Award type：Award from publisher, newspaper, foundation, etc.  Country：Japan

Country：Japan

受賞論文："A new approach to develop the Raman carbonaceous material geothermometer for low-grade metamorphism using peak width", Island Arc 2015, vol. 23, pp. 33-50

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Association of Mineralogical Sciences  

<p>Needle-shaped rutile inclusions occur in garnet within the quartz-eclogite at Mt. Gongen in the Sanbagawa belt, central Shikoku. They are approximately 5-25 µm along the long axis and are typically oriented along three directions, each intersecting at 120°. This indicates that the needle-shaped rutile is a lamella exsolved from the garnet. Garnet with needle-rutile inclusions is restricted to the quartz-poor domain of the quartz eclogite sample, which consist of quartz, garnet, omphacite, phengite, epidote, kyanite, and hornblende. Garnet grains with rutile lamellae show a composition of the almandine-pyrope series with 14-21 mol% grossular content. Rutile exsolution lamellae were concentrated in the range of 27-34 mol% pyrope of garnet crystals. The garnet host with rutile lamellae has a higher TiO₂ content (TiO₂ = 0.06-0.19 wt%) than those in rutile-free areas. These chemical compositional characteristics suggest that Ti was incorporated into the crystal structure during garnet growth and subsequently partially exsolved as rutile lamellae during the retrograde stage. Rutile lamellae in garnet have generally been regarded as indicators of ultrahigh-pressure metamorphism, but the present report from quartz-eclogite of the Sanbagawa belt, where no coesite has been found, provides evidence in a natural sample that the appearance of rutile exsolution lamellae is not necessarily under ultrahigh-pressure conditions.</p>

DOI： 10.2465/jmps.221219d

CiNii Research

Language：English   Publishing type：Research paper (bulletin of university, research institution)  

Minerals are solid state nuclear track detectors - nuclear recoils in a
mineral leave latent damage to the crystal structure. Depending on the mineral
and its temperature, the damage features are retained in the material from
minutes (in low-melting point materials such as salts at a few hundred degrees
C) to timescales much larger than the 4.5 Gyr-age of the Solar System (in
refractory materials at room temperature). The damage features from the $O(50)$
MeV fission fragments left by spontaneous fission of $^{238}$U and other heavy
unstable isotopes have long been used for fission track dating of geological
samples. Laboratory studies have demonstrated the readout of defects caused by
nuclear recoils with energies as small as $O(1)$ keV. This whitepaper discusses
a wide range of possible applications of minerals as detectors for $E_R \gtrsim
O(1)$ keV nuclear recoils: Using natural minerals, one could use the damage
features accumulated over $O(10)$ Myr$-O(1)$ Gyr to measure astrophysical
neutrino fluxes (from the Sun, supernovae, or cosmic rays interacting with the
atmosphere) as well as search for Dark Matter. Using signals accumulated over
months to few-years timescales in laboratory-manufactured minerals, one could
measure reactor neutrinos or use them as Dark Matter detectors, potentially
with directional sensitivity. Research groups in Europe, Asia, and America have
started developing microscopy techniques to read out the $O(1) - O(100)$ nm
damage features in crystals left by $O(0.1) - O(100)$ keV nuclear recoils. We
report on the status and plans of these programs. The research program towards
the realization of such detectors is highly interdisciplinary, combining
geoscience, material science, applied and fundamental physics with techniques
from quantum information and Artificial Intelligence.

DOI： 10.1016/j.dark.2023.101245

Scopus

arXiv

Other Link： http://arxiv.org/pdf/2301.07118v2

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1089/ast.2021.0155

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Association of Mineralogical Sciences  

<p>We estimated the protolith age and peak metamorphic temperature of the Yokokawagawa metamorphic rocks (YMR) east of the Itoigawa-Shizuoka Tectonic Line using detrital zircon U-Pb dating and Raman carbonaceous material geothermometry, respectively. U-Pb dating of a psammitic rock yielded a youngest age of ∼ 100 Ma, which corresponds to the protolith age. Raman carbonaceous material geothermometry results for five pelitic rock samples give metamorphic temperatures of ∼ 350-380 °C. The protolith age is consistent with those of the Sanbagawa metamorphic rocks (SMR), strongly indicating that the YMR are an extension of the SMR. The increase in peak temperature toward intrusive rocks along the eastern margin of the YMR may indicate that the relatively young ages yielded by previous K-Ar dating of the YMR reflect thermal resetting due to contact metamorphism.</p>

