Iwao Kato

Mechanical and chemical studies of cutting core samples

The purpose of the present work is to make a mechanical purification of the cutting samples for detailed chemical and physical investigations of them. 289 cutting samples from Oguchi exploratory well, R8, in the Nagaoka Basin, Niigata Prefecture were classified according to mechanical analysis, and considerations were made based on histograms, cumulative curves and triangular diagrams drawn on the basis of the size fractions, 8 mesh, 8-9 mesh, 9-16 mesh, and the remainders of the respective samples. The other hand, extractable organic constituents of the 36 specimens selected from these 289 samples were determined.

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

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.