1996 年 1996 巻 15 号 p. 9-16
The Kamishiro fault, extending for at least 20 km from the north Hokujyo basin to the south of Lake Kizaki, is one of major active faults along the Itoigawa-Shizuoka Tectonic Line in central Japan. We investigated detailed features of fault morphology along this fault, by interpretation of large scale aerial photographs. It became clear that faulting characteristics at the both ends of the Kamishiro fault are essentially different. At its northern end, the fault has become inactive progressively southward with time. However, the southernmost portion of the fault is still active in Holocene time, and continues southeastward to the Eastern Boundary fault of Matsumoto basin.
At the southernmost portion of the Kamishiro fault, we also found evidence that remarkable thrust-front migration have occurred recently. Young offset features along the main portion of the Kamishiro fault suggest that at least one or two faulting events have occurred in Holocene time, and the latest event occurred probably in historic time.