The Peopling of the Americas I: Beringian Land bridges, Formation and Paleoecology

The peopling of the Americas has caused spirited and sometimes heated academic debate among scientists in the USA for decades.

For centuries the route of entry has generally been accepted as across the Bering Land Bridge.

The first writer to suggest this possible route of the entry of people into the American continent was a Jesuit monk named Jose de Acosta. De Acosta had arrived on the Caribbean coast of South America at Carthagena and travelled onwards to the settlement of Nombre de Dios. From here he journeyed through 18 leagues of tropical forest via the route pioneered by Balboa and De Avila to Panama. Once on the Pacific he took ship once more and reached Lima in the recently conquered Peru. It was while travelling to his new posting that he began recording his experiences and observations of fauna, flora, peoples and geography of the Americas. As an educated European he had read the extant writings of the ancient philosophers and upon crossing the equator he later related “He expected, as professed by the philosophers that he had studied, an unbearable intense heat in crossing the equator, but found it to be so cool in March, that he laughed at Aristotle and his philosophy”¹

De Acosta spent many years in Peru carrying out missionary work and lecturing on theology. Initially assisting the Viceroy, Don Francisco de Toledo he travelled the country for two years gaining a grounding in geography of the country. Subsequently he lived at Juli, on the shores of Lake Titicaca the main seat of the Jesuit order in Peru. His missionary duties required him to travel widely and thus he became intimately acquainted with the native peoples and their customs.

One theological problem that was therefore at the forefront of de Acosta's mind was a basic one: scriptures clearly defined man's origins as being in the Old World, therefore theologians must account for a branch of humanity in the New World. De Acosta phrases it thus:

 “Scripture teaches us that all men are descended from a first man. Hence man must have come to the Indies (The Americas) from Europe, Asia or Africa, but such pronouncements do not tell us the manner of travel or the route. ..How could the human race have traversed so great an immensity of seas and lands? How could so large a number of people have been concealed for so many centuries?”

De Acosta goes on to logically rule out intended voyages using navigation techniques as no evidence of such abilities used by ancient peoples exists in the written or oral traditions of the three continents known up to the discovery of the Americas. He discounts accidental voyages as the great diversity of animal life in the New World also had to arrive there in some manner, and in the case of terrestrial animals this had to be via a land connection with some continent.

He therefore goes on to conclude that the Indians and likewise the animals found in the New World probably arrived via some point in the far north at which the two worlds are either connected or closely approximate. He speculated that the Old and New Worlds in the far north either, “continued and joined with the other” or “they approach on nearer unto another”¹ such that the gap would not greatly hinder migration of animals or man.

In 1587, after 16 years in the Peru and later, Mexico de Acosta returned to Spain and occupied various prestigious offices, including lastly rector of the college at Salamanca. He published three great works based on the extensive manuscripts he had compiled during his time abroad. These were: De Natura Novi Orbis, De promulgatione Evangelii apud Barbaros, sive De Procuranda Indorum salute and above all, the Historia natural y moral de las Indias which contains his theory of the man’s entry into the New World.

Photo credit: Google Digital Commons
















The influence of these works was so profound that de Acosta became known as “the Pliny of the Americas”. Thus the land route for the peopling of the Americas entered the intellectual cannon almost from the beginnings of written history of science.
 
This close approach of one land mass to the other was first discovered by Semyon Dezhnyov in 1648 but news of the confirmed close proximity of the Asian and American continents only reached Europe 80 years later when Danish-born Russian navigator Vitus Bering entered the strait, now named after him, in 1728.
 
