Determination of ages of meteorites and their components using decay of radioactive isotopes 238U and 235U and accumulation of their decay products (daughter isotopes) 206Pb and 207Pb.
Meteorites contain trace amounts of uranium, and their ages can be calculated from the quantities of accumulated radiogenic isotopes of Pb. Two long-lived isotopes of uranium 235U (0.7205 %, half-life 4.468 × 109 year) and 238 U(99.2736 %, half-life 0.704 × 109 year; isotopic abundances based on the data of Brennecka and Wadhwa 2012, half-lives from Jaffey et al. 1971) decay to stable isotopes of lead 207Pb and 206Pb. The dual nature of the U–Pb decay scheme has two important implications for geochronology (Ludwig 1998; Amelin 2006; Schoene 2014). First, consistency of the dates calculated from two parent-daughter pairs, 238U– 206Pb* and 235U– 207Pb* (the asterisk indicates radiogenic Pb),...
KeywordsInductively Couple Plasma Mass Spectrometry Thermal Ionization Mass Spectrometry Radiogenic Isotope Early Solar System Refractory Inclusion
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