Letters to the Editor
“Are radiometric age-dating 40 Bible-Based Does excess Ar methods and their results ap- ’ Geological Timescale support RATE s propriate for biblical geological Possible 6,000-year-old studies (based on the premise of Timeframe Division periods of a young Earth) and could these Accelerated Earth? Upper Radioactive methods and techniques be useful Decay Present in deriving historical age-dates Middle In a recent article in the Journal Age consistent within the biblical of Creation, Dr Russ Humphreys Lower IUDPHZRUN"´ ¿JXUH writes that large amounts of argon 40 I question this conceptual Upper gas were collected from feldspars in leap. First, why is this approach a Precambrian granite from the GT-2 Ice needed? The answer is found in the Age Middle borehole at Fenton Hill, New Mexico. ¿UVWYROXPHRIWKH5$7(ERRNZKHUH Lower This suggests a young age for this Flood the objective is stated: granite, contrary to the conventional Upper radiometric date of more than a billion “… radioisotopes and the age of Flood 1 WKHHDUWKZHUHVLJQL¿FDQWSUREOHPV Middle years. This claim reinforces earlier Event studies that found anomalously high which must be addressed if young- Lower helium concentrations in zircons of earth creationism was to continue the same rock, work done several years WRKDYHVLJQL¿FDQWLPSDFWRQWKH ago as part of the RATE (Radioisotopes issue of origins both within and Antediluvian 9 and the Age of The Earth2) studies.3 outside the Christian community.” (Pre-Flood World) Curse Humphreys has written extensively So the issue regarding the use 4–6 of radiometric age-dates boils down to on the results of this study and Day Seven now writes that he has silenced the two competing ideas: (1) radiometric Day Six ‘dogs of war’.7 I applaud the excellent GDWLQJLVÀDZHGDQGFDQQRWEHXVHG Creation Day Five Day Four Creation Week research and results that Humphreys LQDQ\VLJQL¿FDQWZD\LQ\RXQJHDUWK Day Three research, or (2) the basic methods of Day Two has demonstrated in addressing Day One the problems of excessive helium radiometric dating are valid, but there is a missing ingredient (accelerated and excessive argon gas diffusion Figure 1. This diagram shows my proposed in naturalistic radiometric dating decay) which has led secular scientists biblical geologic timescale with three shaded methods. However, I have questions to invalid results. boxes corresponding to the three periods regarding the relevancy of using either of time when RATE scientists claim that 40 accelerated radiometric decay occurred. excessive helium or excessive argon to Excess helium and excess Ar The darker the box the greater the level of empirically demonstrate a young earth. Another important question to accelerated radiometric decay based on the findings of the RATE project team. resolve for this study: ‘Is finding RATE Results excess helium and/or excess argon 40 The idea that the mantle is the The results of the RATE study a unique or highly unusual condition source of excess helium has also been suggest that young-earth creationists in igneous rocks?’ The answer is ‘no’. proposed for certain Icelandic basalts: can adopt many of the methods of Excess helium and excess argon 40 “The possibility that primordial naturalistic radiometric dating, but often occur in igneous rocks and it is He has diffused into a reservoir the high concentrations of helium and not the result of radiometric decay: with a composition typical of argon gas in zircons and feldspars, “Damon and Kulp have concluded convecting upper mantle cannot respectively, suggest an event(s) of that this [excess helium and excess be ruled out. If so, the process accelerated nuclear decay. RATE 40Ar] is not solely the result of must have occurred after the scientists claim that these excess deeper burial or the increased rate development of existing mantle gases can be used to convert the old of production of helium and argon heterogeneity, and requires the naturalistic age to a young biblical in the past. They have suggested existence of a deep, primordial one.8 However, this appears to present that this effect may have been the He-rich reservoir.”11 DGLI¿FXOWLGHDWKDWFDQQRWEHFUHGLEO\ result of increased heat production Could the same source be defended with present knowledge. in both mantle and crust and assumed for excess argon 40? The This concept of accelerated decay consequent greater mobilization answer is provided by RATE scientist, raises the question: of the inert gases.”10 Dr Andrew Snelling, who stated:
