India, moving northward at a rapid pace, crushed up against Eurasia and created a "crumple zone" we now know as the Himalayan mountains, but analysis of rocks from two regions in the mountains suggest there were actually two collisions, they said.
Scientists at the Massachusetts Institute of Technology say the evidence suggests the tectonic plate bearing India moved northward first collided with a string of islands 50 million years ago before plowing into the Eurasian continental plate 10 million years later.
"India came running full speed at Asia and boom, they collided," MIT geology Professor Oliver Jagoutz said. "But we actually don't think it was one collision ... this changes dramatically the way we think the India/Asia collision works."
The findings may change ideas about the size of India before it collided with Asia, because during the collision part of the ancient Indian plate slid underneath the Eurasian plate, researchers said.
It's not clear how much of India lies beneath Asia, but what is seen of India's surface today is much smaller than it was 50 million years ago, they said.