Bluefish Caves Revisited – Seminal new paper reviewed: Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada. Bourgoen, et al. (2017)

Key findings:

·         The site has at last been accepted as pre-Clovis due to assiduous work carried out by Bourgeon et. al. (2017)

·         Site now firmly established as 24,000 BP, exceeding by at least 5000 years any other accepted site in the Americas

·         Cinq-Mars’ samples used in the analysis proved to be of the dates and to exhibit the human-made, cut-marks he originally contended, thus vindicating his long-held contention of the antiquity of the site

This post is a follow-up to the first long piece I wrote on this site: Pre-Clovis Archaeological Sites of the Americas 6: Blue Fish Caves - Old Crow Basin, Canada. See here.

The site location is:

This is an extremely important paper. I would say a seminal paper, but only time will tell.

Here’s the abstract:

“The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory) from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory) occurred during the Last Glacial Maximum (LGM). This hypothesis proved highly controversial in the absence of other sites of similar age and concerns about the stratigraphy and anthropogenic signature of the bone assemblages that yielded the dates. The weight of the available archaeological evidence suggests that the first peopling of North America occurred ca. 14,000 cal BP (calibrated years Before Present), i.e., well after the LGM. Here, we report new AMS radiocarbon dates obtained on cut-marked bone samples identified during a comprehensive taphonomic analysis of the Bluefish Caves fauna. Our results demonstrate that humans occupied the site as early as 24,000 cal BP (19,650 ± 130 14C BP). In addition to proving that Bluefish Caves is the oldest known archaeological site in North America, the results offer archaeological support for the ªBeringian standstill hypothesisº, which proposes that a genetically isolated human population persisted in Beringia during the LGM and dispersed from there to North and South America during the post-LGM period.” Bourgeon et. al. (2017).

Why is this paper SO important?

Firstly, it answers, unequivocally, a basic question in archaeology:

“What is the earliest date we have so far for when were the Americas were first peopled?”

Secondly, it illustrates that science, although it (meaning the scientific community), presents itself as even-handed and unbiased, is riven by vested interests, self-serving small minded people and bigotry just like the rest of society. As such, this sorry, slow burning episode in archaeology reminds us all, to go back to basics and follow the evidence as good scientists should.

Stepping back a minute, to fully answer the above question, however, requires a, thorough and detailed, examination of the background context to the events surrounding these archaeological discoveries and subsequent claims made by the chief excavator.

This is the story of one scientist’s fight for the acceptance of the facts he had brought to light through his excavation of three small caves in the Yukon territory of Canada. That scientist was Jacques Cinq-Mars and this paper is a vindication of his work which offered firm evidence, that man first colonised the Americas way before the Clovis people.

Jacques Cinq-Mars excavating at the Bluefish caves, from Pringle (2017). Original caption reads: While excavating at Bluefish Caves in northern Yukon during the 1970s and 1980s, Canadian archaeologist Cinq-Mars found cut-marked horse bones and other traces of human hunters that seemed to date to 24,000 years ago—thousands of years before the Clovis people. Photo by Ruth Gotthardt

As Pringle (2017) explains:

“In three hollows known as the Bluefish Caves, he [Cinq-Mars] and his team had discovered something remarkable—the bones of extinct horses and woolly mammoths bearing what seemed to be marks from human butchering and toolmaking. Radiocarbon test results dated the oldest finds to around 24,000 years before the present.

Bluefish Caves directly challenged mainstream scientific thinking. Evidence had long suggested that humans first reached the Americas around 13,000 years ago, when Asian hunters crossed a now submerged landmass known as Beringia, which joined Siberia to Alaska and Yukon during the last ice age. From there, the migrants seemed to have hurried southward along the edges of melting ice sheets to warmer lands in what is now the United States, where they and their descendants thrived. Researchers called these southern hunters the Clovis people, after a distinctive type of spear point they carried. And the story of their arrival in the New World became known as the Clovis first model.”

“Cinq-Mars, however, didn’t buy that story—not a bit. His work at Bluefish Caves suggested that Asian hunters roamed northern Yukon at least 11,000 years before the arrival of the Clovis people..”

“But relatively few of Cinq-Mars’s peers shared his confidence..”

“..rather than launching a major new search for more early evidence, the finds stirred fierce opposition and a bitter debate, Cinq-Mars, however, was not intimidated. He fearlessly waded into the fight. Between 1979 and 2001, he published a series of studies on Bluefish Caves.”

“It was a brutal experience, something that Cinq-Mars once likened to the Spanish Inquisition. At conferences, audiences paid little heed to his presentations, giving short shrift to the evidence. Other researchers listened politely, then questioned his competence. The result was always the same” [rejection and/or denial].

 “In general, the critics focused their attacks on two major fronts. They questioned whether key artifacts at proposed pre-Clovis sites were really, made by humans, as opposed to natural processes. And they pored over presentations and reports for any possible errors in dating.”

“At Bluefish Caves, the crucial evidence consisted of animal bones that were dated to around 24,000 years ago and seemed to be cut, shaped, or flaked by humans. So critics focused on those. They dismissed Cinq-Mars’s identification of butchery marks and tools, and offered alternative explanations. Rockfall from the caves, they suggested, had fractured the bones, leaving splinters that merely looked like human artifacts. Or large carnivores had chomped on a carcass, producing grooves that resembled cut marks or fragments mirroring artifacts. Some skeptics even suggested that living mammoths could have taken bad tumbles nearby, accidentally splintering limb bones. Other critics wanted to see multiple lines of evidence for the presence of early humans at Bluefish Caves, including dated hearths with stone tools in close association.”..