The theory remained in the realms of theological speculation until late in the 19^th century, when Wallace² suggested that the shallow seas separating Siberia and Alaska, specifically the area around the Bering Strait seemed the most likely site of geologically recent Eurasian-American land connections. In 1898 Wallace³, based on  water depth soundings of Bering Sea, Chukchi Sea and Being Strait, wrote that, “in later geologic times, more than once and perhaps during prolonged periods [there existed] a wide terrestrial plain connecting North America and Asia” .
The timing of the Bering Land Bridge formation remained a thorny issue for scientists with best estimates based on the synchronicity of Asian and North American, fossil, mammal faunas as detailed in the works of Osborn⁴ Willis⁵ and Simpson⁶.
The mechanism of Bering Land Bridge formation was initially thought to be related to tectonic events, however in 1934 Daly⁷ brought forward the theory that sea levels fluctuated drastically during the Ice Ages in response to the amount of water stored on land as continental glaciers such as the Laurentide of North America. Finally the area of the land connection was given its name; Beringia or the Bering Land Bridge by Hulten⁸ in 1937. His work noted that while large areas of North America and Southern Siberia were glaciated, large areas to the north of these remained ice-free refugia for many boreal plant species and animals and that the two continents were connected by the Bering land Bridge for a considerably length of time.
Thus the timing and existence of the Bering Land Bridge while firmly based in the, then current scientific evidence, required unequivocal data to fully prove the theory. With the intervention of World War Two the uncovering of definitive, confirmatory evidence had to await the emergence of a new generation of scientists working in the region.
 
One such scientist was David Moody Hopkins. After graduating from the University of New Hampshire in the summer of 1942 with a degree in Geology, he enrolled as a doctoral student at Harvard. Only three weeks into term-time he was offered a job with the U.S. Geological survey in Alaska locating strategic minerals for the war effort. His advisors at Harvard recommended that he take the post and finish his studies later, after al,l at 20 years of age Hopkins was of prime draft age. He thus accepted the job and was at once posted to Alaska. Through the autumn of 1942 and the summer of 1943 Hopkins mapped the distribution of molybdenum and coal deposits but also found time to collect Pleistocene fossils or marvel at, and study the glaciers and mountain scenery around his camps at Muir Inlet and in the Matanuska mountains. Each autumn it was back to Washington D.C. to write up his reports. In late 1944 he chose to write up his reports in Anchorage, Alaska hoping to drafted in Alaska and not back east. Thus it was that he was drafted whilst still in Alaska and did his basic training there. On completion of the course intelligence and aptitude tests were carried on the recruits, by the army to see which assignments they were best suited for. Experience was also a factor. Hopkins thus gave his experience working for the USGS, fictionalised teenage work on the railroad in New Hampshire and lastly experience of meteorological observations based on a class on climatology he had taken at UNH and watching a friend take such measurements. Basically it was an ‘Anything but the Infantry’ strategy. The army took one look at Hopkins’ weatherman experience and posted him 600 miles north to the extremely stormy cold bay, at the base of the Aluetian chain. Here Hopkins spent the rest of the war carrying out meteorological observations and using Hulten’s Flora of the Aluetian Islands to identify and collect plants. He was finally discharged in the spring of 1946 in the wake of the eruption of Okmuk Caldera on Umak Island.
Consequently, he returned safe and sound to Harvard to complete his Ph. D. He studied under Kirk Bryan an early proponent of the multidisciplinary approach to Geology. This approach was certainly absorbed by Hopkins. It was this combined with his experiences in Alaska before and during the war that formed Hopkins approach to Geology, in that he was prepared to take evidence from a wide field of knowledge and synthesise it into new explanations of natural phenomena. It was then that Hopkins began to see himself as more of a paleonaturalist blending the geology of landscape formation and his naturalist interests of early youth. This combination of interests, led him to be one of the first doctoral students to achieve a Ph. D from Harvard in Quarternary Geology.
 
Going back to work for the USGS Hopkins was able to pursue his interest in the Quartenary Geology of Alaska and in particular the history of the cyclic formation and inundation of the Bering land Bridge. By 1948 he was back in the field, in Alaska with a hand-picked team focussing on the subject that would become his life’s work.

Hopkins at Hammum Creek near the Imuruk River 1948.
Photo Credit O’Neill¹⁰

Sigafoos, Quay and Hopkins drying their gear at Lava Lake camp 1948
Photo Credit O’Neill¹⁰

