Radiometric dating is a complex process complicated by amy poehler dating 2016
Potassium - Argon and Argon - Argon dating are based on the current understanding that radioactive Potassium-40 decays to the stable form, Argon-40 with a half-life of approximately 1.25 billion years. The conclusions of Renne and his team read as follows: Ar can be identified in volcanic sanidine, and while perhaps negligible in pre-Holocene rocks, it has important consequences for sample at the limit of the methods applicability.
If one starts with an originally pure sample of parent element, then the proportion of parent to daughter tells us the number of half-lives, which has been used to find the supposed age of igneous rocks. Further improvement in precision of Ar dating are most commonly used to "prove" the ancient age of many life forms, I will discuss these dating methods specifically in more detail and show that they, along with the other common methods of isotope dating, are to be highly questioned.
For example, Naeser and Fleischer (Harvard University) showed that, depending upon the calibration method chosen, the calculated age of a given rock (from Cerro de Mercado, Mexico in this case) could be different from each other by a factor of "sixty or more" - - "which give geologically unreasonable ages.
In addition, published data concerning the length of fission tracks and the annealing of minerals imply that the basic assumptions used in an alternative procedure, the length reduction-correction method, are also invalid for many crystal types and must be approached with caution unless individually justified for a particular mineral." [emphasis added] It is thought that the date of the impact can be dated by using various radiometric dating methods to date the tektites.
That is why it does not matter how long the magma was in the volcano before it erupted.
They believe that when the volcano erupts, all the Scientists are well aware of this problem and use various calibration methods to "correct" for this problem. However, 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.
Also, even if the argon-argon dating method does eliminate the "contamination" problem, it does not solve the problem of original argon. Renne tested Ar-Ar dating by checking it against the 79 A. This is approximately 2,500 times as much Ar as is found in natural muscovite.
A problem with fission-track dating is that the rates of spontaneous fission are very slow, requiring the presence of a significant amount of uranium in a sample to produce useful numbers of tracks over time.Additionally, variations in uranium content within a sample can lead to large variations in fission track counts in different sections of the same sample.Because of such potential errors, most forms of fission track dating use a form of calibration or "comparison of spontaneous and induced fission track density against a standard of known age.The principle involved is no different from that used in many methods of analytical chemistry, where comparison to a standard eliminates some of the more poorly controlled variables.In the zeta method, the dose, cross section, and spontaneous fission decay constant, and uranium isotope ratio are combined into a single constant." This difference might not seem like much, but when it comes to dates of over one or two million years, this difference amounts to about 25-30% in the estimated age value.