Measuring the Age of the Grand CanyonThe Grand Canyon is millions of years old, not thousands; despite the efforts of Young Earthers. Skeptoid Podcast #579 by Brian Dunning Questions abound in our natural world, keeping it ever more engaging for those who study it. One such question is the age of Arizona's Grand Canyon. Two billion years of history are laid bare by the strata it exposes, but what we don't have a complete answer for is when it was laid bare. In science, conclusions are in the millions of years ago. But in other disciplines, claims are far smaller. Today we're going to look at one such claim, and what it means for the state of science in our culture. We can start with the latest science on the age of the canyon. While it's relatively easy to date the rock the canyon is carved from, it's not so straightforward to determine when the canyon itself was carved out of that rock. The two numbers you'll hear most often are 6 million and 70 million years. Now, that's quite a large gap, obviously. The basic technique is to look downstream at the deposits. Deposits can be dated by a variety of methods, and we can look for mineral grains that match part of the exposed rock upstream, then check the age of the deposit it's found in. We can also analyze those mineral grains through a technique called thermochronology, which tells us how long ago that rock cooled. When rock is buried deep, say a kilometer underground, it's hot. When a canyon exposes it, it cools. Thus, thermochronologic data is one way that we can date bits of that silt found in the deposits to learn when it was exhumed from the canyon walls. (Thermochronology, by the way, is fascinating, but beyond the scope of this episode. Put it on your "individual research" list.) 6 million years was the generally accepted result for a long time, until as recently as 2012 when the journal Science published results indicating a possible age of 70 million years. Some of that thermochronologic data can be interpreted to support either age. It's been described as a jigsaw puzzle that's still missing some pieces. Today, although the younger number has broader support, we don't yet have a solid consensus. Geologists generally agree that it's an exciting question, and we're all eager to find out what that final answer will be. But suffice it to say that when we speak of either a young Grand Canyon or an old Grand Canyon, we're talking about either 6 million or 70 million years. But only a few thousand? That particular claim comes from outside of geology, from the Young Earth Creationist crowd. Dedicated to proving the literal truth of the Bible, some creationists have turned their labors to famous "big name" landmarks like the Grand Canyon and invented bogus research projects intended to persuade non-scientists that the Earth is young enough to make Genesis factually true. We talked about one such example in episode 146, How Old is the Mount St. Helens Lava Dome? In this case, the idea is to prove that the Grand Canyon is 4,300 years old, which is the date given for Noah's flood by Biblical literalists. For a long time, the Grand Canyon has been the victim of many such slanders against geology. A recent example was a scientific research permit application received by the park. It was submitted in November 2013 by Dr. Andrew Arthur Snelling, a geologist, who had credentials that appeared legitimate enough to park personnel. His project was to collect samples from inside the park to study folds in layers of soft sediment, and those samples would be collected on two commercial rafting trips coming up in April and July of 2014. Collecting samples of any kind is illegal inside national parks, unless the park grants you a permit to do so. One of the permit's requirements was that at least two peer reviews must be provided, showing that your research has been properly evaluated by other scientists. Snelling provided three. The National Park Service form requires scores be given on a scale of 1 to 5 on each of five aspects of the research. Here are the three peer reviews Snelling provided:
The impressive application landed in the lap of Ronda Newton, the research permitting coordinator at Grand Canyon. Not knowing who these three guys might be, she showed it to Dr. Karl Karlstrom, a professor at the University of New Mexico, who had done a lot of work with the park. The first red flag was that Snelling happens to be the Director of Research for Answers in Genesis, the Young Earth Creationism group that runs the Ark Encounter in Kentucky, perhaps the greatest monument to anti-science on the planet. Karlstrom replied to Newton:
And then of Snelling's three peer reviewers:
Karlstrom pointed out quite a large number of factual and methodological errors in Snelling's proposal, and also pointed out a number of places outside of Grand Canyon where he could collect identical samples:
Dr. Ron Blakey, emeritus professor at Northern Arizona University, was less complimentary of Snelling's proposal:
And finally, Dr. Peter Huntoon, emeritus professor at the University of Wyoming, called a spade a spade, and pointed out exactly what Snelling and his associates were up to:
Newton had heard enough. On March 2, 2014, Grand Canyon advised Snelling that his application was denied, citing only the criterion that this research could be easily done outside the park:
Would that that had been the end of it. Two years later, in February 2016, Snelling resubmitted his proposal, beefed up with a vast bibliography of papers which he believed supported his science. Again, no permit was issued, and in December, a seven-page letter was sent to the park by an attorney at the Alliance Defending Freedom, an enormous nonprofit that litigates legal cases to further the cause of Christian fundamentalism. The letter charged the park with religious discrimination, and closed with a not-very-thinly veiled threat of legal action. A month later in January 2017, the creationists added Congressman Trent Franks to the effort, co-chair for the International Religious Freedom Caucus, and noted anti-abortion advocate. Franks wrote asking for a prompt resolution to Snelling's application, owing to the short time due to the commercial rafting schedules:
And in May 2017, the creationists went thermonuclear and filed the lawsuit on behalf of Snelling, charging the Department of Interior, the National Park Service, and four individuals with violations of the First and Fifth Amendments and of the Religious Freedom Restoration Act. In July of 2017, Grand Canyon acquiesced and granted Snelling's permit. They had to, really; the parks honestly don't have the time or resources available to fight such massively funded efforts. Science is — and should be — done in the field and in the lab. If Snelling was doing science, he would have cheerfully gone to monoclines outside the park three years ago and completed his research. But he didn't, because he wasn't. He took his project instead to lobbyists and to the courtroom. We can now confidently predict headlines trumpeting that new discoveries in the Grand Canyon prove a young Earth, and thus the inerrancy of Genesis as a literal geologic account, despite efforts by the park service to suppress these findings. It's been said that science is true whether you believe in it or not, and this next creationist claim will prove as fleeting as the last; because, somewhere in some lab, real geologists are still working on that question of 6 million vs 70 million years. When we get that finding, one nice thing about it will be that no amount of money from the Alliance Defending Freedom will be able to change it.
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