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TTTTTHE CLASSIC MODEL that domi-nated First Americans studies forhalf a century—that the first immi-

Obsidian projectile points from Kamchatka.

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Following theFollowing theFollowing theFollowing theFollowing theObsidian TObsidian TObsidian TObsidian TObsidian TrailrailrailrailrailFollowing theFollowing theFollowing theFollowing theFollowing theObsidian TObsidian TObsidian TObsidian TObsidian Trailrailrailrailrail

grants trudged across the Bering LandBridge connecting northeast Asia andAlaska, and went on to people the Ameri-cas—has been battered in recent years bythe discovery of Monte Verde and otherpre-Clovis occupations in the New World.Nevertheless, recent discoveries in Alaskaby archaeologists, notably Chuck Holmes(MT 20-1, “Early Americans in EasternBeringia: Pre-Clovis Traces at Swan Point,Alaska”), are convincing evidence for somescientists that at least one wave of migrantspassed through on foot. To keep this theoryalive, though, demands answers to suchquestions as, Where did they come from?How many were they? When were theyhere? Fortunately, the travelers them-selves are giving us many of the answers.They were toolmakers, and one of the moreabundant toolstones available to them inBeringia (eastern Siberia and Alaska) wasobsidian, volcanic glass, a substance thattells a scientist with the knowledge and theright equipment the precise location of thequarry where it was obtained.

The wonders of obsidianJeff Speakman of the Smithsonian Institu-tion, who has traced obsidian artifacts totheir source in North America and Asia,emphasizes the importance of obsidian inresolving the Beringia question. Obsidianis prime toolstone due to its workability and

the extremely sharp edges produced whenit’s knapped. What makes obsidian so valu-able to archaeologists is its unique chemi-cal signature that precisely and unambigu-ously identifies its source. Speakmanexplains that “each source [of obsidian] has

cally invisible in the archaeologicalrecord. Concerning the particularlong-distance migration that archae-ologists are eager to confirm, ofpeoples crossing the Bering LandBridge during the Pleistocene, obsid-ian could be the key to answering thisquestion. If Russian obsidian dating tothe Pleistocene is found in Alaska, thisdiscovery will go a long way to provingthe theory correct.

The sourcing process itself hasevolved over the years, and seems tohave peaked at a fortunate time. Of anumber of processes used to sourceobsidian, three stand out as the mostreliable methods: instrumental neu-tron activation analysis (INAA), laserablation inductively coupled plasma-mass spectrometry (LA-ICP-MS), andX-ray fluorescence spectrometry(XRF).

The grandfather of the group,which has great precision and highaccuracy, is INAA; on the down side, itrequires a nuclear reactor and de-stroys the obsidian sample beingtested.

ICP-MS is as sensitive as INAA,yet less invasive to the artifact beingtested. The drawbacks with ICP-MSare that it is still somewhat destruc-tive to artifacts and quantifying datacan be an arduous task. ICP-MS alsorequires an initial investment of sev-eral hundred thousand dollars and adedicated laboratory and staff. None-theless, such instrumentation is quitecommon at most major research insti-tutions and is rapidly replacing INAAas a preferred method for trace-ele-ment analysis of rocks and minerals.

Jeff Speakman analyzing goldartifacts by PXRF at the MuseoAntropológico Reina Torres de Araúz,Panama City, Panama, July 2007.

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a unique fingerprint, and if you know whatthat fingerprint is . . . you can analyze theartifacts and tell exactly where the artifactscame from.” Much can be discerned byidentifying the source of a fragment of ob-sidian. “By knowing that information,”Speakman says, “you are able to track mi-grations of people, social interactions, tradepaths, and long-distance movement.” With-out obsidian sourcing, such facts are practi-

XRF, though not as sensitive asINAA or ICP-MS, has the great advan-tage of being completely nondestruc-tive and has been used extensively toanalyze obsidian since the 1960s. Butit gets better; XRF has evolved intoPXRF, P for portable, which gives sci-entists the ability to source obsidianin situ. This is especially handy forsourcing museum pieces, particularly

