Superchondritic Sm/Nd ratio of the Earth: Impact of Earth’s core formation

M.A. Bouhifd, M. Boyet, C. Cartier, T. Hammouda, N. Bolfan-Casanova, J.L. Devidal, D. Andrault

Earth and Planetary Science Letters
Volume 413, 1 March 2015, Pages 158–166


Thus, based on the actual Sm and Nd concentrations in the bulk Earth, the core should contain less than 0.4 ppb for Sm and less than 1 ppb for Nd. These estimates are three orders of magnitude lower than what would be required to explain the reported 142Nd excess in terrestrial samples relative to the mean chondritic value, using the core as a Sm–Nd complementary reservoir. In other words, the core formation processes cannot be responsible for the increase of the Sm/Nd ratio in the mantle early in Earth history.