 林竜太郎, 石神慎太郎, 大柳良介, 岡本敦, 福士圭介, 奥野正幸, 荒井章司

    日本地球化学会第61回年会　2014/09

  127. かんらん石―斜長石－水系における蛇紋岩化作用の進行と物質移動

    大柳良介, 岡本敦, 土屋範芳

    日本地質学会第121年学術大会　2014/09

  128. かんらん石－石英境界における熱水変質の反応進行度と空隙率変化

    大柳良介, 岡本敦, 土屋範芳

    日本地球惑星科学連合2014年大会　2014/05

  129. 水熱実験からみるマントル-地殻境界における物質移動と蛇紋岩化作用のカップリング

    岡本敦, 大柳良介, 土屋範芳

    日本地球惑星科学連合2014年大会　2014/05

  130. Si-metasomatism and porosity changes of serpentinization in Ol-Qtz system International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    11th International Workshop on WATER DYNAMICS Deep Carbon Cycle　2014/03

  131. Coupling of silica transport and reactions during serpentinization International-presentation Invited

    Atsushi Okamoto, Ryosuke Oyanagi, Noriyoshi Tsuchiya

    11th International Workshop on WATER DYNAMICS Deep Carbon Cycle　2014/03

  132. Effect of silica transport on serpentinization International-presentation Invited

    Atsushi Okamoto, Ryosuke Oyanagi, Noriyoshi Tsuchiya

    Geofluid-3: Nature and Dynamics of Fluids in Subduction Zones.　2014/02

  133. Hydrothermal experiment on serpentinization at crust/mantle boundary International-presentation

    Ryosuke Oyanagi, Atsushi Okamoto, Noriyoshi Tsuchiya

    American Geophysical Union 2013 Fall meeting　2013/12

  134. 蛇紋岩化作用進行度の空間分布と物質移動

    岡本敦, 大柳良介, 清水浩之, 土屋範芳

    日本地質学会第120年学術大会　2013/09

  135. Effects of pH and silica on the progress of serpentinization deduced from hydrothermal experiments,

    大柳良介, 岡本敦, 土屋範芳

    本地球惑星科学連合2013年大会　2013/05

  136. 蛇紋岩化反応とシリカの拡散とのカップリング

    岡本敦, 小笠原由一, 大柳良介, 土屋範芳

    日本地球惑星科学連合2013年大会　2013/05

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Research Projects 8

  1. Heterogeneous structural evolution and geomechanical impacts of CO2 fluid injection in ultramafic rocks Competitive

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (S)

    Institution: Tohoku University

    2026/04 - 2031/03

  2. 地殻流体の広域的流動特性解明のためのデータセット構築

    大柳 良介

    Offer Organization: 文部科学省

    System: AI for Scienceによる科学研究革新プログラム

    Category: AI for Science萌芽的挑戦研究創出事業 (SPReAD)

    2026/06 - 2027/01

  3. 全地球炭素循環におけるマントルの役割を流体―岩石平衡計算から解読する

    大柳 良介

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 若手研究

    Institution: 国士舘大学

    2023/04/01 - 2026/03/31

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    今年度は(1)前弧マントルにおける岩石―水反応のモデリング、および(2)天然試料の炭酸塩鉱物の解析を進めた。 (1)について、東北日本と西南日本の沈み込み帯において、沈み込む堆積物から放出される流体が前弧マントル域においてどのような鉱物を生成させているかを検討した。その結果、東北日本の沈み込み帯の前弧マントル域では炭素をほとんど固定しない一方で、西南日本の沈み込み帯の前弧マントル域では炭素を炭酸塩鉱物として固定することを見出した。本研究によると、西南日本の沈み込み帯の前弧マントル域における炭素固定フラックスは0.005 Mt C yr－1と見積もられた。これは、西南日本の沈み込み帯における沈み込み炭素フラックスのわずか0.5%にすぎない。よって、両方の沈み込み帯において、沈み込んだ堆積物中の炭素のほとんどはマントルウェッジにリサイクルされず、マントルウェッジの炭素の取り込みは、炭素の流入と流出の間の地球規模の炭素循環とバランスに関する現在のモデルに影響を与えない可能性がある。しかし、このような反応はプレートの境界面のレオロジーに大きな影響を与えている可能性があることがわかり、本研究成果をNature Communication誌に発表した。 (2) について、天然岩石の解析を進めた。長瀞地域の金崎地域に産する蛇灰岩の炭素・酸素安定同位体比、希土類元素、ストロンチウム同位体比の測定により、炭酸塩沈殿を引き起こした流体の特徴について明らかにした。

