Grand Canyon light south rim

The Real Age of the Grand Canyon

Updated Feb 24, 2020

For nearly 150 years, experts have been debating about the age of the Grand Canyon: It’s old! It’s young! It’s really, really old! It’s not as old as you think! So, how long did it take for the grandiose feature to be gouged out by the Colorado River and its tributaries?

Grand Canyon light south rim

Grand Canyon Light photo by Kyong Lee

Well, the Grand Canyon is a hodgepodge of old and new sections, as the researchers found in a recent study published in the Nature Geoscience journal.

Some scientists believe that the Grand Canyon is 70 million years old. Others contend that the natural wonder is only between five and six million years old. Both are right.

Scientists examined rocks from the Grand Canyon with the so-called thermo chronology method. With this method, the U.S. researchers were able to determine when the Earth’s interior hot rock came to the surface and cooled there. Accordingly, two middle sections, called the Hurricane segment and the Eastern Grand Canyon segment, were formed between 50 and 70 million and between 15 and 25 million years ago.

However, two other sections are much younger – they were carved out only five or six million years ago. Their creation formed a single canyon which today averages about 4,000 feet in depth. Over the past four million years ago caused the erosion caused the newly formed giant canyon to grow deeper, wider and longer.

Mother Nature’s way to recycle:
Back when dinosaurs still roamed the Earth, rivers were carving a path through what is now Arizona. Eventually, the rivers dried up, and the canyons remained empty, for tens of millions of years. In close proximity, another canyon was carved, about 20 million years ago. Then, just six million years ago, snowmelt from the Rocky Mountains began seeking a path to the ocean, and the rushing water took advantage of these canyons as it headed west to the Pacific, ultimately becoming the Colorado River.

According to Karl Karlstrom, a geologist at the University of New Mexico at Albuquerque who lead the study, parts of the canyon are very old, but the Colorado River carved the Grand Canyon five to six million years ago.

The Grand Canyon is one of the most dramatic and iconic features on Earth. More than five million people plan a Grand Canyon vacation each year to visit the popular Grand Canyon South Rim and North Rim. This natural wonder automatically raises questions: Why do rivers carve canyons of this magnitude? What is the history of the Grand Canyon? Now scientists have new techniques and more sophisticated methods that allow them to interrogate different parts of this history.

If you want to learn more about the Grand Canyon, from it’s unknown history to it’s amazing beauty, check out our Grand Canyon facts!

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