Document Type
Article
Publication Title
Journal of Glaciology
Rights and Access Note
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Publication Date
12-2010
First Page
749
Last Page
759
Issue Number
199
Volume Number
56
Abstract/ Summary
We report the discovery in the Greenland ice sheet of a discrete layer of free nanodiamonds (NDs) in very high abundances, implying most likely either an unprecedented influx of extraterrestrial (ET) material or a cosmic impact event that occurred after the last glacial episode. From that layer, we extracted n-diamonds and hexagonal diamonds (lonsdaleite), an accepted ET impact indicator, at abundances of up to about 5!106 times background levels in adjacent younger and older ice. The NDs in the concentrated layer are rounded, suggesting they most likely formed during a cosmic impact through some process similar to carbon-vapor deposition or high-explosive detonation. This morphology has not been reported previously in cosmic material, but has been observed in terrestrial impact material. This is the first highly enriched, discrete layer of NDs observed in glacial ice anywhere, and its presence indicates that ice caps are important archives of ET events of varying magnitudes. Using a preliminary ice chronology based on oxygen isotopes and dust stratigraphy, the ND-rich layer appears to be coeval with ND abundance peaks reported at numerous North American sites in a sedimentary layer, the Younger Dryas boundary layer (YDB), dating to 12.9"0.1 ka. However, more investigation is needed to confirm this association.
Repository Citation
Kurbatov, Andrei V.; Mayewski, Paul Andrew; Steffensen, Jorgen P.; West, Allen; Kennett, Douglas J.; Kennett, James P.; Bunch, Ted E.; Handley, Mike; Introne, Douglas S.; Que Hee, Shane S.; Mercer, Christopher; Sellers, Marilee; Shen, Feng; Sneed, Sharon B.; Weaver, James C.; Wittke, James H.; Stafford, Thomas W.; Donovan, John J.; Xie, Sujing; Razink, Joshua J.; Stich, Adrienne; Kinzie, Charles R.; and Wolbach, Wendy S., "Discovery of a nanodiamond-rich layer in the Greenland ice sheet" (2010). Earth Science Faculty Scholarship. 175.
https://digitalcommons.library.umaine.edu/ers_facpub/175
Publisher Statement
MS received 29 September 2009 and accepted in revised form 7 August 2010
DOI
http://dx.doi.org/10.3189/002214310794457191
Version
publisher's version of the published document
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