DOI： 10.2465/jmps.221215

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CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.chemgeo.2022.121049

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2113/2022/3899340

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3749/canmin.2000097

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/iar.12467

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

<p> Constraining the temperature and pressure conditions under which rocks were formed is important information for understanding the environment in the Earth's interior. In this presentation, I will introduce Raman geothermobarometers (Raman carbonaceous material geothermometer and Quartz Raman geobarometer) based on Raman spectroscopy, which is independent of thermodynamic methods traditionally used in the field of petrology. The applications of these techniques and their future possibilities will be presented.</p>

DOI： 10.14862/geochemproc.69.0_135

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

The pattern and timing of tectonic discontinuity and partial melting in the Garhwal Himalaya, resulting from the India-Asia collision, are crucial factors for understanding the evolution of the Himalayan orogen, but these parameters remain poorly constrained. Middle-to high-grade metamorphic rocks from the Main Central Thrust (MCT) zone and the High Himalaya Crystalline Sequence (HHCS) along the Bhagirathi valley in northwest India have been investigated in this study. The primary mineral assemblage of the gneisses and migmatites in the HHCS is garnet + biotite + white mica + quartz + kyanite + rutile +/- ilmenite +/- sillimanite. The metamorphic grade at thermal peak rapidly increases upwards across the MCT from garnet schists (515-550 degrees C, 8-9 kbar) in the footwall to garnet-bearing migmatite (705-735 degrees C, 10-13 kbar) in the hanging wall. The P-T condition decreased upwards in kyanite gneiss of the lower HHCS (690 degrees C, 8.3 kbar), yielding a high field pressure gradient near the MCT. The prominent metamorphic discontinuity could have been caused by the southward extrusion of the HHCS along with the MCT. The base of the HHCS experienced high-grade metamorphism at 38-25 Ma, mainly at 31.9 +/- 0.5 Ma. The new data, combined with previous studies, suggest that the prominent metamorphic discontinuity is characterized by the different periods of peak metamorphism and the overprint in the hanging wall (Eocene-Oligocene metamorphism and Early Miocene overprint) and footwall (Early Miocene metamorphism and Late Miocene to Pliocene overprint) of the MCT. The second metamorphic discontinuity occurred near the migmatite zone in the lower-middle HHCS, which experienced the anatexis (690-740 degrees C, 7-9 kbar) at 37-25 Ma, mainly at 33.9 +/- 1.2 Ma. The Bhagirathi HHCS experienced a regional Barrovian-type Eohimalayan metamorphism associated with fluid-present melting of muscovite + plagioclase + quartz + H2O -> melt +/- kyanite at 34-32 Ma without a strong Miocene overprint. The period of partial melting is significantly older than the intrusion of ca. 22 Ma Early Miocene Gangotri leucogranites at the top of the HHCS. Protracted periods of crystallization (38-22 Ma) indicate a long duration of more than ca. 15 Myr of anatexis, from initiation of migmatization to pluton formation in the Bhagirathi HHCS. The protracted fluid-present melting and subsequent rapid exhumation in the Bhagirathi HHCS could be associated with heterogeneous extrusion forming the tectonic discontinuity in the lower-middle HHCS. The metamorphic grade decreased towards the upper HHCS (620 degrees C, 6.5 kbar) across the Jhala Normal Fault where occurs in the right-way-up sequence. On the other hand, in the central Himalaya, the thrusting occurred between upper HHCS and lower-middle HHCS in the inverted metamorphic sequence. The Early Miocene migmatites in the footwall of the significant tectonic discontinuity are dominant, and diachronous extrusion accompanied with the fluid-absent melting reactions is the common mechanism to exhume the HHCS, unlike the heterogeneous extrusion in the northwest Himalaya.

