Discovery of a heavy silicon isotope mantle reservoir.

ABSTRACT: Silicon cycling between Earth's reservoirs provides critical insights into how the Earth operates. While average crust and the bulk silicate Earth (BSE) share similar silicon isotope (δ³⁰Si) compositions, some mantle-derived magmas exhibit lower δ³⁰Si values than the BSE, implying the existence of an unidentified mantle reservoir with complementary higher δ³⁰Si values. We present silicon isotope data from Cenozoic lamproites and their hosted mantle pyroxenite xenoliths from the Himalaya-Tibet orogen. These mantle-derived rocks have higher δ³⁰Si values than the BSE, which resulted from reaction between mantle peridotite and ³⁰Si-rich silicate melts from subducted Indian continental crust. Our results demonstrate that slab melting can pr

SUBMITTER: Liu MR 

PROVIDER: S-EPMC12658886 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature