Abstract
Numerous geochemical anomalies exist at the K-Pg boundary that indicate the addition of extraterrestrial materials; however, none fingerprint volatilization, a key process that occurs during large bolide impacts. Stable Zn isotopes are an exceptional indicator of volatility-related processes, where partial vaporization of Zn leaves the residuum enriched in its heavy isotopes. Here, we present Zn isotope data for sedimentary rock layers of the K-Pg boundary, which display heavier Zn isotope compositions and lower Zn concentrations relative to surrounding sedimentary rocks, the carbonate platform at the impact site, and most carbonaceous chondrites. Neither volcanic events nor secondary alteration during weathering and diagenesis can explain the Zn concentration and isotope signatures present. The systematically higher Zn isotope values within the boundary layer sediments provide an isotopic fingerprint of partially evaporated material within the K-Pg boundary layer, thus earmarking Zn volatilization during impact and subsequent ejecta transport associated with an impact at the K-Pg.
Recommended Citation
R. Mathur et al., "Fingerprinting the Cretaceous-Paleogene Boundary Impact with Zn Isotopes," Nature Communications, vol. 12, no. 1, article no. 4128, Nature Research, Dec 2021.
The definitive version is available at https://doi.org/10.1038/s41467-021-24419-8
Department(s)
Geosciences and Geological and Petroleum Engineering
Time Period
Cretaceous-Paleogene
International Standard Serial Number (ISSN)
2041-1723
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2021 The Authors, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
01 Dec 2021
PubMed ID
34226532
Comments
The authors appreciate the support for the project from NSF grant proposal no. 1924177.