by Jay Johansen | Jan 4, 2008
Radiometric dating supposedly proves that the Earth is billions of years old. The theory behind radiometric dating sounds very convincing. But does it actually work in practice? When someone tells us that a certain rock is a billion years old, how can we confirm this? No one was there to see it, right?
A recent letter-writer says that radiometric dating is proven because many different methods all give the same results. This would be interesting if true, but it simply isn’t. Many different methods have been proposed to estimate the age of the earth, and they give results ranging from billions of years (e.g. radiometric methods), to a million or so (e.g. influx of salts into the oceans), to thousands (e.g. decay of the Earth’s magnetic field).
One researcher, Dr. David Plaisted, searched the technical journals for studies that compared the results of different dating methods on specific samples. He found only one such study, comparing Potassium-Argon to Rubidium-Strontium, and, he writes, “the results were not good”. He cautiously concludes, “[A]n assumption of agreement appears to be without support so far.”
There are many examples of disagreement.
Potassium-Argon tests on a lava flow from Rangitoto volcano in New Zealand dated it at 400,000 years. Buried in the lava flow are trees trunks, which were carbon-14 dated to 225 years.
Five samples from a lava flow in Washington state were dated by Potassium-Argon, giving ages ranging from 340,000 to 2.8 million years. That’s quite a range! Another dating method gave an even younger age: Eyewitnesses watched that lava flow being formed when Mt. St. Helens erupted in 1980.
Lava flows from Hualalai Volcano in Hawaii were dated at 140 million to 2.96 billion years. In fact Hualalai erupted in 1801.
In some cases the evolutionists offer explanations of what went wrong. They say the lava from Hualalai was under water for many years, which caused certain chemical and physical effects that contaminated the sample. Maybe so. But are they then telling us that all the other sites that have been dated to such long ages were never, ever, in all those supposed billions of years, ever under water or otherwise contaminated?
If when you CAN corroborate the evidence, someone is repeatedly proven to be wrong, perhaps you should be cautious about taking their word for it in cases where there is no way to test their claims.
© 2008 by Jay Johansen
Pharmd143 Mar 16, 2014
Very nice site!
Pharmg911 Mar 16, 2014
Very nice site!
Mike Durbin Mar 18, 2014
I need a little more info. about Hualalai volcano, Hawaii, and Rangitoto volcano, New Zealand... what laboratories did
the rock dating and who was involved? Can you help me?
Jay Johansen Mar 18, 2014
Hualalai: I got this information from "Scientific Creationism", by Henry Morris, page 147. He cites J. G. Funkhouser and JJ Naughton, Journal of Geophysical Research, July 15, 1968, p 4606. I have not read the original journal article. I don't think Funkhouser and Naughton are creationists -- Morris is citing their data, not their conclusions.
Rangitoto: I don't recall where I got that information originally, but a little Internet search turns up a better source than what I likely had to start with: "Age of the Auckland Volcanic Field", by Jan Lindsay and Graham Leonard, School of Environment & Institute of Earth Science and Engineering, The University of Auckland. They cite a large number of researchers and labs as their sources -- they apparently did a bunch of research and collected a large number of data points. See the charts on page 55 and following. They show C-14 dates for materials found within the lava flows ranging from 159 to 1114 years. Then they have K-Ar dates on the lava flows themselves of 146,000 to 465,000. (The discrepancy within each set of dates is not quite as large as those numbers may indicate: there were two separate eruptions which, based on the C-14, they conclude happened ca 225 years ago and 600 years ago.) Note that this study is by no means attempting to discredit radiometric dating and there's no indication that the authors are creationists: the facts I'm citing are side notes to their analysis. In the main text of the article they state: "[A]attempts to date the lava using K-Ar have been unsuccessful due to excess Ar". In other words, we tried to date it using K-Ar, but the answer didn't come out right, so we're ignoring it.
Mike Durbin Mar 22, 2014
Thanks Jay for the response. I bought the 35 pages submitted by Ian McDougall, H.A. Polach, and J.J. Stipp, about the Auckland volcanic field. (Not cheap.) I'm putting a little T.V. program together about the age of the earth so i want to see these papers for myself so i don't end up with egg on my face. The "ABSTRACT" states the findings the same way you do.
I can't find much of anything, "on either side", about the 1997 argon-argon dating method article, by Robert Sanders, Berkeley Geochronology Center, or much of anything about the
argon-argon method itself. Why is that?
Note: If you want a copy of the ABSTRACT or the 35 pages i will send them to you. Thanks.
