Abstract
The Ryoke plutonism took place at the eastern margin of the Eurasian Continent in Cretaceous, before the opening of the Japan Sea. It belongs to the Cretaceous to Paleogene felsic magmatism, extensively occurred in the Inner Zone of the Southwest Japan, which constitutes a segment of the long magmatic belt ranging from Sikhote-Alin, through the southeastern Korea to Fujian, China. The older Ryoke granitic rocks represent a magmatic arc, related to the subduction of the oceanic plate underneath the Eurasian plate in that time. The younger and post-Ryoke granites, however, are not typical volcanic arc magmatism.