DOI： 10.1016/j.lithos.2021.106488

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Geophysical Union (AGU)  

DOI： 10.1029/2021GC010013

Web of Science

Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1029/2021GC010013

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Tokyo Geographical Society  

<p> In the 1950s, the aim of the original mantle drilling projects was to obtain oceanic mantle samples in order to address the unanswered question of what constitutes the Earth's mantle. However, in the 21st century, it is widely accepted that the uppermost mantle is mainly composed of peridotite. Now, the challenge of mantle drilling is to understand crucial unsolved issues of earth science. Today's Earth is different from other planets due to the existence of life and plate tectonics. It is emphasized that mantle drilling is the only way to obtain the oceanic crust from top to bottom and an active mantle sample from an oceanic plate. The crucial issues that can only be addressed by mantle drilling are: (1) limits of life in an oceanic plate and its controlling factors, and (2) formation process of an oceanic plate and its modification. Modification of an oceanic plate, especially the weakening of plate strength, is required for plate tectonics. These two issues are interrelated. Long seismic profiles of oceanic plates reveal the diversity of Moho seismic reflection regions: clear, unclear, diffuse and non-Moho regions. Faults and/or fracturing in oceanic plates and subsequent seawater flow can modify oceanic plates locally, probably causing the diversity of oceanic Moho, as well as the rheological behavior of oceanic plates. Fluid flows along faults/fractures also extend the biosphere of oceanic plates. The first drilling sample should be a reference to the oceanic crust and the uppermost mantle, and define the nature of the Moho at the site, as well as constrain reasons for the diversity of the Moho in other areas. Deep sampling, such as mantle drilling in an old oceanic plate, can penetrate the biosphere/non-biosphere boundary, which tells us about the controlling factors of the limit of life. This information may help us find extraterrestrial life. After mantle drilling is completed, the borehole is the only window from the ocean floor to the mantle. An in-situ mantle observatory in the mantle hole to monitor plate movement and fluid flow with biological activity within an oceanic plate is also suggested. Detecting geoneutrinos at the mantle site allows the amounts and distributions of radioactive elements from the Earth's mantle to be measured. These provide basic information on the Earth's heat sources and the evolutionary history of the mantle.</p>

DOI： 10.5026/jgeography.130.483

Web of Science

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Structural analyses based on field survey and peak-temperature estimations using Raman spectra of carbonaceous-material thermometry were conducted for the Cretaceous subduction complexes on the central Kii Peninsula, southwest Japan, where there is a direct contact region between the Sanbagawa high-P/low-T Metamorphic Complex (MC) and the Shimanto Accretionary Complex (AC). In the study area, the Kosoku, Iro, and Mugitani complexes are arranged in descending order of structural position. The Kosoku and Iro complexes record exhumation-related deformation, which produced schistosity, stretching lineation, and folds, and peak temperatures of 280-440 degrees C. In contrast, the Mugitani Complex records both earlier accretion-related deformation which produced block-in-matrix structures and later exhumation-related deformation, as well as peak temperatures of 280-290 degrees C. The Mugitani Complex shares deformation characteristics with both the Shimanto AC and the Sanbagawa MC, and covers the interval from the upper temperatures of the Shimanto AC to the lower temperatures of the Sanbagawa MC. In addition, the two types of deformation differ in their kinematic patterns, suggesting that they took place diachronously in different tectonic settings in the subduction zone. We propose that exhumation-related Sanbagawa deformation occurred in a warm tectonic environment, such as ridge approach to the subduction zone.

DOI： 10.1016/j.jseaes.2021.104791

Web of Science

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

Raman CM geothermometry applied to 126 samples of pelitic schists collected over an area of 11 km x 7 km reveals the thermal structure of the Asemigawa region of the Sanbagawa metamorphic belt, southwest Japan in unprecedented detail. In general, the estimated temperatures gradually increase from south to north in the range of 288-553 degrees C. However, a temperature gap from similar to 380 to similar to 440 degrees C is identified near the boundary between the chlorite and garnet zones. This temperature region matches the depth of the continental Moho of the Sanbagawa subduction zone. The temperature gradient in the higher-temperature domain is higher than that in the lower-temperature domain, and large-scale tight folds that affect the thermal structure are developed in the high-grade units and in the vicinity of the temperature discontinuity. These geological structures probably reflect that the exhumed slab units was dammed at the Moho depth due to the upward movement being impeded by increase in the coupling strength of the overlying rocks associated with exhumation from beneath serpentinite rocks to a shallower domain overlain by crustal rocks. Changes in the coupling strength along the subduction boundary led the strong folding at the higher-temperature domain and the pre-formed foliation developed at the Moho depth may have acted as the tectonic boundary, resulting in a temperature discontinuity. These results will contribute to elucidating various geological phenomena occurring in the forearc regions of modern subduction zones.