Jay Johansen Mar 23, 2014
I wrote the original article here as a letter to the editor to my local paper, so it's much more terse than I would have liked, not giving any citations, etc. Yes, I understand you wanting to have primary sources to avoid being embarrassed. (Hey, I just gave a lecture on Canaanite religion at a Bible conference, not likely there would be any pro-Canaanites in the audience to argue with me, but I still went back to primary sources and I was rather uncomfortable with the fact that I didn't have primary sources for a couple of important points.) Anyway, I've seen a fair number of articles in the creationist press on radiometric dating anomalies. Specifically on Ar-Ar dating? I can't think of any, but I haven't been keeping a catalog. I can't think of any rebuttals from the evolutionist side on any of this. I've seen a few comments here and there to the effect of "well of course there are experimental errors here and there, so what?", frankly, I couldn't give you citations for those. Whether I'm just not paying attention to the evolutionist literature, they don't have a rebuttal, they see it as a non-issue not worth rebutting, etc, I can't say.
Mike Durbin Apr 1, 2014
Jay, I found a few Ar-Ar articles, "anomalies". I was surprised to read the official statement, "radiometric dating
is a experimental discipline".
Putting a warning label on radiometric dating should have been done 70 years ago. Keep up the good work.
Chris Falter Jun 23, 2015
@Mike Durbin - Appreciate your paying attention to the original studies. According to Brent Dalrymple of TalkOrigins, the Hualalei study dated xenoliths that were carried by the lava flow, rather than the lava itself. www.talkorigins.org/faqs/dalrymple/radiometric_dating.html
Assuming Dalrymple is correct, the Hualalei study should *NOT* be cited as demonstrating the inaccuracy of K-Ar dating.
But of course, I haven't spent the money to read the original study. Since you have, Mike, would you be so kind as to check its methodology to see whether Dalrymple is correct about the xenoliths?
Chris Falter Jun 23, 2015
@Jay - Regarding the "Age of the Auckland Volcanic Field" study: we can conclude that K-Ar dating could be off by up to 400,000 years or so due to the presence of Ar at the time of formation. So if K-Ar dating shows that a rock is 1.0 billion years old, we should subtract 400,000 years and say the rock is 999,600,000 years old instead. I can agree with that.
We are dealing with the precision of the instrument here.
* You cannot use a physician's scale to weigh a postage stamp, but you can use it to weigh a human.
* You cannot use a radar gun to measure the speed of a snail, but you can use it to measure the speed of a thrown pitch.
* You cannot use K-Ar dating to measure the age of a rock that is 100,000 years old, but you can use it to measure a geological formation that is a billion years old.
Jay Johansen Jul 7, 2015
Chris Falter: I certainly agree with the general principle behind what you say. I think both creation-leaning and evolution-leaning physicists cringe when they hear people say that Carbon-14 dating proves that the Earth is billions of years old, as C-14 is useless for such large ages. To borrow your analogy, it's like using a postal scale to weigh Rocky Mountains.
But I don't think your point is relevant here. Yes, K-Ar has a half-life of a little over a billion years, so you might think that the greatest accuracy would be in dating samples 1 billion years old: you'd have 50% parent and 50% daughter element, and measurement errors would be minimized. But in practice K-Ar is a very complex dating method. K-40 has three different decay modes, so there are multiple daughter products to deal with. Labs rarely measure the K-40 directly because it is such a small portion of the total sample compared to the K-39 and K-41 -- about 0.01%. According to physics.info, K-Ar has been used to date samples from 10,000 to 3 billion years old. Other sources I've seen give a much narrower range, typically a lower limit of 100,000 to 200,000 years and an upper limit of millions or tens of millions. Either way, 400,000 is safely within that range.
The Lindsay/Leonard study that I quote in this article gives the margin of error on their 100,000+ year samples of generally 2 - 3%, like on the 465,000 year age they give the margin of error as +/- 11,000 years. When they give K-Ar dates less than 100,000 years their margin of error is often very high compared to the estimated age, but at no point do they concede a margin of error of 400,000 years. The highest I could find is 40,000, an order of magnitude difference.
That is, evolutionary physicists routinely claim that K-Ar is a reliable method for dating samples considerably younger than 400,000 years (and older, but that's not the issue here). If your claim is that the evolutionists who date these samples and publish the results are seriously confused about when the method is useful and the accuracy of the ages they publish ... well, hmmm, you're starting to sound like one of us crazy creationists. :-)