부산대학교 도서관

We investigated structural, mineralogical and geochemical characteristics of the fault rocks from the active Atera fault, Gifu Prefecture, Japan. We recognized three dominant structural zones at the Tase outcrop: light gray fault gouge, brown fault gouge and black fault breccia. The light gray fault gouge is mainly composed of clay minerals, and exhibited intense shear foliation. The brown fault gouge shows the clearest linear continuity at the outcrop, cutting other structural zones, but the degree of shearing in this zone is relatively weak. The black fault breccia is composed of rock fragments, originated from surrounding host rocks, and black matrix. Fault rocks in these structural zones show fluid-mobile trace element compositions essentially consistent with those of host rocks, indicating that no fluid–rock interaction at high temperatures above 250 ºC took place in these fault zones.