Isotopic evidence for pallasite formation by impact mixing of olivine and metal during the first 10 million years of the Solar System

ABSTRACT: Abstract Pallasites are mixtures of core and mantle material that may have originated from the core–mantle boundary of a differentiated body. However, recent studies have introduced the possibility that they record an impact mix, in which case an isotopic difference between metal and silicates in pallasites may be expected. We report a statistically significant oxygen isotope disequilibrium between olivine and chromite in main group pallasites that implies the silicate and metal portions of these meteorites stem from distinct isotopic reservoirs. This indicates that these meteorites were formed by impact mixing, during which a planetary core was injected into the mantle of another body. The impactor likely differentiated within ∼1–2 Myr of the start of the Solar System based on Hf–W chrono

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PROVIDER: S-EPMC9802258 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature