Numerical constraints on the one‐stage and two‐stage Greater India collision models

Abstract

India‐Asia collision is generally believed to have collided since 55 ± 5 Ma, with a total amount of convergence of 2900–4400 km. Besides the overriding Tibetan lithospheric shortening, a large amount of convergence has to be accommodated by the subducting plate of Greater India. Three typical India‐Asia collision models have been proposed, including the Greater Indian Continent (GIC) model, Intra‐Oceanic Arc model and Greater Indian Oceanic Basin model. In this study, a large‐scale 2D numerical model, driven by the reconstruction‐based India‐Asia convergence rate, have been conducted to evaluate these three major models. The model results indicate that the one‐stage GIC model favours later initial collision at ≤50 Ma. For the two‐stage collision, the large amount of convergence can be easily accommodated by modifying the length of oceanic subduction after the first stage of continental collision. This study provides systematic numerical constraints for the favourable conditions of each model.