Synonym: Isotopic age.
The absolute age is the actual age of a rock calculated based on the quantity of decayed products of radioactive isotopes in the rock since its formation. Isotopic age dating methods include the uranium-lead dating, potassium-argon and rubidium-strontium dating methods. Significant progress in isotopic age dating has been made in recent years, and the methods have become more sophisticated and popular, particularly in studies of Precambrian metamorphic rocks. However, because of the limits of the sampling techniques, isotopic ages are still approximate. The obtained age is sometimes also called the numerical age.