What is argon dating Kenyan chatting sites
The isotope potassium-39 makes up about 93% of natural potassium.
Potassium-40 is radioactive but has such a long half-life that it is primordial - it has been around since the earth was being formed. About 10.7% decays to Argon-40 by emitting a positron.
Potassium can be mobilized into or out of a rock or mineral through alteration processes.And when I look at the Wikipedia article, the discussion is so technical and defensive that I can't actually picture what is going on. As noted in the comments the wikipedia articles (at the time this question was submitted) are contradictory.There are quite a few steps to the logic of how argon-argon dating works but none are too complicated, although I won't go into all of the possible interferences.A problem is that it takes two separate measurements to get the potassium concentration and the argon isotope ratios, increasing the uncertainty.Argon-argon dating gets around many of the issues by measuring only multiple isotopes of argon.