Trace element partitioning in a deep magma ocean and the origin of the Hf-Nd mantle array.

ABSTRACT: Crystallization in Earth's deep magma ocean could have caused trace element fractionation in the lower mantle that might be inherited to the isotopic compositions of the present-day mantle. However, the trace element partitioning has been experimentally investigated only up to the uppermost lower-mantle pressures. Here, we determined the bridgmanite/melt partition coefficients D of La, Nd, Sm, Lu, and Hf from 24 to 115 gigapascals, covering the wide pressure range of the lower mantle. Results demonstrate substantial reductions in D_Lu and D_Hf from >1 to ≪1 with increasing pressure to 91 gigapascals. We also found D_Lu/D_Hf > 1 and D_Sm/D_Nd < 1 under deep lower-mantle conditions, e

SUBMITTER: Ozawa K 

PROVIDER: S-EPMC11332654 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature