dating

In geology, the process of determining the age of minerals, rocks, fossils, and geological formations. There are two types of dating: relative and absolute. Relative dating involves determining the relative ages of materials, that is determining the chronological order of formation of particular rocks, fossils, or formations, by means of careful field work. Absolute dating is the process of determining the absolute age (that is the age in years) of a mineral, rock, or fossil. Absolute dating is accomplished using methods such as radiometric dating (measuring the abundances of particular isotopes in a mineral), fission track dating, and even counting annual layers of sediment.