  4. 南極巨大海台から解き明かす白亜紀地磁気非逆転期の地球磁場強度変動

    藤井 昌和, 加藤 千恵, 石塚 治, 清水 健二, 大柳 良介, 竹原 真美, 佐藤 暢, 佐藤 太一, 堀江 憲路, 山本 裕二, 佐藤 哲郎, 北原 優, Qiang Jiang, 松本 廣直

    Offer Organization: 国立極地研究所

    System: 国立極地研究所 2025年度 特別共同研究

    2025/04 - 2026/03

  5. New developments in EBSD analysis applied to characterization of fault rock microstructure

    Wallis Simon

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))

    Institution: The University of Tokyo

    2020/10/27 - 2025/03/31

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    This research was based on collaborative research focusing on high-resolution EBSD (electron backscatter diffraction) analysis of deformed rocks, especially serpentinites rich in antigorite. Thin sections of serpentinite were carefully prepared to preserve crystal orientation for analysis. A massive dataset (over 1TB) was generated and shared. Dictionary Indexing (DI) proved more precise than traditional methods, offering clearer images of crystal structures and revealing previously undetected twin boundaries. In addition, fieldwork in the U.S. and Japan provided diverse samples, including high-strain rocks, for detailed structural studies. Key findings include deformation-driven mineral transformations and improved stress estimation methods. The work has broad implications from mantle dynamics to earthquake processes and even meteorite impact studies. These results were presented at several international conferences and published in scientific journals.

  6. Model selection and parameter extraction for mineral dissolution reactions using a data-driven approach

    Oyanagi Ryosuke

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Early-Career Scientists

    2019/04/01 - 2023/03/31

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    To better understand the chemical changes of rocks in the Earth's interior, it is important to clarify the alteration reaction rates of minerals. In this study, experiments were conducted to clarify the alteration reaction rate of olivine (serpentinization) reactions. In the experiment, hot water at 260-300°C was poured over the olivine powder (circulation-type hydrothermal reaction experiment), and changes in the alteration reaction were observed over time. After the reaction, the surface of the olivine powder was observed with a scanning electron microscope, and serpentinite was found to be precipitated. Comparison of the experimental results with a theoretical model of the alteration reaction showed that the ratio of the rate of olivine dissolution to the rate of serpentinite precipitation reaction varied with temperature and time.

  7. データ駆動型アプローチによる海洋下部地殻および上部マントル変質速度の探索

    大柳 良介

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特別研究員奨励費

    Institution: 国立研究開発法人海洋研究開発機構

    2018/04/25 - 2021/03/31

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    当該年度は，前年度に設計したフォワードモデルと機械学習的アプローチを練成させ，水熱実験の解析を試みた．設計したフォワードモデルには，鉱物の反応表面積に関する項において不確実性が存在した．そのため，データ駆動型アプローチを用いてその不確実性をデータから推定することを試みた．本手法は，考えられるあらゆるフォワードモデルの候補で水熱実験の結果を解析するものである．その中で，クロスバリデーションという情報科学的アプローチを用いて一番実験結果をよく再現するフォワードモデルを推定した．結果，実験結果からフォワードモデルを推定できただけでなく，フォワードモデルを用いて水熱実験を再現することができた．拡散係数や反応速度定数といった未知パラメータを分布として推定し，不確かさを定量的に評価することができた．また，クロスバリデーションで選択されたフォワードモデルは，変質反応の律速過程を客観的にデータから判定した．この判定された律速過程は，既往の研究で報告されている変質反応の律速過程や，鉱物組織から推定する律速過程と調和的であった．このように，これまで主観的に行われてきた反応の律速過程の同定を，データ駆動型アプローチにより客観的に推定できることを示した．これらの成果をEGU general assembly 2019で発表した．他にも，変成岩などシンポジウムや国際研究集会「Water-dynamics」で発表予定だったが，コロナウイルスの影響で発表機会が失われた．

