Two broad categories of dating or chronometric techniques that archaeologists use are called relative and absolute dating.Stratigraphy is the oldest of the relative dating methods that archaeologists use to date things.As minerals crystallise in igneous and metamorphic rocks they trap certain isotopes in their crystal structure that begin to decay radioactively as soon as the mineral forms.These radioactive isotopes are parent isotopes, which decay slowly to daughter isotopes, changing the rock’s isotopic character.
The scholar most associated with the rules of stratigraphy (or law of superposition) is probably the geologist Charles Lyell.
Archaeological scientists have two primary ways of telling the age of artefacts and the sites from which they came: relative dating and absolute dating.
Relative dating in archaeology presumes the age of an artefact in relation and by comparison, to other objects found in its vicinity.
Methods fall into one of two categories: relative or absolute.
Before more precise absolute dating tools were possible, researchers used a variety of comparative approaches called relative dating.