Research from the Research School of Earth Sciences, the University of Kashmir and the University of Delhi has provided evidence that disputes the widely accepted theory of how India and Eurasia came together. Lloyd White said the team used the ANU designed Sensitive High Resolution Ion Microprobe (SHRIMP) to date zircon crystals from north of the ancient plate boundary between India and Eurasia, and found they were the same age as those from the south.
“Many scientists envisage the India-Eurasia collision as a relatively simple system where two continental plates rammed into each other,” White said. “Our research findings show that it was a bit more complicated than that. We don’t really know where to draw a line on the map that defines which bit was India and which bit was Eurasia, and we don’t know if material was transferred from one plate to another. As Gondwana broke apart, new volcanic islands and relatively small tectonic plates were created between India and Eurasia. What we now think is that these islands and small plates got sandwiched between India and Eurasia as they crashed together. It was much more like a multi vehicle freeway pile up than a prang between two cars.”
White said the research fundamentally questioned our assumptions of the tectonic boundary between India and Eurasia.
“We found that the zircons from what many people consider to be Eurasia had the same age record as those from India,” he said. “This indicates that the Karakorum and Pamir regions, north of the Himalayan range, were once a part of, or derived from the Gondwana supercontinent.”
White said more research was needed to create a better understanding of the earth many millions of years ago. “It is important that we know where the ancient boundary existed between these two plates as we try to unravel what the earth looked like before India rammed into Eurasia.”
The article can be accessed at the American Geophysical Union website.