Carbon 14 in fossils?

I was recently pointed to an article by creationists who claim that more sensitive carbon 14 methods detect carbon in fossils, and that this is evidence for these fossils being much more recent.I am wondering: is it correct to say that this carbon "contamination" creates a problem for carbon dating, and what explanation does mainstream science provide for such anomalies (if they are anomalies)?Link: Error | The Institute for Creation Research

Here is a bit of the article:Given the short 14C half-life of 5730 years, organic materials purportedly older than 250,000 years, corresponding to 43.6 half-lives, should contain absolutely no detectable 14C. (One gram of modern carbon contains about 6 x 1010 14C atoms, and 43.6 half-lives should reduce that number by a factor of 7.3 x 10-14.) An astonishing discovery made over the past twenty years is that, almost without exception, when tested by highly sensitive accelerator mass spectrometer (AMS) methods, organic samples from every portion of the Phanerozoic record show detectable amounts of 14C! 14C/C ratios from all but the youngest Phanerozoic samples appear to be clustered in the range 0.1-0.5 pmc (percent modern carbon), regardless of geological ‘age.’
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Anomalous 14C in fossil material actually has been reported from the earliest days of radiocarbon dating. Whitelaw [46], for example, surveyed all the dates reported in the journal Radiocarbon up to 1970, and he commented that for all of the over 15,000 specimens reported, "All such matter is found datable within 50,000 years as published." The specimens included coal, oil, natural gas, and other allegedly ancient material. The reason these anomalies were not taken seriously is because the older beta-decay counting technique had difficulty distinguishing genuine low levels of 14C in the samples from background counts due to cosmic rays. The AMS method, besides its inherently greater sensitivity, does not have this complication of spurious counts due to cosmic rays. In retrospect, it is likely that many of the beta-counting analyses were indeed truly detecting intrinsic 14C.
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How do the various 14C laboratories around the world deal with the reality that they measure significant amounts of 14C, far above the detection threshold of their instruments, in samples that should be 14C dead according to the standard geological time scale? A good example can be found in a recent paper by Nadeau et al. [30] entitled, Carbonate 14C background: Does it have multiple personalities? The authors are with the Leibnitz Laboratory at Christian-Albrechts University in Kiel, Germany. Many of the samples they analyze are shells and foraminifera tests from sediment cores. It would very useful to them if they could extend the range for which they could date such biological carbonate material from roughly 40,000 years ago (according to their uniformitarian assumptions), corresponding to about 1 pmc, toward the 0.002 pmc limit of their AMS instrument, corresponding to about 90,000 years in terms of uniformitarian assumptions. The reason they are presently stuck at this 40,000-year barrier is that they consistently and reproducibly measure 14C levels approaching 1 pmc in shells and foraminifera from depths in the record where, according to the standard geological time scale, there should be no detectable 14C.Their paper reports detailed studies they have carried out to attempt to understand the source of this 14C. They investigated shells from a late Pleistocene coring site in northwestern Germany dated by U/Th methods at 120,000 years. The mean 14C levels measured in the shells of six different species of mussels and snails varied from 0.1 to 0.5 pmc. In the case of one species, Spisula subtruncata, measurements were made on both the outside and inside of the shell of a single individual specimen. The average 14C value for the outside of the shell was 0.3 pmc, while for the inside it was 0.67. At face
value, this suggests the 14C/C ratio more than doubled during the lifetime of this organism. Most of their foraminifera were from a Pleistocene core from the tropical Atlantic off the northwest coast of Africa dated at 455,000 years. The foraminifera from this core showed a range of 14C values from 0.16 to 0.4 pmc with an average, taken over 115 separate measurements, of 0.23 pmc. A benthic species of foraminifera from another core, chosen because of its thick shell and smooth surface in the hope its ‘contamination’ would be lower, actually had a higher average 14C level of 0.58 pmc!The authors then performed a number of experiments involving more aggressive pre-treatment of the samples to attempt to remove contamination. These included progressive stepwise acid hydrolization of the carbonate samples to CO2 gas and 14C measurement of each of four separate gas fractions. They found a detectable amount of surface contamination was present in the first fraction collected, but it was not large enough to make the result from the final gas fraction significantly different from the average value. They also leached samples in hydrochloric acid for two hours and cracked open the foraminifera shells to remove secondary carbonate from inside, but these procedures did not significantly alter the measured 14C values.The authors summarize their findings in the abstract of their paper as follows, The resultsshow a species-specific contamination that reproduces over several individual shells and foraminifera from several sediment cores. Different cleaning attempts have proven ineffective, and even stronger measures such as progressive hydrolization or leaching of the samples prior to routine preparation, did not give any indication of the source of contamination. In their conclusion they state, The apparent ages of biogenic samples seem species related and can be reproduced measuring different individuals for larger shells or even different sediment cores for foraminifera. Although tests showed some surface contamination, it was not possible to reach lower 14C levels through cleaning, indicating the contamination to be intrinsic to the sample. They continue, So far, no theory explaining the results has survived all the tests. No connection between surface structure and apparent ages could be established.

