A5004148161- Geochemistry and Elemental Analysis
- Geology and Paleoclimatology Research
- Geological and Geochemical Analysis
- earthquake and tectonic studies
- Geomagnetism and Paleomagnetism Studies
- Geochemistry and Geologic Mapping
- Geological and Geophysical Studies
- Marine and environmental studies
- Cultural Heritage Materials Analysis
- Paleontology and Stratigraphy of Fossils
- Radioactive element chemistry and processing
- Methane Hydrates and Related Phenomena
- Extraction and Separation Processes
- Archaeology and ancient environmental studies
- Global Energy and Sustainability Research
- Pacific and Southeast Asian Studies
- Geoscience and Mining Technology
- Building materials and conservation
- Geological formations and processes
- Thermal and Kinetic Analysis
- Archaeological Research and Protection
Chiba Institute of Technology
2023-2025
The University of Tokyo
2020-2023
Waseda University
2023
Tohoku University
2018-2022
Graduate School USA
2017
Rare earth element and yttrium (REY)-rich mud around Minamitorishima Island, Japan, in the western North Pacific Ocean has received significant attention as a novel REY resource. In REY-rich muds, industrially critical metals such Co, Ni, Mo occur relatively high concentrations. We show that Fe-Mn micronodules separated from muds are significantly enriched these elements; we measured Co contents of almost 3000 ppm Ni exceed 39,000 ppm. Through experiments, demonstrated reductive chemical...
The purpose of this paper was to identify the types stone used in “Resthouses” along Northwest Royal Road connecting Angkor Cambodia and Phimai Thailand determine their sources through magnetic susceptibility measurements chemical composition analyses. Laterite primary building material for “Resthouses”, except Pr. Ku Sila Khan Thailand. Khan, located at northernmost point Road, primarily built with fine-grained red sandstone. Based on V, Sr, As contents laterite, following pairs were likely...
The origin of deep-sea sediments in the western North Pacific Ocean, which are significantly enriched rare-earth elements and yttrium (REY), its paleoceanographic implications have been poorly constrained. Here, we investigated stratigraphic variations chemical compositions textures ferromanganese (Fe–Mn) micronodules separated from sediments. characteristics an extremely REY-rich mud layer vary almost purely diagenetic to relatively hydrogenetic. This indicates abundant supply organic...
Abstract Areas of old and cold oceanic plate lack conventional volcanism have been assumed to be devoid submarine hydrothermal activity. However, petit-spot volcanoes are common in areas flexure such plates. Here, we report ferromanganese oxides dredged from the vicinity a volcano at 5.7 km water depth an area east Japan Trench. The bulk chemical, lead isotopic mineralogical compositions samples indicate their formation by low-temperature activity, which can interpreted as being caused...
In this study, the Sr isotope ratios (IRs; 87Sr/86Sr) of ferromanganese (Fe–Mn) crusts are analyzed through laser ablation inductively coupled plasma multiple-collector mass spectrometry. A sample collected from off Minamitorishima Island showed uniform IRs (0.70906–0.70927) similar to that present-day seawater with more than 36 mm thickness. Meanwhile, a detritus-rich northeast (NE) Japan wide variation in (0.707761–0.709963). The IR Fe–Mn crust NE suggests detrital influx contributions...
Shimajiri–Mahji refers to dark-red soil covering Ryukyu limestone that is characterized by buried ferromanganese (Fe–Mn) nodules, and it widely distributed in Okinawa Island, southwestern Japan. The formation environment of the Fe–Mn nodules considered closely related pedogenetic process because mineral assemblage similar surrounding soil. There are two competing hypotheses about nodules: marine or terrestrial. In this study, chemical composition was analyzed determine their origin. low Ni...