Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling
A carbon-rich black layer, dating to ≈12.9 ka, has been previously identified at ≈50 Clovis-age sites across North America and appears contemporaneous with the abrupt onset of Younger Dryas (YD) cooling. The in situ bones of extinct Pleistocene megafauna, along with Clovis tool assemblages, occur be...
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Online Access: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994902 http://www.ncbi.nlm.nih.gov/pubmed/17901202 https://doi.org/10.1073/pnas.0706977104 |
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ftpubmed:oai:pubmedcentral.nih.gov:1994902 2023-05-15T16:41:19+02:00 Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling Firestone, R. B. West, A. Kennett, J. P. Becker, L. Bunch, T. E. Revay, Z. S. Schultz, P. H. Belgya, T. Kennett, D. J. Erlandson, J. M. Dickenson, O. J. Goodyear, A. C. Harris, R. S. Howard, G. A. Kloosterman, J. B. Lechler, P. Mayewski, P. A. Montgomery, J. Poreda, R. Darrah, T. Hee, S. S. Que Smith, A. R. Stich, A. Topping, W. Wittke, J. H. Wolbach, W. S. 2007-10-09 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994902 http://www.ncbi.nlm.nih.gov/pubmed/17901202 https://doi.org/10.1073/pnas.0706977104 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994902 http://www.ncbi.nlm.nih.gov/pubmed/17901202 http://dx.doi.org/10.1073/pnas.0706977104 © 2007 by The National Academy of Sciences of the USA Physical Sciences Text 2007 ftpubmed https://doi.org/10.1073/pnas.0706977104 2013-09-01T03:02:05Z A carbon-rich black layer, dating to ≈12.9 ka, has been previously identified at ≈50 Clovis-age sites across North America and appears contemporaneous with the abrupt onset of Younger Dryas (YD) cooling. The in situ bones of extinct Pleistocene megafauna, along with Clovis tool assemblages, occur below this black layer but not within or above it. Causes for the extinctions, YD cooling, and termination of Clovis culture have long been controversial. In this paper, we provide evidence for an extraterrestrial (ET) impact event at ≅12.9 ka, which we hypothesize caused abrupt environmental changes that contributed to YD cooling, major ecological reorganization, broad-scale extinctions, and rapid human behavioral shifts at the end of the Clovis Period. Clovis-age sites in North American are overlain by a thin, discrete layer with varying peak abundances of (i) magnetic grains with iridium, (ii) magnetic microspherules, (iii) charcoal, (iv) soot, (v) carbon spherules, (vi) glass-like carbon containing nanodiamonds, and (vii) fullerenes with ET helium, all of which are evidence for an ET impact and associated biomass burning at ≈12.9 ka. This layer also extends throughout at least 15 Carolina Bays, which are unique, elliptical depressions, oriented to the northwest across the Atlantic Coastal Plain. We propose that one or more large, low-density ET objects exploded over northern North America, partially destabilizing the Laurentide Ice Sheet and triggering YD cooling. The shock wave, thermal pulse, and event-related environmental effects (e.g., extensive biomass burning and food limitations) contributed to end-Pleistocene megafaunal extinctions and adaptive shifts among PaleoAmericans in North America. Text Ice Sheet PubMed Central (PMC) Proceedings of the National Academy of Sciences 104 41 16016 16021 |
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Physical Sciences |
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Physical Sciences Firestone, R. B. West, A. Kennett, J. P. Becker, L. Bunch, T. E. Revay, Z. S. Schultz, P. H. Belgya, T. Kennett, D. J. Erlandson, J. M. Dickenson, O. J. Goodyear, A. C. Harris, R. S. Howard, G. A. Kloosterman, J. B. Lechler, P. Mayewski, P. A. Montgomery, J. Poreda, R. Darrah, T. Hee, S. S. Que Smith, A. R. Stich, A. Topping, W. Wittke, J. H. Wolbach, W. S. Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling |
topic_facet |
Physical Sciences |
description |
A carbon-rich black layer, dating to ≈12.9 ka, has been previously identified at ≈50 Clovis-age sites across North America and appears contemporaneous with the abrupt onset of Younger Dryas (YD) cooling. The in situ bones of extinct Pleistocene megafauna, along with Clovis tool assemblages, occur below this black layer but not within or above it. Causes for the extinctions, YD cooling, and termination of Clovis culture have long been controversial. In this paper, we provide evidence for an extraterrestrial (ET) impact event at ≅12.9 ka, which we hypothesize caused abrupt environmental changes that contributed to YD cooling, major ecological reorganization, broad-scale extinctions, and rapid human behavioral shifts at the end of the Clovis Period. Clovis-age sites in North American are overlain by a thin, discrete layer with varying peak abundances of (i) magnetic grains with iridium, (ii) magnetic microspherules, (iii) charcoal, (iv) soot, (v) carbon spherules, (vi) glass-like carbon containing nanodiamonds, and (vii) fullerenes with ET helium, all of which are evidence for an ET impact and associated biomass burning at ≈12.9 ka. This layer also extends throughout at least 15 Carolina Bays, which are unique, elliptical depressions, oriented to the northwest across the Atlantic Coastal Plain. We propose that one or more large, low-density ET objects exploded over northern North America, partially destabilizing the Laurentide Ice Sheet and triggering YD cooling. The shock wave, thermal pulse, and event-related environmental effects (e.g., extensive biomass burning and food limitations) contributed to end-Pleistocene megafaunal extinctions and adaptive shifts among PaleoAmericans in North America. |
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Text |
author |
Firestone, R. B. West, A. Kennett, J. P. Becker, L. Bunch, T. E. Revay, Z. S. Schultz, P. H. Belgya, T. Kennett, D. J. Erlandson, J. M. Dickenson, O. J. Goodyear, A. C. Harris, R. S. Howard, G. A. Kloosterman, J. B. Lechler, P. Mayewski, P. A. Montgomery, J. Poreda, R. Darrah, T. Hee, S. S. Que Smith, A. R. Stich, A. Topping, W. Wittke, J. H. Wolbach, W. S. |
author_facet |
Firestone, R. B. West, A. Kennett, J. P. Becker, L. Bunch, T. E. Revay, Z. S. Schultz, P. H. Belgya, T. Kennett, D. J. Erlandson, J. M. Dickenson, O. J. Goodyear, A. C. Harris, R. S. Howard, G. A. Kloosterman, J. B. Lechler, P. Mayewski, P. A. Montgomery, J. Poreda, R. Darrah, T. Hee, S. S. Que Smith, A. R. Stich, A. Topping, W. Wittke, J. H. Wolbach, W. S. |
author_sort |
Firestone, R. B. |
title |
Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling |
title_short |
Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling |
title_full |
Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling |
title_fullStr |
Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling |
title_full_unstemmed |
Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling |
title_sort |
evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the younger dryas cooling |
publisher |
National Academy of Sciences |
publishDate |
2007 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994902 http://www.ncbi.nlm.nih.gov/pubmed/17901202 https://doi.org/10.1073/pnas.0706977104 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994902 http://www.ncbi.nlm.nih.gov/pubmed/17901202 http://dx.doi.org/10.1073/pnas.0706977104 |
op_rights |
© 2007 by The National Academy of Sciences of the USA |
op_doi |
https://doi.org/10.1073/pnas.0706977104 |
container_title |
Proceedings of the National Academy of Sciences |
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104 |
container_issue |
41 |
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16016 |
op_container_end_page |
16021 |
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1766031752602583040 |