Absolute and relative dating methods in prehistory
The rate of decay of these elements helps determine their age, and in turn the age of the rocks.
Physical structure of living beings depends on the protein content in their bodies.
As these tree rings represent annual growth, merely by counting rings one can count the age of the tree and hence its association.
The measurement of the earth's magnetic field in several places of the world for centuries has shown that it varies with time.
A number of studies have shown that a record of past magnetic field in the form of angles of declination and dip can be trapped in baked clay.
When clay is heated to a certain degree, the magnetic elements of baked clay realign themselves along lines dictated by the intensity and character of the magnetic field of the earth at that time.
Despite many difficulties found for ESR dating of bones and carbonates, tooth enamel dated by Electron Spin Resonance ESR has been proven as a reliable method in its application to fossil teeth and quartz.
Both of the latter materials have allowed dating of Early and Middle Pleistocene sites which are not datable using other methods.