Across Atlantic Ice

by Dennis J. Stanford

  Jeff Speakman of the Smithsonian’s analytical lab conducted an X-ray fluorescence probe of the biface and compared the results to probes of French gun flints and Solutrean artifacts made of Grand Pressigny flint from France. The results indicated that the biface was made of French flint. Could this artifact be direct evidence of Solutrean settlers of the New World rather than a relic once owned by a seventeenth-century colonist?

  Eppes Island is the remnant of an upland terrace located at the confluence of the James and Appomattox Rivers. This location would have been an excellent camping locality following the LGM. The biface and other prehistoric artifacts were found below a clay chimney base and thus were not likely to have been the possessions of a colonist. Because this is not certain, the laurel leaf is not the smoking gun of our theory, but it is an intriguing piece of evidence. Dennis

  Three alternative conclusions may be derived from this evidence: novice Clovis flintknappers were learning fluting techniques without the benefit of instruction (for instance, a youth might have been trying to emulate adult knappers); non-Clovis individuals were trying to replicate the technique, also without benefit of instruction; or proto-Clovis knappers were experimenting with basal thinning techniques. As there is no immediately available tool stone in the area, we doubt that beginners would have been allowed to practice on so many pieces of raw material without corrective instruction. Although the second scenario could be correct, there is little or no archaeological evidence of non-Clovis people living in the southeast during Clovis times. The total artifact assemblage along with the radiocarbon dates leads to the conclusion that the assemblage is a proto-Clovis technology, and it is not surprising that its radiocarbon dates are older than the earliest accepted dates for Clovis.

  The stratigraphic sequence confirmed by the radiocarbon-dated geologic exposures and associated artifacts indicates that people who used core and blade and bifacial projectile point reduction technologies were established in the Mid-Atlantic region of North America during the early LGM. As yet the data are not robust, but they suggest that a shift to fluting technology took place in the southeast, perhaps in Tennessee, around 14,000 years ago. There is no evidence of proto-Clovis fluting developments north or northwest of the Chesapeake Bay. Instead the smaller indented base projectile points and blades continued to be manufactured by people who moved along the margins of the LGM-YD Great Lakes region and perhaps onto the northern plains.

  NORTH—AND WEST—TO ALASKA?

  The rapid rise in sea level during the climatic warming after the LGM was not disastrous to human hunters and gatherers; on the contrary, as the sea flooded the continental shelf, it created a richer estuarine environment. At the same time, the Laurentide glacier retreated, opening new nutrient-rich inland territories with an expanding biota exploited by both man and beast. Increased biological productivity in both environments could sustain a significant increase in population.

  People had no doubt explored inland from their arrival, and we think this process is recorded at Meadowcroft by the decreasing ages of the hearths. These probably represent short-term camps between 19,000 years ago and the latest Miller Complex occupation between 15,100 and 13,200 years ago. The most recent occupation appears somewhat more substantial than previous camps, and the distant sources of the raw materials represented in the later artifacts indicate that the occupants were familiar with a vast territory, presumably as a result of explorations by their ancestors during the previous millennia. As James Adovasio, the excavator of Meadowcroft, points out, this occupation is only slightly pre-Clovis in age.35 Since the technology of the Miller bifaces does not overlap Clovis, we think that the developed Clovis innovations did not reach southwestern Pennsylvania until later.