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obsidian source in 1970.This source, whose nametranslated from theKoyukon language meansObsidian Hill, is located incentral Alaska. Today wethink of this as remote, butprehistorically, according toSpeakman, it was probablyeasily accessible, whichwould account for its beingthe most common obsidianused by prehistoric peoplethroughout Alaska. Likemany obsidian sources,Batza Tena spawned a num-ber of sites, some associatedwith quarrying activities. Ar-

tifacts made of Batza Tena obsidian were widely dispersed in thelate Pleistocene and early Holocene, reaching distances of 500km. The runner up is Wiki Peak obsidian, at 460 km. Wiki Peakobsidian, although extensively used, wasn’t easy to get. Insteadit is found in what Speakman describes as “fairly isolated pock-ets,” a consequence of the challenging terrain in this part ofAlaska (compared with Batza Tena, which is conveniently lo-cated on a tributary of the Koyukon River). Jeff Rasic, with theNational Park Service and the University of Alaska, another keyplayer in this project, recently visited Wiki Peak. He foundartifacts throughout this area.

Apart from Alaska, there is an obsidian source in the AleutianIslands on a volcano called Okmok. There are dozens of sourcesin British Columbia, the Yukon Territory, and southeast Alaska;obsidian from three of them—Hoodoo Mountain, Suemez Is-land, and Mount Edziza—was used extensively by prehistoricpeople. Obsidian from Mount Edziza, for example, has been

found in the Alaska in-terior, about 1,200 kmfrom its origin.

Post–Cold WarcooperationAfter the fall of the So-viet Union at the end of1991, researchers fromAmerica and theformer Soviet Unionjoined forces in an at-tempt to confirm theBering Strait theory. Itwas thought that whenscientists from thesetwo continents got to-

gether it would be a simple matter of comparing their respec-tive fluted points. However, no Clovis-like material has beendiscovered in Siberia. This doesn’t rule out the possibility thatearly people migrated over the Land Bridge; it simply meansscientists are going to have to get creative to prove it.

Today obsidian sourcing is practiced by scientists in Siberia

those in other countries. Notonly is this device handy, its re-sults are highly accurate. It “isordinarily what I use for sourcing obsidian, even at theSmithsonian,” says Speakman, who considers the instrumentessential in the search for Northeast Asian obsidian in easternBeringia. It yields source data while in the field at Alaskan andRussian sites. What’s more, it harmlessly analyzes obsidianarticles in Russian museums, thereby eliminating the hassle oftransporting a truckload of machines across borders.

May the source be with you . . .There are 32 known sources of obsidian in eastern Beringia,which includes Alaska and the parts of neighboring Yukon andthe Northwest Territories not covered by glaciers. Thesesources are known to the extent that archaeologists are aware oftheir existence; however, only nine of them can be located on amap and only seven are known to have been utilized by prehis-toric peoples. Though the locations of the other sources have yetto be pinpointed, their existence is inferred from their “finger-prints,” which were lifted from obsidianartifacts scattered around Alaska andCanada. It’s just like “CSI”; we haven’tapprehended the culprit, but we knowwho done it.

It isn’t easy to locate a source ofobsidian, particularly in Alaska’sfrigid vastness. Sometimes a locationcan be estimated by consulting geo-logic maps and triangulating in on a

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The obsidian fingerprint: Allobsidian from the same source

has identical proportions ofcertain trace elements, which

makes it possible to matchobsidian artifacts with their

source. This bivariate plot ofzirconium and strontium

elemental concentrations(analyzed by PXRF) shows 2,154

obsidian artifacts and geologicsource samples analyzed by

Speakman and NataliaSlobodina, fall 2007.

Natalia Slobodina, University ofWashington, analyzing obsidian

artifacts from Alaska using PXRF at theSmithsonian’s Museum Conservation

Institute, December 2007.

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source using the distribution of artifacts made of the uniqueobsidian quarried from it, but this involves a lot of guesswork. Most often, Speakman says, “Geologists are the oneswho find the sources first and the archaeologists find outlater.”

Archaeologists took notice of the rediscovered Batza Tena

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in the states of Kamchatkaand Chukotka. Kamchatkais a well-documented area,as far as obsidian is con-cerned. In all, 30 sourceslie within its borders, butonly 16 were used prehis-torically. Interestingly,there is a group of siteshere known as the UshkiLake sites, which containcomponents thought to beolder than 13,000 CALYBP(MT 18-1, “Hunting Pre-Clovis in Siberia: Year 2000Excavations at Ushki, Kam-chatka”).

This obsidian project,spanning continents, is a huge international effort. Collaboratingwith American researchers including Speakman and MichaelGlascock, of the University of Missouri, are Russian scientistsYaroslav Kuzmin, Vladimir Popov, Andrei Grebennikov,Margarita Dikova, and Andrei Ptashinsky. Together they havestudied Ushki Lake and discovered six sources of Kamchatkaobsidian that were utilized in the Pleistocene. This informationconfirms the significant mobility of these early people. It alsosuggests they may have kept moving, right across the LandBridge, to become the first Americans.

The state of Chukotka in northeast Russia is a little lessforthcoming with information. Analysis of obsidian artifactsfrom the surrounding area documents three sources, but onlyone has been located,Krasnoye (Red) Lake.Some 150 artifacts havebeen analyzed from thisstate, and 90 percent ofthem come from theKrasnoye Lake source.

The big questionYou have to be able toidentify East Beringianobsidian so you can dis-tinguish it from Siberianobsidian. But if the loca-tion of a source is un-known, how can youknow whether obsidiancame from Alaska or, say,Siberia? And there are 23 obsidian sources whose locationsremain unknown.

Since the database for Northeast Asian obsidian is very thor-ough, it’s unlikely that unknown obsidian material found inBeringia comes from sources in Northeast Asia. “We’ve ana-lyzed about a thousand artifacts and geologic source samplesfrom Kamchatka,” says Speakman. “We have a very good idea ofwhat the obsidian looks like chemically. So I think that there’slittle likelihood that some of the unknown Alaska groups are

Geologist AndreiGrebennikov (left) andSpeakman examine obsidianat Nachiki, Kamchataka,summer 2004.

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from Kamchatka.” However, he al-lows the slim probability that un-known sources may lie inChukotka and areas west of therebecause these locations are lesswell understood.

With all this information,has any Siberian obsidian beenfound in Beringia? The answer isyes. Unfortunately, none of it is dat-able to the Pleistocene. John Cookof the Bureau of Land Manage-ment in Alaska documented the

first immigrant obsidian from Russia in a 1995 article in ArcticAnthropology; since then, a handful of other pieces have sur-faced. All of these, however, date to the late Holocene. Nonethe-less, Speakman and his Alaskan collaborators, Jeff Rasic andJoshua Reuther (Northern Land Use Research, Inc.,Fairbanks), remain optimistic that Siberian obsidian will befound in Alaskan archaeological sites that date to the latePleistocene or early Holocene.

There are a number of sites dating to the Pleistocene inBeringia. The oldest is the Swan Point site, whose cultural zonehas been dated to about 12,000 RCYBP. Swan Point lies almostdirectly between Batza Tena and Wiki Peak, and all its obsidianartifacts are assumed to be made of material from Alaskan

sources. The puzzle is furthercomplicated, of course, by thenumber of sites that predateSwan Point in both the conti-nental U.S. and South America.

But what can it mean?So why hasn’t Russian obsidianfrom the Pleistocene beenfound in Alaska? The first obvi-ous answer is simply that the

Distribution of Alaskanarchaeological sites known tohave obsidian obtained fromthe Batza Tena source.

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Bering Land Bridge wasn’t the original access to the NewWorld as we thought. This is a difficult bit of information toswallow for those of us who have been taught it since elemen-tary school. It begs the question, Where else? Dennis Stanfordand Bruce Bradley argue that Clovis was introduced by immi-grants from the Solutrean culture in Europe (MT 17-1, “Immi-grants from the Other Side?”). According to this hypothesis,boat people made their way to the New World 15,000 to 20,000years ago by skirting the North Atlantic ice sheet. Other re-

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searchers, including Loren Davis and Roberta Hall (MT 22-1,“Late-Pleistocene Occupations on the Oregon Coast”), andAlan Bryan and Ruth Gruhn (MT 17-2, “The Baja Connec-tion”), envision boat people skirting the Pacific coast and set-tling as far south as Baja California. These theories are stilloverpowered by the classic model of migration over the BeringLand Bridge, and they haven’t been seized upon by the ar-chaeological community at large. But evidence continues tomount in support of both of these scenarios.