Through the late 1940’s and 1950’s Hopkins never missed a season in Alaska, despite the tragically early death of his first wife, a disastrous second marriage and being wed again for a third time! He often based himself around the Seward peninsula and worked with a range of scientist or visited others working in the region such as Louis Giddings and Bob Sigafoos. In 1959, Hopkins‘⁹ long years of work led him to publish his first major paper on the Bering land bridge. In it he theorised about the first formation of a land bridge in the Miocene, its first inundation at the Miocene-Pliocene boundary and its continued cyclic formation and submergence during the Pleistocene. Casting his mind back to that time Hopkins comments¹⁰ that “..it suddenly occurred to me that if we three got together we could perhaps solve the problem of the Bering Land Bridge. We could show whether it existed or not and when it existed or not .. The Land Bridge was in the air. It had been for years.”
Whilst not all of his peers accepted these theories, he was fast becoming the best known and widely published figure in Bering land Bridge research.
Thus it may not seem surprising, that in 1963 he was asked by the International  Association for Quarternary Research to organise an all-day symposium on the land bridge for the 1965 INQUA conference.
This galvanised him to begin reaching out to Russian scientists such as Merklin and Petrov and others to request paper proposals for the upcoming symposium. The back and forth of distributing drafts to symposium participants, the insistence that contributors consider and comment on others’ work and address it in print before the symposium, and the judicious editing of the papers ended up with the event being one of the best organised and productive ever organised. It has since been held up as an example of best practice in organising such events. In the year of the symposium it also led Hopkins to jointly publish 1965 published a paper with Merklin and Petrov and other U.S. scientists¹¹.
The work however had only just begun. Now the symposium and it’s papers needed to be organised and published for their full import to be realised. Hopkins set to work with relish. After two years he had edited the monumental tome “The Bering Land Bridge”. It was published in 1967. Hopkins of course, personally wrote the summary chapter¹².  

 

Hopkins on publication day.

Photo Credit O’Neill¹⁰

 

 

Cover of the ‘Bible’ as colleagues began to call the Bering Land Bridge.

Photo credit N Barden

 

The results presented from many different disciplines and by scientist worldwide and their subsequent analysis and synthesis by Hopkins represented a huge step forward in the understanding of the Bering Land Bridge. In summary the results were:

 

·         During the Pleistocene Era (2 million years ago to 10 000 years ago), Beringia was a large, ice-free land mass during periods of glaciation

·         As the climate warmed and the glaciers melted, the Bering-Chukchi platform would flood, severing the terrestrial connection between North America and Asia. Eventually, the climate cooled and glaciers reformed, exposing the Bering Land Bridge again.

·         When exposed, this land bridge was covered with vegetation and supported a variety of animal life

·         That 4 waves of mammalian immigration had occurred over the land bridge, once during early Miocene, again at the Pliocene-Pleistocene boundary and probably at least twice more during Pleistocene. Furthermore the climate on the land bridge appeared to be temperate, humid and forested in the first two episodes, temperate grasslands in the mid Pleistocene and only in late Pleistocene was the climate significantly colder being represented by tundra, steppe and Taiga plant communities. Additionally there was some back migration from the Americas to Asia.

·         That the land bridge had existed at least nine times during the Pleistocene

 

Table by Reppening showing envisaged mammalian migrations during the late Pliocene and Pleistocene¹³

 

Whilst a huge amount of the work was accepted by the scientific community at large many questions remained for Hopkins. For example was it possible to reconstruct the ancient climate on and near the land bridge and more particularly could he reconstruct the climate during the LAST land bridge. For this it was assumed would allow basic questions about the peopling of the Americas to be, at last, definitively answered.

 

During the editing of The Bering land Bridge in 1966, Hopkins did not forsake his usual Alaskan, summer field season. Whilst camped on the north shore of the Seward peninsula, Dale Guthrie and John Matthews turned up to study fossil insects in sedimentary deposits that Hopkins had previously recommended to them at the adjacent, Cape Deceit on Kotzebue Sound. As Hopkins says¹⁰: “I had reason to think that Cape deceit had a record that went at least back through the last glaciation, the IIlinoian. I had no idea that it would go back, possibly, to the Pliocene.. They started digging at Cape Deceit, which turned out to be one of the most important contributions ever to Beringian Paleoecology.” The Pliocene/Pleistocene boundary fossil faunal were presented in The Bering land Bridge, a year later by Reppening¹³. It was not these fossils, impressive as they were, however, that were of key importance. It was the fossil pollen, plant fragments and body parts of assorted insects that were the real goldmine. For it was in these, that scientist could start to reconstruct the paleoclimate of the Bering Land Bridge. Their work indicated that the early Pleistocene climate in the region had been a dry, scantily clad Tundra which became grassland dominated in mid-Pleistocene and Steppe Tundra at the end of the geologic period and that in warmer interglacials treelines had been considerably further west, and in fact as far west as Cape Deceit, on at least two occasions. In other words there were considerable periods, during which, the migration of large herbivores such as mammoths and presumably their human hunters could have crossed the land bridge throughout the Pleistocene.

