Newly discovered canyon poses questions for Tibet

Yarlung Tsangpo River, Zhongba County, China Yarlung Tsangpo River, Zhongba County, China Shutterstock
28 Nov
Fabled Himalayan kingdom Shangri-la may be a myth, but geologists have uncovered a hidden gorge buried beside the Yarlung Tsangpo River in southern Tibet that throws into doubt previous theories on how the famous gorges of the Himalayas were formed

‘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,’ said Jean-Philippe Avouac, Earle C. Anthony professor of geology at Caltech. ‘That was a big discovery, in my opinion.’

Geologists use old watercourses to understand how rivers interact with the land, and how much has changed in a region. ‘In tectonics, we are always trying to use rivers to say something about uplift,’ Avouac said. ‘In this case, we used a paleocanyon that was carved by a river. It’s a nice example of how, 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.’

The discovery came when engineers from the China Earthquake Administration drilled for cores at five locations on the Yarlung Tsangpo River. Researchers at Caltech analysed the samples and identified a paleocanyon. Distinctive sedimentary conglomerates, gravel and large rocks cemented together, helped to confirm the discovery.

Existing models for the region’s geological development could not account for the canyon. As a result, the team discounted the existing model, called tectonic aneurysm. An aneurysm, according to the model, occurs when a river cuts into the Earth’s crust so fast it causes it to heat up, weakening nearby mountain ranges and allowing the region to uplift.

‘But now we have discovered that the river was able to cut into the plateau way before the uplift happened,’ said Avouac. ‘This shows that the tectonic aneurysm model was actually not at work here. The rapid uplift is not a response to river incision.’

Share this story...

Submit to FacebookSubmit to Google PlusSubmit to Twitter

Related items

Leave a comment

ONLY registered members can leave comments and each comment is held pending authorisation before publishing. Please login or register to voice your opinion.

Geographical Week

Get the best of Geographical delivered straight to your inbox every Friday.

Subscribe Today


Aberystwyth UniversityUniversity of GreenwichThe University of Winchester




Travel the Unknown


Like longer reads? Try our in-depth dossiers that provide a comprehensive view of each topic

  • National Clean Air Day
    For National Clean Air Day, Geographical brings together stories about air pollution and the kind of solutions needed to tackle it ...
    REDD+ or Dead?
    The UN-backed REDD+ (Reducing Emissions from Deforestation and Forest Degradation) scheme, under which developing nations would be paid not to cut dow...
    The true cost of meat
    As one of the world’s biggest methane emitters, the meat industry has a lot more to concern itself with than merely dietary issues ...
    Long live the King
    It is barely half a century since the Born Free story caused the world to re-evaluate humanity’s relationship with lions. A few brief decades later,...
    London: a walk in the park
    In the 2016 London Mayoral election, the city’s natural environment was high on the agenda. Geographical asks: does the capital have a green future,...


NEVER MISS A STORY - follow Geographical

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in PLACES...


The next stage in autonomous vehicles is hoping to transform…


Geographical’s resident data cartographer presents a true picture of the…


What impact could an unprecedented incident of ‘river piracy’ have…


Norway is to undercut a mountainous peninsula to create the…


Benjmain Hennig explores global mortality with maps


Last winter’s cold conditions contributed a further influx of road…


As one of America’s biggest cities, supplying clean drinking water…


Cape Town’s Foreshore Freeway Bridge has been left unfinished for…


An interactive map highlights the shocking number of ongoing conflicts…


Repurposed NASA maps show the racial diversity (and segregation) of…


Benjamin Hennig maps Europe's public train networks


A new map of global landslide susceptibility reveals vast geographical…


For decades, scientists have been divided over how these eerily…


The first count of global tree species reveals how many…


The new ‘world’s longest flight’ now spans a distance of more…


For the Swiss, the iconic yellow postbuses are much more…


After years of inaction, could the clean-up of the Venice lagoon…


Following the recent success of New Zealand’s Whanganui river, India’s…


The UN-backed REDD+ (Reducing Emissions from Deforestation and Forest Degradation)…


Where are Europe's earthquakes located? Benjamin Hennig maps the answer