A5041294101- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- earthquake and tectonic studies
- Geochemistry and Geologic Mapping
- Hydrocarbon exploration and reservoir analysis
- Crystal Structures and Properties
- Geological Studies and Exploration
- Geochemistry and Elemental Analysis
- X-ray Diffraction in Crystallography
- Mineralogy and Gemology Studies
- Paleontology and Stratigraphy of Fossils
- Methane Hydrates and Related Phenomena
- Geology and Paleoclimatology Research
- Crystallization and Solubility Studies
- Seismic Imaging and Inversion Techniques
- Reservoir Engineering and Simulation Methods
- Geological Formations and Processes Exploration
- Diamond and Carbon-based Materials Research
- Astro and Planetary Science
- Machine Learning in Materials Science
- Inorganic Chemistry and Materials
- Polar Research and Ecology
- Aquatic Invertebrate Ecology and Behavior
- Solid-state spectroscopy and crystallography
- Molecular spectroscopy and chirality
Kumamoto University
2015-2024
Kanazawa University
2003-2017
Kumamoto Health Science University
2011-2016
Graduate School USA
2014
Japan Patent Office
2006
Ishikawa Prefectural Nursing School
1996
Peridotite xenoliths from the Avacha volcano, Kamchatka, derived mantle beneath volcanic front of Kamchatka arc, are mainly highly depleted clinopyroxene-poor harzburgites with forsteritic olivine (Fo 90–92) and high Cr-number spinel (0·5–0·7). The peridotites have experienced metasomatism to various extents, formation metasomatic orthopyroxene replacing primary olivine, by infiltration SiO2-rich fluids. orthopyroxenes can be subdivided into two textural types; (1) radially aggregated...
Abstract We summarize chemical characteristics of chromian spinels from ultramafic to mafic plutonic rocks (lherzolites, harzburgites, dunites, wehrlites, troctolites, olivine gabbros) with regard three tectonic settings (mid‐ocean ridge, arc, oceanic hotspot). The range is distinguishable between the in terms Cr# (= Cr/(Cr + Al) atomic ratio) and Ti content. relationships are almost parallel those volcanic rocks, but content slightly lower plutonics than volcanics at a given environment....
[1] Expeditions 304 and 305 of the Integrated Ocean Drilling Program cored logged a 1.4 km section domal core Atlantis Massif. Postdrilling research results summarized here constrain structure lithology Central Dome this oceanic complex. The dominantly gabbroic sequence recovered contrasts with predrilling predictions; application ground truth in subsequent geophysical processing has produced self-consistent models for Dome. presence many thin interfingered petrologic units indicates that...
Abstract Abundant peridotite xenoliths have been found in pyroclasitics of Avacha (Avachinsky) volcano, the south Kamchatka arc, Russia. They are mostly refractory harzburgite with or without clinopyroxene: Fo olivine and Cr/(Cr + Al) atomic ratio spinel range from 91 to 92 0.5 0.7, respectively. metasomatized various extents, metasomatic orthopyroxene has formed at expense olivine. The orthopyroxene, free deformation exsolution, is characterized by low contents CaO Cr 2 O 3 . complicated...
Microseisms are a continuous source of seismic signal which mainly consist Rayleigh waves but known to contain some other types waves. We developed simple processing procedure for single-station three-component data allows us select Rayleigh-wave dominated portions. Application this from Southern California led confirm that excitation the secondary-peak microseisms (the predominant energy at about 0.15 Hz) occurs in coastal regions; directions, viewed each station, do not change very much...
Halogen and noble gas systematics are powerful tracers of volatile recycling in subduction zones. We present halogen compositions mantle peridotites containing H 2 O-rich fluid inclusions collected at volcanic fronts from two contrasting zones (the Avacha volcano Kamchatka arc the Pinatubo Luzon arcs) orogenic a peridotite massif Horoman massif, Hokkaido, Japan) which represents an exhumed portion wedge. The aims to determine how volatiles carried into wedge subducted fluids modify mantle....
Abstract Highly metasomatized parts of peridotite xenoliths from Avacha volcano, Kamchatka, Russia, characteristically contain calcic amphiboles, especially tremolites. They are rich in metasomatic pyroxenes with high Mg-number (= Mg/(Mg+Fe) atomic ratio), up to 0.94–0.98, and Cr-poor aluminous spinels. have the spinel lherzolite mineral assemblage equilibrium temperatures 900–1000 °C or higher, beyond stability field tremolite. The tremolite was therefore retrogressively formed after peak...
It was reported by Meyer and Boyd (1972) that zincian chromite, having 2 wt% to 3 ZnO high (>0.9) Cr# (= Cr/(Cr + Al) atomic ratio), appears as inclusions in diamonds obtained from kimberlite. Zincian chromite is characterized a low (<0.03) Mg# [= Mg/(Mg ferrous Fe Zn Mn Ni Co) ratio] an appreciable amount of MnO (0.4-0.5 wt%). The chemistry very different commonly found (magnesiochromite) diamonds, which contain amounts (<0.1 wt%) manganoan chromites are also meteorites...
Peridotite xenoliths derived from the low velocity zone beneath Avacha frontal volcano, Kamchatka, preserve a ‐axis slip fabrics, comparable with those in back‐arc region of NE Japan. Although low‐velocity zones are commonly attributed to partially melted mantle, migration melt does not erase existing olivine fabrics and related seismic anisotropies. These anisotropies may counteract associated c if they exist, along slab or high‐pressure zone.
An arsenide (low-Ni, high-Co löllingite) was found in a peridotite xenolith, which is strongly metasomatized by slab-derived melt or fluid from Avacha volcano, located the Kamchatka arc. This first finding of mantle within fresh xenolith that may have been precipitated metasomatic fluid/melt ultimately derived subducting slab. The löllingite very low Ni, suggesting Ni-Fe partitioning between and olivine at conditions. contrast to sulfide, favors Ni over Fe. As-bearing thus plays some role Fe...
Abstract Microdiamonds in metamorphic rocks are a signature of ultrahigh-pressure (UHP) metamorphism that occurs mostly at continental collision zones. Most UHP minerals, except coesite and microdiamond, have been partially or completely retrogressed during exhumation; therefore, the discovery microdiamond is crucial to identify understand tectonic history rocks. typically occur as inclusions minerals such garnet. Here we report aggregates matrix metapelite from Nishisonogi unit, Nagasaki...
Abstract Peridotites exposed in the Yugu area Gyeonggi Massif, South Korea, near boundary with Okcheon Belt, exhibit mylonitic to strongly porphyroclastic textures, and are mostly spinel lherzolites. Subordinate dunites, harzburgites, websterites associated Amphiboles, often zoned from hornblende core tremolite rim, found only as neoblasts. Porphyroclasts have recorded equilibrium temperatures of about 1000°C, whereas neoblasts denote lower temperatures, 800°C. Olivines Fo 90–91 lherzolites...