Emergence and evolution of Himalaya: reconstructing history in the light of recent studies
K. S. Valdiya
India collided with mainland Asia at 65 Ma. The pressure rose to 9-11 kbar in the collision zone. As the Indian lithosphere bent down and its upper crust buckled up as an upwarp in the period 35-45 Ma, the southern margin of Asia became the water-divide of the Himalayan rivers.
The sea retreated from the Himalayan province by the early Miocene, even as the crust broke up along faults 20-22 million years ago.
ivers carried detritus generated by the denudation of the fast emerging Himalaya and deposited it in the foreland basin which turned fluvial around 23 Ma.
The Himadri then became high enough to cause disruption of wind circulation, culminating in the onset of monsoon. The climate change that followed caused migration of a variety of quadrupeds from Africa and Eurasia, bringing about considerable faunal turnovers in the Siwalik life.