  There is possible evidence for a westward expansion from Cactus Hill of the basally thinned, indented base point style along the northwestward retreat of the Late Pleistocene ice margin (figure 4.1). For instance, in extreme southeastern Wisconsin, butchered mammoth remains were found associated with simple stone tools, but there were no projectile points at the Schaefer and Hebior sites. The archaeologist William Overstreet and his associates conducted eight radiocarbon tests on wood samples and collagen from the Schaefer mammoth bone.36 The results were remarkably consistent, producing an average age of 12,373±75 RCYBP. They also obtained three collagen accelerator mass spectrometer (AMS) carbon-14 dates averaging 12,530±50 years RCYBP from the Hebior mammoth bone. (AMS takes smaller samples and is more accurate than conventional carbon-14 dating.) Thus there is no doubt that ice age hunters were stalking now-extinct animals near the glacial margin in Wisconsin contemporaneously with or slightly later than the youngest Miller Complex occupation at Meadowcroft. Furthermore, these events took place more than a thousand years before Clovis hunters killed mammoths at Blackwater Draw, New Mexico. Two additional Wisconsin mammoth sites, Mud Lake and Fenske, produced a tight radiocarbon age cluster of 13,500 RCYBP (16,050 years ago).37 There is some evidence that these animals were butchered, but no associated stone tools were found.

  FIGURE 4.12.

  Proposed periglacial point progression from the Mid-Atlantic seaboard to the Brooks Range of Alaska: (a) Cactus Hill; (b) Miller point from Meadowcroft; (c) Chesrow point type; (d) Goshen; (e) fluted point from Alberta; (f) Nenana; (g) Alaska fluted.

  Although no projectile points were recovered at any of these sites, Overstreet makes a case that the hunters used a type known as Chesrow (figure 4.12c).38 Chesrow points and artifacts have been found at several campsites nearby on the Calumet Stage beach of glacial Lake Chicago, an early version of Lake Michigan. Based on a tentative correlation between the landscape positioning and elevation of two of the Chesrow sites and the high water levels of the lake during various climatically induced meltwater surges, he proposes that the Chesrow artifacts were made between 13,700 and 15,000 years ago. While this doesn’t prove that the points were used to kill the mammoth, it may indicate they were contemporary.

  Chesrow weapon tips are comparatively thick, basally thinned bifaces that were occasionally edge ground along the basal margins. Except for greater thickness, they are close to Miller points in overall morphology and manufacture (figure 4.12b). Since these tools are all made of poor-quality, cobble-sized residual cherts from local glacial deposits, their relative thickness is likely due to the difficulties of working small, tenacious cobbles. Blades and blade cores have not been identified for this complex, so it is unclear how Chesrow might relate to the early Mid-Atlantic technologies.

  The exceptionally early dating of mammoths with clear artifact associations is hard for many conservative North American archaeologists to accept. Because of the lack of a robust suite of radiocarbon dates for the Chesrow Complex, the arguments against its antiquity are nearly identical to those leveled against the pre-Clovis age of Suwannee. In light of age and technological correlations between the Wisconsin finds and Meadowcroft and Cactus Hill, however, Overstreet’s interpretation seems reasonable.

  The antiquity of these mid-continent human-mammoth associations is significant for the theoretical peopling of the Americas via the ice-free corridor. Paleoecologists and geologists now estimate that this route could not have been used before 13,000 years ago.39 Since the butchers of the Schaefer and Hebior mammoths in Wisconsin were home long before the corridor opened, their ancestors could not have traversed this inland passage.

  The environment of ice margins and the adjacent tundra remains a key factor in tracing when early pioneers first began to expand to the northwest. Excellent geological and pollen evidence, along with plant and animal remains, indicates that conditions were highly variable, depending on a host of interconnected factors such as elevation, latitude, and distance and direction to major water bodies and the edge of the glacier. This tended to produce ever-increasing environmental diversity as the glaciers retreated northward. Some areas were afforded protection from winds and storms; others basked in the sun; still others were in isolated cold air drainages that preserve
d islands of stagnant ice. Tundra likely gave way to patches of spruce parklands, while well-drained regions became grasslands. Much of the habitat was a mammoth steppe or temperate tundra, with spruce forest closing in on open spruce parklands.

