安定同位体から見た原生代末期ゴンドワナ超大陸形成に関わる流体の地球規模的動態

2009 Fiscal Year Annual Research Report

• Project/Area Number: 20684022
• Research Institution: Shizuoka University
• Principal Investigator: M. Satish Kumar Shizuoka University, 理学部, 准教授 (50313929)
• Keywords: ゴンドワナ超大陸 / テクトニクス / 変成岩 / 安定同位体 / 炭素同位体 / 質量分析計 / 硫化物 / フェムト秒レーザー

Research Abstract

本研究では、温室効果ガス中の炭素-酸素-水素-硫黄(C-O-H-S)元素の地殻-地球大気間の移動について、硫黄の四つの同位体をレーザー切除法で処理することで、1) 「マントル」から「大気」へのC-O-H-S流体の「移動」と広域なテクトニクスとの関係、2) 「堆積物」から「大気」へのC-O-H-S流体の「移動」と大陸衝突との関係、3) C-O-H-S元素が、硫化物やグラファイトとして下部地殻に「固定」される過程、を明らかにすることを目的とする。
本年度は、六フッ化硫黄の四つの同位体を同時に測定するために以下のことを行った。
1) 初期状態のMAT-251では、SF_6の各安定同位体の4つのピーク(質量数127,128,129,131)が、4つのコレクターごとに同時に入射できないため、コレクターを薄くした。
2) 改良したコレクターを用いて六フッ化硫黄標準ガスを質量分析計MAT-251に導入し、129/127をモニタリングした。この実験で精度・確度ともに良い結果を得ることができた。したがって硫黄同位対比^<34>S/^<32>Sが分析可能になった。
3) IAEAが配布している硫黄同位体の国際標準物質(Ag_2S)からSF_6を生成し、同位体分析を行った。
4) 特殊に製作した反応層で、フッ素大気のもと硫化物単結晶にフェムト秒レーザーを照射し、SF_6が生成することを確認した。
現在、生成したSF_6に含まれる不純物の除去方法を模索しつつ、精度・確度を高めるための実験を進めている。さらに、4つの同位体を同時に測定するためにコレクターの改良も引き続き行っている。

