Nuclear methods of dating
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.Among the best-known techniques are radiocarbon dating, potassium–argon dating and uranium–lead dating.By allowing the establishment of geological timescales, it provides a significant source of information about the ages of fossils and the deduced rates of evolutionary change.The temperature at which this happens is known as the closure temperature or blocking temperature and is specific to a particular material and isotopic system.
Isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years (e.g., tritium) to over 100 billion years (e.g., samarium-147).
Radiometric dating is also used to date archaeological materials, including ancient artifacts.
Different methods of radiometric dating vary in the timescale over which they are accurate and the materials to which they can be applied.
and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of the Earth itself, and can also be used to date a wide range of natural and man-made materials.
Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geologic time scale.