Thermal processes of seismogenic zone faults in plate subduction zone revealed by thermochronologic analyses

2014 Fiscal Year Final Research Report

• Project/Area Number: 24340123
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: Kyoto University
• Principal Investigator: TAGAMI Takahiro 京都大学, 理学(系)研究科(研究院), 教授 (80202159)
• Co-Investigator(Kenkyū-buntansha): TSUTSUMI Akito 京都大学, 大学院理学研究科, 助教 (90324607)
• Co-Investigator(Renkei-kenkyūsha): WATANABE Yumiko 京都大学, 大学院理学研究科, 助教 (20509939)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 熱年代学 / 温度履歴 / 震源断層 / 四万十帯 / 付加体

Outline of Final Research Achievements

Thermal history of fault zones were analyzed by thermochronology, in order to reconstruct the history of fault motions as well as to quantitatively assess relevant heat generation and transfer. The estimation of the time of fault motion and modeling of heat generation and transfer were conducted by applying the fission-track and other methods to seismogenic zone faults of plate subduction zone. As a result, the time of heating episode was estimated as 48±6Ma(2SE) by thermal history inversion of zircon FT data. The age is best interpreted by the time of activity of“out-of-sequence thrust” during the formation and evolution of the Shimanto accretionary complex.

Free Research Field

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