Ultra-high precision Sr isotope analysis for Sr isotope stratigraphy of quaternary samples
| Project/Area Number |
18K03814
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 17040:Solid earth sciences-related
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| Research Institution | Japan Agency for Marine-Earth Science and Technology |
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Principal Investigator |
WAKAKI Shigeyuki 国立研究開発法人海洋研究開発機構, 超先鋭研究開発部門(高知コア研究所), 研究員 (50548188)
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| Co-Investigator(Kenkyū-buntansha) |
若木 仁美 高知大学, 海洋コア総合研究センター, 短期研究員 (20817043)
高柳 栄子 東北大学, 理学研究科, 助教 (40729208)
吉村 寿紘 国立研究開発法人海洋研究開発機構, 海洋機能利用部門(生物地球化学プログラム), 研究員 (90710070)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2018: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
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| Keywords | ストロンチウム同位体層序 / 第四紀 / 堆積年代決定 / 高精度同位体分析 / 海洋底掘削コア / 放射起源Sr同位体比 / Sr同位体層序 / 質量分析 / 同位体比質量分析 / Sr同位体比 / 同位体分析 |
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| Outline of Final Research Achievements |
Sr isotope stratigraphy is widely used to determine sedimentation ages of marine sediments and carbonates. However, dating of quaternary samples by this method was difficult so far because the precision of the 87Sr/86Sr ratio measurement was insufficient to distinguish the very small 87Sr/86Sr variation of the seawater during this period. To resolve this technical bottleneck problem, we developed method for an ultra-high precision analysis of 87Sr/86Sr ratio using dynamic-multicollection thermal ionization mass spectrometry. The long-term analytical reproducibility of 87Sr/86Sr ratio achieved in this study was 2 ppm (2RSD). This analytical precision is sufficient to discriminate between 100 ky cycle of glacial-interglacial periods of the quaternary era. Analysis of foraminifera samples separated from oceanic drilling cores suggested that the current seawater Sr isotopic evolution curve may contain very small systematic errors in the quaternary part.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究ではSr同位体層序を用いた第四紀の不連続な地層に対する年代決定の実現に向けた技術的革新を達成した。近年、国際深海科学掘削計画（IODP）で多くの掘削が行われているアクティブなプレート収束帯では、海洋底堆積物に大小様々の断層など地殻変動に由来する不整合が普遍的に存在する。今後Sr同位体層序を用いた第四紀の堆積年代決定が実現すれば、断層などの存在による堆積物の不連続性を証明する強力なツールとして、変動地形の活動度評価など地殻変動・防災に関する研究にも応用が期待される
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Report
(4 results)
Research Products
(14 results)
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[Journal Article] Stable strontium isotopic compositions of river water, groundwater, and sediments from the Ganges, Brahmaputra and Meghna river system in Bangladesh2021
Author(s)
Yoshimura, T., Wakaki, S., Kawahata, H., Hossain, Z., Manaka, T., Suzuki, A., Ishikawa, T. and Ohkouchi, N.
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Journal Title
Frontiers in Earth Science,
Volume: 9
Pages: 1-17
DOI
Related Report
Peer Reviewed / Open Access / Int'l Joint Research
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