When and where did India and Asia collide?

TLDR

The timing of India–Asia collision is a key boundary condition for models of the Himalaya–Tibetan orogenic system, influencing interpretations of Tibetan uplift, continental extrusion, and Cenozoic climate change. The study proposes that continent–continent collision began around the Eocene/Oligocene boundary (~34 Ma) and offers an alternative explanation for events at 55 Ma. The authors use new field evidence from Tibet and reanalyze published data to support their collision timing hypothesis. Refined estimates show India and Asia were not close enough to collide at 55 Ma.

Abstract

Timing of the collision between India and Asia is the key boundary condition in all models for the evolution of the Himalaya‐Tibetan orogenic system. Thus it profoundly affects the interpretation of the rates of a multitude of associated geological processes ranging from Tibetan Plateau uplift through continental extrusion across eastern Asia, as well as our understanding of global climate change during the Cenozoic. Although an abrupt slowdown in the rate of convergence between India and Asia around 55 Ma is widely regarded as indicating the beginning of the collision, most of the effects attributed to this major tectonic episode do not occur until more than 20 Ma later. Refined estimates of the relative positions of India and Asia indicate that they were not close enough to one another to have collided at 55 Ma. On the basis of new field evidence from Tibet and a reassessment of published data we suggest that continent‐continent collision began around the Eocene/Oligocene boundary (∼34 Ma) and propose an alternative explanation for events at 55 Ma.