Radio dating wiki
Potassium is a common element found in many materials, such as micas, clay minerals, tephra, and evaporites.
In these materials, the decay product Ar is able to escape the liquid (molten) rock, but starts to accumulate when the rock solidifies (recrystallizes).
It is based on measurement of the product of the radioactive decay of an isotope of potassium (K) into argon (Ar).
The dating method is usually performed on the mineral zircon.
The mineral incorporates uranium and thorium atoms into its crystal structure, but strongly rejects lead.
Radiometric dating is also used to date archaeological materials, including ancient artifacts.
Radiometric dating methods are used to establish the geological time scale.