[SGL35-P03] Development of direct dating methods of fault gouges focused on the latest fault slip event
Keywords:fault gouge, fault activity, dating, deep borehole drilling, high-velocity friction test, fault damaze zone
This study includes the following 1)-3): 1) AR condition check: We conduct a deep borehole observation throughthe target fault damage zone to measure physical temperature, pressure and geological conditions in which the sample expecting a reliable dating can be acquired. We are now drilling a deep borehole with multiple depths through the Nojima Fault ruptured during the 1995 Hyogo-ken Nanbu earthquake to understand conditions of AR. 2) Luminescence and electron spin resonance (ESR)dating: We apply the luminescence and ESR dating techniques to estimate precisely determination of the age of the latest fault event. 3) Friction test: Rotary-shear high-velocity friction tests using natural fault gouge under water-pressure conditions are expected to clarify frictional behavior of faulting and AR conditions. Combining results from 1)-3), integrated analysis on fault activity will be performed. Our goal of this study is to establish the dating methods of fault gouges for precise determination of the age of the latest fault slip event.