Impact
Source Institution: Smithsonian National Museum of Natural History
Source Exhibit: David H. Koch Hall of Fossils - Deep Time
Source Url: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list
Source Kind: interpretive_topic_or_panel
Use: research inspiration only; SAGE will write original interpretation
Plain Language Explanation: About 66 million years ago, a large extraterrestrial body struck the region now occupied by the Yucatán Peninsula. The buried Chicxulub crater, shocked minerals, impact glass, ejecta and the globally distributed iridium-rich boundary layer form a converging body of evidence linking the impact to the K-Pg boundary.
Evidence: The Chicxulub structure is a large buried impact crater of K-Pg boundary age.; Core material from Chicxulub contains shock-deformed rocks and impact melt.; Shocked quartz and altered impact glass occur in K-Pg boundary deposits.; The boundary layer contains anomalously high iridium consistent with extraterrestrial material.
Examples From Collection: Room 09 intentionally contains no invented specimen object. Its impact case is built from documented geological evidence.
Common Misconception: The asteroid-impact explanation does not depend on one mysterious layer of iridium alone. Crater geology, shocked minerals, ejecta, geochemistry and dating reinforce one another.
What Scientists Still Debate: The occurrence of the Chicxulub impact at the K-Pg boundary is strongly established. Research continues on details such as projectile properties and the exact sequence and magnitude of environmental effects.
Sources: https://www.usgs.gov/publications/new-links-between-chicxulub-impact-structure-and-cretaceoustertiary-boundary; https://www.usgs.gov/publications/shock-induced-microdeformations-quartz-and-other-mineralogical-indications-impact; https://science.nasa.gov/earth/deep-impact-and-the-mass-extinction-of-species-65-million-years-ago/
Dossier Status: scientifically_enriched_room_09
Enrichment Method: Full SAGE scientific concept rewrite; direct impact evidence separated from physical modeling, reconstruction and open questions; seven-field concept contract enforced