continental convergence
introduction
Powered by ridge-push and slab-pull, the closure of oceanic domains leads to plate convergence and to the formation of mountain belts where plates meet. When convergence involves the subduction of an oceanic plate under a continental plate a mountain belt develop on the margin of the continental plate above the subduction zone. The South American cordillera examplified subduction-related mountain belt. Eventually, the closure of oceanic domain drag continental plates together. As the last remant of ocean disapears the collision between the two continental plates lead first the shortening of continental margins then, as the two continents collides, to the deformation of large portion of intra-continental domains some hundred to thousand kilometers away from the suture zone. The Himalaya and central Asia examplified collisional orogens. Convergence can develop across bends along major transcurrent faults. The New Zealand Alps are an example of mountain belt on a transcurrent fault. In this section we examine the characteristics of each types of orogen.