“Stung as he was by the criticism, Cinq-Mars refused to back down. None of the explanations for splintered bones, he noted, could account for the complex chain of steps that produced the mammoth-bone flake tool his team found. But by then, serious doubts about the Bluefish Caves evidence had been sown, taking firm root in the archaeological community: hardly anyone was listening. Cinq-Mars couldn’t believe it. At one presentation he gave, “they laughed at me,” he says angrily today. “They found me cute.” Embittered by the response, he stopped attending conferences, and gave up defending the site publicly. What was the point? To Cinq-Mars, the Clovis first supporters seemed almost brainwashed”

“When Jacques proposed [that Bluefish Caves was] 24,000 BP, it was not accepted,” says William Josie, director of natural resources at the Vuntut Gwitchin First Nation in Old Crow. In his office at the Canadian Museum of History, Cinq-Mars fumed at the wall of closed minds. Funding for his Bluefish work grew scarce: his fieldwork eventually sputtered and died.”

Looking back at the archaeological establishment’s reaction to Cinq-Mars’ work two comments summarise how the prevailing attitudes and entrenched orthodoxy then, is viewed now:

“The scientific atmosphere, recalls Dillehay [excavator and – eventually - vindicated, discoverer of Monte Verde see here and here] was “clearly toxic and clearly impeded science.””

““one of the most acrimonious—and unfruitful [episodes] —in all of science,” noted the journal Nature.”

How does the current paper establish the date of the site and avoid the same criticisms as the original investigator?

Clearly, entering the debate by studying the most contentious bone artifacts attributed as human-modified from Bluefish Caves, could be counter-productive, as it could undermine the authors aim: to re-evaluate the physical evidence gathered and unequivocally date the site.

Therefore, whilst the authors examined a huge number of the specimens collected at Bluefish Caves by Cinq-Mars, some of the oldest and most controversial samples were not included in their analysis.

For example, the unpublished Mammoth limb bone and its attendant re-fitted bone flake (RIDDL-224 and RIDDL-225 respectively) whilst mentioned, were perhaps, wisely not given prominence in the current paper.

However, as we will see later, there may be another reason for this glaring omission. Let’s park that for a minute.

The authors begin by giving an exhaustive explanation in their Materials and Methods section, on the taphonomic processes that affected the bone samples collected and how non-cultural and cultural bone modification can be differentiated. It is worth looking at the criteria they use in detail to underscore how well founded their conclusions are:

·         “A full taphonomic analysis is required, in order to, contextualise and thus correctly identify culturally modified bone. The sedimentary and geological context of an archaeological site affects the taphonomic signature of the faunal assemblages it contains.

·         The faunal material from Bluefish Cave derives from wind-blown (aeolian) loess, which should not produce scratches on bones but can lead to polished surfaces.

·         Cryoclastic debris incorporated into the loess], however, may have abraded the bone surfaces.

·         Rockfall can also modify bone, producing striations and patterns of bone breakage

·         In some cases, these natural traces can mimic cut marks, raising the spectre of equifinality (Equifinality is the principle that in open systems a given end state can be reached by many potential means). This has led some researchers, in the past, to question the cultural origin of some of the bone modifications reported in the literature.”

The authors go on to detail other processes that may mimic human modification of bones:

·         “..large canids, which are capable of applying static pressure on bone resulting in the production of spiral bone fractures and bone flakes similar to the ones produced by human marrow extraction.” 

The authors are at pains to point out the co-indicators for this type of bone-modification in ALL samples studied:

·         “Carnivore activity is also usually accompanied by the presence of digested bone, as well as pits, punctures, scoring and furrows altering the bone surface

·         Carnivore teeth produce traces with characteristically “U” shaped profiles when viewed in cross-section and which are wider and shallower than cut marks, making them easily distinguishable from human modifications” 

The authors are strict in their categorisation of bone modification:

·         “The frequency of tooth marks, spiral fractures and bone flakes were recorded; tooth marks were noted as “certain” or “probable” when the identification couldn't be confidently assessed.”

Further factors affecting the taphonomic state of the bones sample are also considered:

·         “The climatic context of a site is also important because weathering and freeze-thaw cycles can lead to cracks and desquamation of bone surfaces, potentially removing or altering traces of cultural activities.

·         Damage due to climatic factors (e.g., weathering) but also due to biological agents (e.g., root etching, trampling and rodent gnawing) were carefully recorded and quantified”

Next the authors selected those bone samples, most likely to be human-modified for further analysis, highlighting the morphological and morphometrical features used to distinguish human modification from animal (carnivore) and other environmental causes of bone modification:

·         “Shape: cut marks made with stone tools are usually V-shaped (narrow \/ or wide \_/) while carnivore tooth marks or even metal tools will produce grooves with more parallel walls (U or |_|). The cross-sectional shape of a cut mark can be symmetrical (\/) or asymmetrical (√) depending on the inclination of the tool relative to the bone surface. Morphometrical analyses allow us to quantify the profile of potential cut marks by measuring the breadth at the top and at the bottom of the groove

·         Trajectory: cut marks are commonly straight but can sometimes be curved; they are rarely sinuous, as in the case of trampling or root etching

·         Number of striae, size and overlapping: butchering activities can produce multiple striae that should be parallel in orientation and roughly the same size a scraping motion to remove meat may produce overlapping striae; trampling marks will not be oriented in this fashion.

·         Shoulder effect and shoulder flaking: shallow striations along the main groove and edge flaking can sometimes be observed under the microscope at high magnifications in marks produced by butchering; they are rarer in marks created by trampling

·         Internal microstriations: microstriations are common on the inner walls of marks produced by stone tools during butchery; they may also be produced by trampling but will not be observed in cases of root etching or tooth mark scoring

·         Anatomical location and orientation: the anatomical location and orientation of cultural bone modifications must be consistent with the marks produced by specific butchery tasks described in the literature; marks produced by natural processes, however, will not reflect any predetermined intention. Assigning a precise function to a cut mark is subject to equifinality since marks resulting from skinning, defleshing and dismembering can occur in very similar locations and because variability exists in the placement and orientation of butchery marks. Keeping this in mind, we noted the anatomical location and orientation of each cut mark and we proposed a potential butchery task based on comparisons with ethnozooarchaeological data.” 

The authors give further explanation of the diagnostic value of one morphometrical measurement, in particular: 

“The breadth ratio (the ratio between the breadth at the top and the breadth at the bottom of the cut mark) better illustrates the shape of the groove (\/ or |_|) and is a good criterion for distinguishing between cut marks made with stone tools and modifications produced by other effectors. Small ratios are associated with grooves with parallel walls while large ratios are associated with narrow \/ or wide \_/-shaped grooves such as the ones produced by stone tools..” 

Finally from the 36,000 bone samples collected by Cinq-Mars and analysed by Bourgeon and her team 6 were deemed unequivocally human-modified and sent for radio-carbon dating:

“In summary, in order for, a bone modification to be identified as a cut mark in this study, all of the above criteria had to be met. If one of the criteria couldn't be confidently assessed, the mark was consigned to a, ”probable” category of human bone modification.

We selected six bone samples bearing indisputable evidence of butchery activity for radiocarbon dating. The samples were sent to the Oxford Radiocarbon Accelerator Unit (ORAU) for analysis.”

The ¹⁴C BP dates and the calibrated age BP are given in the following table:

The authors therefore come to some firm conclusions in their Discussion section:

1. “While the Yana River sites indicate a human presence in Western Beringia ca. 32,000 cal BP [14, 15], the Bluefish Caves site proves that people were in Eastern Beringia during the LGM, by at least 24,000 cal BP”

2. Our results, therefore, confirm that Bluefish Caves is the oldest known archaeological site in North America.

Emphasis in bold my own.

The two oldest bone samples are shown below:

The oldest specimen, a horse jaw-bone dated to between 23,314 and 24,033 years BP Fig 1 from Bourgeon (2017). Original caption reads: Fig 1. Cut marks on a horse mandible from Cave II. The specimen (# J7.8.17) is dated to 19,650 ± 130 14C BP (OxA-33778). The bone surface is a bit weathered and altered by root etching but the cut marks are well preserved; they are located on the medial side, under the third and second molars, and are associated with the removal of the tongue using a stone tool.

The second oldest specimen, a caribou pelvic bone dated to between 22,176 and 22,731 years BP Fig 2 from Bourgeon (2017). Original caption reads: Fig 2. Cut marks on a caribou coxal bone from Cave II. The specimen (# I5.6.5) is dated to 18,570 ± 110 14C BP (OxA-33777) and shows straight and parallel marks resulting from filleting activity.

Unfortunately, the authors chose to conflate their results with the Beringian standstill theory. In this hypothesis, humans were isolated, physically and genetically, in Beringia from about 23,000 B.P. to 15,000 cal. B.P. and then continued their migration further into the rest of the Americas as an ice-free corridor formed between the Laurentide and Cordilleran ice sheets opened:

(our results) “thus providing long-awaited archaeological support for the “Beringian standstill hypothesis”

Why the authors, feel the need to hang their paper off the coat tails of the current orthodoxy is inexplicable and ironic considering they have just, effectively put the last nail in the coffin of the Clovis-first paradigm!

A good, simple explanation of why this new ‘line in the sand’ rejecting the pre-Ice Age peopling of the Americas, is being drawn was written recently by Marnie Dunsmore (2017), in a blog post with provocative title “Trading One Zombie Model for Another: Why I am Fed Up with the Beringia Standstill Model and the journals and conferences that don't consider alternatives”.

Here are a couple of quotes to give you a different perspective:

“The distribution of mitochondrial DNA haplogroups in the Americas, namely haplogroups A, B, C, and D, according to Behar[3], split from the mitochondrial tree earlier than 30,000 thousand years ago (before the last Ice Age).  Given the distribution for these haplogroups[4][5], it is equally likely that the branching of these mitochondrial haplogroups occurred in the Americas, as in Asia or Beringia. Given that Beringia and Siberia were cold, while many areas in the Americas were temperate [2], during the Ice Age, the likely expansion of the A, B, C and D haplogroups during the Ice Age was in the Americas south of the glaciers, not Beringia or Siberia (as proposed in the Beringia Standstill Model.”

 ..“There is ample evidence that Modern Humans were in Siberia and Beringia tens of thousands of years before the Ice Age.  Given that sea level data indicates that there were long periods before the Ice Age (when Modern Humans were in Beringia) when there was an easily walkable path from Beringia to Florida, to the American Central Plains, to the American East Coast and to points further south, it is highly improbable that highly mobile large game hunters over tens of thousands of years would not easily have moved back and forth between the Americas and Eastern Eurasia[5][8][9][10].”

If you want to check out the timings of the existence of Beringian Land Bridges I put together a detailed post on that here.

An inconvenient truth..

Something really, bothered me about this paper. I read it and re-read, scrolled the screen for several minutes, up and down, up and down. Frustratingly, nothing jumped out. Finally, I went away and thought about something else. Of course THAT did the trick! It was a sin of omission I was missing. Consider the following adapted version of Bourgeon’s table 1:

Notice anything? Two of the oldest specimens, RIDDL-224 and 225 (remember them?) from the Mammoth tibia and the associated refitted flake, are of comparable dates to those determined in the current paper aren’t they? Nothing to see here – move along.

Wrong. Dead wrong. They are radiocarbon (¹⁴C) dates and therefore need calibrating to give actual calenderic ages, i.e. cal. BP years as has been done with the bone samples in this paper.
So let’s calibrate them! I used the Monrepos Museum online Calpal resource (Danzeglocke 2007). Also included is the oldest specimen, a butchered caribou tibia.

Wow now that is quite a bit older isn’t it. So why this omission?

I gave Cinq-Mars’ explanation of how the flake (RIDDL-224) was made from the core (RIDDL-225) by human agency in a previous post, see here.

