Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 117, Issue 41, Pages 25327-25334Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.2004596117
Keywords
Chicxulub impact crater; Cretaceous-Paleogene; polycyclic aromatic hydrocarbons; impact winter; wildfires
Categories
Funding
- European Consortium for Ocean Research Drilling
- International Continental Scientific Drilling Program
- Yucatan State Government
- Universidad Nacional Autonoma de Mexico
- NSF-OCE [1737351, 1736951]
- Natural Environment Research Council [NE/P005217/1]
- Australian Research Council (ARC) [DP180100982]
- Curtin University
- NSF Graduate Research Fellowship [DGE1255832]
- NERC [NE/P005217/1] Funding Source: UKRI
- Directorate For Geosciences
- Division Of Ocean Sciences [1736951] Funding Source: National Science Foundation
- Directorate For Geosciences
- Division Of Ocean Sciences [1737351] Funding Source: National Science Foundation
Ask authors/readers for more resources
An asteroid impact in the Yucatan 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 x 10(14) and 2.5 x 10(15) g 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.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available