  8. 地殻－マントル境界における蛇紋岩化作用の反応メカニズムと物質移動 Competitive

    大柳 良介

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特別研究員奨励費

    Institution: 東北大学

    2016/04/22 - 2018/03/31

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    本年度は，昨年度行ったかんらん石―斜長石―水系における水熱実験（２３０度， ２．８Ｍｐａ）の実験結果のさらなる解析を試みた．水熱実験において，かんらん石と斜長石の境界付近においては磁鉄鉱が生成しなかった．磁鉄鉱の生成について，Ｐｅｒｐｌｅ Ｘ （Ｃｏｎｏｌｌｙ， ２００９）を用いたシュードセクションによる解析を行った．シュードセクションの作成にあたって，通常の熱力学データベースには含まれていない３価鉄を含む蛇紋石の熱力データを作成し，３価鉄の挙動を考慮した．結果，磁鉄鉱の生成はシリカ活動度と酸素フガシティーよって支配されていることが明らかになった．斜長石から高いシリカ活動度を持つ流体が拡散するため，磁鉄鉱が境界付近で生成しなかったのだと解釈される．かんらん石をバルク組成とした場合の３価鉄の蛇紋石の量は最大で３ｖｏｌ％程度で，シリカ活動度が高いほど少なくなる傾向がある．反応の過程で，２価鉄が３価鉄へ変化すると水素が発生する．このことは，海洋底における水素のフラックスを決定する重要な知見である．また，実験で観察されてアルミニウムの量の反応帯について，流体と固相感の局所平衡を仮定した反応ー輸送モデリングを行った．結果，実験で観察されたＡｌの量のプロファイルを概ね再現することに成功した．これらの成果はＪｏｕｒｎａｌ ｏｆ Ｐｅｔｒｏｌｏｇｙに受理された （Ｏｙａｎａｇｉ ｅｔ ａｌ．， ２０１８）．