Although the specimens (RIDDL-224 and RIDDL-225) were described in a peer reviewed journal in 1990, their publication history is quite complex. From the outset, based on contextual, bone taphonomic and sample comparison criteria, Cinq-Mars insisted these bones were pre-Ice Age. It could be argued, that at first, he did not have sufficient high quality evidence to support this assertion. This caused resistance from the archaeological establishment, who firmly rejected this timeframe for the peopling of the Americas and publication problems, after his initial paper appeared. For clarity sake I will summarise the publication history and the radiocarbon ages below:

Looking at the initial date of publication (Cinq-Mars 1990) and the first time, firm dates are attributed to the samples we find they are different. Checking the Canadian Archaeological Radiocarbon Database (CARD) we find the dates of submission for AMS radiocarbon dating are on the same day in April 1997 (Anon 2017 a and b).

And that’s the problem that Cinq-Mars caused. Whilst the argument of how they were produced is detailed and robust, (see here), and Cinq-Mars’ refutation of all published objections, for example Beebe (1983), to these and other specimens is unassailable, he simply did not follow scientific convention. He therefore left himself open to justifiable scientific criticism. This coupled with the extremely old dates, ensured then, and still does today, that Cinq-Mars oldest specimens remain unaccepted.

Image comparisons of RIDDL-224 and RIDDL-225

RIDDL-224 and RIDDL 225 from Harington and Cinq-Mars (2008)

RIDDL-224 and RIDDL 225 from Cinq-Mars (2001)

We can therefore see that these bone artifacts, given their proven human manufacture and most particularly their pre-Ice Age dating would cause Bourgeon et al. great difficulties were they included in their paper. This is because, the authors draw a firm dating ‘line in the sand’ when they link their results so strongly to the Beringian ‘standstill hypothesis’, in their closing discussion.

Conclusions

1. A seminal paper as Bourgeon et al. (2017) prove conclusively that people were in the Americas by 24,000 BP

2. Disappointingly they see the evidence they have gathered as support for the current orthodoxy (the Beringian Standstill hypothesis).

3. Evidence from their own paper regarding the true dates of the peopling of the Americas is ignored.

4. The date of the peopling of the Americas, from data presented above should be at a minimum 27,000 cal BP and perhaps as old as ca. 30,000 cal BP.

Lastly a couple of quotes to which summarise my feelings on the Bluefish Caves saga.

Dunsmore (2017) again:

“I note that prominent conferences such at the Paleoanthropology Conference in Vancouver, British Columbia at the end of March (by the way, to be held on never ceded Salish territory in downtown Vancouver), continue to entertain papers supporting only the Beringia Standstill model, but not alternatives.  Given the weight of evidence, this cannot be seen as objective, and the unlevel funding supporting the Beringia Standstill Model can only be seen as another example of formerly Clovis First too cozy ancient DNA researchers, archaeologists, and their supporters, feeding at the trough.”

The last word should be Cinq-Mars’ (1999), quoting Morlan:

“A program of AMS dating was undertaken on bone cores and flakes “to determine whether the distribution of ages would be random or grouped in time. A random distribution, including ages beyond the limits of radiocarbon measurement, could be explained by the action of one or more long-term natural processes of bone alteration, whereas a restricted distribution younger than the limits of measurement would require the onset of a new process of bone alteration” (Morlan et al. 1990:75). The resulting ages were found to be restricted to “a 15,000 year time span, beginning around 40,000 BP. and ending around 25,000 BP. Since we believe that our measurement methods would have allowed us to measure samples 10,000 years older than those encountered here, this implies that a new agency or process enters into the taphonomic histories of large vertebrates in the Old Crow Basin around 40,000 BP” (Morlan et al. 1990:86).”

Translation: Morlan and Cinq-Mars believe man arrived in the Americas 40,000BP. Enough said.

References

Anon (2017a). Canada / YT / MgVo-2 (Bluefish Cave II) / RIDDL-224. [ONLINE] Available at: http://card.anth.ubc.ca/samples/4593. [Accessed 12 April 2017].

Anon (2017b). Canada / YT / MgVo-2 (Bluefish Cave II) / RIDDL-225. [ONLINE] Available at: http://card.anth.ubc.ca/samples/4592. [Accessed 12 April 2017].

Bourgeon, L. (2015). Humans and Carnivores at the Bluefish Cave ii (Northern Yukon, Canada): Interpretation of the faunal remains [Poster]. Exhibited at Society for American Archaeology 80th Annual Meeting, Session 357: Peopling of the New World and Archaeology of Paleoindians. Hilton Hotel, San Francisco. 18^th April 2015.

Download available at: https://www.academia.edu/24719435/Humans_and_carnivores_at_the_Bluefish_Caves_II_Yukon_-_SAA_San_Francisco_2015

Beebe, B.F., 1983, Evidence of carnivore activity in a Late Pleistocene/Early Holocene archaeological site (Bluefish Cave I), Yukon Territory, Canada, in Lemoine, G.M., and MacEachern, A.S., eds., Carnivores, Human Scavengers, and Predators: A Question of Bone Technology, Proceedings of the 15th Annual Conference of the Archaeological Association of the University of Calgary, University of Calgary, p. 1–14.

Bourgeon L, Burke A, Higham T (2017). Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada. PLoS ONE 12 (1):  e0169486. doi:10.1371/journal.pone.0169486

Cinq-Mars, J, 1990. La place des grottes du Poisson-Bleu dans le Préhistoire béringienne. Revista de Arqueología Americana, No. 1, 9-32.

Cinq-Mars, J. 2001. Canadian Museum of History, Significance of the Bluefish Caves in Beringian Prehistory. [ONLINE] Available at: http://www.historymuseum.ca/learn/research/resources-for-scholars/essays/significance-of-the-bluefish-caves-in-beringian-prehistory/. [Accessed 12 April 2017].

