To progress, it is essential to apply the second type, or relative, dating.
The term refers to the fact that an approximate date can be inferred by comparison with something else of known age.
The slope is proportional to the geologic age of the system.
In practice, the isochron approach has many inherent advantages.
With time each would then develop additional daughter abundances in proportion to the amount of parent present.Many radioactive dating methods are based on minute additions of daughter products to a rock or mineral in which a considerable amount of daughter-type isotopes already exists.These isotopes did not come from radioactive decay in the system but rather formed during the original creation of the elements.The methods work because radioactive elements are unstable, and they are always trying to move to a more stable state. This process by which an unstable atomic nucleus loses energy by releasing radiation is called radioactive decay.The thing that makes this decay process so valuable for determining the age of an object is that each radioactive isotope decays at its own fixed rate, which is expressed in terms of its half-life.