Fig. 1

Location and geology of the Atera fault. a Location maps of the Atera fault (after Kato et al. 2015). b Geologic map of the area around the Tase outcrop of the Atera fault (after Kato et al. 2015). c Photomosaic showing the fault-zone architecture of the Atera fault at Tase. White dots indicate sampling points for mineralogical analyses, white rectangle indicates source of samples for microscopic observation, white dotted boxes indicate positions for photograph images in Fig. 2, and red dotted line indicates the latest slip zone (LSZ). Sample codes: FG fault gouge or fault breccia, HW hangingwall, FW footwall