Tectonic evolution of the Japanese island arc system

Growth of the Japanese are system, which has mainly taken place along the c ontinental margin of Asia since the Permian, is the result of subduction of the ancient Pacific ocean floor. Backarc basin formation in the Tertiary s haped the present-day are configuration. The neotectonic regime, which is c haracterized by strong east-west compression, has been triggered by the eas tward motion of the Amur plate in the Quaternary. The tectonic evolution of the Japanese are system includes formation of rock assemblages common in m ost orogenic belts. Because the origin and present day tectonics of these a ssemblages are better defined in the case of the Japanese are system, study of the system provides useful insight into orogenesis and continental crus t evolution.