Relationship of exchangeable cations in fault gouges with their whole-rock chemical compositions

Kanno, Mizuho; Niwa, Masakazu   ; Shimada, Koji   ; Tateishi, Ryo*

It has been reported that there is a slight difference in the chemical composition of the whole rock between the fault gouge generated by fault activity and the uncrushed host rock. The reason for this is not clear, but since many fault gouges are rich in clay minerals, it is possible that the elements adsorbed on the surface of the clay minerals have some effect. Therefore, exchangeable cations were extracted by substituting cesium ions, which are easily adsorbed on the clay mineral surface, for the fault gaudis of active faults and inactive faults, and compared with the whole rock composition. A concentric logarithmic ratio transformation was used for the comparison. As a result, the concentration of inactive faults tended to be higher than that of active faults in Rb.