This view of the paleoecology of Beringia was not shared by all, however. Another of Hopkins’ associates Paul Colinvaux, had, at Hopkins’ suggestion had carried out sediment coring at Imuruk Lake. The view of the paleoecology of Beringia he drew from the fossil pollen record was in stark contrast to that of Guthrie and Matthews. He viewed Beringia as an  , a windy, forsaken landscape of sparse tundra, “a dusty plain stretching to the horizon, vegetated between the bare patches with a low mat of sedges and grasses looking like a drier version of the modern arctic plain.”¹⁴

Twelve years after the publication of his first book Hopkins arranged a second conference to discuss the current work of the Paleoecology of Beringia, the Wenner-Gren Foundation for Anthropological Research Symposium was held June 8-17, 1979 in Burg Wartenstein Austria. The resulting book¹⁵, The Paleoecology of Beringia was published in 1982.

 

The publication, caused, what has become the longest running argument in Beringian studies. Ritchie and Cwynar stated, in 1982¹⁸ that “We suggest that the ‘Arctic Steppe Biome’ never existed”. Also critical of the productive Mammoth Steppe theory was Collinvaux and West’s 1984¹⁴ view of the Beringian Paleoecology. This was swiftly followed in 1985¹⁶ by Guthrie with his provocatively titled “Woolly Arguments Against the Mammoth Steppe”. Colinvaux’s 1986 reply¹⁷ was equally biting. The situation became so bad that Guthrie is reputed to have dumped a huge, muddy, freshly dug mammoth tusk on Colinvaux’s desk and heatedly told him that he had dated Mammoth remains spanning the whole of the existence of the Bering land Bridge. Colinvaux was unimpressed and continued to insist (in print) that these skeletal remains were the result of migrations of mammoth from distant productive areas. Guthrie’s response “They have to eat every 12 hours!” and evidence in the form of the grass and herbaceous gut contents of mammoth remains sealed in permafrost from Siberia fell on deaf ears.  

 

What was needed was more evidence to demonstrate one way or another whether Beringia was a cold, unproductive arctic desert, or a rich Mammoth Steppe with herbaceous vegetation capable of supporting large herds of grazing animals. Unsurprisingly some of the evidence was actually and literally uncovered by Hopkins himself. In 1988, following up on a 1974 observation of what he believed to be a preserved Pleistocene ground surface, he took his graduate students Claudia Hofle and Victoria Goetcheus to the Devil Mountain-Cape Espenberg area. Here, sealed by a layer of volcanic tephra, they uncovered actual preserved remains of a rich array of herbaceous plants, shrubs and grasses. Furthermore, radiocarbon dating of the remains gave a date of 18000BP, i.e. in the middle of the period disputed by the Palynologists, Colinvaux and Ritchie on one hand and Guthrie and Young on the other. This supported the Mammoth Steppe theory. Later publications by Hofle^{23a and b} and Goetcheus^{24a and b} confirmed this.

 

Further evidence came to light from Cinq-Mars’ excavation of the Blue Fish Caves¹⁹ in the Yukon. Cinq-Mars states:

“More importantly, these results demonstrate that the mammoth steppe.. constituted an essential element of the Glacial Maximum biotope of eastern Beringia (between about 17,000 and 25,000 BP).”

Basically Cinq-Mars is saying that their palynological and other data show that Mammoth Steppe did exist at the time of the sediment formation over height of the last glacial maxima (ca. 22000BP). In other words their data refute the “productivity paradox” of Schweger et al.²⁰ (1982) and the position of Cwynar and Ritchie (1980)²¹ and support the position of Guthrie (1985)¹⁶ and Matthews (1982)²² that the environment was extremely rich and capable of supporting an extensive megafaunal assemblage.

 

Further publications, including Guthrie 2001²⁵ have thus stabilised the view that the Mammoth Steppe had actually existed as suggested and was capable supporting large Pleistocene grazing fauna which, in turn, were followed into the new world by humanity.

 

Here Hopkins’ direct involvement of the investigations of the Bering Land Bridge ends. He died aged 79, in November 2001.

