Out of Asia on Foot
The well-known Beringian land bridge / ice-free corridor theory was originally put forth on the basis of geological studies of the timing and extent of the great North American glaciers, as well as the lowering of the sea level, as a logical explanation of the peopling of the Americas. The archaeological profession quickly adopted the theory because it explained how hunters too primitive to have watercraft could have crossed the Bering Sea. With each retelling, in schools, books, and public lectures, the theory took deeper hold, eventually becoming dogma, and generations of professors have taught it to accepting students. The idea that people walked from northeast Asia to present-day Alaska was transmuted into certainty and is still recognized by many as the only answer to the question of where all prehistoric people in the New World originated. A great deal of research in Alaska and more recently in Siberia has focused on finding the evidence to prove it, without much to show for the effort.
Beringia is the name given by scientists to a massive extent of land that surrounded the Bering Strait, the narrow gap of ocean that separates the northeastern tip of Siberian Russia from the western point of Alaska.1 During the last ice age, sea levels were much lower than today, exposing large sections of ocean floor. As they emerged, the world’s continental shelves created new coastal landforms, including the Bering land bridge, which linked Asia and North America. The surrounding region, Beringia, extended east as far as the edge of the continental glacier near the present-day Mackenzie River and south to the northern terminus of the Cordilleran ice sheet in the mountains of southern Alaska (figure 3.1). Westward it stretched across Siberia to the headwaters of the Lena River and then angled southeast into the Russian Far East. Beringia is nearly twice as wide to the west of the Bering Strait as it is to the east. People traveling by land from Asia to North America would have had to cross this vast, treeless Arctic plain, which was icy during the long, dark winter and wet and buggy during the short summer months.
FIGURE 3.1.
Map of Beringia showing sites mentioned in the text.
Quite a few reasons and quite a few assumptions make the land bridge crossing the dominant theory of the peopling of the New World. Some are based on sound science, others on intuition. For example, it seems reasonable to think that because modern Native Americans look Asian and possess Asian genetic traits, their ancestors must have all come from Asia. But this assumes that all ancient Americans looked like modern Indians and that the earliest people who migrated from northeast Asia must have looked like those who reside there today. Since virtually no late-glacial-age human remains have been found in either North America or northeastern Asia, it is difficult to test this assumption.
Another supporting idea is based on early research indicating that near the end of the last ice age, the two major North American continental glaciers had melted far enough apart to create a passable ice-free corridor from Alaska to the plains of southern Alberta.2This date for an opening would have allowed enough time for the establishment of an environment that supported plants and animals as well as the Clovis ancestors working their way southward to reach the Lower Forty-Eight. Recent paleoecological and geological research has provided persuasive evidence, however, that the biogeographic corridor was not established until sometime between circa 12,000 and 14,000 years ago.3 In our opinion this date for the opening would have been much too late to allow for the pan-continental distribution of Clovis technology by 13,000 years ago. Nevertheless, the impact of the original concept lingers, as in this recent statement by the Arctic archaeologist F. H. West: “Had there been no corridor southward or had that corridor lain to the east of the continental ice sheet, it seems certain that the discovery of America would have had to await the coming of navigators from over the seas.”4
This statement by West includes another assumption, namely, that early hunters could have crossed the Bering Strait only by dry land, because they had no watercraft. Thus they would have been unable to cross even a small stretch of water—or, in West’s view, to walk across a frozen expanse of sea. This, of course, has not been the case in more recent times. Many Holocene groups have crossed the Bering Strait, and Inuit people have gone back and forth frequently in historic times, either in skin boats or over the ice by foot or with dog teams.
Also implicit in the land bridge concept is the conviction that the High Arctic landscape would have been habitable and amenable to foot travel during the Last Glacial Maximum (LGM). Reconstructions by vertebrate paleontologists portray much of the area as being a shrub tundra environment with a diverse community of large game animals.5 Some palynologists, by contrast, read the plant evidence as indicating a bleak, polar desert.6 Other researchers envision much of the region as cold, moderately dry to moist environments with heaths, dry meadows, and shrub tundra interspersed with marshes and small ponds.7 No matter what the climate, the low-lying topography of the land bridge would have been poorly drained in summer and covered with meandering rivers, lakes, ponds, and marshes, making it one of the least desirable land surfaces known for foot travel. Regardless of its specific physiography, most researchers concede that the land bridge was probably harsh and difficult to traverse.
Even today northeastern Siberia is the coldest place on earth, with prolonged and severe winters with temperatures as low as -94°F, exceeding the average low temperature of Antarctica, and short summers with average July temperatures of 59°F.8 In the Late Pleistocene the climate was even more extreme. And along with adverse paleoecological conditions, there were many large rivers, rugged mountains, local glaciers, and numerous other obstacles to foot travel. We can only imagine what challenges this area must have presented during the Late Pleistocene.