DOI： 10.1111/jmg.12584

Web of Science

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Geological Society of Japan  

DOI： 10.5575/geosoc.2021.0010

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Association of Mineralogical Sciences  

<p>Olivine is a major mineral in ultramafic and mafic rocks. Due to the higher Mg/Fe partition coefficient of olivine than the coexisting phases, the occurrences of Mg–poorer olivine grains, especially with Mg#[= Mg/(Mg + Fe²⁺)] = 0.2–0.6, are rarely reported, and thus, their spectroscopic data are limited. Fe–rich olivine phenocrysts showing compositional zoning with Mg# = ~ 0.5 (core) and ~ 0.3 (rim) and microphenocrysts with Mg# = ~ 0.4 (core) and ~ 0.2 (rim) occur in basaltic trachyandesite of Miocene Shitara volcanic rocks in central Japan. These olivine grains were investigated by Raman spectroscopy. Combining our data with the published values, we have revised the equation for Mg#–Raman spectrum relationship proposed by Mouri and Enami (2008) as follows: Mg# = 0.005446<i>ω</i> ² − 0.20259<i>ω</i> + 1.8442 (correlation coefficient <i>r</i> ² = 0.984), where <i>ω</i> is the difference between the doublet peak positions (<i>κ</i>₂ − <i>κ</i>₁).</p>

DOI： 10.2465/jmps.201204

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

The stabilization of coesite is a diagnostic indicator of ultrahigh-pressure metamorphism and in many cases it implies that a rock has been subducted to a minimum depth of 80 km. Coesite typically occurs as rare relicts in rigid host minerals, but most commonly transforms into alpha-quartz pseudomorphs during exhumation. The abundance of coesite-bearing rocks in orogens worldwide is a contentious issue in the petrological community, despite evidence from numerical modeling that suggests that coesite formation should be a common geological process during ultrahigh-pressure metamorphism. This knowledge gap must be addressed to improve the understanding of the geological aspects of subductionzone geodynamics. Here we report that minuscule coesites (<20 mu m) occur as abundant inclusions in garnet-rich layers from the Italian Western Alps. The discovery of such intact inclusions may fill the gaps in the predicted and observed abundances of coesite worldwide. Through integrated approaches with resolutions down to the nano-scale, we show that these garnet-hosted inclusions are composed entirely of coesite. Our results suggest that common coesite-derived quartz pseudomorphs are less typical structures in ultrahigh-pressure metamorphic rocks and the minuscule coesite in many rocks may be overlooked because of its size. These findings open up new research directions for constraining the extent of deeply subducted rocks and their rheology. (C) 2021 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.epsl.2021.116763

Web of Science

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.5026/jgeography.130.85

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Geological Society of Japan  

<p>The Shibukawa region of the Sanbagawa belt, central Japan, is one of the historic jadeite localities in Japan. Although its petrological and mineralogical characteristics of the locality were briefly reported over 35 years ago, no further studies have been conducted since the disappearance of the jadeite-bearing outcrop. Recently, jadeite was discovered within a veinlet in a host dunite boulder, a member of an ultrabasic body that is surrounded by the Sanbagawa crystalline schists in the Shibukawa region. The veinlet is composed mainly of diopside, OH-bearing grossular, jadeite, chlorite, pargasite and serpentine. Relict olivine and spinel, which were probably members of the host dunite, rarely occur in the veinlet. The jadeite grains vary from <1 to 50 µm in size, and occur as patchy aggregates with amoeba-shaped grossular grains. The jadeite grains have Na₂O and Al₂O₃ contents of 14.7-15.4 wt.% and 24.3-25.5 wt.%, respectively, and are 91-98% jadeite contents [(Na-Fe³⁺)×100].</p>

DOI： 10.5575/geosoc.2020.0050

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1111/iar.12419

Web of Science

Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/iar.12419

Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2021.0_221

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.jsg.2020.104151

Web of Science

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Association of Mineralogical Sciences  

