Deformation mechanism of the Nobeoka thrust melange

2014 Fiscal Year Final Research Report

• Project/Area Number: 25800283
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Geology
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: KITAJIMA Hiroko 独立行政法人産業技術総合研究所, 活断層・火山研究部門, 外来研究員 (60635796)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: メランジュ / 付加体 / 変形実験 / 延岡衝上断層

Outline of Final Research Achievements

I experimentally studied mechanical properties and deformation mechanism on an accretionary prism, the Shimanto Belt in Kyushu island, to understand the strain accomodation and release in the subduction system. I conducted triaxial deformation experiments on both phyllite from hanging wall and melange from footwall of the Nobeoka thrust fault, and found that the samples deform brittle at lower effective pressure and ductile at higher effective pressure. I observed a difference in strength across the Nobeoka thrust fault; the phyllite is slightly stronger than the melange.

Free Research Field

岩石力学