302 JAPAN Figure Tectonic map of the Japanese Islands, showing the distribution of pre Neogene terranes and nappes MTL: Median Tectonic Line, TTL: Tanakura Tectonic Line, Legend 1: South Kitakami Terrane, 2: Akiyoshi Terrane, 3: Mino Terrane, 4: Shimanto Terrane, 5: Hida Abukuma Nappe (After Tazawa (2004).) Mino, Kamuikotan, North Kitakami, Chizu, Ryoke, Sanbagawa, Northern Chichibu, and Southern Chichibu Belts and the Gozaisho metamorphic rocks); and (iv) the Shimanto Terrane (Late Cretaceous to Early Neogene accretionary terrane, comprising the Shimanto, Hidaka and Tokoro Belts and part of the Idonnappu Belt) (Figure 6) These terranes are arranged in a NE–SW direction, subparallel with the extension of the Japanese Islands, and younging towards the south-east, from the Japan Sea side to the Pacific side Besides the four terranes, several nappes (Hida Nappe, Abukuma Nappe, Higo Nappe, etc.) in the Hida-Abukuma Nappe, consisting of Palaeozoic and Mesozoic gneisses, schists, amphibolites, crystalline limestones, and granites, all of which experienced medium-pressure metamorphism in the Triassic (250–220 Ma), thrust over the South Kitakami, Akiyoshi, and Mino Terranes towards the east to south-east These metamorphic rocks were probably derived from the Qinling-Dabie Suture Zone, a collision zone between the North China and South China blocks Tectonic Evolution The tectonic framework of the Japanese Islands was formed through long-term subduction onto mostly the eastern margin of North China, since the Early Ordovician The Silurian to Permian marine faunas (brachiopods, cephalopods, and trilobites) and the Permian floras indicate affinities to those of central Asia (Tien Shan, north Xinjiang), Inner Mongolia, North-east China, and Far East Russia (Primorye), except for the Permian TethyanPanthalassan fusulinoid and brachiopod faunas from exotic limestone blocks in the Jurassic melange