82 K. Wakita / Journal of Asian Earth Sciences 72 (2013) 75–87 occurred during the Middle to Late Permian. The components of these accretionary wedges are Carboniferous to Middle Permian limestone associated with basalt, Permian chert including radiolarian remains and sponge spicules, felsic tuff, sandstone, mudstone and conglomerate. These rock types were tectonically stacked to form the accretionary complex, together with the chaotic mélanges of the Tsunemori Formation. Sediment accretion was contemporaneous with the collision between the North and South China blocks. The collision was a the possible trigger for the provision of sediments to the ancient trench which now form the Permian accretionary wedges of the Akiyoshi and Ultra-Tamba belts. Accretionary complexes were neither formed nor tectonically eroded during Early Triassic time.