Jayjay

At TWeb, there's a thread about radiometric dating, and someone brought up Andrew Snelling's paper called Conflicting ‘ages’ of Tertiary basalt and contained fossilised wood, Crinum, Central Queensland, Australia. There's also a shorter summary available at AiG.

Snelling's paper was critiqued in the thread, but I'm still not quite sure what to make of it, so I'm posting the stuff here in case a geologist could help me out with some questions... (I'm a layman, just for the record)

For one thing, the article describes quite a few discrepencies between the estimated ages of the samples, but I'm not sure which of these are serious and which are to be expected:

Discrepancies between the ages reported by different laboratories on the same sample?
Discrepancies between the ages reported by the same laboratory between different samples?
Discrepancies between C14 and K/Ar dating?
Something else?

Which date should we trust, or are the results utterly non-conclusive? Are this kind of discrepancies very usual? Is there a reason to assume deliberate tampering by Snelling (I have the impression he's done it before) to get ambiguous results? Anything else of interest in the article?

Joe Meert

JM: Here's my take on the issue/article. I actually contacted the lab that did the dating. Click on the What about Snellings... question.

http://gondwanaresearch.com/hp/crefaqs.htm

Cheers

Joe Meert

Jayjay

Joe, I took a look at your page when you posted the link at TWeb (thank you very much for it, by the way), but it looks like it's about an altogether different case. Have you looked into this one at all yet?

I am a bit baffled as to why different labs, samples and methods give such disagreeing results, and whether this is unusual in the field of radiometric dating.

Joe Meert

JM: My fault, I assumed it was his wood story. I'll look into it and comment.

Cheers

Joe Meert

Arikay

I wrote something on this not too long ago. Its not very technical, but then again, its amazing how non technical you can be and still refute some of these articles.

---

Hello,

The quotes from the article are in blue.

Dating in Conflict
http://www.answersingenesis.org/docs/1141.asp

“Mainstream geologists would never think of trying to get a radiocarbon (14C) date for the coalified wood in this Mägenwil sandstone, because anything that old should not be datable by this method.”

Yep, they got that correct. Yet for some reason they seem to be doing it anyway. We will see why they should have stuck to their first thought.

“So anything which really was millions of years old would have no detectable radiocarbon left, and would register as giving an ‘infinite radiocarbon age’.”

Right and Wrong.
Right, Anything which is really millions of years old would not give a correct date because it had too little radiocarbon to get a good reading.

Wrong, It will not register “infinite radiocarbon age.”
Using the traditional method (would have been used when this sample was taken).


http://www.talkorigins.org/origins/feedback/may01.html
“The "traditional method" of carbon dating is to concentrate the carbon in a sample, convert it to a gas, and then measure the residual radioactivity of the gas. Even though this is done in a specially shielded chamber, some small amount of background radiation will interfere with the counts. Due to this "noise," even a completely "dead" sample will yield a computed age around 20,000 to 30,000 years (give or take, depending on several factors). That is essentially the limit of the "traditional" assessment technique. For this reason, a result in the 30,000-year range by the "traditional" method is understood to mean "an indeterminately old age." “

So as you can see. It would not have read “infinite radiocarbon age” but will report the noise radiation, which will give it a reading in the 30,000 range.

“Such dating wouldn’t show the wood’s true age, since creationists have long shown that the huge imbalance of carbon in the world due to the global Flood catastrophe would give artificially old radiocarbon dates, especially those from the early post-Flood era.1”

This is the same flood that Fossilized such fragile things as footprints, right?
I have yet to hear how this “catastrophic” flood, could be powerful enough to distort the Carbon dating Method, Yet be calm enough to fossilize these footprints and other fragile things.

“However, if it registered any age at all on the radiocarbon test (and all sources of potential contamination had been eliminated), it would mean that it could not possibly be millions of years old.”

As was shown above, using the traditional method it will always register a date. It is up to the scientist to understand the method well enough to know what that means.

So far, it doesn’t seem like the writer of the article understands how C-14 dating works.

“The result: 36,440 years BP ± 330 years.”

So, we can then decide that there is a huge possibility that the background Noise overwhelmed any readings and gave us an incorrect date in the area of 30,000 years. The date should be read as not enough c14 to beat the background noise, suggesting the sample is Older than 36,000 years.