Newspapers, books, magazines, and museum exhibits have repeatedly illustrated ice age hunters as primitive people who dressed in rudimentary animal skins and eked out their survival with spears and clubs, creating the comic strip conception of the caveman and the die-hard notion that cavemen coexisted with dinosaurs. But even in today’s climate, people who dressed and lived like that would not live long. Therefore, we suggest that ice age people had cold-weather technologies at least as sophisticated as those required for survival during the warmer conditions of the Holocene, a geological epoch that began around 12,000 years ago. At the very least, tailored, waterproof clothing was a necessity, along with substantial all-weather shelters. With the skills to create these items, they no doubt also had the ability to construct sewn-skin boats. One has only to ask whether the peoples who live in Arctic conditions today could survive as they do without adequate clothing, shelter, or boats to cross and travel on rivers and lakes. Lacking good archaeological evidence to the contrary, we assume that this knowledge was integral to successful Arctic colonization.
Another relevant aspect of Beringia is that because much of it is above the Arctic Circle, at 66 degrees north, cultures there must adapt to months of darkness alternating with months of continuous daylight. Why would anybody move into such a region? To answer this question, we need to examine the late Pleistocene archaeological record on the Siberian and Alaskan sides of Beringia. Fortunately, several relevant works are available. One of the most complete, American Beginnings, pulls together much of the information, and we take advantage of this source in this chapter’s review, unless otherwise indicated.9
Virtually everybody who has attempted to summarize the archaeological data from Beringia has employed many qualifiers, because the research is characterized by different theoretical approaches and analytical methods.10 This is partly because of the length of time over which the work has been accomplished but also because of major differences between Soviet and American archaeological approaches to survey coverage and intensity of excavation, as well as what questions are asked and what analytic criteria employed.
Another difficulty is that we are looking at a part of the world that has never been densely occupied. Most archaeological sites were temporary and probably used by small groups of people. As elsewhere, durable material culture represents only a small fraction of what people used, and little of it was left behind at any one place or time. This means that most ancient sites have small artifact inventories, and these represent few of the activities undertaken by the inhabitants. Furthermore, with the exception of rare sites where artifacts and other cultural remains are preserved by permafrost, the Arctic environment is as destructive today as it was during the ice age. Freezing and thawing, solifluction (the movement of saturated sediments on top of frozen deposits), ice wedges, and other frozen-ground phenomena, as well as tectonic uplift, isostatic subsidence and rebound (movements of deposits related to glacial compression and release), erosion, rising and falling sea levels, and shallow sedimentary deposition, are all destructive forces prevalent in the Arctic. All of this results in either archaeological sites with little to no stratigraphy or soil levels that tend to be disturbed and mixed. Thus, most Arctic sites are scatters of artifacts from multiple time periods found mixed on the surface or in shallowly buried contexts. Inaccessibility, short field seasons, and relatively high expense have contributed to the difficulty of doing fieldwork in the north. With all of these handicaps, it is fortunate that we can say anything about the prehistory of Beringia.
We commonly hear that Beringia is so vast and inaccessible that our current knowledge is based on a small fraction of what could be discovered. This is obvious, but not unusual in archaeology. The American southwest has great preservation and a hospitable climate, and its sites are readily accessible compared to those of the Arctic. Yet we have estimated that even in southwestern Colorado, where fieldwork has been conducted for more than one hundred years, less than 1 percent of the available record is well enough known to contribute to modern research interests. Even so, archaeologists must not refrain from interpreting the available record if we expect to make any scientific headway.
What do we know about the late Pleistocene and earliest Holocene archaeology of Beringia? Although it is a vast geographic area, it has been significantly explored and archaeologically surveyed. Investigations tend to focus on the more accessible areas, but if they are convenient today, they were probably used in the past. This is especially true of prime spots on rivers and in river valleys, where fordings, portages, and other transportations were easier, then as now. In eastern Siberia, surveys and less formal explorations have recorded archaeological sites along most of the major rivers and their tributaries. This is also true of much of Alaska and the ice-free part of the Yukon. Of course, a lot of the area has not been examined intensively, and unknown cultural traditions may be waiting to be discovered. New discoveries are being made: for example, the Yana Rhinoceros Horn Site of far western Beringia, some 2,200 kilometers from the Bering Sea coast.11 Dating to 30,000 years ago, this site is the first evidence of pre-LGM habitation in the High Arctic. This is an important discovery, but does it relate directly to the New World colonization issue? At present the answer is unknown, but based on the flaked stone technology found at Yana, a relationship to Clovis seems highly unlikely.
The archaeological data from Beringia can be compiled in several ways. One is to group sites according to artifact assemblages, a common approach since many sites lack radiocarbon dates. Those with similar tools and technologies are considered related historically and presumed to be of a similar age. Their chronological placement is established by comparisons with similar archaeological sites that have been dated. Considering the geographic distribution of sites related technologically creates additional clusters, which archaeologists describe as “cultures” based on various criteria such as tool forms, settlement patterns, and technology. These are not the same as what we might consider cultures today, and there is no assurance that prehistoric people would have recognized our archaeological cultures. For example, the Clovis culture has meaning in terms of its archaeological characteristics, but this doesn’t necessarily mean that Clovis people would all have spoken the same language or believed the same things. Cultures are just a convenient way for archaeologists to communicate. Once established, they can be plotted in time and space and their distributions used to reconstruct the culture history of the region.
With the exception of Yana, the earliest artifact assemblages in Beringia belong to a generalized Asian microblade tradition. (Tradition in this case refers to a shared technology but not necessarily other traits that would qualify it as an archaeological culture.) These early assemblages are classified as the Early Dyuktai Culture. Five sites with Early Dyuktai material have been dated, and quite a few other sites have been classified as Early Dyuktai by the composition of their assemblages. With the exception of Ust Mil 2, where some anomalous older dates were recorded, all of these sites fall between 18,000 and 20,000 years BP (before the present), within the LGM, and all are in far western Beringia. Straight-line overland distances from them to the Bering Strait range from 2,200 to 3,200 kilometers and average more than 2,750 kilometers.
Artifact assemblages vary across these sites, but all are dominated by microblade technology, with wedge-shaped cores made on flakes (figure 3.2a) or bifacial precores (figure 3.2b). The accompanying tools are retouched microblades and blade insets, while the next most common tools are burins, made from both flakes and blades (figure 3.2c). Less common are bifacial knives (figure 3.2d), drills/borers, pebble tools, and side scrapers. Bone and ivory artifacts are rare. They include an ivory needle without an eye, encountered in the 18,000-year-old Verkhne-Troitskaya Site. A possible antler hammer from Ezhantsy is around 17,000 years old, and a bone awl from Ikhine 2 may be as much as 30,000 years old but is more likely around 20,000 years old.
Late Dyuktai assemblages, dating between 10,000 and 13,000 years BP, differ from Early Dyuktai assemblages primarily in an increase in bifacial knife and point production. Microblade technology still dominates, and there is an increase in the presence of microblade insets (figure Intro.3.a–b). Burins are present (figure 3.2f–i). Bifacial manufacture of microblade cores and precores becomes more common (figure 3.2 j–m), and bifacial techniques are used to create finished tools (figure 3.2e). Percussion bifaces are reduced proportionally (see chapter 1 for a description of this method), with rare cases of thinning. Bifacial points were initially percussion shaped and frequently pressure finished, producing thickened cross sections. Fine pressure retouch is rare, and lower-edge grinding of projectile points is unreported.12 The only bone artifacts yet found in a Late Dyuktai collection are a possible projectile point flaked from mammoth ivory and an antler hammer from Dyuktai Cave.
Four Late Dyuktai sites have been dated in western Beringia, but like Early Dyuktai sites they are far from the Bering Strait—2,100 to 3,400 kilometers away, with an average of 2,825 kilometers. Several Late Dyuktai–like sites described by the archaeologist Anatoli Derev’anko are very close to the Bering Strait, but they might just as easily be related to the Denali tradition of eastern Beringia (described below).13 In spite of the intervening Bering Strait, they are geographically closer to Denali sites then they are to any of the dated Late Dyuktai sites.
Several sites in western Beringia do not fit in the generalized Dyuktai tradition. Either they lack microblade technology or it is only a minor component of their flaked stone repertoire. Most of these sites are near Vladivostok, in the part of the Russian Far East known as Primorye, more than 4,000 kilometers by land from the Bering Strait. Radiocarbon assays of several of these sites indicate that they were occupied between 9,000 and 12,000 years ago, and little evidence has been found that their inhabitants spread north and east before 9,000 years ago, if at all. Their technology was based on large blade production (figure 3.3g), although flake tools are also present in significant proportions. Retouched tools, most of which were made on blades, make up only small percentages of the assemblages, dominated by end scrapers (figure 3.3c–d) and burins (figure 3.3e–f). Rare tools include perforators, possible unifacial points, and an occasional proportional biface. A few microblade cores (figure 3.3a–b) and some microblade core debitage are present in these assemblages, but it is not clear if the Primorye flintknappers used the Dyuktai technique to produce pressure microblades.
FIGURE 3.2.
Early and Late Dyuktai artifacts. Early Dyuktai artifacts from Dyuktai Cave: (a) wedge-shaped core with microblade; (b) obverse, cross section, and reverse sides of precore; (c) obverse and reverse sides of burin, with arrows showing direction of spall removal; (d) biface knife. Late Dyuktai artifacts from Level V, Leten Novyy Site: (e) biface; (f–i) burins; (j–k) microblade precores; (l) microblade core. Late Dyuktai artifacts from Kurung Site Layer V1: (m) microblade core.
FIGURE 3.3.
Primorye artifacts: (a–b) microblade cores; (c–d) end scrapers with cross sections; (e–f) burins, with arrows showing direction of spall removal; (g) conical blade core.
Two sites stand out as having non-Dyuktai components. Ushki, on the Kamchatka Peninsula, has a typical Late Dyuktai component in Level VI (figure 3.4a–i) underlain by Level VII, which contains a unique flaked stone assemblage (figure 3.4m–t). It is characterized by small, thick, bifacially flaked stemmed projectile points, which were finished by pressure flaking (figure 3.4m–p), and also contains burins (figure 3.4s), foliate bifaces (figure 3.4a–c and r), and unifacial knives (figure 3.4t). N. N. Dikov, the original investigator, reported that microblade technology was absent, but the presence of percussion bladelets suggests to the Siberian archaeology experts Z. A. Abramova and Roger Powers that a microblade core technology was indeed used at the site (figure 3.4q).14 This assemblage is like no other described in the region, but a few stemmed points similar to those from this Ushki collection have been found in small numbers at undated surface localities (figure 3.4j–l). Level VII was originally dated to around 14,000 years BP, but a recent reanalysis clearly demonstrates that it is only 13,000 years old.15
The other non-Dyuktai site, located above the Arctic Circle and known as Berelekh after the river nearby, has a bone assemblage that dates to between 12,500 and 13,000 years BP. It is best known as a paleontological locality that produced large quantities of mammoth and other Late Pleistocene animal remains. Most of the cultural artifacts were collected during large-scale bone-digging operations, and few were found in good context. It is probable that more than one archaeological component is represented, given the heterogeneity of the flaked stone collection. Though bifaces dominate, a single microblade core was recovered from the mining spoil. The bifaces include well-made fragments that were probably used as knives. There are also some small-point fragments pressure-flaked from thin flakes that closely resemble the Chindadn-style points found in central Alaska (see below). The recovery methods—mainly high-pressure water blasting—and probably mixed nature of this site make it difficult to place chronologically. The Russian archaeologists Y. A. Mochanov and S. A. Fedoseeva conclude that it was probably a very late Dyuktai occupation.16
The Berelekh Site was relatively rich in perishable osseous tools. The collection includes four mammoth bone knives, one leaf-shaped ivory projectile point, two scrapers, and several ribs with abrasions that may indicate use as burnishing tools. Mochanov and Fedoseeva state that these bone artifacts exhibit the same fine pressure flaking seen on the stone points. This is curious and makes us wonder whether the ivory and bone were mineralized when modified. The paleontologists N. K. Vereshechagin and V. V. Ukraintseva also think that the inhabitants of the site used bones mined from fossil deposits as a raw material source for artifact manufacture.17 Although experiments to study the tool-manufacturing flaking properties of large bones—for example, from elephants—have shown that it is possible to make large flakes on dense bones, our experience is that pressure-flaking unmineralized bone is impossible because bone and ivory rapidly lose their workability, even when well preserved. If we are right, the purported pressure flaking on this bone indicates that it was mineralized and that it is not relevant to the dating of the site.
Berelekh is also famous for yielding a fragment of mammoth bone incised with the figure of a mammoth, which suggests that the artist who made the etching saw a live mammoth or even hunted one. It must be remembered, however, that frozen mammoths are commonly found even today melting out of the Siberian permafrost, and the artist may have used a long-frozen specimen as a model. We also know that mammoths were around during Clovis times and that they survived on Wrangle Island, in the Arctic Ocean northwest of the Bering Strait, until long after Clovis times, so this engraving does not necessarily indicate the artist saw a mammoth at a Clovis date.18
FIGURE 3.4.
Akmak artifacts from Ushki Levels VI and VII and Bolshoi Elgakhchan: (a–c) Ushki Level VI projectile points; (d–f) Level VI microblade cores; (g–h) Level VI burins; (i) Level VI end scraper; (j–l) Bolshoi Elgakhchan projectile points; (m–p) Ushki Level VII projectile points; (q) Level VII microblade core; (r) Level VII foliate biface; (s) Level VII burin; (t) Level VII uniface knife. Arrows show direction of spall removal.
It is difficult to assess what all of these bone tools represent culturally, since most of them were found during paleontological salvage operations carried out mainly by high-pressure water excavation, which thoroughly mixes everything. Although the fossil bone deposit is dated to around 13,000 years BP, the human occupation of the site may have been much later. Vereshchagin and Ukraintseva suggest that the occupation evidence was recovered from a depth of 1.5 meters, rather than 2.5 meters as originally reported, and that the human occupation of the site probably occurred around 10,000 years ago.19
Stone pendants and beads are present in some western Beringian Late Dyuktai sites. Eight hundred stone beads were found in Ushki Level VII in association with a human burial (the bone was all but gone), and three stone pendants came from the same level. The younger Ushki Level VI produced several stone pendants and a flat pebble with scratches that, to those with good imaginations, could depict tents. Five stone pendants were found at Berelekh, but their provenances are also questionable. If they were associated with the cultural occupation level, they would be presumed to date to around 10,000 years BP. Two of the pendants have short incised lines or notches along their edges, and all have conical holes, drilled from opposite faces, that meet in the middle, producing an hourglass shape.
It appears that the cultural sequence of western Beringia is relatively straightforward. The Late Paleolithic flaked stone technology is dominated by an inset microblade tradition that is totally absent from Clovis. The few examples of bifacial projectile point technology are either insecurely dated (Berelekh) or have proved to be younger than Clovis (Ushki VII). Although there are local variations within assemblages and technologies, we contend that these variations are minor and are to be expected in such a large region as technologies evolved through ten millennia.
Early Dyuktai technology first appeared in far western Siberia during the height of the LGM. Why this happened is difficult to understand, considering the harshness of the climate, but clearly the people who used it did not move farther eastward across the Kolyma Basin until the end of the glacial period, when environmental conditions made it more feasible to settle the area. It is also possible that they were pushed eastward by early Neolithic peoples who were moving north from central Asia during a warming phase. In any case, there is little doubt that the Late Dyuktai flaking techniques evolved from the microblade techniques developed by earlier Dyuktai flintknappers, as they represent very similar traits. The current archaeological evidence indicates that Late Dyuktai people arrived on the shores of the Bering Sea more than 12,000 years ago. When they finally crossed into the region now known as Alaska, did they find an uninhabited territory, or did they encounter people already living in the area—or even moving westward out of eastern Beringia?
