Neodymium is a light, rare earth element with seven naturally occurring isotopes (142Nd, 143Nd, 144Nd, 145 Nd, 146Nd, 148Nd and 150Nd), two of these are radiogenic 142Nd (decaying from 146Sm with halflife of 68 millions years) and 143Nd (decaying from 147Sm with halflife of 106 billion years). Because of their similar masses stable Nd isotope ratios are functionally invariable, as such the two most commonly used in geological and environmental research are the stable 144Nd and radiogenic 143Nd. Differentiation of Sm and Nd during melting and magma evolution together with ingrowth of 143Nd results in characteristic 143Nd/144Nd fingerprints in rocks, which vary as a function of age and lithology. Our understanding of the early differentiation of the earth’s crust/mantle is enabled by our understanding of Nd isotope systematics, with 147Sm/143Nd and 146Sm/142Nd used as fingerprints of mantle source regions. In nature, it’s typically found in monazite and bastnaesite deposits and is used for a variety of industrial applications including batteries, magnets, glass and wind turbines. Nd enters the ocean via river and wind deposition and leaves by the adsorption onto organic and Fe-Mn oxide crust particle coatings. The balance between the input and output is such that its residence time is less than ocean mixing, which makes it heterogeneously distributed and useful as a tracer.
Sharifi, A., Murphy, L.N., Pourmand, A., Clement, A.C., Canuel, E.A., Beni, A.N., Lahijani, H.A., Delanghe, D. and Ahmady-Birgani, H., (2018). Early-Holocene greening of the Afro-Asian dust belt changed sources of mineral dust in West Asia. Earth and Planetary Science Letters, 481, pp.30-40. DOI: 10.1016/j.epsl.2017.10.001