Geochronological study of high precision zircon microanalysis for crustal evolution

2016 Fiscal Year Annual Research Report

• Project/Area Number: 25287132
• Research Institution: National Institute of Polar Research
• Principal Investigator: 外田 智千 国立極地研究所, 研究教育系, 准教授 (60370095)
• Co-Investigator(Kenkyū-buntansha): 堀江 憲路 国立極地研究所, 研究教育系, 助教 (00571093) ; 清川 昌一 九州大学, 理学(系)研究科(研究院), 准教授 (50335999) ; 谷 健一郎 独立行政法人国立科学博物館, 地学研究部, 研究員 (70359206)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 地質学 / 地球年代学 / 地球化学 / 地殻・マントル物質 / 岩石・鉱物・鉱床学

Outline of Annual Research Achievements

前年度に引き続き、引き続き二次イオン質量分析計（SHRIMP IIe）を用いた分析や試料調整に習熟した特任研究員を雇用し、高精度U-Pb年代分析と複数回にわたる微量元素存在度分析、酸素同位体分析を一連の分析として行う試料調整法の確立した。具体的な成果は以下の通りである。
（１）組成累帯構造をもつ花崗岩体を選定し、ジルコンの高精度U-Pb年代測定とTi及びREE分析から、400万年の期間でトーナル岩質から花崗岩質へ結晶分化するという推定結果を得た。（２）高精度酸素同位体分析の基礎実験を行い、上記のジルコンに応用した結果、結晶分化作用に伴い酸素同位体組成が変化することを見出した。これは世界で最初の報告となる。（３）SelFragと超音波ドリルを用いた試料調整法を検討し、鉱物共生関係を検証しながら高精度年代測定を行うための手法を立ち上げた。（４）ジルコン中の軽元素(Li，K，Ca，Mn，Fe，Mg)分析手法の確立を行い、U-Pb壊変系の乱れと軽元素の混入挙動の関連を見出し、U-Pb壊変系の乱れを評価する尺度を確立した。（５）ジルコン結晶中の水含有量の分析手法を検討し、定量化に向けた基礎実験をおこなった。

Research Progress Status

28年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

28年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Timescale of magma chamber processes revealed by U-Pb ages, trace element contents and morphology of zircons from the Ishizuchi caldera, Southwest Japan Arc (2017)
  • Author(s): Takehara, M., Horie, K., Tani, K., Yoshida, T., Hokada, T., Kiyokawa, S.
  • Journal Title: Island Arc Volume: 26 Pages: 1-14
  • DOI: 10.1111/iar.12182
  • Peer Reviewed
• [Journal Article] Peak and post-peak development of UHT metamorphism at Mather Peninsul, Rauer Islands: zircon and monazite U-Th-Pb and REE chemistry constraints (2016)
  • Author(s): Hokada, T., Harley, S.L., Dunkley, D.J., Kelly, N.M., Yokoyama, K.
  • Journal Title: Journal of Mineralogical and Petrological Sciences Volume: 111 Pages: 89-103
  • DOI: 10.2465/jmps.150829
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] U-Pb zircon geochronology in the western part of the Rayner Complex, East Antarctica (2016)
  • Author(s): Horie, K., Hokada, T., Motoyoshi, Y., Shiraishi, K., Hiroi, Y., Takehara, M.
  • Journal Title: Journal of Mineralogical and Petrological Sciences Volume: 111 Pages: 104-117
  • DOI: 10.2465/jmps.150811
  • Peer Reviewed
• [Journal Article] Possible polymetamorphism and brine infiltration recorded in the garnet-sillimanite gneiss, Skallevikshalsen, Lutzow-Holm Complex, East Antarctica (2016)
  • Author(s): Kawakami, T., Hokada, T., Sakata, S., Hirata, T.
  • Journal Title: Journal of Mineralogical and Petrological Sciences Volume: 111 Pages: 129-143
  • DOI: 10.2465/jmps.150812
  • Peer Reviewed
• [Journal Article] Antarctic geoconservation: a review of current systems and practices (2016)
  • Author(s): Hughes, K.A., Lopez-Martinez J., Francis, J.E., Crame, J.A., Carcavilla, L., Shiraishi, K., Hokada, T., Yamaguchi, A.
  • Journal Title: Environmental Conservation Volume: 43 Pages: 97-108
  • DOI: 10.1017/S0376892915000387
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Contrasting geochemical signatures of Devonian and Permian granitoids from the Tseel Terrane, SW Mongolia (2016)
  • Author(s): Burenjargal, U., Okamoto, A., Tsuchiya, N., Uno, M., Horie, K., Hokada, T.
  • Journal Title: Journal of Geosciences Volume: 61 Pages: 51-66
  • DOI: 10.3190/jgeosci.210
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] U-Pb SHRIMP Ages of Detrital Zircons from Hiriyur Formation in Chitradurga Greenstone Belt and its Implication to the Neoarchean Evolution of Dharwar Craton, South India (2016)
  • Author(s): Nasheeth, A., Okudaira, T., Horie, K., Hokada, T., Satish-Kumar, M.
  • Journal Title: Journal of Geological Society of India Volume: 87 Pages: 43-54
  • DOI: 10.1007/s12594-016-0372-2
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Revised stratigraphy and zircon U-Pb age data of the Hitachi metamorphic formations in the southern Abukuma Mountains, and reconstruction of the basement of the Northeast Japan Arc before the opening of the Japan Sea (2016)
  • Author(s): Tagiri, M., Horie, K., Adachi T
  • Journal Title: The Journal of the Geological Society of Japan Volume: 122 Pages: 231-247
  • DOI: 10.5575/geosoc.2016.0012
  • Peer Reviewed
• [Journal Article] SHRIMP U-Pb zircon dating of the Kinshozan Quartz Diorite Implications for Late Paleozoic granitic activity in Japanese from the Kanto Mountains, Japan Islands (2016)
  • Author(s): Ogasawara, M., Fukuyama, M., Horie, K.
  • Journal Title: Island Arc Volume: 25 Pages: 28-42
  • DOI: 10.1111/iar.12136
  • Peer Reviewed
• [Presentation] 3.Takehara, M., Horie, K., Williams, I.S., Zircon U-Pb geochronology and geochemistry of the Utsubo granitic pluton, Hida Belt, central Japan (2016)
  • Author(s): Takehara, M., Horie, K., Williams, I.S.
  • Organizer: 8th International SHRIMP Workshop
  • Place of Presentation: グラナダ大学（スペイン）
  • Year and Date: 2016-09-06 – 2016-09-10
  • Int'l Joint Research
• [Presentation] Conventional mechanical crushing versus Selfrag Lab. pulverization (2016)
  • Author(s): Takehara, M., Horie, K.
  • Organizer: 8th International SHRIMP Workshop
  • Place of Presentation: グラナダ大学（スペイン）
  • Year and Date: 2016-09-06 – 2016-09-10
  • Int'l Joint Research
• [Presentation] Preliminary report of stable isotope analysis with 5-head advanced multi-collector (2016)
  • Author(s): Horie, K., Takehara, M., Magee, C.W.
  • Organizer: 8th International SHRIMP Workshop
  • Place of Presentation: グラナダ大学（スペイン）
  • Year and Date: 2016-09-06 – 2016-09-10
  • Int'l Joint Research
• [Presentation] Significance of external morphology and chemistry of zircon for precise U-Pb geochronology (2016)
  • Author(s): Takehara, M., Horie, K., Tani, K., Yoshida, T., Hokada, T., Kiyokawa, S.
  • Organizer: Goldschmidt Conference 2016
  • Place of Presentation: パシフィコ横浜（横浜市）
  • Year and Date: 2016-06-26 – 2016-07-01
  • Int'l Joint Research
• [Presentation] Post-tectonic granitoid magmatism in the Natal-Maud-Mozambique Provinces (2016)
  • Author(s): Hokada, T., Grantham, G.H., Arima, M., Saito, S., Armstrong, R., Shiraishi, K.
  • Organizer: 日本地球惑星科学連合2016年大会
  • Place of Presentation: 幕張メッセ（千葉市）
  • Year and Date: 2016-05-22 – 2016-05-26
  • Int'l Joint Research