Cinq-Mars, Jacques and Richard E. Morlan. 1999. “Bluefish Caves and Old Crow Basin: A New Rapport,” in Ice Age Peoples of North America, ed. by Robson Bonnichsen and Karen L. Turnmire, pp. 200-212. Corvallis: Oregon State University Press for the Center for the Study of the First Americans.

Download available from: https://www.academia.edu/5521801/Bluefish_Caves_and_Old_Crow_Basin_A_New_Rapport._Cinqmars_et_al._1999_

Danzeglocke, U 2007. CalPal Online. [ONLINE] Available at: http://www.calpal-online.de/index.html. [Accessed 11 April 2017].

Dunsmore, M. 2017. Trading One Zombie Model for Another: Why I am Fed Up with the Beringia Standstill Model and the journals and conferences that don't consider alternatives. [ONLINE] Available at: http://linearpopulationmodel.blogspot.co.uk/2017/03/why-i-am-fed-up-with-beringia.html. [Accessed 12 April 2017].

Harington, C. R., 2011, Quaternary Cave Faunas of Canada: A Review of the Vertebrate Remains: Journal of Cave and Karst Studies, v. 73, no. 3, p. 162-180.

PDF download available at https://www.sciencebase.gov/catalog/item/5771b897e4b07657d1a6c8e8

Harington, C.R., and Cinq-Mars, J., 2008, Bluefish Caves – fauna and context, Beringian Research Notes, no. 19, p. 1–8.

Download Available at: http://www.tc.gov.yk.ca/publications/Blue_Fish_Caves_2008.pdf

Morlan, R,E,, et al. 1990 Accelerator mass spectrometry dates on bones from Old Crow basin, northern Yukon Territory, Canadian Journal of Archaeology 14:75-92.

Pringle, H.. 2017. From Vilified to Vindicated: the Story of Jacques Cinq-Mars. [ONLINE] Available at: https://www.hakaimagazine.com/article-long/vilified-vindicated-story-jacques-cinq-mars. [Accessed 12 April 2017].







Pre-Clovis archaeological sites of the Americas 3: Meadowcroft Rockshelter Pennsylvania

Site importance

Meadowcroft Rockshelter in Pennsylvania has become one of the most celebrated archaeological sites in the Americas. The now accepted date of initial occupation of approximately 16000 years BP is the oldest in North America.

Meadowcroft holds the distinction of demonstrating the longest occupational sequence of humans in the Americas^1&2. The numerous occupation layers contained over 2,000 stone flakes and tools, 150 fire pits and 1 million animal and plant remains. A heavily cut and burnt deer antler base, dated to 16,175±975 years BP was the oldest bone found at the site³. Additional finds included basketry, the area's earliest corn maize dating to the 300's B.C.E., the area's earliest squash and pottery, dating back to about 1000 B.C.E.. Brian Fagan former lecturer at both the Smithsonian Institution, and the Getty Conservation Institute says “Meadowcroft is the single most complex archaeological excavation I have ever seen,” said world-renowned author and New World habitation expert Brian Fagan. “It’s a classic example of the very best in stratigraphic observation and meticulous recording in the field. The superb excavation methods give one great confidence in the important evidence for the first Americans found in the bottom layers of the site.”⁴

View of rockshelter during excavation
Photo credit: Simon Fraser University Museum of Archaeology & Ethnology

View of Meadowcroft seen from the opposite side of Cross Creek April 1975

Photo credit: Mark McConaughy¹⁴

Discovery

The story of the discovery of the site’s significance is an interesting one. Albert Miller, a native of Washington County whose family have owned the area around the cave since 1795 was an amateur archaeologist, naturalist, local historian and farmer.

Born in 1911 he witnessed first-hand the revolution in mechanised farming which swept through the United States in those years, it was these huge changes and the loss of traditional ways of life that inspired him to begin documenting rural life. He wrote later that he “…became enamored of the idea of how old rural and farm building[s], farm machines, tools and methods might be preserved. I felt that the day would come when demonstrations of the past would fascinate people of all ages.”⁵

The idea set in motion the creation of the future museum at Meadowcroft and the non-profit Meadowcroft Foundation, of which Delvin and Albert were president and vice president respectively. Incidentally Meadowcroft was conceived of as a name by Albert and his brother, Delvin from a contraction of their two adjacent farm names: Meadowlands and Bancroft.

 
In 1955 whilst out with his dogs Miller noted that a large groundhog hole in the vicinity of what would later become known as Meadowcroft Rockshelter had what appeared to be prehistoric debris in the excavated earth, reaching further in he retrieved a pre-historic flint knife. Further evidence came to light in 1967 when Miller enlarged a Badger hole and found lithic flakes, shells and animal bones. To him this proved the pre-historic occupation of the shelter. He thus reported his find to local archaeologists. Five years later, in 1973, a young University of Pittsburgh anthropology professor named Dr. James Adovasio, visited the farm and was shown the original pre-historic flint knife. Astonished by the find, and realising its significance, Adovasio made an application to the Meadowcroft Foundation (essentially Albert and his brother Delvin) to begin excavations. These begun in the summer of 1973 and continued for six years.

Site description and finds

The Meadowcroft Rockshelter is a cave site c. 48km southwest of Pittsburgh near the village of Avella in Washington County, Pennsylvania. The cave itself is on the north bank of Cross Creek, a tributary of the Ohio River.
The surface rocks of this region are layered sedimentary rocks of Middle to Upper Pennsylvanian Age (Casselman Formation). The predominant lithologies are shale, quartz sandstone, limestone, and coal in decreasing order of abundance.
Geologically, Meadowcroft is located in the unglaciated portion of the Appalachian or Allegheny Plateau, west of the valley and ridge province of the Appalachian Mountains, and northwest of the Appalachian Basin.
Present topography was probably generated during the Pleistocene when increased precipitation and runoff caused extensive downcutting. Since the Wisconsin Glacial boundary only extends southward to northern Beaver County (some 40 odd km north), the Cross Creek Valley and Meadowcroft Rockshelter probably existed in nearly their present configuration well before the close of the Wisconsin, ca. 11,000 B.P1¹.

