Strontium has four naturally occurring isotopes (88Sr, 87Sr, 86Sr, 84Sr), with abundances of approximately 83%, 7%, 10% and <1%, respectively. Strontium-87 is produced by beta decay of 87Rb with a half-life of 48.8 billion years. In geologic and environmental investigations, the ratio 87Sr/86Sr is typically used. In the samarium–neodymium (Sm–Nd) system, 147Sm decays to the radiogenic daughter 143Nd with a half-life of 106 billion years.
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