Newly discovered canyon poses questions for Tibet

Yarlung Tsangpo River, Zhongba County, China Yarlung Tsangpo River, Zhongba County, China Shutterstock
28 Nov
2014
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

Geographical Week

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

Subscribe Today

Target Ovarian Cancer

EDUCATION PARTNERS

Aberystwyth UniversityUniversity of GreenwichThe University of Winchester

TRAVEL PARTNERS

Ponant

Silversea

Travel the Unknown

DOSSIERS

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

  • The Nuclear Power Struggle
    The UK appears to be embracing nuclear, a huge U-turn on government policy from just two years ago. Yet this seems to be going against the grain globa...
    The Air That We Breathe
    Cities the world over are struggling to improve air quality as scandals surrounding diesel car emissions come to light and the huge health costs of po...
    Diabetes: The World at Risk
    Diabetes is often thought of as a ‘western’ problem, one linked to the developed world’s overindulgence in fatty foods and chronic lack of physi...
    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...

MORE DOSSIERS

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...

Mapping

Where in America can the country's various hate groups be…

Water

The southern US state is sinking twice as fast as…

Cities

An increase in visitors is putting severe strain on Iceland’s…

Cities

Air pollution campaigners hold a disco roadblock, but can it…

Cities

Cities the world over are struggling to improve air quality…

Forests

HSBC has requested a Roundtable on Sustainable Palm Oil investigation…

Mapping

Benjamin Hennig explores visions of a world made bright by humanity

Forests

The EU has asked the European court to authorise an…

Forests

Was last year’s El Niño a practice run for future…

Cities

Far from being separate threats, scientists have found links between…

Mountains

Is the official height of Mount Everest accurate?

Mapping

Where in the world is the highest density of languages?…

Cities

The next stage in autonomous vehicles is hoping to transform…

Mapping

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

Water

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

Mountains

Norway is to undercut a mountainous peninsula to create the…

Mapping

Benjmain Hennig explores global mortality with maps

Water

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

Water

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

Cities

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