COLLISIONAL OROGENE BETWEEN NORTH AND SOUTH CHINA AND ITS EASTERN EXTENSION IN THE KOREAN PENINSULA

The relative movement between the north China block (Sino-Korean crato n) and the south China block (Yangtze-Cathaysian craton) had been righ t-lateral along a transform fault during the Late Paleozoic. Devonian deep-water deposits on oceanic crust existed only in the east Qinling and Tongbuo areas where subduction of ocean crust is evidenced by meta morphism, magmatism and deformation. Carboniferous and Permian clastic s and minor carbonates of shallow marine and terrestrial facies were d eposited in a series of narrow basins with general east-west trending, and were controlled by the transform fault. The biota of the basins w ere communicated with the contemporary sedimentary basins in south Chi na, north China and west China. There has been no wide Mesozoic oceani c crust between the north and south China blocks. Tectonic framework o f central China during the Late Paleozoic is quite similar to that of western North America during the Cenozoic. Amalgamation of Sino-Korean craton with Siberian craton at the end of Paleozoic changed the movin g direction of the former to the southeast and contraction was prevail ing between the already juxtaposed north and south China blocks and th e intervening Dabie-Su-Lu microcontinent. The southeast corner of nort h China block was slipped into the concave of the microcontinent, and enabled the latter to be underthrusted to a depth of more than 80 km t o form a ultra-high pressure metamorphic complex in Early and Middle T riassic time. Down-going oceanic crust is not a prerequisite of A-type subduction such as the case in Pamir. The Tan-Lu fault, primarily a h inge fault, took place at the climax of contraction between north and south China blocks in the Late Triassic. Differential uplifting and th e consequent erosion of Dabie and Su-Lu terranes, which are constitute d by piles of subhorizontal thrust sheets, led to an apparent left-lat eral offset. Su-Lu was uplifted higher and unroofed deeper than Dabie. An ancient river system along the east-west trending suture had been drained off into Songpan-Ganzi ocean to the west. Collision of the Ind ian plate with the Eurasian plate shifted the relative movement betwee n the north and south China blocks to the left-lateral and initiated t he Fen-Wei graben since Paleogene. The Imjingang belt between North an d South Korea connects to the suture zone in the Dabie-Su-Lu area. To the east, an active continental margin along the southern margin of th e Hida belt of Japanese islands prevailed in the Late Paleozoic. The O gcheon belt in South Korea is an Early Paleozoic rift zone which is th e extension of the Huanan aulacogen in south China. The Gyeonggi and R yeongnam massifs of South Korea recorrelated to Yangtze and Cathaysian massifs in the mainland of China. Copyright (C) 1996 Published by Els evier Science Ltd