A study published in the journal Science on Thursday claims the Grand Canyon is much older than thought. Prior to the study led by geologist Rebecca Flowers of the University of Colorado, it was thought that the gorge was 6 million years old.
But after anlayzing chips of rock taken from the western portion of the canyon, Ms. Flowers and geochemist Kenneth Farley believe dinosaurs used to roam the Grand Canyon, because it’s 70 million years old. Studies conducted to determine the origin of the canyon claim it was formed by the Colorado River.
The LA Times reports:
The prevailing theory that the Grand Canyon was carved 5 to 6 million years ago is supported by the absence of river sediment dating from before that time in certain areas near the canyon. But just because the Colorado River didn’t flow then doesn’t necessarily mean the canyon wasn’t there, Flowers said.
The main challenge in determining how and when the Canyon was formed is to read the carvings in the rocks. In order to be as accurate as possible, the team of researchers measured the presence of helium and its distribution inside a mineral called apatite.
By detecting and measuring how much helium remained in exposed apatite she collected from the Grand Canyon’s walls, Flowers calculated that the rocks had cooled to less than 30 degrees Celsius about 70 million years ago — suggesting that some kind of canyon was already present by then.