Assessing bulk assimilation in granitic xenoliths

• Project/Area Number: 26400517
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Kochi University
• Principal Investigator: Kawabata Hiroshi 高知大学, 教育研究部総合科学系複合領域科学部門, 准教授 (90392943)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2015: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000); Fiscal Year 2014: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
• Keywords: 同化作用 / ゼノリス / 花崗岩類 / 非平衡溶融 / マグマ混合 / 瀬戸内火山岩 / ゼノクリスト / 花崗岩 / 安山岩 / 非平衡部分溶融 / パイロ変成作用 / 部分溶融

Outline of Final Research Achievements

Crustal assimilation is one of the important magmatic processes especially for arc magmas. This study examined the petrological and geochemical evolution during xenolith assimilation on sub-meter scale, using the xenolith-bearing Miocene Setouchi volcanic rocks. A suite of rock samples indicates that xenolith assimilation proceeds through disequilibrium melting of granitic xenoliths and subsequent mixing of xenolith-derived porphyritic magmas with host andesitic magmas. Combined use of phase relations and thermal conductivity of xenoliths allows us to comprehensively understand the thermochemical and petrological change during assimilation.

Research Products

• [Journal Article] Tectonic implications of Early Miocene OIB magmatism in a near-trench setting: The Outer Zone of SW Japan and the northernmost Ryukyu Islands. (2017)
  • Author(s): K. Kiminami, T. Imaoka, K. Ogura, H. Kawabata, H. Ishizuka, and Y. Mori
  • Journal Title: Journal of Asian Earth Sciences Volume: 135 Pages: 291-302
  • Peer Reviewed
• [Journal Article] 40Ar-39Ar dating and tectonic implications of volcanic rocks recovered at IODP Hole U1342A and D on Bowers Ridge, Bering Sea (2016)
  • Author(s): K. Sato, H. Kawabata, DR. Scholl, H. Hyodo, K. Takahashi, K. Suzuki, and H. Kumagai.
  • Journal Title: Deep Sea Research Part II: Topical Studies in Oceanography Volume: 125-126 Pages: 214-226
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Origin of geochemical mantle components: Role of subduction filter (2016)
  • Author(s): Kimura J.-I., Gill J.B., Skora S., van Keken P.E., and Kawabata H.
  • Journal Title: Geochemistry Geophysics Geosystems Volume: 17 Issue: 8 Pages: 3289-3325
  • DOI: 10.1002/2016gc006343
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] 電界放出型走査電子顕微鏡（FE-SEM/EDX）を用いた珪酸塩鉱物の定量分析ースタンダードレス法の評価ー (2015)
  • Author(s): 川畑 博
  • Journal Title: 高知大学学術研究報告 Volume: 64 Pages: 181-192
  • NAID: 120005746300
  • Open Access / Acknowledgement Compliant
• [Presentation] 安山岩質マグマにとりこまれた花崗岩ゼノリスの非平衡溶融・同化過程 (2017)
  • Author(s): 川畑 博、小倉和樹
  • Organizer: JpGU-AGU Joint Meeting 2017
  • Place of Presentation: 幕張メッセ（千葉県・千葉市）
  • Year and Date: 2017-05-20
• [Presentation] 花崗岩ゼノリスの部分溶融と同化過程 (2016)
  • Author(s): 小倉和樹、川畑 博
  • Organizer: 日本地球惑星科学連合2016年大会
  • Place of Presentation: 幕張メッセ（千葉県・千葉市）
  • Year and Date: 2016-05-22
• [Book] ５万分の１地質図幅「観音寺地域の地質」 (2017)
  • Author(s): 野田篤、植木岳雪、川畑博、松浦浩久、青矢睦月
  • Total Pages: 97
  • Publisher: 産業技術総合研究所 地質調査総合センター