The first day of the Cenozoic

Sean P.S. Gulick*, Timothy J. Bralower, Jens Ormö, Brendon Hall, Kliti Grice, Bettina Schaefer, Shelby Lyons, Katherine H. Freeman, Joanna V. Morgan, Natalia Artemieva, Pim Kaskes, Sietze J. De Graaff, Michael T. Whalen, Gareth S. Collins, Sonia M. Tikoo, Christina Verhagen, Gail L. Christeson, Philippe Claeys, Marco J.L. Coolen, Steven GoderisKazuhisa Goto, Richard A.F. Grieve, Naoma McCall, Gordon R. Osinski, Auriol S.P. Rae, Ulrich Riller, Jan Smit, Vivi Vajda, Axel Wittmann

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

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Highly expanded Cretaceous-Paleogene (K-Pg) boundary section from the Chicxulub peak ring, recovered by International Ocean Discovery Program (IODP)-International Continental Scientific Drilling Program (ICDP) Expedition 364, provides an unprecedented window into the immediate aftermath of the impact. Site M0077 includes ∼130 m of impact melt rock and suevite deposited the first day of the Cenozoic covered by <1 m of micrite-rich carbonate deposited over subsequent weeks to years. We present an interpreted series of events based on analyses of these drill cores. Within minutes of the impact, centrally uplifted basement rock collapsed outward to forma peak ring capped in melt rock. Within tens of minutes, the peak ring was covered in ∼40 m of brecciated impact melt rock and coarsegrained suevite, including clasts possibly generated by melt-water interactions during ocean resurge. Within an hour, resurge crested the peak ring, depositing a 10-m-thick layer of suevite with increased particle roundness and sorting.Within hours, the full resurge deposit formed through settling and seiches, resulting in an 80-m-thick fining-upward, sorted suevite in the flooded crater. Within a day, the reflected rim-wave tsunami reached the crater, depositing a cross-bedded sand-to-fine gravel layer enriched in polycyclic aromatic hydrocarbons overlain by charcoal fragments. Generation of a deep crater open to the ocean allowed rapid flooding and sediment accumulation rates among the highest known in the geologic record. The high-resolution section provides insight into the impact environmental effects, including charcoal as evidence for impactinduced wildfires and a paucity of sulfur-rich evaporites from the target supporting rapid global cooling and darkness as extinction mechanisms.

Original languageEnglish
Pages (from-to)19342-19351
Number of pages10
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number39
Early online date9 Sept 2019
Publication statusPublished - 24 Sept 2019


aInstitute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78758; bDepartment of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 79712; cDepartment of Geosciences, Pennsylvania State University, University Park, PA 16801; dCentro de Astrobiología Instituto Nacional de Técnica Aeroespacial-Spanish National Research Council (INTA-CSIC), Instituto Nacional de Técnica Aeroespacial, 28850 Torrejon de Ardoz, Spain; eEnthought, Inc., Austin, TX 78701; fWestern Australian Organic and Isotope Geochemistry Centre, The Institute for Geoscience Research, School of Earth and Planetary Science, Curtin University, Perth, WA 6102, Australia; gDepartment of Earth Science and Engineering, Imperial College London, SW7 2AZ London, United Kingdom; hPlanetary Science Institute, Tucson, AZ 85719-2395; iAnalytical, Environmental and Geo-Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium; jDepartment of Geosciences, University of Alaska Fairbanks, Fairbanks, AK 99775; kDepartment of Earth and Planetary Sciences, Rutgers University, New Brunswick, NJ 08854; lInternational Research Institute of Disaster Science, Tohoku University, Sendai 980-8572, Japan; mDepartment of Earth Sciences, University of Western Ontario, London, ON, N6A 3K7, Canada; nInstitut für Geologie, Universität Hamburg, 20146 Hamburg, Germany; oFaculty of Earth and Life Sciences (FALW), Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands; pSwedish Museum of Natural History, 114 18 Stockholm, Sweden; and qEyring Materials Center, Arizona State University, Tempe, AZ 85287-1704 ACKNOWLEDGMENTS. We thank the captain and crew, drilling team, and technical staff who participated in shipboard and/or shore-based operations. We thank the editor and 2 anonymous reviewers. W. Zylberman and J. Gattacceca are thanked for assistance with paleomagnetic measurements. Data and samples can be requested from IODP. The European Consortium for Ocean Research Drilling (ECORD) implemented Expedition 364 with funding from the IODP and the ICDP. US participants were supported by the US Science Support Program and National Science Foundation Grants OCE 1737351, OCE 1736826, OCE 1737087, OCE 1737037, OCE 1736951, and OCE 1737199. J.O. was partially supported by Grants ESP2015-65712-C5-1-R and ESP2017-87676-C5-1-R from the Spanish Ministry of Economy and Competitiveness and Fondo Europeo de Desarrollo Regional. B.S. thanks Curtin University for an Australian Postgraduate Award. J.V.M. was funded by Natural Environment Research Council Grant NE/P005217/1. K. Grice thanks Australia Research Council for Grant DP180100982 and Australia New Zealand IODP Consortium for funding. The Vrije Universiteit Brussel group is supported by Research Foundation Flanders (FWO) and BELSPO; P.K. is an FWO PhD fellow. This is University of Texas Institute for Geophysics Contribution 3634.

FundersFunder number
Australia New Zealand IODP Consortium
Spanish Ministry of Economy and Competitiveness
University of Texas Institute for Geophysics Contribution 3634
National Science FoundationOCE 1737087, OCE 1737351, 1737199, OCE 1736826, OCE 1736951, OCE 1737037, ESP2017-87676-C5-1-R, ESP2015-65712-C5-1-R, OCE 1737199
United States Science Support Program
Natural Environment Research CouncilNE/P005217/1
Australian Research CouncilDP180100982
Curtin University of Technology
Belgian Federal Science Policy Office
Fonds Wetenschappelijk Onderzoek
Ministerio de Economía y Competitividad
European Regional Development Fund


    • Chicxulub impact crater
    • Cretaceous-Paleogene
    • Peak ring
    • Suevite
    • Tsunami


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