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How did crustal shortening help create the Plateau of Tibet?

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A car drives along the Trans-Canada Highway with Mount Sir Donald's sharp, snow-capped peak rising above forested slopes in the Selkirk Mountains, British Columbia. — mountain Mount Sir Donald in the Selkirk Mountains, British Columbia, looms above a segment of the Trans-Canada Highway.

The Plateau of Tibet was formed primarily through the process of crustal shortening, which occurred following the collision of the Indian subcontinent with Eurasia approximately 40 million years ago.12

As India penetrated thousands of kilometers into the Asian continent, the crust of the Tibetan region underwent severe deformation and shortening, causing its thickness to approximately double. This crustal thickening creates high mountains along the plateau's margins; as these mountains erode, debris is transported into the intervening valleys. Over time, these basins fill with sediment, creating a high-altitude landscape characterized by broad, flat valleys surrounded by eroded peaks—essentially a mountain range buried in its own debris.23

While crustal shortening is the primary driver, the plateau's extreme elevation is also supported by the buoyancy of this thickened crust, which can reach up to 70 kilometers in depth. Additionally, some evidence suggests that thermal expansion and volcanism may have contributed to the plateau's high, flat elevation in certain areas.43