Nanoparticles of iridium and other platinum group elements identified in Chicxulub asteroid impact spherules – Implications for impact winter and profound climate change

Authors

Vivi Vajda, Naturhistoriska riksmuseet
Susan Nehzati, Naturhistoriska riksmuseet
Gavin Kenny, Naturhistoriska riksmuseet
Hermann D. Bermúdez, Montclair State UniversityFollow
Ashley Krüger, Naturhistoriska riksmuseet
Alexander Björling, MAX IV Laboratory
Adriana Ocampo, National Aeronautics and Space Administration
Ying Cui, Montclair State UniversityFollow
Kajsa G.V. Sigfridsson Clauss, MAX IV Laboratory

Document Type

Article

Publication Date

2-1-2025

Journal / Book Title

Global and Planetary Change

Abstract

The Chicxulub asteroid that ended the Cretaceous Era ∼66.05 million years ago caused a prolonged time of global darkness – the impact winter – leading to mass extinctions. Elements from the asteroid, including the platinum group elements (PGEs) osmium, iridium and platinum are known from the globally distributed boundary clay but their carrier elements have so far been unknown. We identify, for the first time in detail, the presence of these PGEs within Chicxulub impact spherules and importantly, we identify their carrier elements. We show through synchrotron Nano-XRF how these PGEs occur in nanostructures as un-ordered cube- and/or needle-like crystals co-localizing with both siderophile and chalcophile elements including Co, Ni, Cu, Zn, and Pb, derived from the asteroid. These crystals are set within a matrix of iron-rich calcium and silica glass revealing the mix of vaporized target rock and the asteroid. The results provide insights into the combination of elements present in the spherules, indicating formation of new minerals. We argue that the nano-shards of unreactive elements such as platinum, iridium and copper acted as nuclei for aerosol formation and potentially contributed to a prolonged impact winter with darkness and cooling leading to a profound and long-term climate change.

Comments

This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

DOI

10.1016/j.gloplacha.2024.104659

Journal ISSN / Book ISBN

85211024780 (Scopus)

MSU Digital Commons Citation

Vajda, Vivi; Nehzati, Susan; Kenny, Gavin; Bermúdez, Hermann D.; Krüger, Ashley; Björling, Alexander; Ocampo, Adriana; Cui, Ying; and Sigfridsson Clauss, Kajsa G.V., "Nanoparticles of iridium and other platinum group elements identified in Chicxulub asteroid impact spherules – Implications for impact winter and profound climate change" (2025). Department of Earth and Environmental Studies Faculty Scholarship and Creative Works. 735.
https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/735

Published Citation

Vajda, V., Nehzati, S., Kenny, G., Bermúdez, H. D., Krüger, A., Björling, A., ... & Clauss, K. G. S. (2025). Nanoparticles of iridium and other platinum group elements identified in Chicxulub asteroid impact spherules–Implications for impact winter and profound climate change. Global and Planetary Change, 245, 104659.