The archaeology of eastern Beringia is also difficult to assess. As in western Beringia, the number of well-dated and stratified sites is meager, but at least two technological patterns are beginning to emerge. The majority of early Alaskan sites, like those in Siberia, seem to have been occupied by people who used microblade technology at about the same time as or shortly after it appeared in northeastern Asia. We suggest this indicates that the microblade-based industry of Siberia spread eastward into Alaska near the end of the Late Dyuktai period. The regional and temporal spread of this microblade technology—and its offshoots—tells us that the people with this technology were well suited to the environment and flourished, developing into distinct groups. However, at about the time when this highly dynamic pan-Siberian technology was becoming established in eastern Beringia, people using non-microblade weaponry were also making an appearance in the area. Where did they come from?
The settlement of Alaska (eastern Beringia) was probably a slow, complex process stimulated by climatic improvement, as the Arctic archaeologist John Hoffecker and his associates suggest.20 Milder weather conditions and nutrients released from the melting glaciers enhanced the productivity of rangelands. Increased subsistence resources no doubt affected the human fertility rate, causing the population expansion reflected in a major increase in the number of sites and the diversity of technologies at this time. Groups with different lithic traditions—and therefore unique signatures—moved into Beringia from different directions.
The Beringia (sometimes called the American Paleo-Arctic) tradition is, in our opinion, an eastward extension of Late Dyuktai. One of the earliest assemblages of this tradition comes from the Onion Portage Site on the Kobuk River, just upstream from Kotzebue.21 This is one of the first deeply stratified sites found in Alaska, and it has provided baseline data for the cultural sequence of northwest Alaska. At the bottom of the site was an unconformity, or buried eroded surface, upon which more than a hundred artifacts were found. The group of artifacts has been named the Akmak Complex. (Complex is basically synonymous with the term archaeological culture: it describes a group of sites that share specific traits, especially those related to tool forms.) This accumulation of cultural debris is thought to have been redeposited from a cache of precores (figure 3.5a–b), wedgeshaped microblade cores (figure 3.5d), and formal tools such as burinated blades, retouched blades (figure 3.5e), blades retouched into scrapers (figure 3.5f), and bifacially edge-re-touched knives (figure 3.5c). A radiocarbon assay of a caribou bone associated with the artifacts indicates that the materials were deposited more than 9,500 years ago. Hence the Akmak tools are older, by an unknown time period. This assemblage is very similar to Late Dyuktai.
Another northwestern interior Alaska site, known as Nogahabara 1, has a toolkit of 267 artifacts that appear to have been lost or abandoned between 12,740 and 13,850 years ago. These artifacts were exposed by the wind deflation of a sand dune. The fact that all of the artifacts were clustered and, with the exception of a single bifacial chert drill, made from the distant Alaskan Batza Tena obsidian source suggests that this is a single assemblage rather than a lag accumulation resulting from, for example, wind deflation of the dune. The assemblage consists of used flakes and flake blanks (figure 3.5g), pressure blades and pressure blade cores (figure 3.5h), notched and indented base lanceolate (leaf-shaped) projectile points or knives in various stages of manufacture (figure 3.5j–l), and unifacial scrapers. Of interest to our discussion is the unambiguous co-association of pressure blade technology with indented base thinned lanceolate bifaces and notched points. While it has been suggested that the notched and the indented base points are two distinct end products of the same manufacturing system, the lack of edge grinding on the concave base bifaces makes it likely that these specimens are late-stage preforms for notched points or reworked pieces, which are also basally thinned.22
FIGURE 3.5.
Akmak artifacts from Onion Portage (a–f) and Nogahabara 1 artifacts (g–l): (a–b) precores; (c) bifacially edge-retouched knife; (d) wedge-shaped microblade core; (e) retouched blade; (f) blade retouched into scraper; (g) retouched flake; (h) pressure microblade core; (i) projectile point preform; (j–k) lanceolate projectile points (possible preforms for notched points); (l) notched point.
FIGURE 3.6.
Pre-Nenana (a–c) and Denali (d–i) artifacts: (a–b) microblades from Swan Point; (c) burin and burin spall from Swan Point; (d) microblade core; (e–f) bifacial points and (g) burin from Broken Mammoth; (h–i) bifacially retouched point.
The lowest level of the Swan Point Site near Delta, Alaska, provided a date of around 14,000 years ago, making it the earliest directly dated microblade occupation in Alaska.23 It contained microblades (figure 3.6a–b), a core tablet (figure 3.6c), and detritus from their manufacture, burins, cobble tools, and hammerstones but no bifaces or bifacial points. This occupation is unique in central Alaska since it is below Nenana Complex levels (see below). This strongly suggests that microblade technologies arrived in this part of Beringia before Nenana, a presumably non-microblade complex. This is important because it may indicate that the first people in the area were most likely related to the Siberian peoples—whereas if Nenana was first it could have led to the non-microblade technologies seen in Clovis.