The argument is basically garbage. The C-14 is due to contamination of one sort or another; this is proven by the fact that the amount of C-14 in such old samples doesn't correlate with much of anything yet there are lots of correlations with the amount of C-14 in younger samples. The amount is far too small to affect the dating of younger samples. They're trying to convince you that all C-14 dates are suspect because the amount doesn't go exactly to zero as we look at older and older samples with incredibly sensitive instruments.The Earth is far older than 6,000 to 10,000 years, and so is life, no matter how much C-14 is found in Phanerozoic samples. Real scientists are trying to extend the useful range of the method and running into diffculties. Big surprise, big whoop.As for where the contamination comes from, well, it's such an incredibly tiny amount that it's hard to figure that out, and research is ongoing. Air and groundwater infiltration, formation in-situ, ... there's lots of possibilities.There's a good article on the subject at Carbon-14 in Coal Deposits

I'm maybe about to get enmeshed in a discussion along these lines on another board. I can handle most of the questions, but I have one so far unanswered for myself: what are the likely precursors for 14C in ancient carbon? I can see some of the nirtogen in coal or petroleum being irradiated to 14C, as it is in the upper atmosphere, but how, say, in diamonds? Neutron capture by 13C? Or what?Added in edit: There's usually more nitrogen than nirtogen in coal. Sorry.[This message has been edited by Coragyps, 04-20-2004]

C-14 can be produced from, IIRC, C-12 by a fairly rare collision with a particle given off by a decay in the Uranium or Thorium series. That is, the expected level of C14 in a diamond is a function of its exposure to Uranium or Thorium.Note that the creationists got a reputable lab to do the measurements, but they did not subtract the background.There's some more discussion here, but I couldn't find the useful information in a quick perusal.

I also saw this on Dr. Wiens page: That being said I don't think the depth factor would be significant for the diamond dating anomaly and would expect it to correlate with radioactivity the way such anomalies do in coal.

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quote:

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Note that the creationists got a reputable lab to do the measurements, but they did not subtract the background.

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Now that sounds like creationist methodology. Anyone with any experience in a lab knows that if your sample is the same as background, it can be considered to be zero or "none-detected".Just out of curiousity, are their measurements by radiation counts or by mass spec, or a combo?

but what does any of this have to do with dating objects?If it is reasonable to assume that newer samples can be acurately dated, say those going back simply to 2-5 half lives, then that will cover a period of 10,000 to 25,000 years. In those instances, we are still dealing with fairly high levels, certainly detectable levels.With that as a baseline, there is certainly other information, geographic and spatial positioning for example, to move beyond that limited time span by several orders of magnitude.Dating does not depend on one measurement. Rather it is the sum of all available data. If you find an undisturbed site that can be accurately dated to 20,000 years ago, whatever is below that came from an earlier period.If we looked only at radiocarbon dating to establish the age of something, it might well be subject to challenge. But that is not the case. Instead, dating is done by looking at the totality of indicators, only one of which is carbon dating. In addition, items are dated based on proximity to other items, condition, geology, geography and all other site and cultural specific factors.

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The measurements were by mass spec. The actual AGU poster is available at The Enigma of the Ubiquity of 14C in Organinc Samples Older than 100Ka (a PDF; the diamond stuff is at the bottom, just to the right of center). Above the diamond stuff is a notation that background was subtracted from their other measurements.The results do indicate that ther's a tiny bit of 14C in there. However, this is a problem if and only if the only means of 14C production is in the upper atmosphere, which is known to be false. The vast, vast majority of 14C is produced up there, but not all of it.

Not a lot. It does have something to do with reassuring the already-convinced who are not knowledgable enough to realize that this kind of effect would change the vast majority of 14C dates by a small fractionof a percent. It's an issue for those trying to extend 14C dating beyond 50 Ka or so.

Thanks for the link to that thread, JonF. There's some good background info there - neutron capture by 13C looks pretty unlikely, but doesn't appear to have any real documentation.

Perfect example of being in denial, dogmatic, and close-minded. Face the reality....the theory has to go. All the "PRE" historic nonsense has to go. Nature confirms History. Do you want truth or fantasy...it seems that you are more interested in fantasy than reality. The fact that any 14C is there "PROVES" the millions or billions...as the theory changes all the time to fit a new model...LOL!!!!....is nothing more than an "IDEA" that we have tested to be false. Next...

Might I suggest...while you are learning to actually debate science in the science fora instead of making assertions without backing...that you look at the dates of the threads you are replying to.This particular thread hasn't been posted to in over a year.

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Yes...but it would still show up as a message to the intended poster's email like it does mine. Uh, instead of harrassing me so much...why don't you pay more attention...as I stated that if carbon 14 is present as it decays in "MUCH LESS" than millions of years...that is evidence that they are not millions of years old. And by the way, reading up and down this "SCIENCE" forum I have come across many offensive statements by those who refuse to discard the evolution theory. And many posts I might add with "NO BACKING WHATSOEVER". Instead of being so BIASED...why don't you show more NEUTRALITY as an Administrator/Director should?

C-14 dating is not used to establish dates past 50,000 years (tops), thus is has little or nothing to do with the finding that the earth is 4.5 billion years old. Please try to keep your dating methods straight.