Onset of slab mantle melting in Earth's lower mantle: Evidence from ferropericlase in superdeep diamonds.

ABSTRACT: Ferropericlase ([Mg_x,Fe_1-x]O), the most common inclusion in sublithospheric diamonds, has a poorly understood crystallization history and depth of origin. Nineteen microscopic ferropericlase grains with different Mg#s were released from Juína and Kankan diamonds with mantle-like carbon, for Mg and Fe isotopic analysis. Two groups of ferropericlase inclusions can be distinguished with respect to diamond growth: high-Mg# inclusions with mantle-like Mg and Fe (δ²⁶Mg = -0.23 ± 0.22‰; δ⁵⁶Fe = 0.00 ± 0.14‰) inferred to be preexisting and lower Mg# inclusions with non-mantle-like heavy Fe (δ⁵⁶Fe up to +0.3‰) and light Mg (δ²⁶Mg down to -1.4‰) inferred to be coeval. We propose that coeval ferropericlase inclusions formed by melting

SUBMITTER: Ni P 

PROVIDER: S-EPMC12526246 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature