Volume 26, Number 3 Center for the Study of the First Americans Department of Anthropology July, 2011 Texas A&M University, 4352 TAMU, College Station, TX 77843-4352 ISSN 8755-6898 World Wide Web site http://centerfirstamericans.org and http://anthropology.tamu.edu The Nanodiamond Controversy, Part I THE 5 A site that has the experts stumped The C. W. Harris site near San Diego is Folsom age without CLOVIS COMET Folsom tools or animal remains, coeval with Desert Culture sites yet lacks grinding implements. Perhaps, says anthropologist Ed REVISITED Knell, it was a shaft factory. 9 When you think of Clovis lithic technology, think blades F DIAMONDS REALLY ARE FOREVER, was, perhaps, warmer than most; over the Blades were once dismissed as as the saying goes, then natural speci- previous few years the world had been occasional finds at Clovis sites. Imens should provide excellent records shaking off its latest Ice Age. In North Now we know they were the basic of geological history—assuming we can de- America, the surviving large animal popula- component of every toolkit. In part cipher the clues hidden in their structures. tions were poised to recover, and an upstart III of her series, lithics analyst Charlotte Pevny tells and shows us That’s precisely what one group of scien- species called humanity—which until re- how toolmakers reduced cores to tists claims to have done for some of cently had been thin on the multipurpose blades. Expert the tiniest diamonds known, a ground—had established a knapper Bill Dickens kibitzes. collection of microscopic Kangerlussuaq, solid foothold on the conti- particles dating from the Greenland nent at last. Things looked 16 Discovery of Bison antiquus end of the Pleistocene ep- promising . until some- has far-reaching consequences och called nanodiamonds. thing smashed into the A remarkably well-preserved If they’re correct, the world like the fist of God. skeleton found on Orcas Island in Arlington Canyon, Washington State bears the very existence of these Santa Rosa Island Entire populations were classic marks of butchering—and minuscule gemstones flash-fried as the fireball a radiocarbon date that means chronicles one of the most exploded high over the the butchers were pre-Clovis dramatic catastrophes ever continent; others died in the humans. At stake is a basic to befall our species: a killer ensuing firestorms, and many premise in the model of peopling of the Americas. comet that slammed into the of the rest perished in the deep Earth, altering the climate and destroying winter that followed. The Clovis culture an entire human culture. vanished with the blast, and with it most of the Extraterrestrial Impact Hypoth- the surviving species of North American esis (EIH) camp, which cites more Fire from the sky? megafauna. than a dozen lines of evidence suggest- It was a day like any other, except that it At least, that’s the theory advocated by ing that an enormous extraterrestrial 2 Volume 26 ■ Number 3 (ET) body struck North America at the have been unable to reproduce the EIH criticism, since there’s only one known end of the Pleistocene. Along with trillions camp’s results, even when working at the way that they can form naturally: in a of nanodiamonds, they’ve documented same sites. One by one, critics have dis- high-temperature, high-pressure envi- peaks of aciniform soot, charcoal, mag- missed most of the evidence supporting ronment such as that of an ET impact. netic microspherules, iridium, and a num- the EIH. Some fault the original Impact But even nanodiamonds have recently ber of other purported impact markers at Team’s conclusions, charging that they come under increased scrutiny, with the Younger Dryas Boundary (YDB), a deliberately stretched the evidence to fit a critics becoming progressively more continent-wide stratigraphic layer that preexisting hypothesis; others condemn vocal in their claims that at least some dates to about 12,900 CALYBP. Unsur- their collecting and analysis techniques, of the particles cited by the EIH sup- prising, not everyone agrees with the or alleged that they’ve simply misinter- porters as nanodiamonds are not, in EIH interpretation; while something preted their findings. fact, diamonds at all. dramatic certainly triggered the 1,000- Nanodiamonds have largely resisted In this two-part story, we’ll take a look year climatic reversal known as the Younger Dryas, they consider mecha- nisms other than an ET impact more likely culprits. The Mammoth Trumpet (ISSN 8755-6898) is published quarterly by the Center for the Study of the First Americans, Department of Anthropology, Texas A&M University, College Station, TX 77843-4352. Phone (979) 845-4046; fax (979) 845-4070; e-mail [email protected]. Periodical postage paid at College Station, TX 77843-4352 and at additional mailing offices. POSTMASTER: Send address changes to: Mammoth Trumpet JAMES KENNETT Department of Anthropology, Texas A&M University Kennett (above) in the field at Taroko 4352 TAMU Gorge, Taiwan, 2006; Kurbatov (below) College Station, TX 77843-4352 in Greenland, 2008. Copyright © 2011 Center for the Study of the First Americans. Permission is hereby given to any non-profit or educational organization or institution to reproduce without cost any materials from the Mammoth Trumpet so long as they are then distributed at no more than actual cost. The Center further requests that notification of reproduction of materials under these conditions be sent to the Center. Address correspondence to the editor of Mammoth Trumpet, 2122 Scout Road, Lenoir, NC 28645. Michael R. Waters Director and General Editor e-mail: [email protected] Ted Goebel Associate Director and Editor, Current Research in the Pleistocene e-mail: [email protected] James M. Chandler Editor, Mammoth Trumpet e-mail: [email protected] Laurie Lind Office Manager C & C Wordsmiths Layout and Design Tops Printing, Inc. Printing and mailing Web site: www.topsprinting.com World Wide Web site http://centerfirstamericans.com The Center for the Study of the First Americans is a non-profit organization. Sub- SOLANA PYNE scription to the Mammoth Trumpet is by membership in the Center. We examined the EIH closely in a four- part series a while back (MT 23-1, -2, -3, Mammoth Trumpet, Statement of Our Policy -4, “The Clovis Comet”), even as inter- Many years may pass between the time an important discovery is made and the acceptance of research ested observers were scrambling to test it. results by the scientific community. To facilitate communication among all parties interested in staying abreast of breaking news in First Americans studies, the Mammoth Trumpet, a science news magazine, In the three years since, dozens of re- provides a forum for reporting and discussing new and potentially controversial information important search teams have published their find- to understanding the peopling of the Americas. We encourage submission of articles to the Managing ings. Many, including geoarchaeologists Editor and letters to the Editor. Views published in the Mammoth Trumpet are the views of Todd Surovell and Vance Holliday (MT contributors, and do not reflect the views of the editor or Center personnel. –Michael R. Waters, Director 25-2, “The Clovis Comet Revisited”), July ■ 2011 3 at the argument from both sides. Part I outlines recent research diamonds, they’re uncertain whether they were carried to supporting the presence of nanodiamonds in YDB deposits, Earth inside an impactor or created in place. They lean toward both in California and the latter. “We’ve performed geochemical analy- on the Greenland ice ses on nanodiamond residues,” says Kennett, sheet. In Part II we’ll “and the results indicate that the nanodiamonds tell you why other re- are not cosmic material, but instead formed from searchers believe that terrestrial material.” Experiments have proven this evidence is either inconclusive, or dead ▲ An overview of the Kangerlussuaq sampling wrong. site. ▲ Greenland team member Jøergen-Peder The nanodiamond Steffensen identifying the YD sampling site record near Kangerlussuaq. Nanodiamonds are so incredibly tiny that that lonsdaleite can be created from millions can get lost in ANDREI KURBATOV oxygen-deficient, very hot carbon va- a liter of soil; it takes exquisitely por quenched in a warm substrate high-powered microscopes simply (such as soil) by a process known as to find them, much less analyze their carbon vapor deposition (CVD). A content and structure. They can take CVD origin for the nanodiamonds a number of forms, including cubic, seems to rule out the possibility that tabular, and near-spherical. Recent they might have been deposited by interest, however, has focused on means of some ET-related process shocked hexagonal nanodiamonds other than an impactor, such as a “cos- known as lonsdaleite. mic rain.” As far as we know, natural lons- The Arlington Canyon team has also daleite occurs only in association isolated a number of proxies suggest- with meteorites and other cosmic im- SOLANA PYNE ing extensive biomass burning at the pacts. Lacking undeniable impact markers such as a crater, tek- YDB contact, including charcoal, carbon spherules, and acini- tites, and shocked quartz, many EIH supporters cite the form soot, which resembles tiny clusters of grapes. (This form lonsdaleite found in YDB deposits as convincing evidence that of soot is extremely rare in the geological record, known only to an impact may have triggered the Younger Dryas. Geologist be associated with ET impacts.) In addition, electron micros- James Kennett of the University of California, Santa Barbara copy studies revealed cubic nanodiamonds and metastable “n- summarizes the argument when he states, “Lonsdaleite has diamonds” embedded in the carbon spherules. Both cubic never been found associated with diamonds that formed through diamonds and n-diamonds are also impact markers; and like regular terrestrial pro- lonsdaleite, n-diamonds are never associ- cesses, so its presence in ated with terrestrial formation processes.