Potassium dating fossils
As the mineral cools, the crystal structure begins to form and diffusion of isotopes is less easy.At a certain temperature, the crystal structure has formed sufficiently to prevent diffusion of isotopes.Finally, correlation between different isotopic dating methods may be required to confirm the age of a sample.
This transformation may be accomplished in a number of different ways, including alpha decay (emission of alpha particles) and beta decay (electron emission, positron emission, or electron capture).
Precision is enhanced if measurements are taken on multiple samples from different locations of the rock body.
Alternatively, if several different minerals can be dated from the same sample and are assumed to be formed by the same event and were in equilibrium with the reservoir when they formed, they should form an isochron. In uranium–lead dating, the concordia diagram is used which also decreases the problem of nuclide loss.
For instance, carbon-14 has a half-life of 5,730 years.
After an organism has been dead for 60,000 years, so little carbon-14 is left that accurate dating cannot be established.