Framework and evolution of the middle Paleozoic orogenic belt between Siberian and North China Plates in northern Inner Mongolia

A middle Paleozoic subduction-collision orogenic belt between the Siberian and North China Plates has been recognized in Xilinhot-the south of Sonid Left Banner-Erdaojing area, northern Inner Mongolia, China. It comprises five subunits: mélange belt, foreland deformation belt, molasse and littoral basin, are diorite series and syncollision granitoid series. Evolution history of the orogenic belt can be divided into subduction stage (500-400 Ma) and collision stage (400-320 Ma). The formation of the orogenic belt caused the convergence between the Siberian and North China Plates during the late Devonian. Suture zone corresponding to the mélange belt extends from Erdaojing, Qagan Ura to Honggor. Project supported by Fok Ying Tung Education Foundation in Hong Kong.