Why the Permian accretionary complex of Japan was formed ?

• Project/Area Number: 25400487
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: Yamaguchi University
• Principal Investigator: WAKITA KOJI 山口大学, 理工学研究科, 教授 (80358366)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000); Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2013: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 付加体 / メランジュ / 海洋プレート層序 / 放散虫化石 / 砕屑性ジルコン年代 / マンガン炭酸塩岩 / 秋吉帯 / 超丹波帯 / 舞鶴帯 / 砕屑性ジルコン / ペルム紀 / 錦層群 / 芳井層群 / チャート角礫岩 / 後背地 / ジルコン年代

Outline of Final Research Achievements

The radiolarian age dating and detrital zircon age dating revealed two types of lithostratigraphic units in the Nishiki Group of the Akiyoshi Belt. New stratigraphic sequences of chert breccia are recognized in the Yoshiki Group, eastern Hiroshima. The Ultra Tamba Belt of the Obama area is underlain by the melange and coherent units, while the one of the estern Okayama contains highly disrupted slump deposits. 　The detrital zircon dating and sedimentary petrology on sandstones show that different ages of Late Paleozoic volcanic activities, which provide detrital sediments to the Akiyoshi, Ultra Tamba and Maizuru Belts.

Research Products

• [Journal Article] OPS melange: a new term for melanges of convergent margins of the world化石 (2016)
  • Author(s): Wakita, K.
  • Journal Title: International Geology Review Volume: 57 Issue: 5-8 Pages: 529-539
  • DOI: 10.1080/00206814.2014.949312
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Recognition of ocean plate stratigraphy in accretionary orogens through Earth history: A record of 3.8 billion years of sea floor spreading, subduction, and accretio (2013)
  • Author(s): T.M. Kusky, B.F. Windley, I. Safonova, K. Wakita, J. Wakabayashi, A. Polat, M. Santosh
  • Journal Title: Gondwana Research Volume: 24 Issue: 2 Pages: 501-547
  • DOI: 10.1016/j.gr.2013.01.004
  • Peer Reviewed
• [Presentation] Tectonic significance of chert breccia in the Permian accrenonary complex of the Akiyoshi Belt, southwest Japan (2015)
  • Author(s): Watanabe, R. and Wakita, K.
  • Organizer: the 4th Symposium of the International Geosicences Programme (IGCP) 589
  • Place of Presentation: チュラロンコン大学 (タイ、バンコク)
  • Year and Date: 2015-10-26
  • Int'l Joint Research
• [Presentation] Geology of the Hon Chuoi Island, and its tectonic implication (2015)
  • Author(s): Wakita, K.
  • Organizer: the 4th Symposium of the International Geosicences Programme (IGCP) 589
  • Place of Presentation: チュラロンコン大学（タイ、バンコク）
  • Year and Date: 2015-10-26
  • Int'l Joint Research
• [Presentation] 秋吉帯”芳井層群”のチャート角礫岩の産状と形成プロセス (2015)
  • Author(s): 渡邉亮太・脇田浩二
  • Organizer: 日本地質学会年会
  • Place of Presentation: 信州大学工学部 (長野県長野市）
  • Year and Date: 2015-09-13
• [Presentation] 山口市周南市地域で新たに発見したマンガン炭酸塩岩の産状と放散虫化石 (2015)
  • Author(s): 田中菜月・中川孝典・脇田浩二
  • Organizer: 日本地質学会年会
  • Place of Presentation: 信州大学工学部 (長野県長野市）
  • Year and Date: 2015-09-12
• [Presentation] ベトナム南部ホンチュオイ島の地質 (2015)
  • Author(s): 脇田浩二
  • Organizer: 日本地質学会年会
  • Place of Presentation: 信州大学工学部 (長野県長野市）
  • Year and Date: 2015-09-11
• [Presentation] ペルム紀付加体の形成史 (2015)
  • Author(s): 中川孝典
  • Organizer: 日本地質学会西日本支部例会
  • Place of Presentation: 山口大学 （山口市）
  • Year and Date: 2015-02-21
• [Presentation] 秋吉帯”芳井層群”中のチャート角礫岩とチャート中の砂岩岩脈 (2015)
  • Author(s): 渡邉亮太・脇田浩二
  • Organizer: 日本地質学会西日本支部例会
  • Place of Presentation: 山口大学 (山口市）
  • Year and Date: 2015-02-21
• [Presentation] 秋吉帯ペルム紀付加体中のマンガン炭酸塩団塊から抽出した放散虫化石群集 (2014)
  • Author(s): 中川孝典
  • Organizer: 放散虫研究集会
  • Place of Presentation: 福島県立博物館 (会津若松市）
  • Year and Date: 2014-11-29 – 2014-11-30
• [Presentation] 秋吉帯の錦層群から産出したマンガン炭酸塩団塊とペルム紀放散虫化石 (2014)
  • Author(s): 中川孝典・脇田浩二
  • Organizer: 日本地質学会第121年学術大会
  • Place of Presentation: 鹿児島大学 (鹿児島市）
  • Year and Date: 2014-09-15
• [Presentation] What is “a melange”? - A comparative study on unit of melanges in Mino and Shimanto accretionary complexes, Southwest Japan (2013)
  • Author(s): Wakita, K.
  • Organizer: Geological Society of America, Cordileran Section Meeting
  • Place of Presentation: フレズノ(アメリカ合衆国）
• [Presentation] Permian Tectonic Setting for the Akiyoshi Limestone and Adjacent Geologic Units (2013)
  • Author(s): Wakita, K. and Igawa, T
  • Organizer: The second international symposium of the International Geoscience Programme Project 289
  • Place of Presentation: パナイ島(フィリピン）