  This checkerboard of habitats was peppered with a liberal dose of wetlands, ponds, and lakes. As the glaciers ebbed, their underlying topography, depressed for eons by the weight of the once-overlying ice mass, became inward-slanting basins that collected meltwater. Some of these glacial lakes were so large that they are considered inland seas. Our Great Lakes are mere shadows of this once immense system of lakes. Inevitably water filled the basins beyond their capacity, breaching divides and spilling across the landscape to create new canyons, rivers, and wetlands. Glacial Lake Missoula in western Montana drained so rapidly that it carved out thousands of square miles of countryside, creating the vast scablands of eastern Washington. Before the ice retreated across the St. Lawrence spillway, the majority of the meltwater east of the Continental Divide drained into the Mississippi River and significantly lowered the temperature of the Gulf of Mexico.

  The melting of the continental glaciers was neither a constant nor a consistent process. During episodes of global cooling the glaciers advanced, retaking healed landscapes. Some of these fluctuations resulted in ice fronts advancing and retreating as much as 500 kilometers in just a few hundred years. These re-expansions no doubt destroyed evidence of the activities of earlier ice age hunters.

  As the glaciers gouged their way across the earth’s surface, they abraded the underlying basal rock into a fine-grained mineral powder known as loess. Some of the crushed rocks contained phosphates and potassium, essential nutrients for plant growth. Substantial concentrations of formerly atmospheric nitrogen that had accumulated in the ice sheets for thousands of years were also deposited on the periglacial landscape as the ice front melted. With such high concentrations of fertilizer along the margins of the ice sheet, plants would have begun growing relatively soon and been especially nutritious to the herbivores grazing in these areas.40 The result would have been a potentially greater number of herbivores and their predators. Vast amounts of loess were blown south and east by catabolic winds—which occur when air cooled by moving over a glacier meets warm air over land—and deposited in deep beds in the upper Midwest, creating extremely productive rangeland there as well.

  Different animals exploited different environments. Caribou herds and moose were no doubt major components of the temperate tundra, while other ungulates grazed on the margins of the spruce parklands and down into the forests. Mammoth, horse, bison, and camel fed on the drier grasslands, scattered among sage and stands of pioneer trees and sun-tolerant shrubs. As the nutrient-rich lake basins warmed and bloomed, migratory waterfowl no doubt flocked to them for summer breeding grounds.

  The new environment bursting forth was ideal for hunting societies, and there is little doubt that ancient human bands moved into it. The same act was playing out all over the Northern Hemisphere as ice age climates gave way to the warmer regimes enjoyed today. But traces of the passing of prehistoric humans are difficult to find; most were destroyed by the dynamic geological processes that were resculpting the landscape, especially soil upheavals caused by frozen ground phenomena, such as ice wedges and solifluction, and tongues of ice expanding across the plains.

  If the thin indented base point is an index fossil of early human population expansion, it should have been encroaching on the plains and moving northward through the ice-free corridor as environmental conditions allowed, through a succession of styles. An enigmatic complex known as Goshen (figure 4.12d) from sites on the northwestern plains contains thin unfluted points that might be later relatives of the Miller Complex. Dates from the Mill Iron Site in eastern Montana of circa 11,500 RCYBP (13,350 years ago), as well as those around 11,100 RCYBP (13,020 years ago) from a Goshen occupation at the Jim Pitts Site in South Dakota, suggest that people were hunting bison on the northern plains while Clovis were beginning to push westward.41

  Projectile points from Alberta also indicate that descendants of the early indented-base-point folks colonized the ice-free corridor as soon as the environment could sustain animal life (figure 4.12e). This process no doubt took place much earlier along the warmer southern end of the corridor than it did in the north. In fact, one can imagine the opening as convergent melting from both ends, but starting first and continuing more rapidly in the south as it moved north, east, and west to the mountains. Although it is theoretically possible that people traversed the entirety of the corridor by as early as 14,000 years ago, fossils from the area, with few exceptions, are younger than 13,200 years old. As soon as the plains of Alberta were habitable, fauna with southern affinities moved northward, including horses and the plains bison, B. bison antiquus. The first evidence of its Arctic cousin, B. bison occidentalis, appeared at the Tabor Site near the far southern end of the corridor between 10,000 and 10,500 RCYBP (11,480 to 12,520 years ago). According to Mike Wilson, a prehistoric bison specialist, “These northern bison may signal not the physical opening of the corridor (for that was likely earlier), but the biotic opening of the corridor.”42

