Problems in the radioisotope dating method
An event like metamorphism could heat the crystal to the point where Pb will become mobile.
Other minerals that also show these properties, but are less commonly used in radiometric dating are Apatite and sphene.Prior to 1905 the best and most accepted age of the Earth was that proposed by Lord Kelvin based on the amount of time necessary for the Earth to cool to its present temperature from a completely liquid state.Although we now recognize lots of problems with that calculation, the age of 25 my was accepted by most physicists, but considered too short by most geologists. Recognition that radioactive decay of atoms occurs in the Earth was important in two respects: Principles of Radiometric Dating Radioactive decay is described in terms of the probability that a constituent particle of the nucleus of an atom will escape through the potential (Energy) barrier which bonds them to the nucleus.The dating equation used for K-Ar is: Carbon Dating Radiocarbon dating is different than the other methods of dating because it cannot be used to directly date rocks, but can only be used to date organic material produced by once living organisms. At their request, physicist Dr Jim Mason, of CMI Canada, reviewed the material from the meeting and his response was published on 2 April 2015 (see Response to Geochronology: Understanding the Uncertainties, a presentation by Dr Justin Payne).