Plate Tectonics, the India-Eurasia Collision, and Long-term Global Cooling

Abstract

The Tibetan Plateau, arguably the most dramatic expression of continental collision to have occurred in the last 600 million years, is the result of the ongoing collision and convergence of the Indian sub-continent with Eurasia. The rapid convergence of India with Eurasia, both before and after convergence, as demonstrated by basic plate tectonic theory and the constraints of sea-floor spreading the global oceans. However, a number of “mysteries” remain. For example, why did India move at nearly double the fastest rates of convergence observed across other subduction systems? Why was no major deformation observed in Tibet until nearly 15 million years after collision? Why has fairly rapid convergence continued for 50 million years after collision. Our research suggests that the answers to these long standing problems can be resolved by reexamining the basic assumptions about the collision, and suggests that the India-Eurasia convergence may be responsible for two periods of significant global cooling at approximately 80 and 50 million years ago.