The Denali Complex, according to F. H. West, represents the first colonization of eastern Beringia, at about 12,000 years BP, and remained little changed until its disappearance around 8,000 years BP or later.24 There is little difference between Late Dyuktai and Denali artifacts, and there is general acceptance that they were closely related. Denali sites, which are widespread in Alaska, are dominated by microblade inset technology but also contain a significant component of bifacial knives and points. Microblades were made primarily on wedge-shaped bifacial cores (figure 3.6d), and bifacial points were intentionally thickened and finished with pressure flaking and lower edge grinding (figure 3.6e–f and h). There are also bifacially retouched flakes (3.6i). Pressure flaking techniques range from selective and nonpatterned to serial and diagonal. Burins are common and take a variety of forms (figure 3.6g).
Trail Creek Cave 2 and Lime Hills Cave 1 are Denali sites. Both produced slotted antler points (figure 3.7a–f), which have bases that are beveled for hafting to a spear shaft. It is clear from these specimens that inset projectile point technology accompanied microblade technology. The remarkably preserved perishable tools from Lime Hills Cave 1 included the base of an antler point or knife and most of a slotted antler projectile point (figure 3.7f).25 The slots run along opposite sides and were designed to hold microblade segments, some of which were found in association. The artifacts from these sites date to about 9,500 years BP.
Several fluted points were found during the 1940s and 1950s along the Utukok River in northern Alaska. Since all of the points were surface finds and not directly datable, archaeologists used the tried and true typological approach to cross-date them. Because they were fluted and looked somewhat like Clovis, they were considered evidence of an Alaskan antecedent to Clovis. The real clincher for the pre-Clovis case was that the Alaskan fluting technique was significantly different from that of Clovis, suggesting that it was an early developmental phase of the technology. And, after all, the points were found where the prevalent origin theory predicted they would be.
This pre-Clovis notion seemed to be confirmed by further work on the North Slope during the 1960s and 1970s. First, Robert Humphrey, while a PhD student at the University of New Mexico, conducted a reinvestigation of the Utukok River area in the hope of finding more diagnostic artifacts in a datable context. He discovered a site that produced additional fluted point fragments, along with evidence of the manufacture of weapon tip replacements.26 A radiocarbon date of 17,300±800 years BP was obtained from a mammoth bone found eroding out of a nearby bank. Perhaps the date was too old, because it meant a gap of almost 6,000 years between it and Clovis, but nonetheless it was pre-Clovis.
Additional fluted points were recovered a few years later at the Putu Site, on the North Slope of the Brooks Range, and a charcoal date suggested that their age might be 11,470±500 RCYBP (radiocarbon years before the present).27 This date was absolutely perfect, establishing fluted-point makers in the American Arctic at least 200 years before their arrival on the plains. Unfortunately, when the geologists Tom Hamilton and Steve Porter undertook geological studies in the area, they discovered that the location was beneath a glacier until around 13,000–13,500 years ago.28 According to environmental reconstructions, the site would have been, at the very best, part of an unattractive, barren pile of rocks until long after Clovis times. To clarify this situation, Mike Kuntz and Rick Reanier conducted new excavations, which confirmed a younger date for the fluted points.29
FIGURE 3.7.
Slotted antler points and ivory tools: (a–e) antler points from Trail Creek Cave 2 (cross-section outlines of b and e illustrate grooves for microblade insets); (f) antler points from Lime Hills Cave 1; (g–h) Nenana ivory tools from the Broken Mammoth Site, not slotted for microblade.
In 1966 I accompanied Robert L. Humphrey Jr. in a search for Clovis sites along the Utukok River, where an Alaskan fluted point had been found in 1949. We were fortunate to find a campsite where early people had lived and manufactured fluted points, surely evidence of the first Clovis peoples in northwest Alaska. We were also hoping to find charcoal that would date older than the radiocarbon assays from Clovis sites in the Lower Forty-Eight. Unfortunately, we found no charcoal at our campsite, but instead we dated a sample from a mammoth bone that was eroding out of the adjacent riverbank. The mammoth bone dated to more than 17,000 years old, likely too old to be associated with the fluted point campsite.
I have spent many more field seasons over the past forty years in various parts of Alaska searching for evidence of the peopling of the Americas. It was not until the summer of 2005 that Bob Gal, National Park Service archaeologist for northwest Alaska, found the first fluted point site in Alaska with associated charcoal. The assay of the charcoal suggested that the descendants of Clovis people started living in Alaska no more than 12,000 years ago . . . long after mammoth hunters camped at the springs of Blackwater Draw. Dennis
Although more fluted points have been found on the surface at several locations in the Brooks Range, none has been in a good geological context. Since these finds, geological mapping and controlled excavations have demonstrated that the Alaskan fluted point complex is younger than Clovis rather than being a Clovis ancestor. In fact, some archaeologists have argued that these points represent an intrusion of late Clovis people into the Arctic, or at least a northward diffusion of the post-Clovis mid-continental fluting technology.30 Current excavations at the Serpentine Hot Springs Site in western Alaska, where fluted points have been found in good context, have yielded radiocarbon dates of around 12,000 years ago.31 Support for the idea also comes from the ice-free corridor in Canada.
