Sunday, January 14, 2007

Ancient Stone Tools Found In Minnesota

A very modest headline, which does its best to conceal what might turn out to be one of the most important archaeological finds of recent times, namely the discovery of crude stone tools, which might date back as far as 15,000 years, a couple of millennia earlier than the posited arrival of the Clovis people, thought for many years to have been the First Americans.

Minnesota, aka the North Star State, is an area of the American mid-west about which I know precious little about, other than it nestles close up against the southern borders of Canada - accordingly, the town of Walker, near the Leech Lake Indian Reservation, is new to me too, but if these finds are validated, this site could become one of the most famous in the field of palaeoanthropology.

"Archaeologists in the northern Minnesota town of Walker dug up the items, which appear to be beveled scrapers, choppers, a crude knife and several flakes that could have been used for cutting, said Colleen Wells, field director for the Leech Lake Heritage Sites Program...

...Wells and other archaeologists discovered around 50 objects this past year while investigating a route for a planned road that would serve a major community development project in Walker. The items were found beneath a layer of glacial deposits that had been covered by windblown deposits. Based on what's known about the geology of the area, they believe the objects are between 13,000 and 15,000 years old."

Although nothing as yet has been conclusively dated, the geological context looks promising, but some are questioning whether the rocks found were really fashioned by human hand, or whether instead they had modified by natural, environmental factors, such as fracturing as a result of coming onto contact with contemporary ice.

In support of the idea that humans could have been present so far north, during the Ice Age, the attached map reveals that the site of the finds at 15,000 years ago, corresponded with an ice-free 'oasis' - which would have meant that the putative residents of the time were living as close to the towering ice sheets as was humanly possible.

Moreover, a human presence at this location at that time, would indicate to many that these people may have entered the North American continent by using the famed Beringia land-bridge. Research published last year implied that it had in fact disappeared a thousand years earlier than thought meaning that the Clovis model of hunter-gatherers coming in from Asia couldn't have happened as suggested. But 15,000 years ago, the land bridge was still there, and although incredibly inhospitable to man and beast, the possibility of earlier people entering America still holds.

Of the 50 objects recovered so far, only 2 are depicted here, making it difficult to form an impression of the finds as a whole, but at first glance, if these are tools, they appear to be somewhat primitive, and nothing like those of the Clovis culture that came into being as the Ice Age drew to its abrupt end.

In a previous incarnation of this essay, I suggested that the tools looked more Mousterian in nature, simply because they appear to be roughly fashioned and lacking much in the way of grace - whereas other tools from the same period, particularly in Eurasia, had by this time become very sophisticated, both in style and use, so to see these seemingly cruder American stone tools at such a late date of 15,000 years ago, comes as something of a surprise.

Of course, just because these two examples, and maybe others, appear rough and ready, it doesn't necessarily follow that the people who made them were incapable of making better-looking objects, or were in any way relatively unskilled hunter-gatherers, but it does raise one single nagging doubt - might these tools really have been Mousterian, and if so, would that definitely imply that Neanderthals had somehow found their way to a land, one which many would believe it impossible for them to have reached.

Furthermore, when we consider that Europeans are thought by some to have made landfall in the Americas around 20,000 years, and who are thought to have brought the elegant Solutrean approach to stone tool manufacture, we might expect tools from 15,000 years ago to more closely resemble that industry.

Although the Beringia land-bridge may have seen occasional human activity, some like Dennis Stanford,of Center for the Study of the First Americans believe that people from Solutrean Europe may have made a sea-crossing to North America around 20,000 years or more ago - a marked similarity between Solutrean and Clovis technology has been interpreted as a possible clue in support of this idea, though as yet, no conclusive evidence has come to light.

However the tools shown only bear a passing resemblance to Mousterian assemblages, and it may be the case that the materials involved weren't ideally suited to knapping, and that the manufacturer(s) may simply have been too inexperienced to have fully realised their own knapping potential - but for the purposes of this essay, I'm going with the conceit that they could in fact be Mousterian.

As mentioned in previous posts, the Topper site in South Carolina currently looks as if it will confirm a human presence in the Americas going back 50,000 years, a figure so far off the Clovis scale that it scarcely seems credible. Albert Goodyear, who excavated at the South Carolina site of Topper, dug down nearly 15 feet below the levels of the earliest accepted Clovis dates to uncover stone tools which according to received wisdom, shouldn't have been there.

Footprints believed to be 40,000 years old were found near Puebla in Mexico in 2003, leading one of the site's discoverers, Dr. Silvia Gonzalez to opine that early American arrivals made their way there by boat, 'island hopping along the Pacific coast'. This might sound surprising, until we consider that it was around this time that people were making their way into Australia by sailing there, thought to be evidenced by a 40,000 year-old rock painting depicting a boat.

At Meadowcroft Rockshelter, about 36 miles SW of Pittsburgh, Pennsylvania, a site excavated by James Adovasio between 1973-78, where stone tools have been found in deposits that have been radiocarbon dated to between 16,000 and 19,000 years - although detractors have claimed that these dates may have been skewed by the presence of nearby coal, which they claim may have been introduced to the site. According to the Wikipedia entry, as well as an assortment of bifaces and blades from Meadowcroft, ceramics have also been recovered - which surprised me, as although the Jomon culture of Japan is thought to have been capable of producing such wares around 15,000 years ago, I'm not sure that there was an equivalent tradition in the Americas at such an early date. Hopefully further research will clarify this claim.

