THE AGE OF COLLISION BETWEEN INDIA AND EURASIA

One of the major tectonic questions in the study of Tibetan Plateau geology is what was the precise age of collision between India and Eurasia. Obviously, the arc-continental, continent-continental collision between the India and Asian continents is a process that is rather difficult to define. Many controversies have focused on the age of initial collision between these two continents in recent years. As for the definition of collision, the collision process of arc-continent, continent-continent between India and Eurasia has been divided into three stages, which consist of initial collision, the climax of collision and post-collision, every stage could continues for a long period. Based on the synthetic analysis of paleo-geomagnetism, stratigraphy, and paleontology, this paper firstly discusses the age of initial collision between the India and Asian continents and points out that the age of initial collision between India and Asia might start in the late part of Late Cretaceous (about 70～65 Ma). The ages of climax of collision and post-collision have been preliminary discussed in this paper according to the response events of petrology and structural deformation in the process of collision between India and Eurasia. The authors suggest that the ages of climax of collision and post-collision between India and Eurasia maybe occur at about 55～50 Ma and 45～35 Ma respectively, and subsequently shift to intra-continental convergent stage.