Ruthenium isotopes show the Chicxulub impactor was a carbonaceous-type asteroid

• 成果类型: Article
• 署名作者: Fischer-Goedde, Mario; Tusch, Jonas; Goderis, Steven; Bragagni, Alessandro; Mohr-Westheide, Tanja; Messling, Nils; Elfers, Bo-Magnus; Schmitz, Birger; Reimold, Wolf U.; Maier, Wolfgang D.; Claeys, Philippe; Koeberl, Christian; Tissot, Francois L. H.; Bizzarro, Martin; Muenker, Carsten
• 署名单位: University of Cologne; Vrije Universiteit Brussel; University of Florence; Consiglio Nazionale delle Ricerche (CNR); Istituto di Scienze Marine (ISMAR-CNR); Leibniz Institut fur Evolutions und Biodiversitatsforschung; University of Gottingen; Hamburg University of Technology; Lund University; Universidade de Brasilia; Cardiff University; University of Vienna; California Institute of Technology; University of Copenhagen
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-14014
• DOI: 10.1126/science.adk4868
• 发表日期: 2024-08-16
• 页码: 752-756
• 关键词: barberton greenstone-belt; highly siderophile elements; platinum-group elements; archean spherule beds; SOUTH-AFRICA; drill core; crater; projectile; meteorite; origin

摘要

An impact at Chicxulub, Mexico, occurred 66 million years ago, producing a global stratigraphic layer that marks the boundary between the Cretaceous and Paleogene eras. That layer contains elevated concentrations of platinum-group elements, including ruthenium. We measured ruthenium isotopes in samples taken from three Cretaceous-Paleogene boundary sites, five other impacts that occurred between 36 million to 470 million years ago, and ancient 3.5-billion- to 3.2-billion-year-old impact spherule layers. Our data indicate that the Chicxulub impactor was a carbonaceous-type asteroid, which had formed beyond the orbit of Jupiter. The five other impact structures have isotopic signatures that are more consistent with siliceous-type asteroids, which formed closer to the Sun. The ancient spherule layer samples are consistent with impacts of carbonaceous-type asteroids during Earth's final stages of accretion.