Updated on 2024/02/06


Graduate School of Science Department of Geosciences Associate Professor
School of Science Department of Geosciences
Associate Professor
Institute of Science


  • Graduate School of Science Department of Geosciences 

    Associate Professor  2022.04 - Now

  • School of Science Department of Geosciences 

    Associate Professor  2022.04 - Now


  • 博士(理学) ( Osaka University )

Research Areas

  • Natural Science / Solid earth sciences

Research Interests

  • Deformation of crustal rocks

  • Deformation microstructure

  • Naturally deformed rocks

  • Rock mechanics

  • Rock deformation experiment

  • Water in rocks and minerals

  • Structural geology

Professional Memberships

  • The Geological Society of Japan

    2009.06 - Now

  • American Geophysical Union

    2007.08 - Now

  • Japan Association of Mineralogical Sciences

    2006.06 - Now

  • Japan Geoscience Union

    2006.01 - Now

Job Career (off-campus)

  • Osaka Metropolitan University   Department of Geosciences

    2022.04 - Now

  • Kobe University   Department of Planetology

    2020.04 - 2022.03

  • Kobe University   Research Center for Inland Seas   Researcher

    2019.06 - 2020.03

  • Osaka City University   Department of Geosciences

    2018.04 - 2019.05


  • Water release and homogenization by dynamic recrystallization of quartz Reviewed

    Junichi Fukuda, Takamoto Okudaira, Yukiko Ohtomo

    Solid Earth   14 ( 4 )   409 - 424   2023.04( ISSN:18699510

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    Authorship:Lead author, Corresponding author   Publishing type:Research paper (scientific journal)  

    Abstract. To evaluate changes in water distribution generated bydynamic recrystallization of quartz, we performed infrared (IR) spectroscopymapping of quartz in deformed granite from the Wariyama uplift zone in NEJapan. We analyzed three granite samples with different degrees ofdeformation: almost undeformed, weakly deformed, and strongly deformed.Dynamically recrystallized quartz grains with a grain size of∼10 µm are found in these three samples, but thepercentages of recrystallized grains and the recrystallization processes aredifferent. Quartz in the almost-undeformed sample shows wavy grainboundaries, with a few bulged quartz grains. In the weakly deformed sample,bulging of quartz, which consumed adjacent host quartz grains, forms regionsof a few hundred micrometers. In the strongly deformed sample, almost allquartz grains are recrystallized by subgrain rotation. IR spectra of quartzin the three samples commonly show a broad water band owing to H2Ofluid at 2800–3750 cm−1, with no structural OH bands. Water contents inhost quartz grains in the almost-undeformed sample are in the range of40–1750 wt ppm, with a mean of 500±280 wt ppm H2O. On theother hand, water contents in regions of recrystallized grains, regardlessof the recrystallization processes involved, are in the range of 100–510 wt ppm, with a mean of 220±70 wt ppm; these values are low andhomogeneous compared with the contents in host quartz grains. These low watercontents in recrystallized regions also contrast with those of up to 1540 wt ppm in adjacent host grains in the weakly deformed sample. Watercontents in regions of subgrains are intermediate between those in host andrecrystallized grains. These results for water distribution in quartz implythat water was released by dynamic recrystallization.

    DOI: 10.5194/se-14-409-2023

  • Water release and homogenization by dynamic recrystallization of quartz

    Fukuda, J., Okudaira, T., Ohtomo, Y.

    EGUsphere [preprint]   2023.01

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    Authorship:Lead author, Corresponding author   Publishing type:Research paper (scientific journal)   International / domestic magazine:International journal  

    DOI: 10.5194/egusphere-2022-1487

  • Enhancement of ductile deformation in polycrystalline anorthite due to the addition of water Reviewed

    Junichi Fukuda, Jun Muto, Sanae Koizumi, Sando Sawa, Hiroyuki Nagahama

    Journal of Structural Geology   156   104547 - 104547   2022.02( ISSN:0191-8141

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    Authorship:Lead author, Corresponding author   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.jsg.2022.104547

  • Development of dynamic recrystallization of quartz and change in water contents

    FUKUDA Junichi, OKUDAIRA Takamoto, OHTOMO Yukiko

    Annual Meeting of the Geological Society of Japan   2022 ( 0 )   50   2022( ISSN:13483935

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  • A centennial-resolution terrestrial climatostratigraphy and Matuyama–Brunhes transition record from a loess sequence in China Reviewed

    Masayuki Hyodo, Kenta Banjo, Tianshui Yang, Shigehiro Katoh, Meinan Shi, Yuki Yasuda, Jun-ichi Fukuda, Masako Miki, Balázs Bradák

    Progress in Earth and Planetary Science   7 ( 26 )   1 - 18   2020.12

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    Publishing type:Research paper (scientific journal)  

    <title>Abstract</title>Terrestrial records of the last geomagnetic reversal often have few age constraints. Chronostratigraphy using suborbital-scale paleoceanic events during marine isotope stage 19 may contribute to solving this problem. We applied the method to an 8 m long, high-resolution paleomagnetic record from a loess sequence in China and revealed millennial-to-sub-centennial scale features of the Matuyama–Brunhes (MB) transition. All samples were subjected to progressive thermal demagnetization with 14–15 steps up to 650–680 °C. As a result, 96% of the samples yielded a high-quality remanent magnetization. The MB transition terminated with a 75 cm thick zone with nine polarity flips. The polarity flip zone, dated at about 779–777 ka, began between the warm events “I” and “J” and terminated at the end of the cooling event coincident with the lowest axial-dipole strength interval. Most polarity flips occurred within 70 years. The virtual geomagnetic poles (VGPs) in the upper polarity flip zone clustered in the SW Pacific region, where the MB transitional VGPs from lavas of the Hawaiian and Canary Islands and lacustrine deposits of Java also clustered. These sites were probably dominated by dipolar fields. The absence of transitional fields across polarity flips implies a short time span for averaging fields due to a thin loess-magnetization lock-in zone. The reverse-to-normal polarity reversal dated at about 778 ka in Lingtai occurred at the end of the SW Pacific VGP zone, an important key bed for MB transition stratigraphy. The reversal is a good candidate for the main MB boundary. We found an excursion at about 766 ka spanning about 1 ka.

