Physical Sciences and Mathematics Commons^™

Discovery Of A Nanodiamond-Rich Layer In The Greenland Ice Sheet, Andrei V. Kurbatov, Paul Andrew Mayewski, Jorgen P. Steffensen, Allen West, Douglas J. Kennett, James P. Kennett, Ted E. Bunch, Mike Handley, Douglas S. Introne, Shane S. Que Hee, Christopher Mercer, Marilee Sellers, Feng Shen, Sharon B. Sneed, James C. Weaver, James H. Wittke, Thomas W. Stafford, John J. Donovan, Sujing Xie, Joshua J. Razink, Adrienne Stich, Charles R. Kinzie, Wendy S. Wolbach

Earth Science Faculty Scholarship

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 …