Grand Canyon Age Intrigues

I don't have an opinion here, but I think it's an interesting debate to have, nonetheless:

Though the exposed rocks are ancient, most scientists believe the Grand Canyon itself was forged in the recent geologic past, created when tectonic forces uplifted the land that the Colorado River later carved through.

The new work by researchers at the University of Colorado Boulder and California Institute of Technology argued that canyon-cutting occurred long before that.

...Their interpretation: The western Grand Canyon is 70 million years old and was likely shaped by an ancient river that coursed in the opposite direction of the west-flowing Colorado.

Lead researcher Rebecca Flowers of the University of Colorado Boulder realizes not everyone will accept this alternative view, which minimizes the role of the Colorado River.

...It's not the first time that Flowers has dug up evidence for an older Grand Canyon. In 2008, she authored a study that suggested part of the eastern Grand Canyon, where most tourists go, formed 55 million years ago. Another study published that same year by a different group of researchers put the age of the western section at 17 million years old.

...Geologist Richard Young of the State University of New York at Geneseo said his own work suggests there was a cliff in the place of the ancient Grand Canyon.

Flowers "wants to have a canyon there. I want to have a cliff there. Obviously, one of us can't be right," he said.

Whatever the age, there may be a middle ground, said Utah State University geologist Joel Pederson.

Researchers have long known about older canyons in the region cut by rivers that flow in a different direction than the Colorado River. It's possible that a good portion of the Grand Canyon was chiseled long ago by these smaller rivers and then the Colorado came along and finished the job, he said.