Posted on 03/07/2008 12:18:12 PM PST by rosenfan
WASHINGTON (Reuters) - The Grand Canyon, carved out over the eons by rushing river water, began to form 17 million years ago, making it nearly three times older than previously thought, scientists said on Thursday.
The general consensus among geologists had been that the famed natural landmark in Arizona was about 6 million years old.
But now University of New Mexico scientists say it is far older based on their findings using a technique called uranium-lead isotope to date mineral deposits in caves from nine sites in the canyon's walls.
The cave formations provided a record of a dropping water table as the canyon deepened.
The gorge is 277 miles long, 1.1 miles deep at its deepest point and up to 18 miles wide. The Colorado River that runs through it arises in the Rocky Mountains of Colorado and flows southwest about 1,400 miles to the Gulf of California.
The scientists found that there is a kind of dual history to the canyon, with the western portion starting to form about 17 million years ago when water from a predecessor to the Colorado River began the slow, inexorable process of eroding the rock, they said.
(Excerpt) Read more at reuters.com ...
Popcorn
Impossible. I hear the earth is only 6,000 years old.
Oh, really?............
Clark: ...Its only the biggest gd hole in the world!
Aunt Edna: Clark! Watch your language!
Clark: Make that the second biggest.
Been hearing that for 50 years. Must be 6050 by now.
Ping
helen thomas is older than previously thought too !
I believe that man is around 6000 years old...the earth, nobody really knows.
While it looks like it, "that man" in post 8 is supposedly a women.
Its old as dirt.
One of the most awe inspiring sights on the planet.
Anyone who has not seen this thing of unimaginable beauty should make it a goal to see it before they die.
It is well worth the time and money.
I remember when it was the Grand Gulch.
I second your thought. Finally saw it from ground level a few years ago. Well worth the trip.
Sorry, I thought this thread was about Helen Thomas. Carry on.
More wild guesses.
Technically not, since dirt has been around a lot longer than 17 million years.
Once we get the kids out of the house I want to take her again and spend more time. Maybe go to the bottom like you did. Maybe see it from the North rim.
If I was younger maybe I would take one of the raft trips.
Uranium-lead isotope dating is a "wild guess"?
That’s because for 11 million years it kept telling people it was “39”.
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