抄録
Precision of the degree of graphitization (GD) is evaluated based on repeated experiments on a sample of pelitic schist, and analyses on ten pelitic schists collected from an outcrop. The experimental error is ±2 in two sigma confidential level at GD=31 and GD=26, respectively. The results suggest that if GD value difference is larger than 6, two neighboring samples have the discontinuous metamorphic grade. The systematic sampling and experiments along the direction normal to the strike, revealed the discontinuous boundaries of the metamorphic grade existing at a upper stream of the Sanbagawa-river and at an outcrop of the Arakawa-river, i.e., the boundaries between the shuffled cards Miyashiro (1994). The former boundary is serpentinitic greenschist within the pelitic schists, the latter one, the thrust plane in pelitic schists. A thick layer having continuous GD value also exists in the Sanbagawa metamorphic terrain as revealed by the experiments of the Kamabuse-yama boring core of 280m depths.