Research Products

• [Journal Article] Exsolution of dolomite and application of calcite-dolomite solvus geothermometry in high-grade marbles : An example from Skallevikshalsen, East Antarctica. (2010)
  • Author(s): Mizuochi, H., Satish-Kumar, M., Motoyoshi, Y., Michibayashi, K
  • Journal Title: Journal of Metamorphic Geology ((in press))
  • Peer Reviewed
• [Journal Article] Fingerprinting a multistage metamorphic fluid-rock history : Evidence from grain scale Sr, O and C isotopic and trace element variations in high-grade marbles from East Antarctica. (2010)
  • Author(s): Satish-Kumar, M., Hermann, J., Miyamoto, T., Y.Osanai
  • Journal Title: Lithos 114 Pages: 217-228
  • Peer Reviewed
• [Journal Article] A new SF_6 inlet system with a modified faraday collector alignment of Finnigan MAT-251 mass spectrometer for sulfur isotope measurement. (2010)
  • Author(s): Satish-Kumar, M., Matsuda, J., Yamazaki, R, Takano, A., Wada, H.
  • Journal Title: Geoscience reports of Shizuoka University 37((in press))
• [Journal Article] Origin of graphite in glimmerite and spinellite in Achankovil Shear Zone, southern India. (2009)
  • Author(s): Rajesh, V.J., Arai, S., Satish-Kumar, M.
  • Journal Title: Journal of Mineralogical and Petrological Sciences 104 Pages: 407-412
  • Peer Reviewed
• [Journal Article] Low-density CO_2-rich fluid inclusions from charnockites of southwestern Madurai Granulite Block, southern India ; implications on graphite mineralization. (2009)
  • Author(s): Baiju, K.R, Nambiar, C.G., Jadhav, GN., Kagi, H., Satish-Kumar, M.
  • Journal Title: Journal of Asian Earth Sciences 36 Pages: 332-340
  • Peer Reviewed
• [Presentation] Laser ablation sulfur isotope. analytical system at Shizuoka University (2009)
  • Author(s): Yamazaki, R, Matsuda, J., Takano, A., Satish Kumar, M., Wada, H.
  • Organizer: The 29^<th> Symposium on Polar Geosciences, National Institute of Polar Research
  • Place of Presentation: Tachikawa, Tokyo.
  • Year and Date: 20091008-20091009
• [Presentation] Chemostratigraphy of marbles from East Gondwana : Constraints on the whereabouts of the Mozambique Ocean (2009)
  • Author(s): Satish-Kumar, M., Miyamoto, T., Hermann, J., Windley, B., Grantham, G, Dunkley, D., Osanai, Y., Motoyoshi, Y, Hiroi, Y, Shiraishi. K., Wada, H.
  • Organizer: The 29^<th> Symposium on Polar Geosciences, National Institute of Polar Research
  • Place of Presentation: Tachikawa, Tokyo
  • Year and Date: 20091008-20091009
• [Presentation] Carbon isotopic composition of graphite from Skallevikshalsen, Lutzow Holm Complex, East Antarctica (2009)
  • Author(s): So, H., Satish-Kumar, M., Motoyoshi, Y.
  • Organizer: The 29^<th> Symposium on Polar Geosciences, National Institute of Polar Research
  • Place of Presentation: Tachikawa, Tokyo
  • Year and Date: 20091008-20091009
• [Presentation] Graphite with growth spirals in Mg-Al-rich granulite from Skallevikshalsen (2009)
  • Author(s): Hiroi, Y, Satish-Kumar, M., Dunkley, D., Kato, M., Adachi, T.Hokada, T., Motoyoshi, Y., K.Shiraishi
  • Organizer: The 29^<th> Symposium on Polar Geosciences, National Institute of Polar Research
  • Place of Presentation: Tachikawa, Tokyo
  • Year and Date: 20091008-20091009
• [Presentation] Andalusite and corundum + quartz in pelitic migmatites from the Kerala Khondalite Belt, South India (2009)
  • Author(s): Kato, M., Mitsui, H., Hiroi, Y., Satish-Kumar, M., Dunkley, D.
  • Organizer: The 29^<th> Symposium on Polar Geosciences, National Institute of Polar Research
  • Place of Presentation: Tachikawa, Tokyo
  • Year and Date: 20091008-20091009
• [Presentation] Fingerprinting multistage fluid-rock history during metamorphism : Evidence from grain scale Sr, O and C isotopic and trace element variations in high-grade marbles from East Antarctica (2009)
  • Author(s): Satish-Kumar, M., Hermann, J., Miyamoto, T., Osanai, Y., Motoyoshi, Y.
  • Organizer: Annual Meeting of Japan Association of Mineralogical Sciences
  • Place of Presentation: Sapporo, Japan
  • Year and Date: 20090908-20090910
• [Presentation] Chemostratigraphy of metacarbonates deposited in the "Mozambique Ocean" between East Gondwana and West Gondwana (2009)
  • Author(s): Satish-Kumar, M., Miyamoto, T., Hermann, J., Windley, B., Grantham, G, Dunkley, D., Motoyoshi, Y, Osanai, Y, Hiroi, Y, Shiraishi, K., Wads, H.
  • Organizer: The 116th annual meeting of the Geological Society of Japan
  • Place of Presentation: Okayama, Japan
  • Year and Date: 20090904-20090906
• [Presentation] Zircon regeneration in the skams of Skallevikshalsen, East Antarctica : multistage infiltration metasomatism during prolonged granulite metamorphism (2009)
  • Author(s): Dunkley D.J., Hiroi, Y., Satish-Kumar, M.
  • Organizer: "MicroAnalysis Processes and Time" Meeting
  • Place of Presentation: Edinburgh, UK
  • Year and Date: 20090831-20090902
• [Presentation] Fluid enhanced element mobility along lithological contacts : An example from Skallevikshalsen, Lutzow Holm Bay, East Antarctica. (2009)
  • Author(s): Satish-Kumar, M. Hiroi, Y, Motoyoshi, Y.
  • Organizer: Japan Geoscience Union Meeting
  • Place of Presentation: Makuhari, Tokyo
  • Year and Date: 20090516-20090521
• [Presentation] Zircon production and modification in the skarns of Skallevikshalsen, East Antarctica, and the role of fluids in Zr mobilization. (2009)
  • Author(s): Dimkley D.J., Hiroi, Y., Satish-Kumar, M.
  • Organizer: Japan Geoscience Union Meeting
  • Place of Presentation: Makuhari, Tokyo
  • Year and Date: 20090516-20090521
• [Presentation] 三波川帯上昇期に形成した鉱物脈の空間分布 (2009)
  • Author(s): 諸橋啓介・岡本敦・Satish-Kumar, M.・土屋範芳
  • Organizer: Japan Geoscience Union Meeting
  • Place of Presentation: Makuhari, Tokyo
  • Year and Date: 20090516-20090521