India-Asia collision was at 24°N and 50 Ma: palaeomagnetic proof from southernmost Asia.

How and when India collided with Asia is crucial for global climate and continental dynamics. We present new palaeomagnetic data showing that the Xigaze forearc basin of southern Tibet was located at 24.2 ± 5.9°N during 54-57 Ma, providing a direct constraint on the position of the southernmost margin of Asia at this crucial stage. Our study suggests 1) the age and locus of the initial India-Asia collision are at ~50 Ma and ~24°N, respectively; 2) Tibet resisted India's northward push during the first ~16 Ma of initial impact from the collision and experienced little latitudinal displacement; and 3) Sometime a little after 34 Ma, Greater India was consumed and thicker Indian Craton subsequently made contact with Asia, resulting in ~6° northward drift of Asia. Our model has implications for the process by which the high proto-Tibetan plateau formed and for the two slowdowns of India's convergence rate with Asia.