from Wiens (
Radiometric Dating)
15. Low abundances of helium in zircon grains show that these minerals are much younger than radiometric dating suggests.
Zircon grains are important for uranium-thorium-lead dating because they contain abundant uranium and thorium parent isotopes. Helium is also produced from the decay of uranium and thorium. However, as a gas of very small atomic size, helium tends to escape rather easily. Researchers have studied the rates of diffusion of helium from zircons, with the prediction from one study by a young-Earth creationist suggesting that it should be quantitatively retained despite its atomic size. The assumptions of the temperature conditions of the rock over time are most likely unrealistic in this case.
I find it interesting that this appears to be the opposite result? One set of zircons with too little helium and another with too much?
You might want to contact Wiens and see what he has to say.
we are limited in our ability to understand
by our ability to understand
Rebel
AAmerican
.Zen
[Deist
{{{Buddha walks off laughing with joy}}}
™ Version 4.2