  One can only guess how long it took the northern bison to move south to Tabor, but they might have passed the human migrants who were moving north around 12,900 years ago and who left traces at several sites in Canada and central Alaska. It was in this general region that they interacted with the Asian makers of microblades who came across the Bering land bridge, creating the Nenana Complex, which has a median age of roughly 11,500 years. Like the other artifacts discussed in this chapter, Nenana projectile points (figure 4.12f) are very similar in size, shape, and technology to the Miller projectile point type. The Nenana people, like Chesrow and early Goshen people, did not have a well-developed blade component in their tool inventory—whomever they descended from, they did not retain this form of technology. The remainder of Nenana artifacts, including ivory rods and basic biface technology, are somewhat similar to Clovis. Some investigators accept that Nenana is in some way ancestral to Clovis, whereas others opt for a common ancestor. We prefer the latter point of view but differ in the identification of the common ancestor and its place of origin. Finally, we see the Alaskan fluted point as a possible fusion between the unfluted early indented base points and a microblade technology (figure 4.12g). Unlike Clovis fluted points, Alaskan fluted points exhibit scars indicative of pressure removals that are also quite similar to scars on pressure microblade cores.

  Though some as yet unknown technology along the trail from Lake Baikal in south central Siberia to North America may have given rise to the Nenana Complex, in total or in part, we contend that the spread of early Mid-Atlantic technology shows an east to west cline—not west to east across the northern margin of Europe to Asia, as suggested by some geneticists, but westward across the Atlantic. Successfully adapting to new and enriched environments, the migrants who used this technology nearly circumscribed the globe.

  5

  THE SOLUTREAN

  Ice Age Innovators

  Since the Beringian evidence includes no suitable, old enough archaeological assemblage that might have given rise to pre-Clovis and Clovis technology, the question is, where in the Paleolithic world was there a technology that shared enough traits with them to suggest a historic relationship? For years scholars have noted superficial similarities between Solutrean and Clovis tools and technologies, but several seemingly irresolvable obstacles have prevented them from postulating a historical connection—chiefly a gap of some 5,000 years and the conviction that Paleolithic peoples could not have crossed the Atlantic Ocean.1 But we now have pre-Clovis artifact assemblages in North America that overlap Solutrean in age (see chapter 4), and the evidence of very early sea navigation is growing (see chapter 10). It is time to give the Solutrean a more careful look.

  UPPER PALEOLITHIC CULTURES OF SOUTHWESTERN EUROPE

  The Upper Paleolithic in southwestern Europe has been divi
ded into several major cultural periods based on stratigraphic relationships and changes in artifact types. Stone tool manufacture changed from modifying flakes during the Middle Paleolithic to making and using prismatic blades. Large blade technologies are the hallmark of the Upper Paleolithic, especially in areas rich in flint resources. This holds true throughout most of Europe, western Asia, and northern Africa.

  Although our particular interest is a single period (16,500–25,000 years ago) in southwestern France and northern Spain, this brief overview of the European Upper Paleolithic sequence places our observations and interpretations into a broader archaeological and cultural context. This is important because it shows just how different and special the Solutrean materials were, even in their homeland. Keep in mind that these are generalized summaries combining many materials that may have wide ranges of variation through time and space.

  AURIGNACIAN (CIRCA 33,000–27,000 YEARS BP)

  There have been heated discussions among European prehistorians about whether the Aurignacian archaeological culture, named after the location in France (Aurignac) where it was first recognized, represents a single flaked stone industry with variations or multiple independent industries, and it is subdivided into various units that identify time and space differences. However, the general similarities between the artifact assemblages and subsistence and settlement patterns of its users link them in a unified archaeological culture. Many researchers view the Aurignacian as a direct development from the preceding regional Middle Paleolithic industries rather than an intrusion, but this interpretation is now hotly contested.2