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Yokoyama, Tatsunori
Isotope News, (764), p.11 - 14, 2019/08
no abstracts in English
Horiike, Takumi*; Dotsuta, Yuma*; Nakano, Yuriko*; Ochiai, Asumi*; Utsunomiya, Satoshi*; Onuki, Toshihiko; Yamashita, Mitsuo*
Applied and Environmental Microbiology, 83(20), p.e00855-17_1 - e00855-17_11, 2017/10
Times Cited Count：18 Percentile：58.91(Biotechnology & Applied Microbiology)Radioactive strontium (
Sr) leaked into the ocean from the Fukushima Daiichi Nuclear Power Plant after the nuclear accident. Since the removal of Sr using general adsorbents is not efficient at high salinity, this study investigated removal of soluble Sr from a saline solution by biogenic carbonate minerals. An isolate, Bacillus sp. strain TK2d, from marine sediment removed more than 99 % of Sr in a saline solution. Sr adsorbed at the cell surface and then carbonate minerals containing Sr developed outside the cells.
Miyakawa, Kazuya; Mizuno, Takashi; Hirota, Akinari*; Komatsu, Daisuke*; Tsunogai, Urumu*
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Murakami, Takuma; Mizuno, Takashi; Sasamoto, Hiroshi; Kokami, Takayuki*; Sasaki, Takayuki*
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no abstracts in English
Yokoyama, Tatsunori; Kokubu, Yoko; Murakami, Hiroaki; Hirata, Takafumi*; Sakata, Shuhei*; Danhara, Toru*; Iwano, Hideki*; Chang, Q.*; Kimura, Junichi*
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The chronological information about carbonates is useful for modeling and enables forecast of geological and geochemical environmental changes by simulating. The U-Th-Pb dating method for carbonates which were formed at reducing environment remain to be established. The final goal of our study is to establish in situ U-Th-Pb dating method for carbonates which are filling cracks in pervious rock like fault rocks. In this study, the U-Th-Pb elemental and isotopic two-dimension distribution for an ammonite fossil were visualized by "Imaging" method using Laser-ablation ICP Mass Spectrometry. In U-Pb isotope analysis for carbonates in cracks of granites, we could not obtain significant U-Pb age data by the lack of uranium and influence of non-radiogenic common lead. When the concentration of lead is sufficiently high for the measurement, we obtained reliable isotopic data from carbonates and their lead isotopic composition reflected characteristic composition of their origin water.
Yokoyama, Tatsunori; Kokubu, Yoko; Murakami, Hiroaki; Watanabe, Takahiro; Hirata, Takafumi*; Sakata, Shuhei*; Danhara, Toru*; Iwano, Hideki*; Maruyama, Seiji*; Miyazaki, Takashi*; et al.
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Chronological and geochemical studies of carbonates, which are commonly found as fracture filling minerals in rocks, can provide information about geochemical conditions present during formation including in deep subsurface environments. A dating technique for the carbonates using laser ablation-multiple collector-inductively coupled plasma mass spectrometry (LA-MC-ICPMS) is still immature partly because of a lack of a consensus international carbonate standard for the in-situ dating technique. In this study, we performed a survey on the carbonate standard materials that may be suitable for high precision U-Th-Pb dating using LA-MC-ICPMS. We examined carbonate standard materials JCp-1 and JCt-1 issued by the Geological Survey of Japan (GSJ). Based on solution-based bulk analysis using MC-ICP-MS, heterogeneities in Pb isotope compositions were confirmed. Nevertheless, the 206Pb-based isotopic compositions were all within 1.2 per mill variations acceptable for a standard used for age determination using LA-MC-ICPMS. Additional tests on the heterogenities in U-Th-Pb compositions of the carbonate standards along with determinations of other trace elements using a 2D imaging LA-ICP-MS are ongoing. Examinations on both natural standards and synthetic standards are ongoing for further efforts in determination of the standard suitable for U-Th-Pb dating of carbonates.
Murakami, Hiroaki; Kokubu, Yoko; Yokoyama, Tatsunori; Watanabe, Takahiro; Yuguchi, Takashi*; Fujikawa, Masayuki*; Nishiyama, Tadao*
no journal, ,
In order to observe micro-growth layers in carbonate, we consider availability and measurement procedure of cathodoluminescence for various carbonates. Optical-CL image and SEM-CL image provide layering structures of entire area and microscale distribution of layering structures, respectively. Thus, the approach in the order of Optical-CL measurement to SEM-CL measurement is powerful means of microscale observation of carbonate.
Yokoyama, Tatsunori; Kokubu, Yoko; Murakami, Hiroaki; Watanabe, Takahiro; Mitsuguchi, Takehiro
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no abstracts in English
Yokoyama, Tatsunori; Kokubu, Yoko; Mitsuguchi, Takehiro; Murakami, Hiroaki; Hirata, Takafumi*; Sakata, Shuhei*; Danhara, Toru*; Iwano, Hideki*; Maruyama, Seiji*; Chang, Q.*; et al.
no journal, ,
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Yokoyama, Tatsunori
no journal, ,
no abstracts in English
Yokoyama, Tatsunori; Kokubu, Yoko; Mitsuguchi, Takehiro; Murakami, Hiroaki; Hirata, Takafumi*; Sakata, Shuhei*; Danhara, Toru*; Iwano, Hideki*; Maruyama, Seiji*; Miyazaki, Takashi*; et al.
no journal, ,
Chronological and geochemical studies of calcium carbonates can provide precious information for changes in geochemical condition in deep geological environments. Because the carbonate can be found as common filling minerals in rocks, age zoning and spatial distribution of chemical composition in the carbonate could be a wide-use indicator to reconstruct the past environmental changes. Calcite and other carbonate materials have been dated by Isotope Dilution-Thermal Ionization Mass Spectrometry. On the other hand, a few of U-Pb dating studies in a micro scale area (less than 10 micrometer) such as using laser ablation-multiple collector-inductively coupled plasma mass spectrometry (LA-MC-ICPMS) has been conducted on the carbonate. The U-Pb dating technique for the carbonates using LA-MC-ICPMS is still immature partly because of a lack of consensus international carbonate reference materials for the in-situ dating technique. In order to solve this problem, we performed a survey on the carbonate reference materials that may be suitable for high precision U-Pb dating using LA-MC-ICPMS. Additionally, we conducted experiments to make compositionally homogeneous carbonate (calcite) reference materials.
Yokoyama, Tatsunori; Kokubu, Yoko; Mitsuguchi, Takehiro*; Murakami, Hiroaki; Hirata, Takafumi*; Sakata, Shuhei*; Danhara, Toru*; Iwano, Hideki*; Maruyama, Seiji*; Chang, Q.*; et al.
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no abstracts in English
Miyajima, Yusuke*; Saito, Ayaka*; Kagi, Hiroyuki*; Yokoyama, Tatsunori; Hirata, Takafumi*
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no abstracts in English
Kamata, Kento*; Nara, Yoshitaka*; Fujii, Hirokazu*; Zhao, Y.*; Matsui, Hiroya; Ozaki, Yusuke
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The precipitation of carbonate minerals in rock is expected to close the fracture opening. In Horonobe URL, we perform the carbonated water injection test to heal the EDZ by the carbonate mineral precipitation. We compare the permeability before and after the injection to evaluate the closure of fractures in the EDZ. The significant change in permeability is not recognized at the present due to the short injection period and continuous injection would be required to change the permeability of EDZ by the precipitation.