 

Research has of course, continued. In fact Hopkins’ hypothesis in 1967 that the Bering Land Bridge had existed at least nine times has been updated by workers such as Pielou (1991) who theorises²⁶ that the Bering Land bridge has existed at least 20 times during the Pleistocene.

 

The Bering land Bridge at the height of the Illinoian glaciation. From Hopkins¹² p462

 

 

 

The Bering land Bridge at the height of the Wisconsin glaciation. From Hopkins¹² p462

 

References

1. Joseph de Acosta, Edward Grimston, Clements Robert Markham, The Natural and Moral Historie of the Indies, Hakluyt Society, 1880 pp.i-ii

 

2. Wallace, H. R. 1876. The geographical distribution of animals: harper, New York 2 vols.

 

3. Dawson, G. M. (1898). Geologic notes on some of the coasts and islands of Bering Sea and vicinity: Geol. Soc. American Bulletin., v.5 p117-146

 

4. Osborn, H. F. 1909. Cenozoic mammal horizons of western North America: US Geol. Survey Bull. 361 138p.

 

5. Willis, Bailey. 1909. Paleogeographic maps of North America: 13, Eocene-Oligocene North America: Jour. Geology v.17 p506-508; Quarternary North amerioca: Jour. Geology v17 p600-602

 

6. Simpson, G. G. 1947. Holarctic mammalian faunas and continental relationships during the Cenezoic: Geol. Soc. America Bull., v.58 p.613-687

 

7. Daly, R.A. 1934. The changing world of the Ice Age: Yale Univ. Press, 271p.

 

8. Hulten, Eric. 1937. Outline of the history of arctic and boreal biota during the Quarternary Period: Bokforlags Aktiebolaet Thule, Stockholm, 168 p.

 

9. Hopkins, D.M. 1959. Cenozoic history of the Bering Land Bridge. Science, 129, 1519–1528.

 

10. O’Neill, D. 2004. In The Last Giant of Beringia. Westview Press Boulder Colorado p. 107

 

11. Hopkins, D.M., MacNeil, F.S., Merklin, R.L. and Petrov OM (1965) Quaternary correlations across Bering Strait. Science, 147, 1107–1114.

 

12. Hopkins, D.M. 1967. The Cenozoic history of Beringia—A Synthesis., in The Bering Land Bridge Hopkins, D.M, ed. Stanford University Press.

 

13. Reppening, C. 1967 Palearctic-Nearctic Mamalian Dispersal in the Late Cenozoic. In The Bering Land Bridge Hopkins, D.M, ed. Stanford University Press.

 

14. Colinvaux, Paul A. and Frederick H. West. 1984. The Beringian Ecosystem. The Quarterly Review of Archaeology, Sept issue 1984.

 

15. Hopkins, D.M., Matthews, J.V., Schweger, C.E. and S.B. Matthews. 1982. The Paleoecology of Beringia. Wenner-Gren Foundation for Anthropological Research. Symposium. New York : Academic Press.

 

16. Guthrie, R. Dale. 1985. Woolly Arguments Against the Mammoth Steppe - A new look at the Palynological Data. The Quarterly Review of Archaeology, Sept 1984.

 

17. Colinvaux, Paul, A. 1986. Plain Thinking on Bering land Bridge Vegetation and Mammoth Populations. The Quarterly Review of Archaeology, March 1986. 

 

18. Ritchie, J.C. and L. Cwynar. 1982. “The Late Quaternary Vegetation of the North Yukon.” In: Paleoecology of Beringia, ed. D.M. Hopkins et al. (New York, Academic Press) pp. 113-126.

 

19. 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.

 

20. Schweger, C.E., J.V. Mathews, Jr., D.M. Hopkins and S.B. Young (eds.) 1982.

“Paleoecology of Beringia – A Synthesis.” In: Paleoecology of Beringia, ed. D.M. Hopkins et al. (New York, Academic Press) pp. 425-444.

 

21. Cwynar, L. and J.C. Ritchie.1980. Arctic steppe-tundra: A Yukon perspective. Science Vol. 208, pp. 1375-1377.

 

22. Matthews, J.V., Jr. 1982. East Beringia during Late Wisconsin Time: A Review of the Biotic Evidence. In: Paleoecology of Beringia, ed. D.M. Hopkins et al. (New York, Academic Press) pp. 127-150.