    DOI: 10.1186/s40645-020-00337-z

    Other URL: https://link.springer.com/article/10.1186/s40645-020-00337-z/fulltext.html

  • Water distribution in quartz schists of the Sanbagawa Metamorphic Belt, Japan: infrared spectroscopic mapping and comparison of the calibrations proposed for determining water contents Reviewed

    Jun-ichi Fukuda, Ichiko Shimizu

    Earth, Planets and Space   71 ( 136 )   1 - 14   2019.12

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    Authorship:Lead author, Corresponding author   Publishing type:Research paper (scientific journal)  

    <title>Abstract</title>We evaluated water distributions in deformed quartz in schists along the Asemi River, Central Shikoku, in the Sanbagawa Metamorphic Belt, Japan, using infrared spectroscopic (IR) mapping. The water trapped in quartz as molecular H<sub>2</sub>O showed a broad IR absorption band at 2800–3750 cm<sup>−1</sup>. A necessary step before assessing the quartz water content was to evaluate and compare six previously proposed IR calibrations in terms of the molar absorption coefficients of H<sub>2</sub>O (L/mol H<sub>2</sub>O cm<sup>2</sup>). The coefficients vary from 24,100 to 89,000 L/mol H<sub>2</sub>O cm<sup>2</sup>, and the values of the coefficients show a rough increase with increasing component of structural –OH in the IR spectra. We used Paterson’s calibration, which does not require input regarding the mineral species, but which was modified in his paper for measurements of molecular H<sub>2</sub>O in quartz. The absorption coefficient is 38,000 L/mol H<sub>2</sub>O cm<sup>2</sup>. IR mapping was performed on Sanbagawa metamorphic rocks with increasing grades of metamorphism, where the mean grain size of quartz increases from ~ 40 to ~ 120 µm. The absorption bands that are only from the quartz can be distinguished on the basis of microstructural observations and the corresponding mapping results. The IR spectra of quartz commonly show dominant molecular H<sub>2</sub>O bands at 2800–3750 cm<sup>−1</sup> with no additional bands associated with crystalline –OH when only quartz is measured. The water contents of quartz in all our samples were 40–310 ppm, and these values are about one-third of previously reported values measured using point analyses with the unified Paterson’s calibration. This difference seems to reflect the incorporation of phyllosilicates in previous measurements that showed a broad band around 3600 cm<sup>−1</sup>. The lowest and highest water contents in our quartz samples are associated with intragranular water and grain boundary water, respectively. We estimated the grain boundary widths to be at most ~ 10 nm on the basis of the water contents at grain boundaries.

    DOI: 10.1186/s40623-019-1117-4

    Other URL: http://link.springer.com/article/10.1186/s40623-019-1117-4/fulltext.html

  • Experimental grain growth of quartz aggregates under wet conditions and its application to deformation in nature Reviewed

    Junichi Fukuda, Hugues Raimbourg, Ichiko Shimizu, Kai Neufeld, Holger Stünitz

    Solid Earth   10 ( 3 )   621 - 636   2019.05

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    Authorship:Lead author, Corresponding author   Publishing type:Research paper (scientific journal)  

    Abstract. Grain growth of quartz was investigated using two quartz samples
    (powder and novaculite) with water under pressure and temperature
    conditions of 1.0–2.5 GPa and 800–1100 ∘C. The compacted powder
    preserved a substantial porosity, which caused a slower grain growth than in
    the novaculite. We assumed a grain growth law of
    with grain size d (µm) at time t (seconds), initial grain size
    d0 (µm), growth exponent n, a constant k0 (µmn MPa−r s−1), water fugacity
    fH2O (MPa) with the exponent r,
    activation energy Q (kJ mol−1),
    gas constant R, and temperature T in
    Kelvin. The parameters we obtained were n=2.5±0.4, k0=10-8.8±1.4, r=2.3±0.3, and Q=48±34 for the powder and n=2.9±0.4, k0=10-5.8±2.0, r=1.9±0.3, and Q=60±49 for the novaculite. The grain growth parameters obtained for
    the powder may be of limited use because of the high porosity of the powder
    with respect to crystalline rocks (novaculite), even if the differences
    between powder and novaculite vanish when grain sizes reach ∼70 µm. Extrapolation of the grain growth laws to natural conditions
    indicates that the contribution of grain growth to plastic deformation in the
    middle crust may be small. However, grain growth might become important for
    deformation in the lower crust when the strain rate is &lt; 10−12 s−1.

    DOI: 10.5194/se-10-621-2019

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  • 脆性-塑性遷移領域における石英の破壊と微小剪断


    日本地質学会第130年学術大会  2023.09 

  • 花崗岩質マイロナイト中の動的再結晶石英粒子の含水量分布:大阪府岸和田地域の領家帯内部剪断帯の場合


    日本鉱物科学会2023年年会  2023.09 

  • Water in deformed quartz: Changes in contents and distributions by development of dynamic recrystallization

    Junichi Fukuda, Takamoto Okudaira, Yukiko Ohtomo