Argon radiometric dating brian hallisay dating joanna garcia
The mineral sanidine, the high-temperature form of potassium feldspar, is the most desirable.
But micas, plagioclase, hornblende, clays, and other minerals can yield good data, as can whole-rock analyses.
Because Ar has a very short half-life, it is guaranteed to be absent in the sample beforehand, so it's a clear indicator of the potassium content.
The advantage is that all the information needed for dating the sample comes from the same argon measurement. This method is commonly called "argon-argon dating." The Ar-Ar method is considered superior, but some of its problems are avoided in the older K-Ar method.
However, there may be other explanations for this apparent age. I also believe that the evidence indicates that the earth has recently undergone a violent catastrophe.The potassium-argon (K-Ar) isotopic dating method is especially useful for determining the age of lavas.Developed in the 1950s, it was important in developing the theory of plate tectonics and in calibrating the geologic time scale.Also, the cheaper K-Ar method can be used for screening or reconnaissance purposes, saving Ar-Ar for the most demanding or interesting problems.These dating methods have been under constant improvement for more than 50 years.