A5029814244- Geological and Geochemical Analysis
- earthquake and tectonic studies
- High-pressure geophysics and materials
- Geochemistry and Geologic Mapping
- Isotope Analysis in Ecology
- Geology and Paleoclimatology Research
- Geochemistry and Elemental Analysis
- Astro and Planetary Science
- Radioactive element chemistry and processing
- Planetary Science and Exploration
- Radioactive contamination and transfer
- Analytical chemistry methods development
- Groundwater and Isotope Geochemistry
- Geological and Geophysical Studies
- Geological Studies and Exploration
- Paleontology and Stratigraphy of Fossils
- Nuclear Physics and Applications
- Solid-state spectroscopy and crystallography
- Hydrocarbon exploration and reservoir analysis
- Radioactivity and Radon Measurements
- Mineralogy and Gemology Studies
- Crystal Structures and Properties
- Space Science and Extraterrestrial Life
- Geomagnetism and Paleomagnetism Studies
- Pleistocene-Era Hominins and Archaeology
Okayama University
2015-2024
Advanced Science Research Center
2022-2023
University of Toronto
1983-2022
Institute of Geology and Geophysics
2020-2021
Chinese Academy of Sciences
2020-2021
Tohoku University
2017
Okayama Prefecture
2017
University of Niigata Prefecture
2017
Kavli Institute for the Physics and Mathematics of the Universe
2007
Planetary Science Institute
1990-2005
Abstract C-type asteroids 1 are considered to be primitive small Solar System bodies enriched in water and organics, providing clues the origin evolution of building blocks life. asteroid 162173 Ryugu has been characterized by remote sensing 2–7 on-asteroid measurements 8,9 with Hayabusa2 (ref. 10 ). However, ground truth provided laboratory analysis returned samples is invaluable determine fine properties other planetary bodies. We report preliminary results analyses on from particle size...
Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned C-type asteroid Ryugu by Hayabusa2 mission. On average consist 50% phyllosilicate matrix, 41% porosity 9% minor phases, including organic matter. The abundances 70 elements in close agreement with those CI chondrites. Bulk show higher δ18O, Δ17O, ε54Cr values than As such, sampled most primitive least-thermally processed protosolar nebula reservoirs. Such finding is...
Research Article| December 01, 1996 Possible eastward extension of Chinese collision belt in South Korea: The Imjingang Jin-Han Ree; Ree 1Department Earth and Environmental Sciences, Korea University, Seoul 136-701, Search for other works by this author on: GSW Google Scholar Moonsup Cho; Cho 2Department Geological National 151-742, Sung-Tack Kwon; Kwon 3Department Geology, Yonsei 120-749, Eizo Nakamura 4Pheasant Memorial Laboratory, Institute Study the Earth's Interior, Okayama University...
A method for the determination of major, minor and trace elements in silicate samples by ICP‐QMS ICP‐SFMS applying isotope dilution‐internal standardisation (ID‐IS) multi‐stage internal has been developed. Samples with an enriched 149 Sm (spike) were decomposed a HF/HCIO 4 mixture stepwise drying finally diluted. In ID‐IS element analyses Q‐pole type ICP‐MS (ICP‐QMS), concentration was determined ID, while other (Li, Be, Rb, Sr, Y, In, Cs, Ba, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb,...
Abyssal peridotites, the depleted solid residues of ocean ridge melting, are most direct samples available to assess upper oceanic mantle composition. We present detailed isotope and trace element analyses pyroxene mineral separates from Southwest Indian Ridge abyssal peridotites pyroxenites in order constrain size length scale heterogeneity. Our results demonstrate that can be highly heterogeneous <1 km even <0.1 m scales. Examination Nd isotopes relation modal, trace, major...
Rationale The precise determination of Δ' 17 O values in terrestrial material is becoming increasingly important to understand the mass‐dependent fractionation processes that cause variations oxygen isotope ratios. San Carlos olivine widely used as reference for measurements and extraterrestrial materials. We report new were independently determined two different laboratories (Geoscience Center [GZG], University Göttingen) Institute Study Earth's Interior [ISEI], Okayama University, Misasa)...
For decades, deep sea hydrothermal vents have been a preferred setting for the Origin of Life, but "The Water Problem" as relates to polymerization organic molecules, together with propensity dilute critical prebiotic elements well number other crucial factors, suggests that terrestrial hot spring field capacity wet-dry cycling and element concentration may represent more likely candidate. Here, we investigate 3.5 billion-year-old, anoxic from Pilbara Craton (Australia) show its veins...
All life on Earth contains amino acids and carbonaceous chondrite meteorites have been suggested as their source at the origin of Earth. While many meteoritic are considered indigenous, deciphering extent terrestrial contamination remains an issue. The Ryugu asteroid fragments (JAXA Hayabusa2 mission), represent most uncontaminated primitive extraterrestrial material available. Here, concentrations from two particles different touchdown sites (TD1 TD2) reported. show that N,N-dimethylglycine...
Abstract Ultra‐high‐pressure eclogites from the Dabie orogen that formed over a range in temperatures (∼600 to > 700 °C) have been investigated with combined Lu–Hf and Sm–Nd geochronology. Three eclogites, sampled Zhujiachong, Huangzhen Shima, yield ages of 240.0 ± 5.0, 224.4 1.9 230.8 5.0 Ma corresponding 222.5 217.6 6.1 224.2 2.1 respectively. Well‐preserved prograde major‐ trace‐element zoning garnet Zhujiachong eclogite suggests age mostly reflects an early phase growth continued time...
Major and trace element have been analyzed from alkaline basalts southwestern Japan, Korea, northeastern China. No significant differences were found in the immobile incompatible ratios, such as Zr, Y, Hf, Th, Ti. These well normalized patterns, resemble those of continental oceanic island basalts. However, Japanese show evidence K, Ba, Rb enrichment a slight depletion Ta relative to La, implying weak arc signature. Korean Chinese do not Rare earth elements (REE) near‐constant La/Sm ratios...
Isotopic compositions of Pb, Sr, and Nd concentrations trace elements were determined for Quaternary island arc basaltic rocks from northeastern Japan. Sr Pb isotopic ratios decrease, increase the volcanic front toward back arc. The nearest side are nearly identical to those mid‐ocean ridge basalt (MORB). high field strength heavy rare earth show homogeneous MORB‐like characteristics. These observations indicate that mantle wedge beneath Japan originally had a MORB‐type composition was...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSuppression of boron volatilization from a hydrofluoric acid solution using boron-mannitol complexTsuyoshi. Ishikawa and Eizo. NakamuraCite this: Anal. Chem. 1990, 62, 23, 2612–2616Publication Date (Print):December 1, 1990Publication History Published online1 May 2002Published inissue 1 December 1990https://doi.org/10.1021/ac00222a017RIGHTS & PERMISSIONSArticle Views490Altmetric-Citations97LEARN ABOUT THESE METRICSArticle Views are the...
Records of micrometeorite collisions at down to submicron scales were discovered on dust grains recovered from near-Earth asteroid 25143 (Itokawa). Because the sampled very near surface asteroid, by Hayabusa spacecraft, their surfaces reflect low-gravity space environment influencing physical nature exterior. The was examined description grain and asteroidal scenes reconstructed. Chemical O isotope compositions five lithic grains, with diameters 50 μm, indicate that uppermost layer...