The Tonaru epidote amphibolite mass is one of several tectonic blocks occurring in the Sambagawa metamorphic belt，central Shikoku，Japan．It consists mainly of various types of epidote-amphibolites with diverse lithology，and minor eclogites surviving after amphibolitization．There are two types of amphibolite：T-I and T-II type amphibolites．T-I type amphibolite is composed of clinopyroxene-amphibolite and serpentinite，and T-II type amphibolite is composed of epidote-amphibolite and eclogite．
EPMA analyses of the constituent minerals in the Tonaru mass show that garnets in T-II type amphibolite are of almandine-rich type，and that omphacites in T-II eclogites have maximum Jd contents of 45 mol.%．Amphiboles from the epidote amphibolites in both T-I and T-II type amphibolites are classified mostly as Ca-amphiboles．Amphibole inclusions in the garnets in T-II eclogites are Na- and Na-Ca amphiboles，whereas symplectitic amphiboles in the matrix
of the eclogites are Ca-amphiboles．White micas in T-II type amphibolites include both paragonite and phengite．