Isotope ratios of Nd are key geochemical tracers for unraveling the compositional evolution of terrestrial planets, as well as an important geochronometer. Neodymium has seven natural isotopes: 142Nd (27.153 %), 143Nd (12.173 %), 144Nd (23.798 %), 145Nd (8.293 %), 146Nd (17.189 %), 148Nd (5.756 %), and 150Nd (5.638 %) (Meija et al., 2016). 147Sm decays to 143Nd through α-decay with a half-life of 1.06 × 1011 year that corresponds to a decay constant (λSm147) of 6.54 × 10−12 year−1. 146Sm decays to 142Nd through α-decay and a half-life estimated between 68 × 106 year (Kinoshita et al., 2012) and 103 × 106 year (Meissner et al., 1987; Marks et al., 2014). Due to its slightly lower ionic radius , Sm is generally more compatible than Nd in the Earth’s mantle. The fractionation of Sm from Nd during melting and crystallization processes changes the Sm/Nd ratios in minerals, which, over time, will change the relative abundance of 143Nd and 142Nd. These changes in Nd isotopes are...
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