 

23a. Hoefle, C. L. Buried Soils on Seward Peninsula, Northwest of the Bering Land Bridge. Masters thesis, University of Alaska Fairbanks, August 1995.

 

23b. C. Hoefle, C. L. Ping, D. Mann and M. Edwards

Buried Soils on Seward Peninsula: A Window into the Paleoenvironment of the Bering Land Bridge. Current Research in the Pleistocene Vol. 11, 1994.

 

24a. Goetcheus, Victoria G. 1995. The vegetation of A 17 Buried Surface on the Northern Seward Peninsula. 24^th Artic Workshop, Quebec. Abstracts, 1995.

 

24b. V. G. Goetcheus, D. M. Hopkins, M. E. Edwards and D. H. Mann

Window on the Bering Land Bridge: A 17,000-year-old Paleosurface on the Seward Peninsula, Alaska Current Research in the Pleistocene Vol. 11, 1994

 

25. Guthrie, Dale. R. 2001. Origin and causes of the mammoth steppe: a story of cloud cover, woolly mammal tooth pits, buckles, and inside-out Beringia

Quaternary Science Reviews 20 ps.549-574

 

26. Pielou, E.C. 1991.  After the Ice Age: The Return of Life to Glaciated North America. University of Chicago Press, Chicago

 

 

 

Siberian Archaeology 1: Strashnaya “Scary” Cave Altai

A brief post today - one of my favourite news stories of the year, was from the Siberian Times. (See here)

 

 

In summary:

 

·         The cave is around 125 kilometres west of the more famous Denisova Cave

 

·         Fragments of an early human skull and rib were found in Pleistocene era layers in Strashnaya Cave, said to be 'no younger than 50,000 years' old, he said.

 

·         Another find, dating to at least 35,000 years ago, was a tiny fragment of finger bone - a nail phalange.

 

·         It is the first discovery of man's remains at the cave since 1989

 

·         One academic said that 'in an ideal world we would like to have the nail phalange to belong to a modern man, carrying genes of both Neanderthal and Denisovan man, and the older find (the skull) belonging to Neanderthal Man, and the oldest fragment - the rib - to be from Denisovan man.'

 

·         However, the scientist cautioned: 'Right now, however these are just my fantasies.  As we know, analysis results might turn out to be completely unexpected. But whatever the results, they will help us understand the interaction of modern humans, Neanderthals and Denisovans in the Altai territory.'

I love this guy!

Pre-Clovis Archaeological Sites of the Americas 6: Blue Fish Caves - Old Crow Basin, Canada

The Blue Fish Caves in Canada’s Old Crow Basin have excited controversy since the lead archaeologist, Jacques Cinq-Mars, reported early Radiocarbon dates for the site of ca. 28000 years BP on human altered remains of mid-Wisconsinian age fauna. The author experienced a great deal of difficulty having his results published. He explains these difficulties in the forward of an online, translation of his eventual French language publication¹:

 
“This is a translation of a paper originally published, in French, in Revista de Arqueología Americana, No. 1, (1990): pp. 9-32. But for a few minor corrections and the presentation of upgraded illustrations (Fig. 1- 5) and faunal list (Table 1), this Web version is essentially the same as the original one.

The 1989 article by Cinq-Mars and Morlan (referred to in the text as “Cinq-Mars and Morlan 1989”) was finally published as:

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.

On the other hand, the article by Cinq-Mars and Nelson (1989 — also referred to in the text) has not as yet appeared.”

 
Site location

The Blue Fish Caves lie 54km southwest of the Vuntut Gwichin community of Old Crow, itself being approximately 300km N of Dawson City, Yukon Territory, Canada.

 

 

 

Cinq-Mars¹ Fig 1.

 

Map from “Ice Age Old Crow”² drawn by Tanya Handley

The authors describe the setting of the site in their initial section Location and environment:

“As previously noted the Bluefish Caves lie 54 km sw of the village of Old Crow, overlooking the middle course of the Bluefish River, a tributary of the Porcupine River (Fig.1). This is a region of Devonian limestone hills at the northern end of the Keele Range, which in turn forms the foothills of the great massif of the Ogilvie Mountains that mark the centre of the Yukon. These hills also mark the southwestern edge of the enormous network of lacustrine basins, which during the upper Pleistocene were inundated by the waters of the Bluefish, Old Crow and Bell glacial lakes (Hughes 1972).”

