calculating the age of rocks requires investigating the original amount of the elemental isotopes of the parent isotopes
luminescence_dating is estimating_age. radioisotope is isotope. oxygen_18 is isotope. radioactive_isotope is isotope. dating is chemical_analysis. radioactive_dating is measurement. geological_age is geological_time_period. radiometric_dating is estimating_age. need_to has oxygen_in_mines_and_excavations estimating_age is calculating.