Structural deformation of Gaochuan Terrain in western Dabashan Tectonic belt and its significances

The Mianlue tectonic belt, trending in west to east, was regarded as the suture zone between the North China and South China continents during the Indochina movement and it is very important for the formation and evolution of China continent. But the extension of the belt eastwards and westwards hasn’t been got an affirmative conclusion. Especially, from Mianxian of Shaanxi province to Suizhou of Hubei province, there have been no any evidences about the suture zone were found. In some previous important papers, the authors regarded the Mianlue suture zone turn to south from Lianghekou town of Ningshan county. Then it goes through the Gaochuan slab and along the arc belt of Dabashan to Suizhou of Hubei province eastwards. In our paper, the authors found that the Gaochuan slab is an allochthonous geological terrain and named it as the Gaochuan Terrain. The Gaochuan Terrain is a dextral strike slipping system composed of some strike slipping faults trending in nearly south to north and some strike slipping shearing folds with axes trending in nearly south to north. The authors directed that the Terrain was wedged into the Dabashan belt from original the Mianlue suture zone when the Dabashan thrust belt thrust towards south. It is only a shallow geological slab of the crust under duress between the Dabashan thrust belt and the Dabashan foreland belt. The present location of the Gaochuan Terrain doesn’t represent the eastern extension of the Mianlue suture zone. Therefore, the arc Dabashan tectonic belt isn’t the location of the final collision of the south and north China continents.