Organic matter from the Chicxulub crater exacerbated the K-Pg impact winter
An asteroid impact in the Yucatán Peninsula set off a sequence of events that led to the Cretaceous-Paleogene (K-Pg) mass extinction of 76% species, including the nonavian dinosaurs. The impact hit a carbonate platform and released sulfate aerosols and dust into Earth's upper atmosphere, which...
| Main Authors: | , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
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NATL ACAD SCIENCES
2020
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7568312/ http://hdl.handle.net/20.500.11937/90120 |
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| author | Lyons, S.L. Karp, A.T. Bralower, T.J. Grice, Kliti Schaefer, Bettina Gulick, S.P.S. Morgan, J.V. Freeman, K.H. |
| author_facet | Lyons, S.L. Karp, A.T. Bralower, T.J. Grice, Kliti Schaefer, Bettina Gulick, S.P.S. Morgan, J.V. Freeman, K.H. |
| author_sort | Lyons, S.L. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | An asteroid impact in the Yucatán Peninsula set off a sequence of events that led to the Cretaceous-Paleogene (K-Pg) mass extinction of 76% species, including the nonavian dinosaurs. The impact hit a carbonate platform and released sulfate aerosols and dust into Earth's upper atmosphere, which cooled and darkened the planet - a scenario known as an impact winter. Organic burn markers are observed in K-Pg boundary records globally, but their source is debated. If some were derived from sedimentary carbon, and not solely wildfires, it implies soot from the target rock also contributed to the impact winter. Characteristics of polycyclic aromatic hydrocarbons (PAHs) in the Chicxulub crater sediments and at two deep ocean sites indicate a fossil carbon source that experienced rapid heating, consistent with organic matter ejected during the formation of the crater. Furthermore, PAH size distributions proximal and distal to the crater indicate the ejected carbon was dispersed globally by atmospheric processes. Molecular and charcoal evidence indicates wildfires were also present but more delayed and protracted and likely played a less acute role in biotic extinctions than previously suggested. Based on stratigraphy near the crater, between 7.5 × 1014and 2.5 × 1015g of black carbon was released from the target and ejected into the atmosphere, where it circulated the globe within a few hours. This carbon, together with sulfate aerosols and dust, initiated an impact winter and global darkening that curtailed photosynthesis and is widely considered to have caused the K-Pg mass extinction. |
| first_indexed | 2025-11-14T11:33:32Z |
| format | Journal Article |
| id | curtin-20.500.11937-90120 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:33:32Z |
| publishDate | 2020 |
| publisher | NATL ACAD SCIENCES |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-901202023-04-26T09:09:53Z Organic matter from the Chicxulub crater exacerbated the K-Pg impact winter Lyons, S.L. Karp, A.T. Bralower, T.J. Grice, Kliti Schaefer, Bettina Gulick, S.P.S. Morgan, J.V. Freeman, K.H. Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics Chicxulub impact crater Cretaceous-Paleogene polycyclic aromatic hydrocarbons impact winter wildfires POLYCYCLIC AROMATIC-HYDROCARBONS CRETACEOUS-TERTIARY BOUNDARY ASTEROID IMPACT CLIMATE-CHANGE PALEOGENE BOUNDARY THERMAL-RADIATION GLOBAL WILDFIRES EXTINCTION SOOT SEDIMENTS An asteroid impact in the Yucatán Peninsula set off a sequence of events that led to the Cretaceous-Paleogene (K-Pg) mass extinction of 76% species, including the nonavian dinosaurs. The impact hit a carbonate platform and released sulfate aerosols and dust into Earth's upper atmosphere, which cooled and darkened the planet - a scenario known as an impact winter. Organic burn markers are observed in K-Pg boundary records globally, but their source is debated. If some were derived from sedimentary carbon, and not solely wildfires, it implies soot from the target rock also contributed to the impact winter. Characteristics of polycyclic aromatic hydrocarbons (PAHs) in the Chicxulub crater sediments and at two deep ocean sites indicate a fossil carbon source that experienced rapid heating, consistent with organic matter ejected during the formation of the crater. Furthermore, PAH size distributions proximal and distal to the crater indicate the ejected carbon was dispersed globally by atmospheric processes. Molecular and charcoal evidence indicates wildfires were also present but more delayed and protracted and likely played a less acute role in biotic extinctions than previously suggested. Based on stratigraphy near the crater, between 7.5 × 1014and 2.5 × 1015g of black carbon was released from the target and ejected into the atmosphere, where it circulated the globe within a few hours. This carbon, together with sulfate aerosols and dust, initiated an impact winter and global darkening that curtailed photosynthesis and is widely considered to have caused the K-Pg mass extinction. 2020 Journal Article http://hdl.handle.net/20.500.11937/90120 10.1073/pnas.2004596117 English https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7568312/ http://purl.org/au-research/grants/arc/DP180100982 NATL ACAD SCIENCES unknown |
| spellingShingle | Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics Chicxulub impact crater Cretaceous-Paleogene polycyclic aromatic hydrocarbons impact winter wildfires POLYCYCLIC AROMATIC-HYDROCARBONS CRETACEOUS-TERTIARY BOUNDARY ASTEROID IMPACT CLIMATE-CHANGE PALEOGENE BOUNDARY THERMAL-RADIATION GLOBAL WILDFIRES EXTINCTION SOOT SEDIMENTS Lyons, S.L. Karp, A.T. Bralower, T.J. Grice, Kliti Schaefer, Bettina Gulick, S.P.S. Morgan, J.V. Freeman, K.H. Organic matter from the Chicxulub crater exacerbated the K-Pg impact winter |
| title | Organic matter from the Chicxulub crater exacerbated the K-Pg impact winter |
| title_full | Organic matter from the Chicxulub crater exacerbated the K-Pg impact winter |
| title_fullStr | Organic matter from the Chicxulub crater exacerbated the K-Pg impact winter |
| title_full_unstemmed | Organic matter from the Chicxulub crater exacerbated the K-Pg impact winter |
| title_short | Organic matter from the Chicxulub crater exacerbated the K-Pg impact winter |
| title_sort | organic matter from the chicxulub crater exacerbated the k-pg impact winter |
| topic | Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics Chicxulub impact crater Cretaceous-Paleogene polycyclic aromatic hydrocarbons impact winter wildfires POLYCYCLIC AROMATIC-HYDROCARBONS CRETACEOUS-TERTIARY BOUNDARY ASTEROID IMPACT CLIMATE-CHANGE PALEOGENE BOUNDARY THERMAL-RADIATION GLOBAL WILDFIRES EXTINCTION SOOT SEDIMENTS |
| url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7568312/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7568312/ http://hdl.handle.net/20.500.11937/90120 |