Sep 4, 2015. Keywords Age dating, Radiochronometry, Plutonium, Nuclear. IRMM-185 (certified n(235U)n(238U) is (2.00552 0.00060) 102) isotopic.
Radiometric dating is the process of using the concentrations of radioactive substances. Uranium-238 decays to lead-206 with a half-life of 4.47 billion years. U is well documented in radiometric dating methods, with its decay into 206Pb with a half-life of 4.5 billion years. The spontaneous fission of 238U is much. U232Th) isochron diagram, dating of numer-. range in 238U232Th ratios displayed by the differ-. groundmass the larger the UTh range, the better.