JOURNAL OF CREATION 26(1) 2012 37 Letters
“All of this evidence clearly shows will not invalidate radiometric age- 9DUGLPDQ/6QHOOLQJ$$DQG&KDI¿Q that excess 40Ar is ubiquitous in dating methods in naturalism. Rather, E.F. (Eds.), Radioisotopes and the Age of the Earth: A Young-Earth Creationist Initiative, volcanic rocks, and that the excess it demonstrates the model-driven Institute for Creation Research, El Cajon, CA, 40 Ar was inherited from the mantle results of their theory, none of which and Creation Research Society, St. Joseph, source areas of the magmas.”12 is relevant or required in creation MO, 2000. science. 3. Humphreys, D.R., Young helium diffusion What about the He and 40Ar Humphreys’ assessment that age of zircons supports accelerated nuclear GHFD\ LQ 9DUGLPDQ/6QHOOLQJ$$DQG age-dates? employing accelerated decay rates of radiometrically derived age- &KDI¿Q() (GV Radioisotopes and the Humphreys claims that the dating of igneous rocks containing age of the Earth: Results of a young-earth creationist research initiative, Institute newly calculated 40Ar age-date for 40 excess helium and excess Ar can for Creation Research, El Cajon, CA, and the Precambrian granite corresponds support the biblical framework of Creation Research Society, Chino Valley, AZ, to that derived earlier from helium. earth history appears unfounded. The pp. 25–100, 2005. Is this empirically true? Humphreys RATE proposal of accelerated nuclear 4. Humphreys, D.R., “Helium Evidence For reported the age of the igneous rock decay cannot be based on ambiguous A Young World Remains Crystal-Clear”, calculated from excess helium in data that can yield almost any desired Publically archived at: www.trueorigin.org/ zircons as “Combining rates and result, especially if the method (e.g. helium01.asp#b2, 2005. retentions gives a He diffusion age of 40K-40Ar) has previously been rejected 5. Humphreys, D.R., “Helium Evidence For ı \HDUV´13 by young-earth creationists.12,15 A Young World overcomes pressure”, Humphreys then calculated the age Publically archived at: www.trueorigin.org/ Additionally, any resulting accel- helium02.asp, 2006. of the Precambrian granite using 40Ar erated derivative age-date should found in feldspar as 5,100 (+3,800/- 6. Humphreys, D.R., “Helium evidence for a be statistically relevant in age (i.e. young world continues to confound critics”. 2,100) years. Although both are within concordant) when compared to the Publically archived at: creation.com/helium- the timeframe of biblical history, the same rock or those immediately evidence-for-a-young-world-continues-to- difference between the two declared adjacent if we are to believe that confound-critics, 2008. ages is 15% and not statistically the accelerated radiometric dating is 7. Humphreys, D.R., Critics of helium evidence same.14 It would appear that excess viable. for a young world now seem silent, J. helium radiometrically age-dates this What young-earth creationists Creation 24(1):14–16, 2010. rock to the Creation Week, where need is an empirical method of 8. Vardiman, L. et al., Summary of Evidence excess 40Ar might correspond to either determining how excess He/Ar gases IRUD
38 JOURNAL OF CREATION 26(1) 2012 Letters
12. Snelling, A.A., ‘Excess Argon’: The Eight helium atoms eight helium 4 atoms, there should ‘Achilles’ Heel’ of potassium-argon and also be a lot of helium 4 deposited argon-argon ‘dating’ of volcanic rocks, ICR Impact #307, 1999. Snelling concluded that U-238 in the crystals. It turned out that in “All K-Ar and Ar-Ar ‘dates’ of volcanic rocks the coolest zircons we studied, we are questionable, as well as fossil ‘dates’ found 80% of the helium that would calibrated by them.” have been deposited by 1.5 billion 13. Humphreys, ref. 3, p. 25. years worth of decay. So in the very 14. Humphreys does not explain why there is FU\VWDOVZKHUHZH¿QGXUDQLXP Pb-206 VXFKDVLJQL¿FDQWDJHGHYLDWLRQFDOFXODWHG concentrated, we also find over a for the excess argon age. This wide range billion years worth of both helium 4 allows the proposed accelerated age to be Nuclear decay in zircon and lead 206 (at today’s decay rates). highly variable, including the possibility that Isn’t the simplest explanation that it is older than