Grant-in-Aid for Scientific Research (A)
Scientific Drilling was conducted to reveal the fault mechanism and evolution of the seismogenic splay fault in subduction zone. Target fault is the Nobeoka Thrust in Kyushu, which is a fossilized splay fault. Core analysis recoverd by drilling and bore-hole logging was operated.The result presents that the physical properties of elastic wave velocity, porosity, and electoric resistivity clearly show a systematic variation around the fault core of cataclasite originated from fault gouge and surrounding damaged zone.Micro cracks and faults with slicken-sided fault surface present ancient stress field in terms of inversion method of fault analysis. The result clearly suggests that the stresss field changed from reverse fault regime to normal fault regime. This change in stresss field might be related to the dynamic change before and after the seismogenic thrust.
Earth, Planets and Space
Progress in Earth and Planetary Science
Proc. IODP, 333
Journal of Structural Geology
Geochem. Geophys. Geosyst.
Earth and Planetary Science Letters
Geochemistry, Geophysics, Geosystems
Volume: (In press)
Earth Planet. Sci. Lett.
Attribution of KAKENHI