It is notable that the area was not a glaciated one but within close proximity to it lay the Laurentide Ice Sheet. This undoubtedly affected the paleoclimate to a lesser or greater extent.

  Location of Meadowcroft Rockshelter with respect to the maximum extent of the Laurentide Ice Sheet c. 20000ya. Credit: Adovasio 2002⁶.

The excavation slowly uncovered 11 stratigraphic levels with stratum XI being at the top, or current ground surface, whilst stratum I was found to be the lowest. Finds were made in all levels, including level I. From Adovasio 1975:
“Extent: This, the basal stratum at the site, has been exposed thus far only outside the drip line in a limited section of "deep-hole." It lies directly beneath Stratum II and is presumed to be continuous across the site. The large roof fall on the western edge of the site rests on the surface of this stratum.
Composition: Stratum I consists of badly decomposed, foliated sandstones (possibly roof fall?) interbedded with lenses of charcoal. Compositional analysis of this unit is presently incomplete.
Associations: The upper 1,0 cm of this unit contains 5 lithic artifacts which may represent intrusions from Stratum IIb, otherwise this unit is sterile.”

Crucially sufficient charcoal was discovered for radiocarbon dating. Lithic artifacts (stone flakes) were also found. In this context ‘lithic artifacts’ means the excavator believes that the flakes recovered are of human manufacture. Charcoal lenses can be read as hearths or fires.

 
Of stratum II the report says:
“Stratum II Extent: Thickness of this unit varies from 40-120 cm. The upper 50 cm are distinguished as Stratum Ha which is continuous across the site. IIa is separated from the lower deposits (lIb) by massive roof fall. IIb has been exposed thus far only outside the drip line in the "deep-hole," Stratum II lies above Stratum I and directly beneath Stratum III. Associations: Lithe materials, bone, firepits and fire floors, floral remains, shell.”
 
The lithics and other artifacts excavated contained some fine specimens:

Selected Bifaces from Paleoindian levels. Mungai Knife is the centre biface.

Photo source: Mark McConaughy¹⁴

Lamellar Blades from Paleoindian levels.
Photo source: Mark McConaughy¹⁴

Lithic Assemblage from Meadowcroft Rockshelter.
The now famous Miller Lanceolate point, named for Albert Miller, is at left.
Photo source: Mark McConaughy¹⁴ (Original source: Heinz History Centre)

Large Basketry Fragment photographed in situ at Meadowcroft Rockshelter.
Photo source : Meadowcroft a pre-Clovis site¹⁵ (Original source Meadowcroft Rockshelter and Historic Village Collection. Heinz History Centre)

Corn Cob Fragments from Meadowcroft Rockshelter
Photo source : Meadowcroft a pre-Clovis site¹⁵ (Original source Meadowcroft Rockshelter and Historic Village Collection. Heinz History Centre).

Bone Artifacts from Meadowcroft Rockshelter
A good number of bone artifacts were recovered at Meadowcroft. These were made from the bones of animals the occupants killed for food. The awl far left has been grooved at one end to accept a cord, so that it could be placed around the neck, ready for use in sewing tasks.
Photo source : Meadowcroft a pre-Clovis site¹⁵ (Original source Meadowcroft Rockshelter and Historic Village Collection. Heinz History Centre).

A summary of the finds per stratum were included in Adovasio’s table 2¹:

Note the reference to Ash/Charcoal lenses (2) AND Lithic Concentrations (1) for stratum I



Later in the report Adovasio produces a table (table 3) showing the radiocarbon dates obtained from the Charcoal for most of the early (lower) strata:

 

The shocking part was that FIVE of the radiocarbon ages pre-dated the accepted age for Clovis of about 11500BC! At first reaction was muted, but as Adovasio continued to publish on Meadowcroft^7,8 serious objections began to be raised about the site’s dating. The main objections raised were by Vance Haynes⁷ and centred around the possible contamination of the charcoal samples used to date the site by lignite or coal. Adovasio calmly and consistently rebutted these claims of contamination⁹ and published greater deatil¹⁰. However the attacks just kept on coming. Particularly prominent were the criticisms by Dincauze (1981)¹¹, Kelly (1987)¹² and Tankersley, Munson and Smith (1987)¹³ to name but three. In fact the situation became so bad and relations within the archaeological community so fraught that Adovasio coined the phrase ‘Clovis Mafia’ to describe those constantly making, what he saw as, unwarranted and baseless criticisms. In 1990, Adovasio²  attempted to firmly and finally quash the contamination, paleoenvironmental and stratigraphic issues raise by his critics by publishing new AMS radiometric dates obtained by four different laboratories. The dates are shown in his 1990 figure 1 below:

Original caption reads:
Plot of 52 Meadowcroft Rockshelter radiocarbon dates showing one standard deviation. Four reversals (asterisks) are noted: SI-2056 is actually from the lowest one-third of stratum IIb; SI-2363 is from the upper one-third of stratum IV; SI-2363 is from the upper one-third of stratum IX. Both SI-1681 and 2056 respectively were small heavily diluted samples. Adapted and and expanded from Stuckenrath et al. (1982: Figure 2).


Of particular note are that the dates for the lowest stratum, stratum I are confirmed and retained.

Having dealt with the stratigraphic and paleoenvironmental objections in separate publications^16-18 he turned his attention to the contamination of the radiocarbon samples issue. Adovasio has this to say:

“With regard to particulate contamination, we repeat that there is no coal seam in or near the rockshelter. ..There are small, isolated, discontinuous fragments of vitrinized Pennsylvania-age wood west of the back (north) wall of the rockshelter, but these in situ fragments are circumscribed occurrences and are not represented en bloc within 7m of the hearths that produced the earlies Meadowcroft dates. ..Every radiometric sample from the Pleistocene-age levels was examined for coal particles using both optical and scanning-electron microscopy. No coal particles were ever identified by four radiocarbon laboratories or by independent researchers.. We forcefully reiterate that during these scrutinies, selected lower and middle stratum IIa samples underwent not only reflectance analysis but also paleobotanical examination for Densosporites and other commonly occurring spores of Pennsylvanian-age coal. In all cases, the results were negative..”