This is why we should use Radiometric dating within is given range, and also understand what readings we will get if it is outside the dating methods range. That way we will get correct readings.
Scientists know this, unfortunately creationists don’t seem to.

“in line with what one would expect, based on the true history of the world given in the Bible by the One who made all, and Who alone is infinite in knowledge, wisdom and power. The real age is probably less than four thousand years.”

I found this interesting. This sample is supposed to have been distorted by the flood.

The earliest YEC dates of creation are based on Usshers calculations using genealogies in the Bible. They put creation at around 6000 years ago, and the flood at around 4350 years ago.

If this sample was Less than 4000 years old, it would have missed the flood by at least 350 years.

This is an interesting Error, as it seems to either falsify the claim that it was distorted by the flood. Or falsify the belief, using the bible, that creation was 6000 years ago.

Not to mention that he makes a rather arbitrary assumption of the age, and gives no evidence to support it.

“It seems that long-age believers are left with only three options”

Or we are actually left with a fourth Option. That is that the article only gives half the information, and gets the dating system and facts wrong.

Now the question is, Was the writer ignorant of the facts and use of the C-14 dating system? Or, did they purposely give misleading information?

“misplaced faith in the ‘absolute’ ages given by radiometric methods.”

Anyone who understands Radiometric dating would understand that it very rarely gives us “absolute” ages. But it does give us correct ages within the Methods range, when the method is understood and used correctly.
When it is misunderstood and used incorrectly, it will give you bad dates.


As you can see, the only “conflict” is between the writers understandings and reality.

-Ari

Jayjay

Yes, but the dating was performed by (as far as I understand it) two respected laboratories, both of whom gave out dates, implying that the results were within range of whatever method they were using. I'm trying to figure out why the labs didn't notice anything... I think one sample was deemed "undateable", but that's all.

Arikay

From the small amount that I understand, they gave out the dates knowing that the scientist should know that the dates are suggesting that it is beyond the method.

Its similiar to K/Ar datings of 50 year old Lava. The lava was definatly outside of the dating method, and possibly had contamination, but it was still given a date.

The thing is, it seems like few radiometric dating methods gives "out of range" when an object is out of range. It still returns some sort of date. The scientists should know what possible dates and information they will get if the radiometric method is being used out of its range.

In the case of the wood I was talking about, a date that should have been considered out of range, or at least, Highly suspect, was given. Then the creationists quoted it as an accurate fact.

Coragyps

I haven't read the full "peer reviewed" article yet, but how many miners handled these tiny bits of wood before they got packaged for sending off to the labs? Whose pocketknife was used to dig the chips out of the basalt, and had the last traces of Vegemite, or whatever Aussie coul miners eat, been cleaned from it first? What was the uranium content of the basalt - could its neutrons generate traces of 14C in the wood?

Joe Meert

JM: I looked at the article in question and it's really much ado about nothing. If you look back at the link I provided, it indicates why the cleaning methods employed by geochron labs may not have been sufficient to take care of contamination in what are essentially zero-14C samples. Others have pointed out the absurdity of the 'infinite-age' claim. "Standard' C-14 dating does have a practical limit, but the AMS method used here extends the range to near its practical limit. The K-Ar method is sometimes useful in young glassy basalts, but phenocrystic samples can and will produce 'anomalous' ages. What should have been done in this case, is to try the Ar-Ar system which is capable of showing the presence of excess argon or argon loss in the samples. K-Ar is cheap and fast, but does indeed have a host of problems which is exactly why the Ar-Ar method was developed. So, my simple conclusion is that this is a long-winded bag of nothing. I did enjoy reading it as it reminded me of a colleague in grad school. This guy was what I call a methodologist. Methodologists choose a sample and run every possible test they can and then invent a problem to go along with the data.

Cheers

Joe Meert

Jayjay

I still have some questions... forgive me, I'm really not up to date with all these methods. But I'm learning, hopefully.

What does "phenocrystic" mean?

I'm going to do a google search on K/Ar and Ar/Ar right after posting this, but I wonder if there's an easy and short explanation what the problem with K/Ar is, and why Ar/Ar doesn't have this problem? I did some reading at talkorigins on these methods once, but I never did grok what the fundamental difference between the two was...