http://creation.com/argon-from-rate-site

A second noble gas testifies to the biblical 6,000 years

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Recently a critic1 of the Radioisotopes and the Age of the Earth (RATE)2 creation research project inadvertently helped me find a new line of evidence supporting the biblical 6,000-year age of the world.3 The latest issue of theJournal of Creation has a technical article4 detailing the new evidence I outline here. It comes from a site that RATE had previously studied, a borehole that penetrated miles deep into the granitic rock of the earth’s crust near a volcanic crater in northern New Mexico, USA. (Figure 1 below).

Photo courtesy of US National Park Service. Valle-Grande

Figure 1. Valle Grande, New Mexico, USA, is inside Valles Caldera, a 16-km-wide volcanic crater. The borehole from which RATE’s zircons came, and the feldspar for this study, is just outside the caldera’s western rim.

Tiny radioactive crystals of zircon extracted from the borehole samples contain uranium-238 and its nuclear decay product lead-206. Assuming today’s slow decay rates, uniformitarian5 geoscientists estimate the rock formation is 1.5 billion years old. But creation scientists found the zircons retained surprisingly high amounts of the helium that the uranium-to-lead decay would have produced. On the assumption that the rock temperature in the past was about the same as it is now, the leak rates we measured of helium from those zircons gave us an age for the rock of only (6,000 ± 2,000) years.6

Over a billion years’ worth of nuclear decay (at today’s rate) made the helium in the zircons during a period of only thousands of years.

This result indicates that over a billion years’ worth of nuclear decay (at today’s rate) made the helium in the zircons during a period of only thousands of years. That is consistent with RATE’s hypothesis of accelerated nuclear decay and accelerated removal of the heat generated thereby.7 RATE found a number of other lines of evidence supporting the hypothesis.8 Uniformitarians, of course, do not want to accept that idea, so they have instead tried to re-interpret the RATE data in order to retain their long ages of geologic time.

The critic wanted to increase the helium-leak age to over a billion years by having the formation be very much cooler in the past than it is at present. That would slow the leakage. He depended heavily on a 1986 paper in the Journal of Geophysical Research9 by geoscientists from three US universities. They modelled past temperatures in the formation using argon data in the borehole as a constraint. Though the paper was one of three I had used as references on the formation’s temperature, it seemed unclear to me and I did not go over it carefully. But the new criticism made me examine it much more closely.

Photo courtesy of NASA.

Valles-CalderaFigure 2. Valles Caldera photographed from space shuttle. GT-2 is RATE borehole. Annotated by Humphreys.

1986 article ignored nearby volcano

To my surprise, I found that this paper had completely ignored the heat that the nearby volcano (Figure 2) would have applied to the formation during the alleged one million years since its eruption. Instead they assumed the temperature of the formation was incredibly low until relatively recently, an assumption that the helium critic welcomed because it supported his assertions. The other two papers I had cited contradicted the low-temperature assumption, one with much more reasonable heat models, the other with actual data.

In my reply10 to the helium critic, I reviewed all three papers carefully, concluding that in the uniformitarian view, past temperatures in the formation would have been significantly higher than today, high enough for long enough to almost completely eradicate helium from the zircons. That means that RATE’s assumption of constant temperatures was actually quite generous to uniformitarians. But Harrison et al.9wanted much lower temperatures than today for most of the alleged million years since the volcano erupted. Why did they want to ignore its heat?

FeldsparFigure 3. Feldspar from Colorado, of the same type (microcline) as in the RATE borehole. Impurities in this variety (amazonite) colour the normally-white crystals blue-green. Black crystals are smoky quartz.
Photo by Wikipedia.

A million-year-old volcano would eliminate argon

The answer relates to the fact that not only helium, but also argon, can leak from minerals. The hotter the minerals, the faster the leaks.11 Feldspar, a common mineral in the granitic rock (Figure 3), contains a lot of potassium, about 0.01% of which is the radioactive isotope potassium-40. Today it decays very slowly into the stable isotope argon-40. Comparing the two isotopes and assuming today’s rate of decay is the basis for the familiar ‘potassium-argon’ dating method, Harrison et al. found that in the deepest, hottest part of the borehole, over 20% of the nuclear-decay-generated argon has leaked out of the feldspar crystals. They also measured how fast argon leaks from the feldspar at various depths in the borehole. Using those data, I show that even assuming that the deepest sample did not get hotter than its present temperature, it would have lost nearly all of its argon in a million years.12 That is why Harrison et al. were forced to assume the temperature was very low until relatively recently. Then, they assumed that some unknown, unspecified source of heat rapidly raised the temperature in just twenty thousand years up to today’s high temperature. Creationist geophysicist Dr John Baumgardner told me that “given the small value for the measured heat conductivity of granite, such a temperature scenario for this site is not defensible, since it violates the simple and well-known physics of heat diffusion.”

Argon data say the site is young

The rock in the borehole is dry, which combined with its low heat conductivity means that its temperature cannot change rapidly. Even if we assume Harrison et al. were correct in postulating a recent (and as yet completely unobserved) intrusion of lava very close to the borehole, the temperature could not have changed by more than 50°C (120°F) over the past five millennia.13 That is a relatively small change. More reasonable uniformitarian heat models14 for the site done by Los Alamos National Laboratory give much smaller changes. That allows us to assume (for simplicity of calculation) that the rock temperature has been roughly constant over those past few thousand years.

The uniformitarian scenario of long ages would leave the rocks with almost no helium and little argon, contrary to the observations of both RATE and Harrison et al.

Then, using Harrison’s own data and equations, I calculate that the feldspar in the rock formation would have lost the observed amount of argon in only 5,100 years, give or take a few millennia according to my estimate of the experimental uncertainty in the data. This age is consistent with results in the Harrison et al. paper, although they wanted to regard the numbers as indicating only the duration of their assumed fast heating pulse after their alleged eons of incredible coolness.

This 5,100-year argon diffusion age is consistent with RATE’s helium diffusion age of (6,000 ± 2,000) years for the same rock formation. So now we have two different age measurements using two different gases from two different types of nuclear decay in two different minerals—and the two methods agree within their error bounds. In contrast, the uniformitarian scenario of long ages would leave the rocks with almost no helium and little argon, contrary to the observations of both RATE and Harrison et al.

Scriptures such as 2 Corinthians 13:1 say that “ … every fact is to be confirmed by the testimony of two or three witnesses.” Helium from the RATE borehole has already testified to an earth that is thousands, not billions, of years old. Now, argon from the same site has become a second noble-gas witness confirming the biblical youth of the world.

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