Shock-Synthesized Hexagonal Diamonds in Younger Dryas Boundary Sediments

Details

• Personal Author:
  Bunch TE ; Culleton BJ ; Erlandson JM ; Johnson JR ; Kennett DJ ; Kennett JP ; Mercer C ; Que Hee SS ; Sellers M ; Shen F ; Stafford TW Jr. ; Stich A ; Weaver JC ; West A ; West GJ ; Wittke JH ; Wolbach WS
• Description:
  The long-standing controversy regarding the late Pleistocene megafaunal extinctions in North America has been invigorated by a hypothesis implicating a cosmic impact at the Allerod-Younger Dryas boundary or YDB (approx. equal to 12,900 +/- 100 cal BP or 10,900 +/- 100 14C years). Abrupt ecosystem disruption caused by this event may have triggered the megafaunal extinctions, along with reductions in other animal populations, including humans. The hypothesis remains controversial due to absence of shocked minerals, tektites, and impact craters. Here, we report the presence of shock-synthesized hexagonal nanodiamonds (lonsdaleite) in YDB sediments dating to approx. equal to 12,950 +/- 50 cal BP at Arlington Canyon, Santa Rosa Island, California. Lonsdaleite is known on Earth only in meteorites and impact craters, and its presence strongly supports a cosmic impact event, further strengthened by its co-occurrence with other nanometer-sized diamond polymorphs (n-diamonds and cubics). These shock-synthesized diamonds are also associated with proxies indicating major biomass burning (charcoal, carbon spherules, and soot). This biomass burning at the Younger Dryas (YD) onset is regional in extent, based on evidence from adjacent Santa Barbara Basin and coeval with broader continent-wide biomass burning. Biomass burning also coincides with abrupt sediment mass wasting and ecological disruption and the last known occurrence of pygmy mammoths (Mammuthus exilis) on the Channel Islands, correlating with broader animal extinctions throughout North America. The only previously known co-occurrence of nanodiamonds, soot, and extinction is the Cretaceous-Tertiary (K/T) impact layer. These data are consistent with abrupt ecosystem change and megafaunal extinction possibly triggered by a cosmic impact over North America at approx. equal to 12,900 +/- 100 cal BP. [Description provided by NIOSH]
• Subjects:
  Geology Occupational Health Safety
• Keywords:
  Author Keywords: Arlington Canyon Biomass Burning Climatic Effects Cosmic Impact Ecological Systems Environmental Physiology Geologic Formations Hexagonal Nanodiamonds Megafaunal Extinctions Nanomaterials Natural Disasters

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• ISSN:
  0027-8424
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Arizona ; California ; Colorado ; Illinois ; Oregon ; OSHA Region 10 ; OSHA Region 5 ; OSHA Region 8 ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  106
• Issue:
  31
• NIOSHTIC Number:
  nn:20058365
• Citation:
  Proc Natl Acad Sci U.S.A. 2009 Aug; 106(31):12623-12628
• Contact Point Address:
  Douglas J. Kennett, Department of Anthropology, University of Oregon, Eugene, OR 97403
• Email:
  dkennett@uoregon.edu
• Federal Fiscal Year:
  2009
• Performing Organization:
  University of California Los Angeles
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Proceedings of the National Academy of Sciences of the United States of America
• End Date:
  20270630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:7ae2523d687b63eb6ca9c8301af853a6062b0fa7b67cafaefa3c678d7146efda91af9ef6cae7666087058fc4229137cc62eb38e9e5cd4d73ce171c93976ff35c
• Download URL:
  https://stacks.cdc.gov/view/cdc/221480/cdc_221480_DS1.pdf
• File Type:
  [PDF - 4.53 MB ]