Grand Canyon
Grand Canyon is just six million years old, researchers say.

The Grand Canyon is over ten times younger than was previously thought, being just five or six million years old.

Scientists at the University of New Mexico in Albuquerque published their findings in Nature Geoscience, saying they have ended an age-old debate about the Grand Canyon's origins.

Previous research had suggested the landscape dated to around 70 million years. However, the researchers say this is not the case, and that it formed a maximum of six million years ago when older, shorter canyons linked together, Nature magazine reports.

Karl Karlstrom, a geologist involved in the study, said: "I think we've resolved the 140-year-long debate about the age of the Grand Canyon."

The colourful layers of rock that make up the Canyon date to around 1.8 billion years but the age at which it formed, becoming the iconic landscape it is today, has been strongly debated over the years.

Karlstrom believes that while parts of the canyon may date back tens of millions of years, as a whole it is much younger.

The team used the helium technique, which determines dates of minerals by looking at the helium atoms produced by radioactive uranium decay that diffuse out of the mineral depending on how warm a rock is, as well as other dating methods to find out the Grand Canyon's age.

Two stretches of rock near the canyon's middle were very old. One was between 15 and 25 million years old, while the other was 50-70 million years old, the researchers found.

However, other segments of the canyon were much younger: "Different segments of the canyon have different histories and different ages, but they didn't get linked together to form the Grand Canyon with the Colorado River running through it until five to six million years ago," Karlstrom said.

While their evidence points to a younger canyon, other researchers remain adamant it is older.

Rebecca Flowers, of the University of Colorado Boulder, whose 2012 study estimated the Grand Canyon to be 70 million, said: "It will take a bit more time to understand fully why their interpretations are so different from ours."

Geologist Brian Wernicke, who has also argued for a more ancient canyon, added: "That just hit me like a ton of bricks. They're not thinking this through."