Zinc isotope anomalies in primitive meteorites identify the outer solar system as an important source of Earth's volatile inventory

The source of and timing delivery the volatile elements to Earth is a question that fundamental understanding how our planet evolved. Here, we show primitive meteorites have resolved mass-independent Zn isotope anomalies from terrestrial reservoir. Carbonaceous chondrites (CC), likely originating outer Solar System are distinct non-CC, intermediate between these two components. Modelling based on data indicates around 30% Earth's budget other moderately material derives participation 6% CC-like materials during accretion, with remaining coming NC meteorites. This implies that, despite relatively minor mass thought derive material, CC component was significantly volatile-enriched; this in line observation elemental abundance pattern could be explained by carbonaceous source, chondrite-like isotopic more volatile-rich accreted later accretion history (e.g. Hg, Se, N, noble gases).