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Teaching Experience 7

  1. Laboratory Experiment A　Tohoku University

  2. 基礎理学演習　国士舘大学

  3. 卒業研究　国士舘大学

  4. 基礎力学B　国士舘大学

  5. 基礎力学A　国士舘大学

  6. AIとサイエンス　国士舘大学

  7. 人と宇宙　国士舘大学

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Works 1

  1. 防災教育教材「減災アクションカードゲーム」の開発

    2015 - 2018

    Type: Educational material

Media Coverage 13

  1. 東北大と海洋研究開発機構、沈み込む炭素がプレートをマントルとの境界で滑りやすくすることを発見

    日本経済新聞

    2024/09/05

    Type: Internet

  2. 沈み込む炭素がプレートをマントルとの境界で滑りやすくすることを発見 ～炭素循環と地震活動との関連性を示唆～ Myself

    東北大学　2024年のプレスリリース・研究成果

    2024/09/05

  3. プレートの沈み込み帯の短期的な流体移動の痕跡を上盤マントルで発見 ―沈み込み帯における地震活動と流体との関係を示唆―

    東北大学　2023年のプレスリリース・研究成果

    2023/04/06

  4. 東北大など、プレート沈み込み帯で流体移動の痕跡発見 スロー地震活動と類似

    日刊工業新聞

    2023/04

    Type: Newspaper, magazine

  5. 沈み込み帯における流体移動の痕跡をキャッチ ―プレート境界地震のメカニズム解明へ ：東北大学/高エネルギー加速器研究機構ほか

    つくばサイエンスニュース

    2023/04

    Type: Internet

  6. Clarification of the mechanism of seawater circulation in ultra-deep sea mantle rocks by JAMSTEC and collaborators

    Science Japan

    2022/02

    Type: Internet

  7. 超深海のマントル岩石で海水循環のメカニズムを解明

    科学新聞

    2022/01/14

    Type: Newspaper, magazine

  8. 日本近海で炭素・海水の数万年の循環プロセスを明らかに ―マントルは大規模な炭素貯蔵庫、生命活動の解明にも関連か

    つくばサイエンスニュース

    2021/12/03

  9. 超深海の変質したマントル岩石の内部で炭素を含む海水が循環していることを明らかに

    JAMSTEC プレスリリース

    2021/12

  10. JAMSTECなど、EEZ内で炭素大循環の痕跡を発見

    環境展望台 国内ニュース

    2021/12

    Type: Internet

  11. 海洋研究開発機構・東北大・新潟大など、超深海の変質したマントル岩石の内部で炭素を含む海水が循環していることを解明

    日本経済新聞

    2021/12

    Type: Newspaper, magazine

  12. 東北大・海洋研究開発機構・新潟大、沈み込み帯のマントル起源である蛇紋岩体に炭酸塩脈が発達していることを発見

    日本経済新聞

    2021/08/26

    Type: Newspaper, magazine

  13. 沈み込み帯における二酸化炭素の固定化がマントルの破壊を引き起こす ― 炭素の循環とプレート境界での地震現象との関係性を示唆 ―

    東北大学　2021年のプレスリリース・研究成果

    2021/08

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    炭酸塩または有機物起源の炭質物として1兆トンを超える炭素が、毎年、プレートとともに沈み込んでいます。地球内部の炭素循環は、表層環境に大きな影響を与えますが、沈み込み帯付近でのその実態はよくわかっていません。 東北大学大学院環境科学研究科の岡本敦教授、宇野正起助教、大学院生の吉田一貴氏、海洋研究開発機構の大柳良介日本学術振興会特別研究員（現、国士舘大学講師）、新潟大学理学部のマドスーダン サティシュクマール教授、鹿島建設株式会社の清水浩之博士は、沈み込み帯のマントル起源である蛇紋岩体（マントルが水を吸収した岩体）に炭酸塩脈が発達していることを発見し、産状の観察、化学分析と熱力学的解析を行いました（図1, 2）。その結果、この岩体は均質に蛇紋岩化したのちに、破壊が起こりながら複数の炭酸塩鉱物（二酸化炭素を結晶内に含む鉱物）が析出していることを見出しました（図3）。さらに、この蛇紋岩の炭酸塩化は、固体体積が収縮しながら脱水する反応で、間隙水圧の上昇が起こるために、き裂形成・物質移動・反応が自己促進的に進行することをつきとめました（図4）。この反応が起こる、沈み込み帯のマントルの最も浅い部分では、スロースリップなどの地震現象が起こっており、地球内部の炭素循環とプレート境界の流体化学と地震活動を結びつける新しい研究の解明が期待されます。 本成果は、2021年8月3日、英国Nature Research社が発行する科学誌Communications Earth & Environmentに掲載されました。

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Academic Activities 5

  1. 日本地質学会第132年学術大会「変成岩とテクトニクス」セッションコンビーナー

    2025/09/14 - 2025/09/16

  2. 日本地質学会第131年学術大会「変成岩とテクトニクス」セッションコンビーナー

    2024/09/08 - 2024/09/10

    Activity type: Academic society, research group, etc.

  3. 日本地質学会第130年学術大会「変成岩とテクトニクス」セッションコンビーナー

    2023/09 -

    Activity type: Academic society, research group, etc.

  4. 日本地質学会第129年学術大会「変成岩とテクトニクス」セッションコンビーナー

    2022/09 -

    Activity type: Academic society, research group, etc.

  5. 日本地質学会第125年学術大会「岩鉱一般」セッションコンビーナー

    2018/09 -

    Activity type: Academic society, research group, etc.