Relative dating of rocks ppt
Absolute dating, also called numerical dating, arranges the historical remains in order of their ages.
Whereas, relative dating arranges them in the geological order of their formation.
For example, fission track dating measures the microscopic marks left in crystals by subatomic particles from decaying isotopes.
Another example is luminescence dating, which measures the energy from radioactive decay that is trapped inside nearby crystals.
Each isotope is identified with what is called a ‘mass number’.
This Science Struck post enlists the differences between the absolute and relative dating methods.
Geological specimens that are unearthed need to be assigned an appropriate age.
The table below shows characteristics of some common radiometric dating methods.
Geologists choose a dating method that suits the materials available in their rocks. Measuring isotopes is particularly useful for dating igneous and some metamorphic rock, but not sedimentary rock.