the 6,000-year-old Earth. This Figure 1. When zircons form, they chemically raises the question of the utility of accepting attract uranium atoms and reject lead. over a billion years worth of nuclear an accelerated age-date that lies beyond Afterward, the uranium decays, depositing decay occurred in the crystal? If so, ZKDWZHPLJKWGH¿QHDVELEOLFDODJHOLPLWV both lead and helium within the crystal. the helium we found was not ‘excess’ Do young-earth creationists need to employ helium from elsewhere, but simply accelerated nuclear decay if the derived data give wide variability within test results? First of all, studies of zircon that which nuclear decay released crystals forming from melts in the right in the zircons. 15. Snelling, A.A., Potassium-Argon and Argon- Argon dating of crustal rocks and the problem laboratory show that they chemically 6LPLODUO\VLQFHZH¿QGRYHUD of excess Argon, ICR Impact #309, 1999. attract uranium atoms and reject billion years worth of the nuclear Snelling states “We have no way of knowing OHDGDWRPV ¿JXUH 7KDWLVZKDW decay product argon 40 in feldspars if any of the 40Ar measured in crustal rocks geochemists expected from the size nearby, in the same rock, is it not even KDVDQ\VLJQL¿FDQFH´ and valence (number of chemical more reasonable to suppose that over ‘hooks’) of the ions (electrically a billion years worth of nuclear decay Russell Humphreys replies: charged atoms) in the melt. In took place in the rock? particular, the most common type It is peculiar to find a young- The fact that neither as much RIOHDGLRQLVWRRELJWR¿WLQWRWKH earth creationist disliking the results helium nor as much argon would be zircon lattice as it forms, and it has of a young-earth creationist research present in the minerals after more the wrong valence. The upshot is that initiative, Radioisotopes and the than thousands of years of diffusion is when a zircon forms, it contains a Age of the Earth (RATE), and only strong evidence that the ‘billion years’ very low concentration of lead and a speaking up about it seven years after worth of nuclear decay actually took very high concentration of uranium. In the project ended. After all, RATE place within thousands of years. It fact, almost all of the uranium in this offered good solutions to a major puzzles me that Mr. Froede apparently granitic rock is located in the zircons. cannot see that for the helium and conundrum: a century of evidence Next, after the zircon forms, it argon diffusion dates, the error bars for large amounts (up to billions of is a very hard, high-melting-point, overlap. I.e. for 6,000 (r 2,000) years years’ worth) of nuclear decay having dense crystal with a very tight lattice. and 5,100 (+3,800/–2,100) years, the occurred within the short (6,000 ,WLVYHU\GLI¿FXOWIRUXUDQLXPRUOHDG dates overlap from 4,000 to 8,000 years or so) history of this planet. atoms to move into or out of it. It is years. Within their limits of accuracy, One would think every young-earther almost the ‘closed system’ theorists the two methods agree. would welcome a straightforward dream about. So zircons start out with My biggest puzzle is why Mr answer to that problem. very little lead, and very little can Froede resists the simple conclusion In the particular case at hand, move into them. But in the zircons that accelerated nuclear decay has minerals in the granitic rock deep in we examined, looking at the amount occurred. If he were a uniformitarian borehole GT-2 at Fenton Lake, New of uranium present, we found as insisting that decay rates must stay Mexico, US, Mr Froede questions much lead as would be expected from the same throughout all time, I that the helium 4 in the zircons and 1.5 billion years worth of decay (at could understand. But he is not a argon 40 in the feldspar necessarily today’s rates). Moreover the lead was uniformitarian. originated from nuclear decay in mainly isotope 206, the descendant of those minerals. Instead he suggests the principal uranium isotope in the D. Russell Humphreys, Ph.D. that those gases are ‘excess’ could zircon, 238. Chattanooga, TN have come from elsewhere. But a If the lead were produced by UNITED STATES OF AMERICA close consideration of the zircons in decay, then because each uranium 238 particular should dispel that notion. atom decaying to lead 206 releases
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