3-million-year-old canyon discovered under the Brahmaputra in Tibet


A huge 3-million-year-old canyon, thousands of feet deep in places, has been discovered buried under a major river in Tibet.

The canyon buried along the Yarlung Tsangpo (called the Brahmaputra in India) in south Tibet was discovered by a team of researchers from California Institute of Technology (Caltech) and the China Earthquake Administration. The geologists say that the ancient canyon — thousands of feet deep in places — effectively rules out a popular model used to explain how the massive and picturesque gorges of the Himalayas became so steep, so fast.

“When I first saw the data, I said, ‘Wow!’ It was amazing to see that the river once cut quite deeply into the Tibetan Plateau because it does not today. That was a big discovery, in my opinion,” said Prof. Jean-Philippe Avouac of Geology at Caltech. “We used a paleocanyon that was carved by a river. It’s a nice example where by recovering the geometry of the bottom of the canyon, we were able to say how much the range has moved up and when it started moving,” Prof. Avouac added.

Last year, civil engineers from the China Earthquake Administration collected cores by drilling into the valley floor at five locations along the Yarlung Tsangpo.



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