Adovasio goes on, acidly, at length about the absurdness of the claims of particulate coal contamination. Given all he had put up with it is worth seeing what he had to say:

“For criticisms about particulate contamination (or stratigraphic perturbation) to beto be credible, the mechanical introduction of vitrinized Pennsylvanian-age wood into earlier Meadowcroft fire pits would have required some unknown (and unspecified) mechanism so precise and of such duration that it nevertheless resulted in consistent stratigraphic order among the early dates. Then about 12,800 years ago, any mechanism that was making the early dates too early would have to have discontinued so that all the successive younger (more recent) dates were valid.. The absence ofany objective evidence for the lack of particulate contamination and lack of any mechanism for the selective injection of contaminants solely into the pre-12,800-year-old samples renders the argument for particulate contamination unconvincing.”

 
In other words, to his critics “You are making fools of yourselves making weak criticisms. Shut up!”.
 
With regard to non-particulate contamination of the charcoal samples, Adovasio says this:

“1. Vitrinized wood cannot be dissolved in ground water..

2. If vitrinite is not the source of any dissolved contaminent, there are no other candidates as the underlying shale (stratum I) that is the basal unit is not carbonaceous.”

 
Here Adovasio is making a direct jibe at Vance Haynes who famously kept a piece of vitrinized wood in a beaker of water on his desk for months.. nothing happened!
 
Adovasio continues:

“3. Assuming the presence of an as-yet-undiscovered potential source of contamination, there is no viable mechanism for its transport as the present water table lies nearly 5m below the deepest occupation surface at the site and it was never higher prehistorically..

4. Most basic to all questions of nonparticulate contamination is a misreading of the available data..”

 
Adovasio explains his detractor’s confusion to them. Tellingly, this matter is never raised again.

 
 Adovasio disavows his earliest 32000 year old cultural materials

Now we come to an extremely important passage regarding the charcoal with associated lithic assemblage, dated to 32000 year ago, obtained from stratum I. Regarding this Adovasio says:

“The last, diminutive sample from the pre-cultural levels at the site was sent for processing in the Oxford AMS system. The sample already had been scrutinized for particulates and Densosporites spores, but the Oxford lab also examined it and detected no contaminants. The solid fraction was extracted with no need to arrest the reaction and subsequently date, as was the soluble fraction. The results for the solid fraction was 31,400 +/- 1.200 years, 29450 BC (OxA-363). The soluble fraction was dated at 30,900 +/- 1,100 years, 28,950 (OxA-364) (see Gillespie et al. 1985:241). These dates conform very closely to the previously calculated Smithsonian lab date of 30,710 +/- 1,140 years 28,760 B.C. for this level, which to repeat, is not associated with any artifacts and apparently dates to well before the initial occupation of the site by humans (Adovasio 1975: 16, Table 3).” See below for more on this issue.

 
Adovasio, then sets out his preferred date for the site, rather tentatively, thus:

“The Meadowcroft dates suggest, rather conservatively, that humans were present at the site perhaps 2,000-3,00 years earlier than the well-established 11,500-year horizon marker”

In other words: My site is proven pre-Clovis beyond reasonable doubt! He continues:

“The frequently cited eighteenth millennium B>C> dates (SI-2060 and SI-2062) were both very small, diluted samples, one of which, SI-2060, has a very high standard deviation of 2,400 years. If the younger range of both of these dates is averaged, then the earliest possible occupation of the site may have occurred ca. 16,770 years ago.”

This date has become the accepted date for site. It seems that the weight of continued criticism had finally worn Adovasio down. He was prepared to be conservative to silence his critics.

 
Unfortunately it wasn’t to be criticisms were STILL raised throughout the 1990’s¹⁹.

It wasn’t until 1999 that an independent study²⁰ finally laid to rest the sceptics last shreds of dissent. Meadowcroft WAS inhabited by pre-Clovis humans 16,770 years ago.

Dissent of a different kind

Mark McConaughy, a member of the field crew that carried out the excavations during 1974 on the earliest levels and who personally collected many of the samples that produced the earliest dates has made some extremely persuasive comments to the effect that Meadowcroft is most likely older than current accepted age¹⁴.

Archaeologist Mark McConaughey excavates on the Rockshelter’s east wall, July 1974.

Photo source : Meadowcroft a pre-Clovis site¹⁵ (Original source Meadowcroft Rockshelter and Historic Village Collection. Heinz History Centre)

 

 

 

Here is what he had to say:

“The early radiocarbon dates from Meadowcroft have been criticized by Haynes (1980, 1991), Kelly (1987), Mead (1980), Tankersley, Munson and Smith (1987), Tankersley and Munson (1992) and others as being the result of various types of coal contamination or incongruities concerning floral and faunal associations. According to these people, either particulate coal or soluable humates and carbon ions from coal percolated through the clays in ground water at the shelter and were embedded in the charcoal collected and radiocarbon dated. This contamination supposedly resulted in the samples producing anomalous dates. These criticisms have also been addressed by Adovasio et al. (1980), Adovasio, Donahue and Stuckenrath (1990) and Adovasio, Donahue and Stuckenrath (1992). Generally, they disagree with the view that coal contamination of the samples resulted in dates that are too old or that the floral and faunal associations do not indicate a Pleistocene occupation at the site.

I personally do not believe any of the radiocarbon dates from the early levels at Meadowcroft are erroneous. I think they properly date the samples submitted and are not contaminated by coal. However, I am hardly an unbiased observer.

