Mechanical analysis of the sandstones of the Shinjo group. (III)

Abstract

Statistical studies of the clastic sediments of the Shinjo group have been carried out under the same mechanical treatment as in the previous work. In this paper the Masugata and Kawaguchi areas are used as the test areas for investigating the characteristics and the variations of the sediments. Four types are recognized as the result of the mechanical analysis (median diameter, coefficient of sorting, standard deviation, skewness, and kurtosis). The types Ma and Mb in the Masugata area are practically correlated with the Mitsumori-Sakegawa-Yamuke and Shimizu-Izumikawa formations, and the types Ka and Kb in the Kawaguchi area with the Sakegawa-Yamuke and Shimizu-Izumikawa formations respectively. At least it is possible to be recognized that the marker bed K4 between the Yamuke and the Shimizu is found to be the clear indicator in the vertical differentiation also in these areas as shown in the previous discussion.