Relative dating technique
When ‘parent’ uranium-238 decays, for example, it produces subatomic particles, energy and ‘daughter’ lead-206.Isotopes are important to geologists because each radioactive element decays at a constant rate, which is unique to that element.Absolute age is a quantitative measurement while relative age is a qualitative measurement.Absolute dating works better for igneous and metamorphic rocks while relative dating works better for sedimentary rocks having layered arrangement of sediments.It is a less advanced technique when compared to absolute dating.
The precision in absolute ageing is high while the precision of the relative ageing is low.
These rates of decay are known, so if you can measure the proportion of parent and daughter isotopes in rocks now, you can calculate when the rocks were formed.
Because of their unique decay rates, different elements are used for dating different age ranges.
Geologists often need to know the age of material that they find.
They use absolute dating methods, sometimes called numerical dating, to give rocks an actual date, or date range, in number of years.