<p>Attenuated total reflection infrared (ATR–IR) spectroscopy allows measurements to be made directly from the surface of one–sided, diamond polished thin sections of geological samples. This method greatly reduces the sample preparation time when compared to other IR spectroscopy methods and opens the possibility of using infrared spectroscopy to study thin–section scale microstructures. ATR–IR spectroscopy of antigorite, chrysotile, and lizardite in samples from the Mt. Shiraga serpentinite body, central Shikoku, SW Japan, reveals clear spectral differences in the 650–1250 cm⁻¹ region associated with the vibration of the Si–O bonds in SiO₄ tetrahedra and in the 3300–3750 cm⁻¹ region associated with the vibration of the O–H bond in MgO₂(OH)₄ octahedra. A data–processing algorithm developed in this study allows the absorbance intensity and wavenumber of a particular absorbance peak to be used to create serpentine mineral phase maps based on the highest intensity Si–O absorbance bands for antigorite, chrysotile, and lizardite. Our methodology can be used to map serpentinite microstructures in thin sections illustrating the potential of ATR–IR as a relatively un–explored analytical tool in petrological studies. A combination of ATR–IR and electron microprobe data shows that for antigorite the wavenumber of the O–H absorbance band is correlated with the Fe content. Metamorphic reactions of serpentine minerals play a key role in the hydrodynamics of the earth’s lithosphere, and the new information on serpentine mineral hydroxyl group behavior obtained by applying the technique outlined in this study are of great potential interest to researchers in a wide range of different fields.</p>

DOI： 10.2465/jmps.190807

Web of Science

CiNii Research

Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (other academic)   Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

<p></p>

DOI： 10.14862/geochemproc.67.0_131

CiNii Research

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2019.0_119

CiNii Research

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：GEOLOGICAL SOC AMER, INC  

The crystallinity of carbonaceous material (CM) in metasedimentary schists in the Yuli belt, eastern Taiwan, shows unusual diversity. The difference between the maximum and minimum temperatures estimated by a Raman CM geothermometer reaches 200 degrees C, which is much wider than those in other metamorphic belts and contact aureoles. In light of these results, we considered two possible explanations: (1) a mixture of detrital and metamorphic graphite grains, and (2) a mixture of different reactive CM during short-lived metamorphism. One sample shows a near-bimodal peak, suggesting the former hypothesis, while the other two samples show a continuous single peak, suggesting the latter possibility. Detailed analyses of CM crystallinities have the potential to extract information relating not only to the peak metamorphic temperature, but also to the pre-metamorphic history or the duration of heating in a metamorphic belt.

DOI： 10.1130/G45934.1

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CiNii Research

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

© 2019, The Author(s). The microtexture of graphite exposed on the polished surface was studied using confocal laser scanning microscopy, laser Raman spectroscopy, and focused ion beam–transmission electron microscopy (FIB–TEM) to elucidate the effect on surface condition and crystallinity of graphite by polishing process. The polished surface of the graphite was divided into a flat part with no irregularities and a grooved band with a width of < 1 μm and a depth of < 100 nm. Raman analyses revealed that the original structure of the graphite covered by the host mineral was a well-ordered graphite, whereas the polished graphite at the surface had a reduced crystallinity, particularly in the flat part of the sample. Based on scanning TEM observations of an ultra-thin FIB section, fractures that developed during sample preparation were concentrated in the region extending from the surface to a depth of 1 μm. Furthermore, graphite sheets were peeled away by shearing, with scraped graphite sheets filling in the gap. Our results demonstrate that the original microtexture of graphite was easily deformed by shearing during polishing, and careful attention should be paid to sample preparation. In addition, we also need to pay more attention to the effects of natural shearing such as faulting on the graphite or sheet-like minerals. [Figure not available: see fulltext.].

DOI： 10.1186/s40645-019-0271-4

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Scopus

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/jmg.12456

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2019.0_98

CiNii Research

Authorship：Lead author   Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2019.0_116

CiNii Research

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2019.0_399

CiNii Research

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

<p></p>

DOI： 10.14862/geochemproc.66.0_242

CiNii Research

Authorship：Lead author   Language：Japanese   Publishing type：Research paper (other academic)   Publisher：Japan Association of Mineralogical Sciences  

Infrared spectroscopy is one of effective analytical methods for detecting water in minerals, but there was a disadvantage that it takes time to prepare samples. In this study, we used a ATR method that can analyze using ordinary rock polished thin sections. Water of several to several hundred ppm order in olivine and garnet grains was not detected, but the sharp peak at ~3700 cm^-1 was detected within the olivine porphyroclast in the ultra-mylonite. Further improvement is necessary, but it is expected that the ATR method will develop as a useful analytical method in the future.

