Evolution of Permian island arc in the Kurosegawa Belt based on petrology of clastics

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400495
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Hara Hidetoshi 国立研究開発法人産業技術総合研究所, 地質情報研究部門, 主任研究員 (60357811)
• Research Collaborator: HIRANO Miho ; UEDA Hayato ; TAKAHASHI Toshiro ; IMANAKA Rikako
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 黒瀬川帯 / ペルム紀 / 砕屑岩 / 化学組成 / 砕屑性ジルコン年代

Outline of Final Research Achievements

We have studied the petrography, geochemistry, and detrital zircon U-Pb ages of sandstones from shallow-marine forearc sediments, and accretionary complexes (ACs) within the Kurosegawa belt of Southwest Japan. The provenance, source rock compositions, and U-Pb ages for the sediments and accretionary complexes have allowed us to reconstruct the geological history of the Permian arc and forearc regions of the Kurosegawa belt. During the Middle Permian, the ACs were accreted along the eastern margin of the South China block. The Middle Permian arc was an immature oceanic island arc consisting of andesitic to felsic volcanic rocks. During the Late Permian, the ACs formed in a mature arc, producing voluminous felsic volcanic rocks. A forearc basin developed during the late Middle to Late Permian. These rocks formed in a forearc region of a Permian island arc associated with the subduction of Panthalassa oceanic crust along the eastern margin of the South China block.

Free Research Field

地質学