"The type of diamond we have found –– lonsdaleite –– is a shock-synthesized mineral defined by its hexagonal crystalline structure," said Douglas Kennett, associate professor of anthropology at the University of Oregon. "It forms under very high temperatures and pressures consistent with a cosmic impact. These diamonds have only been found thus far in meteorites and impact craters on earth, and appear to be the strongest indicator yet of a significant cosmic impact [during Clovis]."
The diamonds were found in association with soot, which forms in extremely hot fires, and they suggest associated regional wildfires, based on nearby environmental records. Such soot and diamonds are rare in the geological record. They were found in sediment dating to massive asteroid impacts 65 million years ago in a layer widely known as the K-T Boundary, known to be associated with the extinction of dinosaurs and many other types of organisms.
James Kennett, former director of the Marine Science Institute at UCSB, is considered by some of his peers to be the "father" of marine geology and paleoceanography. The native of New Zealand notes that the sedimentary layers beneath the Santa Barbara Channel provide a unique window on the history of the world's climate and ocean changes. The area is one of the best locations in the world for this type of geological research.
Douglas Kennett received his bachelor's, master's, and Ph.D in anthropology at UCSB.
Co-authors on the PNAS paper are Jon M. Erlandson and Brendan J. Culleton, of the University of Oregon; Allen West of GeoScience Consulting in Arizona; G. James West of UC Davis; Ted E. Bunch and James H. Wittke, of Northern Arizona University; Shane S. Que Hee of UCLA; John R. Johnson of the Santa Barbara Museum of Natural History; Chris Mercer of UCSB and National Institute of Materials Science in Japan; Feng Shen of the FEI Company; Thomas W. Stafford of Stafford Research Inc. of Colorado; Wendy S. Wolbach and Adrienne Stich, of DePaul University in Chicago; and James C. Weaver of UC Riverside.
The National Science Foundation provided primary funding for this research.
Gail Gallessich | EurekAlert!
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