1949 年 55 巻 644-645 号 p. 59-64
The gneissic rocks, tire oldest rocks outcropping in the Kosiri District of the Santyoku Coal Field, had a ridge-shaped form on its surface at the beginning of the Cambrian Epoch., The Tyosen System becomes somewhat thinner at the apot which covers the ridge., The structural graben in NNE direction was formed by the faulting during the Mesozoic Era, succeeded by the Bukkokuzian mazmatic action., The imbrication in the southern part was due to the existence of the ridge-shaped Pre-Cambrian mass.,