Abstract
From the fundamental studies on the petrographical constituents, the author describes some petrographical problems concerning to the trend of coalfication in Kayanuma coalfield.This coalfield, in spite of the narrow area extends from north to south about 2 kilometers, has occured in various rank from anthracite to sub-bituminous coal.
It has been recognized thal vitrite is rich in north area, and exinite-durite south area;most of vitrite in north area microscopically consists of rock types vitrinized called it Vitrinization) from the other constituents;moreover, the distribution of exinite-durite, specially exinite, decreases gradually from north to south.It is seemed that the cause of such changes had increased in the degree of coalfication due to ignious rock intrusion.Additionally, have examined proximate analyses, calorific values and botan number, Audibert-Arnu's dilatometer test and cqmpared with the petrographical constituents.
Thus, the author have recognized the interesting results that inclination of coalfication in this coalfield is similar to same curves obtained from the various rank coals in Japan.
