Japan Geoscience Union Meeting 2014

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Symbol S (Solid Earth Sciences) » S-IT Science of the Earth's Interior & Techtonophysics

[S-IT40_1PM1] Geofluids: their distribution and role in the Earth's dynamics

Thu. May 1, 2014 2:15 PM - 4:00 PM 416 (4F)

Convener:*Michihiko Nakamura(Division of Earth and Planetary Materials Science, Department of Earth Science, Graduate School of Science, Tohoku University), Hiroshi Sakuma(Department of Earth and Planetary Sciences, Graduate School of Science and Engineering, Tokyo Institute of Technology), Masahiro Ichiki(Graduate School of Science, Tohoku University), Tsutomu Takahashi(Institute for Research on Earth Evolution Japan Agency for Marine-Earth Science and Technology), Chair:Tetsuya Yokoyama(Department of Earth and Planetary Sciences, Graduate School of Science and Engineering, Tokyo Institute of Technology), Keika Horiguchi(Crustal Fluid Research Group, The Institute of Geology and Geoinformation, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology)

2:15 PM - 2:30 PM

[SIT40-P10_PG] Applications of rapid and precise 11B/10B isotopic analysis to water and rock samples

3-min talk in an oral session

*Masaharu TANIMIZU1, Kazuya NAGAISHI2, Tsuyoshi ISHIKAWA1 (1.Kochi Institute, JAMSTEC, 2.Marine Works Japan Ltd.)

Boron isotope ratio is a powerful tracer in the fields of geochemistry, biochemistry, and environmental chemistry. Boron isotope ratios are determined by TIMS or MC-ICP-MS with precisions of better than 0.1 % RSD, but a large inter-lab discrepancy of 0.6 % is still observed for actual carbonate samples (Foster, 2008). Here, we are trying to determine B isotope ratio by MC-ICP-MS with a simple and common analytical techniques using a quartz sample introduction system with a PFA nebulizer, and compared to recently developed precise B isotope ratio analysis techniques by TIMS in positive ion detection mode determined as Cs2BO2+ ions with sample amount of <100 ng (Ishikawa and Nagaishi, 2011) and by MC-ICP-MS (Foster, 2008, Louvat et al., 2011). In this year, our developed B analytical method above for carbonate and water samples are applied to rock samples. Resultant analytical reproducibility (twice standard deviation) was +/-0.04 % with a consumption of 50 ng B for several geochemical reference rocks issued from GSJ. Their relative differences from the standard were consistent with those determined by the positive TIMS within analytical uncertainty. Current potential B isotopic analysis by MC-ICP-MS will be discussed.