The earliest remains from Meadowcroft did not come from excavations within the drip-line of the rockshelter. Most came from an area excavated beside the Old Roof Fall (an immense rock that fell from the top of the shelter prior to anyone living at the site).

Two samples I recovered were dated to ca. 19,000 years ago. Unfortunately, the two 19,000 B.P. samples were not directly associated with stone tools. ..It is for this reason that the bark was only tentatively identified as a basket fragment in Meadowcroft reports, and the dates questioned as being associated with a Paleoindian occupation.”

 

With regard to the very oldest materials recovered from stratum I McConaughy says this:

“Most other charcoal samples taken and dated from the earliest levels, (and dated as 33000 years old) or the "Deep Hole" as it was named by the crew, consisted of pieces of charcoal found with ash and burned earth. These were interpreted as surface hearths that had been put out (i.e., kicked out, spreading some of the ash and charcoal around). Stone tools were found in association with these samples lending support to the interpretation of them being extinguished hearths.”

 

This directly contradicts Adovasio 1990, but is supported by Adovasio 1975. One can only, therefore, conclude that Meadowcroft is probably older than ca. 16,000 years old as currently quoted and most probably 33000 years old.

 

One can only assume that Adovasio chose in 1990 to take the road more travelled by at last, just to get Meadowcroft within the mainstream of accepted sites.

 

One final thought from Adovasio 1975¹: Stratum I consists of badly decomposed, foliated sandstones (possibly roof fall?) - perhaps this indicates that the bedrock was not actually reached and further unexcavated levels remain below…

 

References

1. Excavations at Meadowcroft Rockshelter, 1973-1974: A Progress Report

By J. M. Adovasio, J. D. Gunn, J. Donahue, and R. Stuckenrath

1975. Archaeologist 45(3), pp.1-30.

2. The Meadowcroft Rockshelter Radiocarbon Chronology 1975-1990

J. M. Adovasio, J. Donahue and R. Stuckenrath

American Antiquity Vol. 55, No. 2 (Apr., 1990), pp. 348-354

3. Dr. Richard Shutler, Department of Archaeology, Simon Fraser University. Retrieved 07/12/15 from http://www.sfu.museum/journey/an-en/postsecondaire-postsecondary/meadowcroft

4. Quoted in Tom Imerito   Pittsburgh Quarterly Fall 2012 online

“Ancient dig discovering man in America: Archaeological finds at Meadowcroft Rockshelter turned back the clock on humankind’s first migration to the new world

Retrieved 07/12/15 from http://www.pittsburghquarterly.com/index.php/Discoveries/ancient-dig.html

5. In Albert Miller: Renaissance Man April 27, 2015 by Mark Kelly

Retrieved 06/11/2015 from http://www.heinzhistorycenter.org/blog/discover-meadowcroft/albert-miller-renaissance-man

6. The First Americans: In Pursuit of Archaeology's Greatest Mystery

by James M. Adovasio with  Jake Page. 2002. Random House.

7. Haynes, C. V.1980 Paleoindian Charcoal from Meadowcroft Rockshelter: Is Contamination a Problem? American Antiquity 45:582-587.

8. Mead, J. I. 1980 Is It Really that Old? A Comment about the Meadowcroft Rockshelter "Overview." American Antiquity 45:579-582.

9. Adovasio, J. M., J. D. Gunn, J. Donahue, R. Stuckenrath, J. E. Guilday and K. Volman1980 Yes Virginia, It Really is that Old: a Reply to Haynes and Mead.

American Antiquity 45:588-595.

10. Carlisle, R. C. and J. M. Adovasio, eds. 1982. Meadowcroft: Collected Papers on the Archaeology of Meadowcroft Rockshelter and the Cross Creek Drainage. Department of Anthropology, University of Pittsburgh, Pittsburgh.

11. Dincauze D. F 1981. The Meadowcroft Papers. Quarterly Review of Archaeology :3-4

12. Kelly, R.L. 1987 A Comment on Pre-Clovis Deposits at Meadowcroft Rockshelter. QuaternaryResearch 27:332-334

13. Tankersley, K. B., C. A. Munson and D. Smith. 1987 Recognition of Bituminous Coal Contaminants in Radiocarbon Samples. American Antiquity 52:318-330.

14. Mark McConaughy. Retrieved from:

 http://people.delphiforums.com/MCCONAUGHY/meadowcroft/pbiface1.htm

15.Retrieved from:  http://donsmaps.com/meadowcroft.html

16. Meadowcroft Rockshelter: A 16000 Year Chronicle. In Amerinds and Their Paleoenvironments in Northeastern North America, edited by W. S. Newman and B. Salwen, pp. 137-159. Annals of the New York Academy of Sciences 288. New York.

17. Adovasio et al. 1984. Meadowcroft Rockshelter and the Pleistocene/Holocene Transition in Southwestern Pennsylvania. In Contributions in Quaternary Vertebrate Paleontology: A Volume in Memorial to John E. Guilday, edited by H.H. Genoways and M. R. Dawson pp. 347-369. Special Publications No. 8. Carnegie Museum of Natural History, Pittsburg.

18. Adovasio et al. 1985 Paleoenvironmental Reconstruction at Meadowcroft Rockshelter, Washington County, Pennsylvania. In Environments and Extinctions: Man in Late Glacial North America edited by J. I. Mead and D. J. Meltzer, pp 73-110. Peopling of the Americas Edited Volume Series, Centre for the Study of Early Man, Orono, Maine.

19. Tankersley, K. B. and C. A. Munson 1993 .Comments on the Meadowcroft Rockshelter Radiocarbon Chronology and the Recognition of Coal Contaminants. American Antiquity 57: 321-326.

20. Goldberg, P and Arpin, T. L. 1999. Micromorphological Analysis of Sediments from Meadowcroft Rockshelter, Pennsylvania: Implications for Radiocarbon Dating

Journal of Field Archaeology Vol. 26, No. 3 (Autumn, 1999), pp. 325-342