Volatile components in island arc magma trapped in anorthite megacrysts

• Project/Area Number: 16K20921
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Petrology/Mineralogy/Economic geology; Geochemistry/Cosmochemistry
• Research Institution: Akita University
• Principal Investigator: Echigo Takuya 秋田大学, 国際資源学研究科, 准教授 (30614036)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2016: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: 灰長石巨晶 / 揮発性成分 / 島弧マグマ / メルト包有物 / 灰長石 / LA-ICP-MS / ストロンチウム同位体 / 微量元素 / オストワルト熟成 / 塁帯構造 / マグマ混合 / 包有物 / EPMA / 岩石・鉱物・鉱床学 / マグマ

Outline of Final Research Achievements

Mafic melt inclusions in anorthite megacrysts from Japanese island arc were analyzed to examine how much volatile components such as sulfur and chlorine are contained in them. Electron microprobe analysis showed that melt inclusions in anorthite megacrysts from Ogi Peninsula, Niigata contains 0.05-0.30 wt % of SO3 and 0.01-0.12 wt % of Cl. Sr-isotope analysis with MC-LA-ICP-MS revealed that 87Sr/86Sr of those anorthite are 0.70280-0.70340 and suggested that they are crystallized from primitive magma without assimilation of crustal components.

Academic Significance and Societal Importance of the Research Achievements

マグマ中の揮発性成分（水や二酸化炭素、硫化水素、二酸化硫黄、塩素など）はプレートの剛性や噴火現象にとって重要である。しかし、これまでマグマだまり深部における揮発性成分の種類や量を直接分析する方法はなかった。本研究では、マグマだまり深部で成長した灰長石巨晶に着目し、そのメルト包有物を分析することによって深部マグマの揮発性成分量を見積もることに成功した。また、日本海側に位置する佐渡島の灰長石巨晶およびそのメルト包有物を調べることによって、太平洋側から沈み込んだ硫黄や塩素などの揮発性成分が日本海側にまで達していることを初めて明らかにした。