DOI： 10.14824/jakoka.2018.0_21

CiNii Research

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2018.0_408

CiNii Research

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2018.0_126

CiNii Research

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2018.0_119

CiNii Research

Language：English   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2018.0_406

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Extremely negative delta C-13 values (as low as -48%) of blocky calcite cements filling cavities, sheet-cracks, and fractures in the basal Ediacaran cap dolostone of the Doushantuo Formation in South China have been considered as evidence for methane release possibly associated with gas hydrate destabilization in the aftermath of the terminal Cryogenian snowball Earth glaciation. Alternatively, these extremely negative delta C-13 values may have resulted from oxidation of thermogenic methane derived from localized hydrothermal activity long after the deposition of the Doushantuo cap dolostone. The latter interpretation was based on carbonate clumped isotope thermometry suggesting that the precipitation of extremely C-13-depleted calcite occurred at temperatures up to 476 degrees C (mean = 378 degrees C, n = 4) whereas carbonate fabrics with moderately negative delta C-13 values (generally &gt; -10%) were formed at much lower temperatures (mean = 112 degrees C, n = 4). To assess these competing hypotheses, we systematically investigated the petrography, carbonate carbon and oxygen isotopes, and carbonaceous material (CM) Raman spectroscopy of the Doushantuo cap carbonate. Raman geothermometry suggests that CM associated with different microfabrics and delta C-13 signatures including sedimentary fabrics with moderately negative delta C-13 values (e.g., peloids, stromatolite laminae, microbial mat fragments), diagenetic fabrics with moderately negative delta C-13 values (e.g., some void-filling or crack-filling cements), and diagenetic fabrics with extremely negative delta C-13 values (e.g., void-filling or crack-filling blocky and bladed calcites) experienced temperatures generally &lt;300 degrees C (largely 200-300 degrees C). Contrary to temperature estimates based on carbonate clumped isotopes, CM Raman geothermometry reveals that different microfabrics show largely overlapping paleotemperatures and that there is no apparent relationship between delta C-13 signatures and paleotemperatures. Whereas the origins of these extremely negative delta C-13 values remain unresolved, the Raman geothermometric data challenge the previous interpretation that they were derived from thermogenic methane related to localized hydrothermal activity at temperatures up to almost 500 degrees C that only affected the thermal history of the calcite with extremely negative delta C-13 values. Instead, the new data suggest that the analyzed microfabrics experienced the same peak temperatures &lt;300 degrees C, probably related to the burial history of the host rocks or pervasive hydrothermal activity that affected all micro fabrics in the Doushantuo cap dolostone. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.precamres.2017.06.013

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/iar.12212

Web of Science

Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

We analyzed micro-Raman spectra of carbonaceous materials (CM) in natural and experimentally deformed fault rocks from Longmenshan fault zone that caused the 2008 Wenchuan earthquake, to characterize degree of disordering of CM in a fault zone. Raman spectral parameters for 12 samples from a fault zone in Shenxigou, Sichuan, China, all show low-grade structures with no graphite. Low crystallinity and delta C-13 values (-24%o to -25%) suggest that CM in fault zone originated from host rocks (Late Triassic Xujiahe Formation). Full width at half maximum values of main spectral bands (D1 and D2), and relative intensities of two subbands (D3 and D4) of CM were variable with sample locations. However, Raman parameters of measured fault rocks fall on established trends of graphitization in sedimentary and metamorphic rocks. An empirical geothermometer gives temperatures of 160-230 degrees C for fault rocks in Shenxigou, and these temperatures were lower for highly sheared gouge than those for less deformed fault breccia at inner parts of the fault zone. The lower temperature and less crystallinity of CM in gouge might have been caused by the mechanical destruction of CM by severe shearing deformation, or may be due to mixing of host rocks on the footwall. CM in gouge deformed in high-velocity experiments exhibits slight changes towards graphitization characterized by reduction of D3 and D4 intensities. Thus low crystallinity of CM in natural gouge cannot be explained by our experimental results. Graphite formation during seismic fault motion is extremely local or did not occur in the study area, and the CM crystallinity from shallow to deep fault zones may be predicted as a first approximation from the graphitization trend in sedimentary and metamorphic rocks. If that case, graphite may lower the friction of shear zones at temperatures above similar to 300 degrees C, deeper than the lower part of seismogenic zone. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.tecto.2017.01.015

