Ni isotopes provide a glimpse of Earth's pre-late-veneer mantle.

ABSTRACT: Moderately siderophile (e.g., Ni) and highly siderophile elements (HSEs) in the bulk silicate Earth (BSE) are believed to be partly or near-completely delivered by late accretion after the depletion caused by metallic core formation. However, the extent and rate of remixing of late-accreted materials that equilibrated with Earth's pre-late-veneer mantle have long been debated. Observing evidence of this siderophile element-depleted pre-late-veneer mantle would provide powerful confirmation of this model of early mantle evolution. We find that the mantle source of the ~3.8-billion-year-old (Ga) Narssaq ultramafic cumulates from Southwest Greenland exhibits a subtle ⁶⁰Ni/⁵⁸Ni excess of ~0.05 per mil and contains a clear HSE deficiency of ~60% relative to the BSE. The in

SUBMITTER: Xu Y 

PROVIDER: S-EPMC11649070 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature