Differentiated planetesimals record differing sources of sulfur in inner and outer solar system materials

• 成果类型: Article
• 署名作者: Heiny, Elizabeth A.; Stolper, Edward M.; Eiler, John M.
• 署名单位: California Institute of Technology
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-15279
• DOI: 10.1073/pnas.2418198122
• 发表日期: 2025-05-06
• 关键词: isotopic composition; parent bodies; origin; meteorites; earth; s-33; anomalies; fractionation; enstatite; sulfide

摘要

The isotope anomalies of noncarbonaceous (NC) and carbonaceous (CC) extraterrestrial materials provide a framework for tracing the distribution and accretion of matter in the early solar system. Here, we extend this framework to sulfur (S)-one of six life-essential volatile elements [T-C similar to 664 K]-via the mass-independent S-isotope compositions of differentiated meteorites. We observe that on average, NC and CC iron meteorites are characterized by distinct Delta S-33 (Delta S-33(NC) = 0.013 +/- 0.003 parts per thousand; Delta S-33(CC) = -0.021 +/- 0.009 parts per thousand; 2 SE). The average Delta S-36 of NC and CC irons are less well resolved (Delta S-36(NC) = -0.006 +/- 0.039 parts per thousand; Delta S-36(CC) = -0.101 +/- 0.114 parts per thousand; 2 SE), but the Delta S-36 values of the CC irons are concentrated in the lower half of the range of those observed for iron meteorites. A lack of CC achondrite S-isotope analyses prevents direct comparison of the Delta S-33 and Delta S-36 of NC and CC achondrites, but the average Delta S-33 and Delta S-36 of NC achondrites (Delta S-33 = 0.02 +/- 0.008; Delta S-36 = -0.019 +/- 0.064 parts per thousand; 2 SE) overlap with those of the NC irons. The average Delta S-33 values of NC achondrite groups also correlate with nucleosynthetic anomalies of other elements (e.g., Cr) previously used to define isotopic heterogeneity within the NC reservoir. The position of the Earth in Delta S-33-Delta S-36 composition space implies that similar to 24% of terrestrial S derives from CC materials, while the majority (similar to 76%) was delivered by NC materials.