20°c A few clouds
7°c Sunny
Winnipeg Free Press - PRINT EDITION
Grand Canyon older than believed?
May have been home to dinosaurs: study
Jake Bacon / The Associated Press archives Tourists visit the western end of the Grand Canyon. (CP)
LOS ANGELES -- The awe-inspiring Grand Canyon was probably carved about 70 million years ago, much earlier than thought, a provocative new study suggests -- so early dinosaurs might have roamed near this natural wonder.
Using a new dating tool, a team of scientists came up with a different age for the western section of the gorge in the U.S. southwest, challenging conventional wisdom much of the canyon was scoured by the mighty Colorado River in the last five million to six million years.
Not everyone is convinced with the latest viewpoint published online Thursday in the journal Science. Critics contend the study ignores a mountain of evidence pointing to a geologically young landscape and they have doubts about the technique used to date it.
The notion the Grand Canyon existed during the dinosaur era is "ludicrous," said geologist Karl Karlstrom of the University of New Mexico in Albuquerque.
How the Grand Canyon became grand -- with its vertical cliffs and flat plateaus -- has been debated since John Wesley Powell navigated the whitewater rapids and scouted the sheer walls during his famous 1869 expedition.
Some five million tourists flock to Arizona each year to marvel at the 445-kilometre-long chasm, which plunges 1.6 km deep in some places. It's a geologic layer cake with the most recent rock formations near the rim stacked on top of older rocks that date back two billion years.
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 the Colorado River later carved through.
The new work by researchers at the University of Colorado Boulder and California Institute of Technology argue canyon-cutting occurred long before that.
They focused on the western end of the Grand Canyon occupied today by the Hualapai Reservation, which owns the Skywalk attraction, a horseshoe-shaped glass bridge that extends from the canyon's edge.
To come up with the age, the team crushed rocks collected from the bottom of the canyon to analyze a rare type of mineral called apatite. The mineral contains traces of radioactive elements that release helium during decay, allowing researchers to calculate the passage of time since the canyon eroded.
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.
"Arguments will continue over the age of the Grand Canyon, and I hope our study will stimulate more work to decipher the mysteries," Flowers said in an email.
It's not the first time 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.
If the Grand Canyon truly existed before dinosaurs became extinct, it would have looked vastly different because the climate back then was more tropical. Dinosaurs that patrolled the American West then included smaller tyrannosaurs, horned and dome-headed dinosaurs and duckbills.
-- The Associated Press
Republished from the Winnipeg Free Press print edition November 30, 2012 A21
More Latest News
- Back to Top
- Return to Latest News
Poll
Most Popular Latest News
- Man dies after being pulled from vehicle submerged in Winnipeg retention pond
- Grocer Joe Cantor dies at 88
- Winnipeg woman camps out in front of legislature to protest child welfare
- New owner for lumber stores
- Peeping Tom portrayed as sexual deviant in court
- 87-year-old woman tells jurors, 'Somebody had to stand up to' Donald Trump
- Two men now facing first-degree murder charges in Tim Bosma test drive death
- Famous city grocer loved job, customers
- Man killed after test drive a regular guy, and it cost him his life: widow
- Man shot to death in Fla. while being questioned in Boston Marathon bombing investigation
- 87-year-old woman tells jurors, 'Somebody had to stand up to' Donald Trump
- Man dies after being pulled from vehicle submerged in Winnipeg retention pond
- Aboriginal leader Elijah Harper dies
- Woman killed in head-on crash in southwestern Manitoba
- Horrific crash kills minivan driver near Brandon
- Charleswood deaths being investigated as domestic incident
- Grocer Joe Cantor dies at 88
- Winnipeg woman camps out in front of legislature to protest child welfare
- Rainfall warning issued for southern Manitoba
- Crushing blow for amateur sport
- Seattle man dribbling soccer ball to Brazil killed by car on Oregon Coast
- 87-year-old woman tells jurors, 'Somebody had to stand up to' Donald Trump
- Man dies after being pulled from vehicle submerged in Winnipeg retention pond
- Driver crashes into tree near golf course
- Arrests made after raids on local head shops
- Aboriginal leader Elijah Harper dies
- News of city's $17-million winner leaks out on FB
- Passengers from diverted flight to leave Winnipeg Thursday night
- No threat from bag found at Winnipeg Square
- Susan Griffiths dies in Switzerland
- New owner for lumber stores
- Grocer Joe Cantor dies at 88
- Famous city grocer loved job, customers
- Developers to unveil plans for bold downtown tower
- Order of Manitoba recipients announced
- Paying bills and consumer consumption hurting Canadians' ability to save: study
- MP Bruinooge says Bill 18 could infringe on religious freedoms
- Horrific crash kills minivan driver near Brandon
- Two charged in golf course burglary
- Creative industries can fuel a city's economic engine
- New owner for lumber stores
- Aboriginal leader Elijah Harper dies
- Grocer Joe Cantor dies at 88
- Marsh Madness: Photographers Fred Greenslade and Joe Bryksa capture spring migration's grandeur at Delta Marsh
- Horrific crash kills minivan driver near Brandon
- Prominent Canadians back petition to rename Victoria Day to honour aboriginals
- Famous city grocer loved job, customers
- Animals are animals, new ads say
- Skin picking gets status as distinct disorder, should help sufferers access help
- Order of Manitoba recipients announced
- New owner for lumber stores
- Aboriginal leader Elijah Harper dies
- Dogs can experience separation anxiety and depression just like humans
- Ontario steps in to help save ELA
- Saskatchewan professor wants to test the health benefits of nose-picking
- 'Revenge of the redheads': Ginger-haired Montrealers gather in celebration
- An uncommon phenomenon
- Passengers from diverted flight to leave Winnipeg Thursday night
- Hundreds pitch in to dig out houses damaged, destroyed by Ochre Beach ice floe
- Grocer Joe Cantor dies at 88
Ads by Google
You can comment on most stories on winnipegfreepress.com. You can also agree or disagree with other comments. All you need to do is register and/or login and you can join the conversation and give your feedback.
Have Your Say
New to commenting? Check out our Frequently Asked Questions.
The Winnipeg Free Press does not necessarily endorse any of the views posted. By submitting your comment, you agree to our Terms and Conditions. These terms were revised effective April 16, 2010.