The plains of Alberta and areas northward toward the ice-free corridor have yielded fluted points.32 Like the Alaskan specimens, most of these artifacts are neither well fluted nor representative of classic Clovis technology. This situation can be interpreted in two ways. One is that the artifacts represent early Clovis technology evolving as people moved southward. Conversely, they might represent a post-Clovis fluting strategy that was spreading northward. It would be great if the former could be proved, but there are several arguments against a pre-Clovis antiquity of the Canadian specimens.
Also like the Alaska specimens, the Canadian points are surface finds without good contextual data—with one exception. A single fluted weapon tip was recovered from a stratified site known as Charlie Lake Cave, on the very western edge of the ice-free corridor in British Columbia.33 A radiocarbon assay yielded a date of 12,000 years ago for the fluted point level. This date fits the new deglaciation chronology reasonably well and is consistent with the information coming out of Alaska. Furthermore, the dating of fossil remains from the ice-free corridor suggests that animals were not living in the corridor before 13,000 years ago. At present the Charlie Lake Cave radiocarbon date, along with the younger age estimates for the Alaskan specimens, supports the existence of a post-Clovis technological link between the Northern Plains and the Arctic. In addition, the technology of these Canadian points is more like that of some of the post-Clovis fluted points found in the northeastern and upper midwestern United States and eastern Canada. Perhaps all of these types represent Clovis-derived people who followed the retreating ice front northward through the opening corridor into Alaska.
The lanceolate projectile points found at the Mesa Site suggest the possibility of a second technological intrusion into northern Alaska.34 Although similar projectile points are known from surface collections, Mesa is the first site where they are found in a reasonable stratigraphic context and dated by charcoal from associated hearths. The Mesa Site, like the Putu Site, is on the North Slope of the Brooks Range, just ninety miles, not far in Alaskan terms, from the location of the first fluted point finds. The site sits atop a prominent flat-top landform (hence its name) and overlooks the wide expanse of the North Slope in all directions.
Numerous fire hearths at Mesa provided charcoal, whose radiocarbon dates range from about 14,000 to 12,000 years ago. If the outlier assays are eliminated, there is a strong cluster of dates between 9,900 and 10,200 years RCYBP. The 7,600 years RCYBP date may have been a laboratory error, and redating the same sample placed the hearth in the 10,000 years BP cluster. Mike Kuntz and Rick Reanier, the principle investigators of the site, suggest that the oldest dates represent an earlier occupation by the same group, but the evidence for this is not compelling.35 In a review of early Alaskan archaeological data, Tom Hamilton and Ted Goebel mention the possibility that 1,400-year-old wood was used for fuel in the single earlier-dated hearth.36 This explanation is reasonable because ancient wood is widely preserved in permafrost and commonly found in exposed cut banks and river gravels. These windfall gifts are collected and burned in many parts of northern Alaska, where combustible materials are in short supply.
Artifacts from the Mesa Site include flake tools, small end scrapers and gravers, large bifaces, and lanceolate projectile points (figure 3.8a–c). There is also a massive collection of waste flakes from tool manufacture and resharpening. In broad outline, the Mesa Site projectile points are similar to Agate Basin Paleo-Indian weapon tips found on the High Plains and Rocky Mountain areas of the mid-continent.37 However, Agate Basin sites date slightly older than the Mesa Site. Moreover, there is a major technological difference. Mesa projectile points are thick relative to their width, a trait they share with other Beringian points. Agate Basin technology, by contrast, strove for weapon tips that were longer, thinner, and flat. A better analogy for the Mesa points is the Intermountain lanceolate point types found in the western Rockies and northern Plateau.38 These weapon tips, like the Mesa ones, have thickened cross sections, slightly indented bases, and ground lower edges.
FIGURE 3.8.
Projectile points: (a–c) Mesa Site; (d–f) Sluiceway Site.
One plausible interpretation is that the Mesa Site represents a hunting overlook occupied by a Paleo-Indian group whose origin was the Plateau or the Rocky Mountains of North America. If this interpretation is correct, at least two of the earliest archaeological cultures in eastern Beringia originated not from western Beringia in eastern Asia but from North America to the southeast. This is compatible with research indicating that the ice-free corridor was not a viable option for human habitation until around 13,000 years ago, or about the time when Paleo-Indian sites appear in eastern Beringia. Also, when the corridor finally opened, it did so from the south, providing ever-increasing opportunities for people and animals living in the mid-latitude areas to move northward.
Another group of sites just to the west of Mesa produced lanceolate projectile points that are also not associated with microblades. Known as Sluiceway points, they are between 12,000 and 13,000 years old.39 These weapon tips are much more robust than the Mesa points, but like Mesa points they are very thick relative to their width. They are bi-pointed, finished by pressure flaking, and basally ground (figure 3.8d–f). Several of the Sluiceway sites are game overlooks, where weaponry was replaced and repaired, and one is at a chert source, where new projectile point stock was manufactured.
The Mesa and Sluiceway overlook sites were likely locations of male-dominated activities; campsites that would tell us about group composition and yield tools from the activities of both genders have not been found. If the radiocarbon dates are correct, Sluiceway is slightly older than and may represent a precursor of the Mesa technology, making it unnecessary to search for a plains antecedent for Mesa. If one wants to see their origins as Asian, an argument could be made that the absence of microblades simply reflects the fact that Sluiceway and Mesa are task-specific sites, and both of these groups might have used antler points inset with microblades while hunting different prey or at different times of the year.40 However, we see this as unlikely, as microblades have only occurred with Sluiceway points in surface assemblages.
