Abstract
On the southern slope of Mt. Ogi and Momokura in Yamanashi Prefecture, there runs a thrust fault line where an easy slope lies toward the River Katsuraa Though it seems as if it were the river terrace of the River Katsura, the slope consists of rock dust called Miyatani rock-dust-bed containing rock-dustbed slate, hornfels, diorite and andesite and the fine material bed alternately. According to the results of my observation, it is 24.82 meters thick at Jakotsuzawa, and the Miyatani rock-dust-bed runs down with a dip of 8°_??_14° from Mt. Momokura to the River Katsura or the River Kuzuno, The upper part is seen even when the surface of the earth is cut, and blue-grayband of clay material containing tiny plantseeds lies in the lower.
Judging from the facts I conclude as follows:
1) The bed rock is of the conglomerate of the River Katsura.
2) Upon the bed rock were deposited in the still water blue-gray band and Miyatani rock-dust-bed.
3) After that the bed rock was elevated and the present surface was formed, but rejuvenation took place again.