Web of Science

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC GEOLOGICA ITALIANA  

This paper reports the major, minor and trace element abundances and Nd isotope compositions of bulk rock samples of eclogites from the Stak Valley in northwestern Himalaya and discusses their protolith. Major element compositions confirm the basaltic nature of the protolith. Trace element abundances normalized to the primitive mantle show almost flat patterns at ten times the primitive mantle values with slightly high concentrations of Th and light rare earth elements. These patterns are similar to those of enriched MORBs. Neodymium isotope compositions are chondritic and the values of eNd lie between those of MORB and old Indian continental crust. Immobile trace element contents of Stak eclogites are similar to those of the Permian Panjal Traps and significantly different from those of the Deccan Traps erupted at 73-66 Ma in the northwestern Indian plate, suggesting that the Panjal Traps is the protolith of the Stak eclogites. The protoliths of ultra-high pressure eclogites in the Kaghan and Tso Moran massifs in northwestern Himalaya are also interpreted to be the Panjal Traps. The results of this study suggest that a large Permian igneous province developed at the northwestern margin of the Indian plate before the collision with the Eurasian continent.

DOI： 10.3301/IJG.2015.41

Web of Science

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

<p>The ubiquitous occurrence of sedimentary-pore-fluid-like halogens and noble gases in metamorphic rocks from the Sanbagawa belt is best explained by a model where water with a pore-fluid signature is incorporated into subducting oceanic lithosphere as serpentine along fracture zones developed at the outer rise and released to the mantle wedge associated with the serpentine dehydration without significant modification in the halogen and noble gas compositions.</p>

DOI： 10.14862/geochemproc.64.0_36

CiNii Research

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

Program canceled for typhoon. However, This presentation was performed on the special session. This abstract is quotable and viewable on PDF.

DOI： 10.14863/geosocabst.2017.0_378

CiNii Research

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Geological Society of Japan  

Program canceled for typhoon. However, This presentation was performed on the special session. This abstract is quotable and viewable on PDF.

DOI： 10.14863/geosocabst.2017.0_379

CiNii Research

Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/jmg.12203

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.lithos.2015.10.022

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.epsl.2015.05.037

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.150713a

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.140403

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/iar.12075

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/iar.12057

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2138/am.2014.4427

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/j.1525-1314.2010.00919.x

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/j.1525-1314.2010.00896.x

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.090217

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/j.1440-1738.2009.00690.x

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Poster presentation  

Venue：京都大学   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Poster presentation  

Venue：京都大学   Country：Japan  

Event date： 2023.9

Language：English   Presentation type：Poster presentation  

Venue：京都大学   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪公立大学   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Poster presentation  

Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Poster presentation  

Venue：幕張   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：新潟大学   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：高知大学   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Poster presentation  

Venue：幕張   Country：Japan  

Event date： 2022.5

Language：English   Presentation type：Oral presentation (general)  

Venue：幕張   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張   Country：Japan  

Event date： 2022.3

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン  

Event date： 2021.9

Language：Japanese   Presentation type：Poster presentation  

Venue：オンライン  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：オンライン（Youtube）  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：オンライン（zoom）  

Event date： 2021.5 - 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：online  

Event date： 2021.5 - 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：online  

Event date： 2021.5 - 2021.6

Language：English   Presentation type：Poster presentation  

Venue：online  

Event date： 2021.5 - 2021.6

Language：English   Presentation type：Poster presentation  

Venue：online  

Event date： 2021.5 - 2021.6

Language：English   Presentation type：Poster presentation  

Venue：online  

Event date： 2021.3

Language：English   Presentation type：Poster presentation  

Event date： 2020.11

Language：Japanese   Presentation type：Poster presentation  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Event date： 2020.9

Language：Japanese  

Event date： 2020.9

Language：Japanese   Presentation type：Oral presentation (general)  

Event date： 2020.7

Language：English   Presentation type：Poster presentation  

Event date： 2020.7

Language：English   Presentation type：Oral presentation (invited, special)  

Event date： 2020.7

Language：English   Presentation type：Poster presentation  

Event date： 2020.7

Language：English   Presentation type：Poster presentation  

Event date： 2020.7

Language：English   Presentation type：Poster presentation  

Event date： 2020.7

Language：English   Presentation type：Poster presentation  

Event date： 2019.9

Language：Japanese   Presentation type：Poster presentation  

Venue：山口大学吉田キャンパス  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学吉田キャンパス  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学吉田キャンパス  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学吉田キャンパス  

