Zircons retain too much helium for an old earth (Talk.Origins)

Claim CD015:

Uranium and thorium in zircons produce helium as a by-product of their radioactive decay. This helium seeps out the the (sic) zircons quickly over a wide range of temperatures. If the zircons really are about 1.5 billion years old (the age which conventional dating gives assuming a constant decay rate), almost all of the helium should have dissipated from the zircons long ago. But there is a significant amount of helium still inside the zircons, showing their ages to be 6000 +/- 2000 years. Accelerated decay must have produced a billion years worth of helium in that short amount of time.

Source:
 * Helium diffusion rates support accelerated nuclear decay by Russell Humphreys, Steven Austin, John Baumgardner, and Andrew Snelling. 2003. International Conference on Creationism.
 * Helium diffusion age of 6,000 years supports accelerated nuclear decay by Russell Humphreys, Steven Austin, John Baumgardner, and Andrew Snelling. 2004. Creation Research Society Quarterly 41(1): 1-16.

CreationWiki response:

For a more detailed rebuttal, please read Response to criticism of RATE’s helium diffusion dates

Humphreys' experiments dealt with variable temperatures so that factor is considered in the results. He also considered the problem of pressure, and after researching it he found that in the case of zircons the difference in pressure would affect the diffusion rates by less than 1%, placing it within the margin of error. The affect on the biotite mica would be about one order of magnitude, and Humphreys corrected for it.

The onus here seems to be more properly placed on TalkOrgins & Henke. As Humphreys points out in the conclusion of his response: Indeed.


 * Helium Evidence for A Young World Overcomes Pressure

WRONG! The possibility of contamination was studied, and Talk Origins' would know that if they actually took the time to read the scientific papers. The concentrations of He in the zircons is about 200 times that of biotite, which eliminates the possibility of contamination. The laws of diffusion say that diffusion goes from the greater amount to the lesser, and not the other way around.

In addition the helium diffusion rate fits creation model's predicted values exactly, thus making contamination unlikely.

Duplicate experiments including other locations are planned. Getting duplicate results is just a matter of time.

Also, RATE's zircon data matches that of a site called Fish Canyon Tuff.

P. W. Reiners, K. A. Farley, and H. J. Hickes, "He diffusion and (U-Th)/He thermochronometry of zircon: Initial results from Fish Canyon Tuff and Gold Butte, Nevada," Tectonophysics 349(1-4):297-308, 2002.

That is because they are not large enough to be relevant. For there to be an error large enough to salvage the 1.5 billion year date it would have to reduce the measurements by a factor of 100,000.

Talk Origins must have based this on the wrong location.

This is a baseless claim. What math errors? Besides, the retention level predicted by the uniformitarian model would be so small that it would be at equilibrium with the biotite instead of 200 times the levels of the biotite.

If they did, they clearly corrected it in the 2004 paper, since the total yield was 42% of what would result from nuclear decay.

On [http://www.icr.org/research/icc03/pdf/Helium_ICC_7-22-03.pdf pg. 3] they do suggest the possibility of measurement error and account for it. The fact is that sample 5 is right where it is predicted to be, suggesting that the measurement is not in error.

It turns out that sample 6 is at equilibrium with the biotite around it. Its predicted diffusion rate is consistent with this.

First, this assumes that sample 5 is a result of measurement error despite the fact that it fits the curve perfectly. Secondly, it assumes that the four data points used in calculating the date are the only samples. There are 28 data points that were used to calculate the diffusion rates. They back up the calculated date.

The two typographical errors were found and corrected and as such were not part of the calculations. This was done by checking with the original source.

This is a very small possibility, considering that the data fits the creation model perfectly, while not being even close to the uniformitarian model. This is particularly the case given the insufficiency of the above objections.

Actually he does have a possible solution involving the expansion of space. Humphreys indicates that it is not fully developed, but that progress is being made.

While checking for 3He is a good suggestion, the simple fact is that the Helium (He) concentration of the zircons is 200 times that of the surrounding biotite. This fact invalidates both possibilities.

All that is necessary for this equilibrium to be maintained is for the change to be proportional in each element.

For related information go to Radiometric dating falsely assumes rates are constant (Talk.Origins)