Arizona's Grand Canyon is Much Younger (And Older) Than Previously Thought

Geologists have debated the age of Arizona's Grand Canyon for years. Some estimated that was only 6 million years old, while others have proposed its existence dates back 70 million years.

Geologists from the University of New Mexico propose that is it neither exclusively young nor old. Instead, it's actually both.

Karl Karlstrom and his team of geologists at UNM published their new findings about the Grand Canyon in the Nature Geoscience journal. They believe that the canyon as a whole is relatively young while certain sections of it are ancient.

"We're making a major leap, from thinking of a canyon that has a simply history... to a more sophisticated understanding of how landscapes actually evolve through time," said Karlstrom via an article from NPR.

The Grand Canyon is originally said to have been carved by the Colorado River at least 17 million years ago. The river continued to erode and form the canyon over time into its current formation. But Karlstrom believes that the river found its way across a path of the Colorado plateau only 6 million years ago through canyons that already existed at the time.

Karlstrom was previously part of a team that created a walking path called the "Trail of Time" in 2010 where signs told visitors along the south rim of the canyon that the Colorado River carved the Grand Canyon in the last 6 million years. This was considered a scientific consensus at the time. But having studied the canyon for over 30 years, Karlstrom did not halt his search for answers.

The scientists utilized a new technique to determine erosion. This allowed them to analyze the chemistry of minerals in canyon rocks. In the end, it helped the scientists arrive at the conclusion that the Grand Canyon was cut about 70 million years ago, creating propositions that it is perhaps both young and old.

But now with all of these recent findings, no theory particularly dominates the topic of debate. And scientists and geologists alike, such as Karlstrom, are excited to see where the discussion goes from here.