^1,2Yao Sun, ²Jonas Tusch, ¹Xiaorui Fan, ¹Jifeng Xu, ³Chao Li, ⁴Kristoffer Szilas, ²Carsten Münker, ¹Jingao Liu, ²Mario Fischer-Gödde
Earth and Planetary Science Letters 684, 120012 Link to Article [https://doi.org/10.1016/j.epsl.2026.120012]
¹State Key Laboratory of Geological Processes and Mineral Resources, and Frontiers Science Center for Deep‐time Digital Earth, China University of Geosciences, Beijing 100083, China
²Institut für Geologie und Mineralogie, Universität zu Köln, Cologne 50674, Germany
³National Research Center for Geoanalysis, Beijing 100037, China
⁴Natural History Museum of Denmark, University of Copenhagen, Copenhagen 1350, Denmark
Copyright Elsevier

The mass-independent Mo isotope composition of the Bulk Silicate Earth (BSE) bears great potential to investigate the origin of the Earth’s latest 10–20% planetary building blocks. However, currently different estimates for the Mo isotope composition of the BSE render constraints on the composition of late-stage accretionary materials difficult. To address this issue and to revisit the Mo isotope composition of the BSE, we report high-precision molybdenum isotope data for a comprehensive set of terrestrial molybdenites from different locations around the globe covering mineralization ages that extend from the Archean to the Phanerozoic. The molybdenite results are used to constrain the Mo isotope composition of the BSE as follows: ε92Mo = 0.04 ± 0.06, ε94Mo = 0.03 ± 0.03, ε95Mo = 0.01 ± 0.01, ε97Mo = 0.02 ± 0.02, ε100Mo = 0.05 ± 0.06 (n = 16, 95% confidence interval, relative to the NIST SRM 3134 Mo standard). In contrast to previous studies, no resolvable ε94Mo and ε95Mo anomalies were observed, suggesting a BSE composition with predominantly non-carbonaceous chondrite provenance. Considering the analytical uncertainties of our new BSE estimate and literature data for carbonaceous and non-carbonaceous meteorites, it remains a viable option that 12±10% of the present-day Mo budget in the BSE derives from carbonaceous meteorite material delivered during late-stage accretion. This amount of Mo is consistent with the fraction of Mo that was delivered to Earth during its final 0.5% of accretion by the late veneer.