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Hikari Hasegawa Takashi Mikouchi Akira Yamaguchi Masahiro Yasutake Richard C. Greenwood Ian A. Franchi 《Meteoritics & planetary science》2019,54(4):752-767
Northwest Africa (NWA) 6112, Miller Range (MIL) 090206 (plus its pairs: MIL 090340 and MIL 090405), and Divnoe are olivine‐rich ungrouped achondrites. We investigated and compared their petrography, mineralogy, and olivine fabrics. We additionally measured the oxygen isotopic compositions of NWA 6112. They show similar petrography, mineralogy, and oxygen isotopic compositions and we concluded that these five meteorites are brachinite clan meteorites. We found that NWA 6112 and Divnoe had a c axis concentration pattern of olivine fabrics using electron backscattered diffraction (EBSD). NWA 6112 and Divnoe are suggested to have been exposed to magmatic melt flows during their crystallization on their parent body. On the other hand, the three MIL meteorites have b axis concentration patterns of olivine fabrics. This indicates that the three MIL meteorites may be cumulates where compaction of olivine grains was dominant. Alternatively, they formed as residues and were exposed to olivine compaction. The presence of two different olivine fabric patterns implies that the parent body(s) of brachinite clan meteorites experienced diverse igneous processes. 相似文献
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Shigeru TERASHIMA Shiro ITOH Masumi UJIIE Hikari KAMIOKA Tsuyoshi TANAKA Hitoshi HATTORI 《Geostandards and Geoanalytical Research》1993,17(1):1-4
Three new rock reference samples, Rhyolite JR-3, Gabbro JGb-2 and Hornblendite JH-1 have been prepared by the Geological Survey of Japan for collaborative studies on their chemical composition. Twenty-eight major, minor and trace elements were determined and presented. The results of homogeneity tests showed that all elements are considered to be distributed homogeneously in each reference sample. Geological and mineralogical characteristics are also described. 相似文献
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Shiro ITOH Shigeru TERASHIMA Noboru IMAI Hikari KAMIOKA Naoki MITA Atsushi ANDO 《Geostandards and Geoanalytical Research》1993,17(1):5-79
Abstract: Analytical data for fourteen rare-earth elements, scandium, yttrium, zirconium and hafnium, received by May 1992, have been compiled on twenty-six GSJ (Geological Survey of Japan) reference samples. Seventeen of them are 'Igneous rock series' and nine are "Sedimentary rock series". The reported data including personal communication were evaluated under the consideration on analytical methods and geochemical evidences. No significant difference has been observed between the values obtained by the different analytical methods. Based on the selected available data, 1992 compilation values were tabulated. 相似文献
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Analysis of summertime atmospheric transport of fine particulate matter in Northeast Asia 总被引:1,自引:0,他引:1
Hikari Shimadera Hiroshi Hayami Yu Morino Toshimasa Ohara Satoru Chatani Shuichi Hasegawa Naoki Kaneyasu 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(3):347-360
In Northeast Asia, the effect of long-range transport of air pollutants is generally pronounced in spring and winter, but can be important even in summer. This study analyzed summer-time atmospheric transport of elemental carbon (EC) and sulfate (SO4 2?) with the Community Multiscale Air Quality (CMAQ) model driven by the Weather Research and Forecasting (WRF) model. The WRF/CMAQ modeling system was applied to regions ranging from Northeast Asia to the Greater Tokyo Area in Japan in summer 2007. In terms of EC, while the model simulated well the effect of long-range transport, the simulation results indicated that domestic emissions in Japan dominantly contributed (85%) to EC concentrations in the Greater Tokyo. In terms of SO4 2?, the simulation results indicated that both domestic emissions (62%) and long-range transport from the other countries (38%) substantially contributed to SO4 2? concentrations in the Greater Tokyo. Distinctive transport processes of SO4 2? were associated with typical summer-time meteorological conditions in the study region. When a Pacific high-pressure system covered the main island of Japan, domestic emissions, including volcanic emission, dominantly contributed to SO4 2? concentrations in the Greater Tokyo. When a high-pressure system prevailed over the East China Sea and low-pressure systems passed north of Japan, synoptic westerly winds associated with this pressure pattern transported a large amount of SO4 2? from the continent to Japan. In addition, although heavy precipitation and strong wind decreased SO4 2? concentrations near the center of a typhoon, peripheral typhoon winds occasionally played an important role in long-range transport of SO4 2?. 相似文献
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