The Grand Canyon, according to researchers at the University of New Mexico, is not nearly so old as generally presumed. The canyon runs 277 miles through the state of Arizona, 18 miles across at its widest and a staggering 6,000 feet in depth. One of the greatest natural wonders the Continental U.S. has to offer, it sees nearly 5 million visitors from all over the world, every year.
The exact age of the Grand Canyon has been the subject of polite debate among geologists for many years, with numbers cited usually in the 70 million year range. Into that debate, a new study conducted by Karl Karistrom, University of New Mexico, Albuquerque, strives to refute the previously held theory that the Grand Canyon – in its entirety – was carved out so many years ago. “We are also refuting the ‘Young Canyon Model’ which claims the canyon was cut entirely in the last six million years.” Karistrom told BBC news. The team used a method known as Thermochronology to determine the age of certain segments of the canyon. By measuring the amount of helium trapped in the rock’s crystals, Karistrom’s team can determine how long the rock has been cooling. Their findings, published in Nature Geoscience has given compelling evidence that the Grand Canyon’s age, is varied by segments.
Hurricane Canyon, a tributary of the Grand Canyon, has been dated to be 50-70 million years old; where as Eastern Grand Canyon has dated 15-25 million years in origin. Both Marble Canyon and the Westernmost sections of the Grand Canyon have been dated at just 6 million years. These findings, according to Karistrom, suggest around 6 million years ago the Colorado river flowed southwest and caused the two larger, much older canyons to merge into the system we know today. Which is primarily what the university bases its claim that the Grand Canyon is not so old on, in part. “We show that the Colorado River used old segments as it found its path from the Rockies to the Gulf of California in the past six million years” Karistrom stated.
This theory would entirely refute the ‘Old Canyon Theory’ proposed in the Journal Science in 2012 by Geologist Rebecca Flowers with the University of Colorado. She states that the geologists making the study knew the age they proposed was going to be controversial. Karistrom, at the time, commented his opinion on the proposal as being “simply ludicrous.”
With so many competing theories and data, Karistrom affirms that these latest studies help shape a more inclusive theory of how the Grand Canyon might have formed. “Whats different here, I think,” said Karistrom to the BBC news, “is that we finally have a description of the Grand Canyon that honors all the hard-won data.” Even so, many scientist still hold to the ‘Old Canyon’ views. California Institute of Technology Geologist, Brian Wernicke for instance, insists that supposing that rock filled the westernmost grand canyon until six million years ago, is rather ludicrous. Wernnicke calls the very idea, in his words “a nonstarter.”
What this all means for the popular Grand Canyon, is also a point of debate. These new findings might eventually bring a decisive consensus, but that is what good science is all about. The origin of the majestic Grand Canyon could remain a mystery forever, or be proven to within a century in the next few weeks. “It continues to deepen today, of course.” Karistrom said, speaking on the pace at which the Grand Canyon grows. “Right now, over the course of the last half a million years or so, its been deepening by about the thickness of a piece of paper every year.” he concludes.
However, even if the University of New Mexico’s claims are correct, and the Grand canyon is not nearly so old as previously believed, it will still remain one of the most breathtaking and majestic natural formations in the world.
By Eric Onofre