41  Deviations in Radiometry

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Various radiometric methods can be used to determine the age of a rock, depending on whether the rock contains various unstable radioactive isotopes. Generally, for reasons of cost, only one single method is used. However, if the same rock is measured using different methods, it is possible to get distinguished and systematic deviations.



Today, a number of various methods based on radioisotopes are used for determination of age. If the results of these methods are to be credible, they should agree at least within the usually estimated tolerance limits. As a rule, they do not even come close. Since the measurements show systematic and repeatable deviations, a systematic error must be present in the measuring methods and/or the evaluation.

 For confirmation of such observations, a piece of Cardenas basalt, a lava stone from the Grand Canyon with a conventional age of allegedly 1.1 billion years, was analyzed using four different methods (1). Here are the results:



Potassium-Argon: 516 million years
tolerance +/- 30 million
on 14 specimens
beta decay
Rubidium-Strontium:
892 million years
tolerance +/- 82 million
on 22 specimens
beta decay
Samarium-Neodym:
1588 million years
tolerance +/- 170 million
on 8 specimens
alpha decay
Lead-Lead:
1385 million years
tolerance +/- 950 million
on 4 specimens
alpha decay


These studies showed that specimens subject to alpha decay usually show higher age values than those subject to beta decay. During alpha decay, helium nuclei are formed while beta decay radiates electrons. This shows that the apparent age is higher the heavier the atoms of the parent isotope.

Unfortunately, only few comparative measurements have been performed to date. For this reason, the statistical relevance is relatively low. On further specimens from ten different locations, the measured results were so different that evaluation was not possible. Others, by contrast, could be evaluated well, however yielded distinctive and systematic deviations (2).
 

Accelerated radioactive decay:

A possible explanation for the systematic differences is that the radioactive decay was accelerated during a certain period. It is imaginable that the Earth’s crust was subject to massive neutron radiation during its early development and/or a catastrophic event for a limited time with an increased production of daughter isotopes.

 
Conclusion:
 
It would be desirable for public universities to perform comparative measurements to an increasing extent on materials on which various methods could be used. Since this has hardly been done to date, it is difficult to avoid the suspicion. Someone does not necessarily want the results of radiometry to be questioned. When a rock is tested for its age, normally only one of the possible methods is used.



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References:

(1) Don DeYoung, Thousands¬Ö not Billions, Challenging an Icon of Evolution, Master Books, 2005, page 126.
(2) Larry Vardiman, Andrew A. Snelling, Eugene F. Chaffin, Radioisotopes and the age of the Earth, Vol. 2, Institute for Creation Research, El Cajon, CA, 2005, page 422.
 

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