Event date： 2019.9

Language：English   Presentation type：Poster presentation  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学  

Event date： 2019.5

Language：English   Presentation type：Oral presentation (general)  

Venue：幕張メッセ   Country：Japan  

Event date： 2019.5

Language：English   Presentation type：Poster presentation  

Venue：Makuhari Messe International Conference Hall   Country：Japan  

Event date： 2019.5

Language：English   Presentation type：Poster presentation  

Venue：Makuhari Messe International Conference Hall   Country：Japan  

Event date： 2019.5

Language：English   Presentation type：Poster presentation  

Venue：Makuhari Messe International Conference Hall   Country：Japan  

Event date： 2018.12

Language：English   Presentation type：Poster presentation  

Venue：Washington DC   Country：United States  

Event date： 2018.9

Language：Japanese   Presentation type：Poster presentation  

Venue：山形大学 小白川キャンパス   Country：Japan  

Event date： 2018.5

Language：English   Presentation type：Oral presentation (general)  

Venue：Makuhari Messe International Conference Hall   Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Makuhari Messe International Conference Hall   Country：Japan  

Event date： 2017.9

Language：Japanese   Presentation type：Poster presentation  

Venue：愛媛大学城北キャンパス   Country：Japan  

Event date： 2016.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Makuhari Messe, Chiba   Country：Japan  

Event date： 2016.5

Language：Japanese   Presentation type：Poster presentation  

Venue：Makuhari Messe, Chiba   Country：Japan  

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2015.5

Language：Japanese   Presentation type：Poster presentation  

Country：Japan  

Event date： 2015.5

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2015.5

Language：Japanese   Presentation type：Poster presentation  

Country：Japan  

The aim of this course is to help students acquire the basic knowledge of geology of Japan and understand geologic phenomena in a subduction zone.

The aim of this course is to help students acquire the necessary skill and knowledge needed to understand earth scientific phenomena in a field.

This main aims of this course to guide students in obtaining English reading ability of basic knowledge in Earth Planetary Science and cultivating capability to summarize and make presentations in these contents.

Field and microscopic observation is the most basic observation method in petrology, structural geology, and sedimentology. In this experiment, we will conduct practical training focusing on each of these fields. Several field trips will be conducted, and simple analysis of data will be acquired through laboratory experiments. The goal of this class is for students to acquire the basics of petrological experimental methods in a broad sense and to deepen their understanding of this field by analyzing the tissue and measurement data they observe in the field and in the laboratory.

Learn the fundamental knowledge of the earth's surface crust to the deep mantle-core structure and plate tectonics. This course aims to grasp the overall picture on the solid earth through learning about the physical mechanism behind the various phenomena occurring inside the earth and the relationship with a field of different academic areas.

The aim of this course is to help students to acquire an understanding of the fundamental principles of earth science, focusing on the developmental process of the solid earth, plate tectonics, atmosphere, oceans, and biosphere.

The aim of this course is to help students acquire the necessary skill and knowledge needed to understand earth scientific phenomena in a field.

Field and microscopic observation is the most basic observation method in petrology, structural geology, and sedimentology. In this experiment, we will conduct practical training focusing on each of these fields. Several field trips will be conducted, and simple analysis of data will be acquired through laboratory experiments. The goal of this class is for students to acquire the basics of petrological experimental methods in a broad sense and to deepen their understanding of this field by analyzing the tissue and measurement data they observe in the field and in the laboratory.

The aim of this course is to help students acquire the basic knowledge of geology of Japan and understand geologic phenomena in a subduction zone.

The aim of the course category is to develop the ability to analyze and understand various phenomena in the natural sciences in an interdisciplinary and comprehensive manner, and to understand the relationship between these phenomena and other academic fields.
The purpose of this course is to acquire basic knowledge about the origin and current state of our planet, the Earth, and to comprehensively understand it using physics, chemistry, and biology. The course will cover the birth of the universe, the formation of the solar system, the birth of the earth, and the subsequent changes in the rocks, minerals, and biological fossils found on the earth, by moving the scope from large to small scales of the objects and phenomena.

The aim of this course is to help students acquire the necessary skills and knowledge needed to solve global issues from the viewpoint of geology and acquire the ability to create new academic fields for the next generation.
This course is to help students acquire the abilities to understand the problem and significance of the scientific papers in relation to your research, when you read some papers.