title: Geochemical evidence for combustion of hydrocarbons during the K-T impact event.
abstract: It has been proposed that extensive wildfires occurred after the Cretaceous-Tertiary (K-T) impact event. An abundance of soot and pyrosynthetic polycyclic aromatic hydrocarbons (pPAHs) in marine K-T boundary impact rocks (BIRs) have been considered support for this hypothesis. However, nonmarine K-T BIRs, from across North America, contain only rare occurrences of charcoal yet abundant noncharred plant remains. pPAHs and soot can be formed from a variety of sources, including partial combustion of vegetation and hydrocarbons whereby modern pPAH signatures are traceable to their source. We present results from multiple nonmarine K-T boundary sites from North America and reveal that the K-T BIRs have a pPAH signature consistent with the combustion of hydrocarbons and not living plant biomass, providing further evidence against K-T wildfires and compelling evidence that a significant volume of hydrocarbons was combusted during the K-T impact event.
authors.affiliation: Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom. claire.belcher@ucd.ie
authors.forename: Claire M
authors.initials: CM
authors.lastname: Belcher
authors.forename: Paul
authors.initials: P
authors.lastname: Finch
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Collinson
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Scott
authors.forename: Nathalie V
authors.initials: NV
authors.lastname: Grassineau
mesh_terms: D004190:Disasters / Q000266:history*; D055593:Geological Phenomena; D049690:History, Ancient; D006838:Hydrocarbons / Q000737:chemistry*; D019110:Meteoroids; D009656:North America; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D053260:Soot
chemical_list: D006838:Hydrocarbons; D011084:Polycyclic Aromatic Hydrocarbons; D053260:Soot