CaltechAUTHORS
Published August 16, 2024 | Version Supplemental material
Journal Article Open

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

Creators

  • 1. ROR icon University of Cologne
  • 2. ROR icon Vrije Universiteit Brussel
  • 3. ROR icon University of Florence
  • 4. ROR icon Institute of Marine Science
  • 5. ROR icon Museum für Naturkunde
  • 6. ROR icon University of Göttingen
  • 7. ROR icon Hamburg University of Technology
  • 8. ROR icon Lund University
  • 9. ROR icon University of Brasília
  • 10. ROR icon Cardiff University
  • 11. ROR icon University of Vienna
  • 12. ROR icon California Institute of Technology
  • 13. ROR icon University of Copenhagen

Abstract

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.

Copyright and License

© 2024 the authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original US government works. https://www.science.org/about/science-licenses-journal-article-reuse.

Acknowledgement

We thank F. Wombacher, R. Schmitt, and A. Katzemich for their help and support. We thank J. Day, H. Sato, and another anonymous reviewer for constructive comments that improved the manuscript.

Funding

M.F.-G. was supported by DFG grant no. FI 1704/5-1 within the priority program SPP 1833, “Building a Habitable Earth.” C.M. was supported by the European Commission through ERC grant no. 669666, “Infant Earth.” P.C. and S.G. were supported by the Research Foundation Flanders (FWO), BELSPO (DESIRED project), and the VUB Strategic Research Program. A.B. was supported by the research infrastructure ECORD participating in the ITINERIS project, EU – Next Generation EU Mission 4 “Education and Research” CUP B53C22002150006. W.U.R. was supported by the Brazilian Coordination for the Improvement of Higher Education Personnel, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brazil (CAPES) – Finance Code 001.

Data Availability

Samples were obtained from the locations and sources listed in table S1 and have been archived for further study; see supplementary materials for details. All data shown in figures or used for modeling are listed in tables S1 to S4. Our Ru isotope measurements (raw, corrected, and normalized) are provided in data S1.

Supplemental Material

Supplementary Materials: Materials and Methods; Tables S1 to S4; References (45–53).

Data S1

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Additional details

Identifiers

PMID
39146402

Funding

Deutsche Forschungsgemeinschaft
FI 1704/5-1
European Research Council
669666
Research Foundation - Flanders
Belgian Federal Science Policy Office
European Union
CUP B53C22002150006
Coordenação de Aperfeicoamento de Pessoal de Nível Superior

Dates

Submitted
2023-08-24
Accepted
2024-07-15

Caltech Custom Metadata

Caltech groups
Division of Geological and Planetary Sciences (GPS)
Publication Status
Published