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

• DOI: 10.1126/science.adk4868
• Publication Date: 2024-08-15T17:58:56Z
• Authors: Mario Fischer-Gödde; Jonas Tusch; Steven Goderis; Alessandro Bragagni; Tanja Mohr-Westheide; Nils Messling; Bo-Magnus Elfers; Birger Schmitz; Wolf U. Reimold; Wolfgang D. Maier; Philippe Claeys; Christian Koeberl; François L. H. Ti...; Martin Bizzarro; Carsten Münker
• Keywords: Paleogene

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