There’s another alternative to tossing the dominant BeringLand Bridge theory out the window: Perhaps the Clovis culturenever existed in Northeast Asia. “Clovis could be a New Worldmanifestation,” Speakman suggests, “but the actual peoplethemselves are migrants that could have come across theBering Strait, or by boat along the North Atlantic ice sheet.” Hisline of thinking opens an entirely new can of worms labeled pre-Clovis, and he shares it with good company. For example, SteveHolen of the Denver Museum of Nature & Science attributesbroken mammoth leg bones at sites in Nebraska and Kansas tohuman intervention—bones dated to 7,000 radiocarbon yearsbefore Clovis (MT 23-1, “Early Mammoth Bone Flaking on theGreat Plains”). Perhaps, Holen proposes, the first colonizersmade the trek across the Land Bridge, just as the classic theorydictates, but thousands of years before the Clovis culture flour-ished in North America.

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Suggested ReadingsCook, J. P. 1995 Characterization and Distribution of Obsidian in

Alaska. Arctic Anthropology 32:92–100.

Glascock, M. D., V. K. Popov, Y. V. Kuzmin, R. J. Speakman, A. V.Ptashinsky, and A. V. Grebennikov 2006 Sources of Obsidianon Kamchatka Peninsula (Russian Far East) and Their Use inPrehistory: Initial Results. In Archaeology in Northeast Asia: On thePath to Bering Strait, edited by D. E. Dumond and R. L. Bland, pp.73–88. University of Oregon Anthropological Papers No. 65. Uni-versity of Oregon, Eugene.

Goebel, T., R. J. Speakman, and J. D. Reuther 2008 Results ofGeochemical Analysis of Obsidian Artifacts from the WalkerRoad Site, Alaska. Current Research in the Pleistocene 25:88–90.

Phillips, S. C., and R. J. Speakman in press Initial Source Evalua-tion of Archaeological Obsidian from the Kuril Islands of theRussian Far East by Portable X-ray Fluorescence. Journal of Ar-chaeological Science.

Reuther, J. D., N. Slobodina, J. T. Rasic, J. P. Cook, and R. J.Speakman 2009 Gaining Momentum—The Status of ObsidianSource Studies in Alaska and Their Importance for Developing aBetter Understanding of the Regional Prehistory. In ExplainingLithic Assemblage Variability Across Beringia, edited by T. Goebeland I. Buvit. College Station: Texas A&M Press. (in press).

Shackley, M. S., editor 1998 Archaeological Obsidian Studies:Method and Theory. New York & London: Plenum Press.

Speakman, R. J., C. E. Holmes, and M. D. Glascock2007 Source Determination of Obsidian Artifacts from SwanPoint (XBD-156), Alaska, Current Research in the Pleistocene24:143–45.

Speakman, R. J., M. D. Glascock, V. K. Popov, Y. V. Kuzmin, A. V.Ptashinsky, and A. V. Grebennikov 2005 Geochemistry ofVolcanic Glasses and Sources of Archaeological Obsidian onthe Kamchatka Peninsula (Russian Far East): First Results.Current Research in the Pleistocene 22:11–13.

✷A Center for the Study of the First Americans publication.

Though none have been found yet, there may be sites thatpredate Clovis in western Beringia. Any such site would be ofenormous interest to North American archaeologists, but find-ing it is proving difficult. The Ushki Lake sites in Kamchatka,thought to be older than Clovis by a few hundred years, provedto be younger when it was re-dated by Mike Waters and TedGoebel of CSFA.

The question of the Bering Land Bridge migration stillhasn’t been resolved. After all, only a handful of immigratedRussian obsidian artifacts dating to the Holocene have beenfound. There’s still a lot of looking to do, and lots of obsidian tosource. A piece of Pleistocene-aged obsidian from Russiafound in Alaska may be sitting in Speakman’s lab as you readthis, waiting to be sourced.

–Katie Hill

How to contact the principal of this article:Jeff SpeakmanHead of Technical StudiesSmithsonian Museum Conservation Institute4210 Silver Hill RoadSuitland, MD 20746-2863e-mail: SpeakmanJ@si.edu