Research Products

• [Journal Article] Chemical Characteristics of Zircon from Khaldzan Burgedei Peralkaline Complex, Western Mongolia (2018)
  • Author(s): Sarangua Nergui、Watanabe Yasushi、Echigo Takuya、Hoshino Mihoko
  • Journal Title: Minerals Volume: 9 Issue: 1 Pages: 1-20
  • DOI: 10.3390/min9010010
  • Peer Reviewed / Open Access
• [Journal Article] Mineralogical characterization and formation process of spherulite in the rhyolitic welded tuff from Aga town, Niigata Prefecture, Japan (2018)
  • Author(s): 越後拓也・齋藤 庸一朗・木股三善・清水雅浩・西田憲正・滝沢茂
  • Journal Title: Japanese Magazine of Mineralogical and Petrological Sciences Volume: 47 Issue: 2 Pages: 69-81
  • DOI: 10.2465/gkk.160214
  • NAID: 130007429497
  • ISSN: 1345-630X, 1349-7979
  • Peer Reviewed
• [Journal Article] The genesis of organic minerals and surface structures and reactivity of nanominerals (2018)
  • Author(s): 越後拓也
  • Journal Title: Japanese Magazine of Mineralogical and Petrological Sciences Volume: 47 Issue: 1 Pages: 34-42
  • DOI: 10.2465/gkk.180115
  • NAID: 130006516911
  • ISSN: 1345-630X, 1349-7979
• [Journal Article] Differential Fractionation of Rare Earth Elements in Oxidized and Reduced Granitic Rocks: Implication for Heavy Rare Earth Enriched Ion Adsorption Mineralization (2017)
  • Author(s): Yasushi Watanabe, Yoshiaki Kon, Takuya Echigo, Atsushi Kamei
  • Journal Title: Resource Geology Volume: 67 Issue: 1 Pages: 35-52
  • DOI: 10.1111/rge.12119
  • NAID: 40021058885
  • Peer Reviewed / Open Access
• [Journal Article] Manganese contents in volcanic pyroxenes in island arcs: case study from the South Yatsugatake Volcanic area, Japan (2016)
  • Author(s): Ayumi Miyasaka, Mitsuyoshi Kimata, Mihoko Hoshino, Takuya Echigo, Masahiro Shimizu,Norimasa Nishida
  • Journal Title: Neues Jahrbuch fuer Mineralogie Volume: 193(3) Issue: 3 Pages: 311-323
  • DOI: 10.1127/njma/2016/0306
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Evolution of the oxidation state of sulfur in the Grasberg porphyry copper-gold deposit, Papua, Indonesia (2018)
  • Author(s): Adi Sulaksono, Yasushi Watanabe, Antonio Arribas, Takuya Echigo, Reza A. Furqan, Clyde A. Leys
  • Organizer: MGEI "Southwest Pacific Resources 2018”
  • Int'l Joint Research / Invited
• [Presentation] Sulfate reduction promoted by magnetite formation in the Grasberg porphyry Cu-Au deposit, Indonesia (2018)
  • Author(s): Sulaksono, A., Watanabe, Y., Echigo, T., Arribas, A.
  • Organizer: 資源地質学会第68回学術講演会
• [Presentation] Lithology, alteration and mineralization of Target H area, Mumbwa Iron-Oxide Copper-Gold district, Zambia (2018)
  • Author(s): Simusokwe, M., Echigo, T., Watanabe, Y.
  • Organizer: 資源地質学会第68回学術講演会
• [Presentation] 秋田県北部発盛地域水沢鉱床における黒鉱中の金銀鉱物の産状 (2018)
  • Author(s): 鈴木照洋，渡辺寧，越後拓也
  • Organizer: 資源地質学会第68回学術講演会
• [Presentation] ウォーターバーグ白金族鉱床の構成岩石および白金族鉱物 (2018)
  • Author(s): 北村未佳，渡辺寧，越後拓也
  • Organizer: 資源地質学会第68回学術講演会
• [Presentation] 愛知県豊田市北部地域における瀬戸陶土層の岩相と構成鉱物 (2018)
  • Author(s): 金澤季生，渡辺寧，越後拓也
  • Organizer: 資源地質学会第68回学術講演会
• [Presentation] 有機鉱物の生成機構およびナノ鉱物の表面構造と反応性に関する研究 (2017)
  • Author(s): 越後拓也
  • Organizer: 日本鉱物科学会年会2017年年会
  • Invited
• [Presentation] 灰長石巨晶の包有物から探る島弧マグマの揮発性成分：佐渡島小木半島産灰長石巨晶を例として (2017)
  • Author(s): 越後拓也・西間木志野・星野美保子・木股三善・清水雅浩・斎藤静夫・西田憲正
  • Organizer: 日本鉱物科学会年会2017年年会
• [Presentation] 佐渡島小木半島産灰長石巨晶の成長機構：包有物が示唆するオストワルト熟成 (2016)
  • Author(s): 越後拓也・西間木志野・木股三善・清水雅浩・斎藤静夫・西田憲正・星野美保子
  • Organizer: 日本鉱物科学会年会2016年年会
  • Place of Presentation: 金沢大学
  • Year and Date: 2016-09-25
• [Presentation] Mineral and melt inclusions in anorthite megacrysts in Japanese island arc: clues to the magma reservoir processes (2016)
  • Author(s): Takuya Echigo, Shino Nishimaki, Mitsuyoshi Kimata, Masahiro Shimizu, Shizuo Saito, Norimasa Nishida, Mihoko Hoshino
  • Organizer: The 26th Goldschmidt Conference
  • Place of Presentation: パシフィコ横浜
  • Year and Date: 2016-07-01
  • Int'l Joint Research
• [Presentation] 溶結凝灰岩における球晶の形成機構：揮発性成分が誘発する脱ガラス化作用 (2016)
  • Author(s): 越後拓也・齋藤 庸一朗・木股三善・清水雅浩・西田憲正・滝沢茂
  • Organizer: 日本地球惑星科学連合2016年大会
  • Place of Presentation: 幕張メッセ
  • Year and Date: 2016-05-26