Relationship between fault activity and chemical composition of fault gouge; An Attempt by linear discriminant analysis

Tateishi, Ryo*; Shimada, Koji   ; Niwa, Masakazu   ; Sueoka, Shigeru   ; Shimizu, Mayuko   ; Kanno, Mizuho; Ishii, Chikako; Ishimaru, Tsuneari 

The major difference between active faults and inactive faults is the elapsed time after the latest activity, and while active faults are considered to be on the order of to years, inactive faults are over years. Therefore, even if the phenomena caused by fault activity are the same in both cases, the chemical changes that occur during the subsequent rest period of fault activity may differ significantly. In this study, the chemical composition of fault clay was collected by literature values and actual analysis, and the feasibility of discrimination by the chemical composition examined by linear discriminant analysis. According to the 11 elements selected based on the AIC, 45 active fault samples and 51 inactive fault samples were identified with a discrimination rate of 96%. Among the elements, TiO and PO tended to be concentrated as the latest activity period was newer. These concentration mechanisms are for future work.