Spatial distribution and features of fracture zones in and around the Atotsugawa Fault, northern Gifu Prefecture

Niwa, Masakazu   ; Ishimaru, Tsuneari ; Kurosawa, Hideki; Shimada, Koji   ; Moriya, Toshifumi*; Takahashi, Kazuharu*

It is suggested that fracture zones formed by fault activities have an effect on hydrologic feature of surrounding rocks. Spatial distribution and features of fracture zones in surveyed areas are informative for site selection and design of geological repositories. Here we show a case study in the Atotsugawa Fault, northern Gifu Prefecture. Field mapping in the study area indicates that the number of fracture zone is sharply reduced, and width of each fracture zones falls within 2 m, with distance of more than 500 m from the surface trace of the Atotsugawa Fault.