Abstract
Ruthenium and Ir are the least mobile platinum group elements (PGEs) within the Cretaceous-Tertiary (K-T) boundary clay. The Ru/Ir ratio is therefore the most useful PGE interelement parameter for distinguishing terrestrial and extraterrestrial contributions to the boundary clay. The Ru/Ir ratio of European marine K-T sections (1.67 ± 0.38) is statistically different from that of the North American continental sections (0.76 ± 0.26). It is unlikely that this difference is due to secondary PGE remobilization, PGE input to the boundary clay during multiple impacts, or volcanic emissions. The global difference in Ru/Ir ratios in the boundary clay may therefore be primary. The positive correlation between distance from the Chicxulub impact structure, Yucatán, Mexico, and Ru/Ir ratio and the more than 1000°C difference in the condensation temperatures of these elements lead us to propose that fractionation of Ru from Ir during condensation from the ejecta cloud may have occurred, resulting in the global difference in Ru/Ir ratios.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