Cactus Hill in Virginia, about 45 miles south of Richmond has produced both Clovis material, as well as what are described as points, blades and cores, lying some distance below the Clovis levels, tentatively dated to between 15,000 and 17,000 years, as described by Larry Kimball, who apparently sees the finds as 'a logical precursor to fluted Clovis points'

Moving on down to South America, and Chile in particular, we come to the site of Monte Verde, which so far is the only site that has been unequivocally accepted as being pre-Clovis. According to a Nature abstract from March 1998, Monte Verde has a definite date of 13,000 years ago, with another radiocarbon estimate from the site possibly stretching back to 33,000 years - which is quite near another set of dates estimated for Brazilian site called Boqueirao do Sitio da Pedra Fur, for which traces going back 32,000 years have been suggested.

Brazil is host to one another enigmatic site, Serra Da Capivara, at which charcoal and stone tools indicate a human presence there dating back 50,000 years, and is the site best known for its human remains, dating from between 9,000 and 12,000 years, which seem to imply that these people's ancestors had somehow found their way to Brazil all the way across the Pacific from Australia - the most famous of the skulls there has been named Lucia, I think in honour of Lucy, the African australopithecine. Her descendants are thought to have partially lived on in people who today dwell in Terra del Fuego, and could be mute testament to the sailing and navigational skills of people negotiating the open seas, tens of thousands of years before such feats were believed possible.

So, having come to terms with the idea that humans have been inhabiting the New World for tens of millennia, I can't help wondering if archaic humans, such as Neanderthals, could also have made the journey there, and looking at the stone tools depicted, it's tempting to see them as Mousterian, or a derivative thereof.

But before I leap ahead and say that this is plausible evidence for a late Neanderthal survival in America, living, as they are thought to have done in Eurasia, at the very edges of habitable zones, one or two details should be borne in mind. First, this suggested date of 15,000 years for Leech Lake is at least 10,000 years later than Neanderthals' are presumed to have disappeared from Eurasia into the cold, thin air, and it would be odd if there were no surviving artifacts or remains from this interim period - although like the pre-Clovis sites before they were discovered by people who dug deeper, if no-one is looking for such clues, few, if any, will probably come to light.

Second, there is the possibility that amongst the earlier arrivals in the Americas, i.e. people of the Solutrean culture from near present-day Marseilles in south-western France, say between 20,000 and 30,000 years ago, there could have been a mix of Neanderthal and modern, either individually in person, or genetically mixed, and in this instance it seems fair to assume that a more modern tool-kit would have featured - sites in Eurasia that display these traits of hybridised fossils are normally associated with more modern, or sophisticated, lithic assemblages than those typically associated with Neanderthals.

Third, it would appear unlikely that such long distance travel to the Americas would have been undertaken by Neanderthals alone - much of what is known about their preferred lifestyles indicates an essentially sedentary people who preferred to remain close to home, occupying an area of countryside with which they were intimately familiar, and from which they rarely ventured.

Fourth, if we are to suppose Neanderthals made it to the Americas, either alone or with moderns, there seems to be little sign of them in Australia, (also thought to have first been occupied around 50,000 years ago), or indeed anywhere further east than say, Iran - but who knows what fossils may be still lying hidden in obscure locations across the planet, currently considered far beyond the reach of their explorations. But for the time being, if Neanderthals did disperse farther and wider than thought, there is precious little, if any, archaeological evidence to support that idea.

However, because the world of around 50,000-60,000 years ago appears to have witnessed the sudden start of an extraordinarily quick dispersal of anatomically modern humans out of Africa to some of the most distant parts of the world, (having languished in Africa for the previous 150,000 years), it's very difficult to judge what typical behaviour, migratory or otherwise, would have meant back then.

If we could discover the drivers, or motives behind this headlong flight from Africa into the world at large, we might better understand why people went to such great lengths to distance themselves from their lands of origin, or were just very keen on exploring new lands - or whether instead, more populations either evolved in situ from older stock, in which case these impressions of later and earlier migrations out of Africa, are merely illusory.

Overall though, I don't have a problem with early arrivals in the Americas; I think those lands could have been visited many times over the millennia, by different groups of people, who, due to their small numbers, simply died out, leaving behind them only scant traces of their ephemeral existences.

Update here

Archaeology Channel: They Were Here: Ice Age Humans In South Carolina (26 mins)

Meadowcroft Rock Shelter - 'Unearthing Mysteries' BBC Radio 4 (Real Player req'd)

Book - Bones, Boats and Bison, by E.J. Dixon

Minnesota Ice Man - who he?


Martin said...

The Solutrean - Clovis link appears to be untenable. There's a paper on that issue by Jason Colavito in Skeptic Magazine 12:3 (2006).

Tim said...

Thanks Martin, I hadn't seen that, just off to take a closer look.

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