Are there any other possibilities for the origins of Clovis technology in eastern Beringia? An intriguing group of sites in central Alaska, along the Tanana and Nenana Rivers and their tributaries, has drawn the attention of archaeologists searching for Clovis origins. However, there are some critical problems with this interpretation, not the least being that these sites are contemporary with or younger than Clovis. Hence some investigators, including Thomas Hamilton and Ted Goebel, have hypothesized that Clovis and Nenana are historically related through a common, as yet unidentified, ancestor.41 We think they may be correct but look to the southeast, to assemblages that predate Clovis, such as the Miller Complex in Pennsylvania, as probably ancestral, rather than to eastern Asia.
Nenana sites are located on the tops of alluvial terraces in wind-deposited sediments. A few of them are stratified, with cultural levels in good unmixed contexts. They have yielded some of the earliest dates in eastern Beringia, although as usual there is a wide range of dates. Hamilton and Goebel dismiss the earliest dates and place the Nenana Complex around 13,000 years old.
Artifacts from Nenana Complex sites consist of bifacial waste flakes, bifacially retouched tools (figure 3.9a), end scrapers (figure 3.9b), gravers (figure 3.9c), side scrapers (figure 3.9d), retouched flakes (figure 3.9e), ovoid bifaces (figure 3.9f), triangular points (figure 3.9g), and retouched bladelike flakes (figure 3.9h). These small bifaces, known as Chindadn points, are slightly retouched thin flakes that have been interpreted as small hafted knives rather than points.42 No large blades, blade cores, or blade-manufacturing debris have been found to verify the existence of a Nenana large-blade technology.
The few Nenana bone and ivory tools include possible ivory points without basal bevels (figure 3.7g–h), an eyed bone needle, and three poorly preserved mammoth ivory rods that date to around 10,300 years BP. One of these rods is bipointed, and the other two are not complete enough to assess their original forms. None of them has a beveled base like the Clovis rods. Although no formal bone tools were found in the Nenana occupation levels at the Swan Point Site, several pieces of worked mammoth tusk were recovered among the associated faunal remains.
FIGURE 3.9.
Nenana artifacts: (a) bifacially retouched tool; (b) end scraper; (c) graver; (d) side scraper; (e) retouched flake; (f) ovoid biface (Chindadn point); (g) triangular bifacial point; (h) retouched bladelike flake.
A clue about Nenana technology is found at Broken Mammoth, where along with the remains of a few medium-sized ungulates, there are a considerable number of migratory waterfowl bones, suggesting a summer occupation.43 If trapping and netting were the main techniques used to procure these resources, that would explain the absence of large stone projectile points or even slotted bone points. At another site or in a different season, the same people who used these tools may well have used other weaponry systems. For instance, we know that microblades at Trail Creek Cave were fitted into slotted antler projectile points, and later Arctic peoples used similar but unslotted projectile points for hunting caribou. However, since caribou migrate out of central Alaska during the summer, such projectile points are not used at and generally do not appear in the debris of campsites oriented to other economic endeavors such as plant collection and processing and fishing. After additional work at Swan Point, Barbara Crass and Charles Holmes presented a paper indicating that Nenana is clearly related to the Late Dyuktai microblade tradition.44
Overall, the archaeological record of eastern Beringia holds together well as representing the wide-ranging continuation of a slow eastward expansion of a generalized, Arctic-adapted Upper Paleolithic microblade tradition. The derivation of the Denali Complex from the western Beringian Dyuktai is evident. This does not, however, explain all of the early assemblages in eastern Beringia. The interesting obstacle to the seemingly straightforward single-Asian-origin explanation is the probability that the early fluted point technology of the northern slope of the Brooks Range ultimately derives from the Paleo-Indian traditions of the subglacial portions of North America, specifically the High Plains and Rocky Mountain regions. There is also the possibility that the Sluiceway-Mesa Complex had its origins in the south as well. The absence of an early microblade tradition in the ice-free corridor east of the northern Rockies, in spite of the apparent use of this corridor for the introduction of southern elements into the north, further erodes the likelihood of the greater Beringian microblade technology being the historical ancestor of Clovis.
After decades of research, there are still no well-documented sites that provide evidence that people moved into northeastern Siberia or Alaska much before 12,000 years ago. Moreover, the technologies that were carried from Asia to America were almost exclusively microblade based, with only a minor emphasis on bifacial flaking. Large blade sites are not documented in northeastern Siberia and eastern Beringia until very late after Clovis, with the earliest evidence of their use appearing in the Aleutian Islands around 11,000 years ago.
The Beringian archaeological record is lacking in the thinned bifacial technology accompanied by large blade manufacturing we see in Clovis. Combined with the fact that humans did not colonize eastern Beringia until the climate became more hospitable, after the ice age ended around 12,000 years ago, Beringian hunters cannot be ancestors of Clovis peoples. In fact, just the reverse might prove to be the answer to the question of the peopling of the American Arctic.
