Talkorigins radiometric dating
In order for an age to be calculated by the 40Ar/39Ar technique, the J parameter must be known.
For the J to be determined, a standard of known age must be irradiated with the samples of unknown age.
This is because 40Ar is an inert gas that does not combine chemically with any other element and so escapes easily from rocks when they are heated.
However, if these known ages are incorrect, then fission track dating that is based on these ages is also incorrect.
Thus fission track dating is not an independent test that helps to verify the accuracy of other tests.
Because this (primary) standard ultimately cannot be determined by 40Ar/39Ar, it must be first determined by another isotopic dating method. while it is often easy to determine the age of the primary standard by the K/Ar method, it is difficult for different dating laboratories to agree on the final age.
Let me emphasize again that this dating method is a relative dating method.In other words, it must be calibrated relative to a different dating method before it can be used to date materials relative to that other dating method.The result is that radiometric dating in general is in danger of being based on circular reasoning.The K-Ar method is the only decay scheme that can be used with little or no concern for the initial presence of the daughter isotope.
Special emphasis is on demonstrating that discrepant results are not the exception, but the rule, and that arguments used to justify so-called good dates are, when closely examined, arbitrary and without foundation. But the reality of the day is that any method based on assumptions can never offer absolute results.All radiometric dating methods rely upon important assumptions usually not mentioned by evolutionists... rely on these few basic assumptions: - Beginning Conditions Known - Beginning Ratio of Daughter to Parent Isotope Known (zero date problem) - Constant Decay Rate - No Leaching or Addition of Parent or Daughter Isotopes - All Assumptions Valid for Billions of Years - There is also a difficulty in measuring precisely very small amounts of the various isotopes What most people dont realize, or at least dont discuss, is that Ar/Ar method is not an absolute dating method.