A good representation of the approximate paleogeography at the time from Ice Age Old Crow²:

 

They continue: “The environment [in the late Pleistocene] is characteristic of boreal forest in mountainous regions (Ritchie et al., 1982)¹⁵, with spruce trees (Picea glauca and Picea mariana) on the pediments and more or less continuous tundra zones along ridges over 750 m high. The climate is typical of this boreal type of environment, and the landscape has been shaped by multiple periglacial processes characteristic of continuous permafrost regions.”

The Geomorphological context is explained thus:

“The caves are found at the western extremity of a ridge dominating a narrowing of the Bluefish River. They are nestled at the foot of a series of limestone outcrops standing about 250 m above the river valley. There are three caves (I, II and III), actually small cavities whose volume ranges from about 10 m³ to 30 m³ (Fig. 2). These cavities are the remains of a former, greatly reduced karst network uncovered by the erosion of the slopes.” Noted later: “cliff faces rise about 10 m over the entrances."

 

 

 

A better view of Blue Fish Cave II by Ruth Gotthardt³

Cinq-Mars¹ sampled and excavated the cave deposits both inside and outside the 3 caves, the mode and sequence of deposition that he found, can summarised thus:

 

• A floor is a bedrock surface studded with cryoclastic fragments

 

• The sediment overlying this, is of eolian (windblown) origin, and is a relatively homogeneous loess. This reaches 1m deep and contains some of cryoclastic elements, fallen from the walls and ceiling

 

• Granulometric and sedimentological analyses demonstrate that the loess can be divided into three facies, analysis indicates their place of origin as lake basins to the north

 

• Overlying the loess, gradually or discomformably, is a layer of humus-rich cryoclastic rubble. Outside of the caves is ca. 1m deep and declines rapidly at the cave entrances and becomes, on towards the interior, a simple organic enrichment of the upper portion of the loess.

 

• Finally, the surface fill is characterised by herbaceous and shrubby vegetation on the exterior of the caves, and by a discontinuous cover of ferns, mosses and lichens on the interior.

 

These layers can be seen in Cinq-Mars’ Fig 3:

 

The authors explain the difficulty in reading the sedimentation history and their response: “action of periglacial phenomena such as cryoturbation and congelifluction, and which can sometimes make interpretation difficult. These deposits do not lend themselves readily to a precise stratigraphic reading, and more than in most locations, decoding them requires the contribution of other types of data.”

 

“Palynological data

The analysis of sediments from the interior of Cave I and the exterior of Cave II has provided pollen diagrams which, despite the nature of the deposits, are indicative of a certain degree of depositional integrity. ..diagrams published (Cinq-Mars 1979⁹; Ritchie et al. 1982¹⁵).. the most significant details:

 

•First,.. lower level of the loess, a pollen assemblage presenting the characteristics of tundra rich in herbaceous species.

•Above.. the upper level of the loess, is a zone characterised by.. a predominance of birch (Betula).

 

•Finally, in the.. humus-rich rubble, a third assemblage is characterised by a.. decrease of herbaceous species and a significant increase in spruce (Picea) and alder (Alnus).

 

The authors, although admitting that the pollen biostratigraphy is somewhat weakly defined, conclude, especially with reference to other studies carried out in the immediate region confirm that the stratigraphy is largely intact despite some periglacial mixing.

 

They thus envisage this sequence of biomes:

1. Xeric herbaceous tundra environment to 14Kya BP

2. Shrubby birch Tundra rich in herbaceous plants 14-13.5Kya BP

3. Boreal spruce forest by 10Kya BP. 

 

Next the authors review the Palaeontological data collected, in summary these were:

 

·         All three cave yielded thousands of bones

·         These were located in the humus rich (more recent) layer and the late Pleistocene, loess layers

·         Large and small mammals were found including microtines (mice, voles and muskrats), and also fish and birds

·         Extinct megafauna characteristic of late Beringinian mammoth steppe were found in abundance, these included “horse (Equus lambei), caribou or reindeer (Rangifer tarandus), sheep (Ovis dalli), bison (Bison priscus), moose (cf. Alces alces), wapiti or elk (Cervus elaphus) and mammoth (Mammuthus primigenius). There are also saiga (Saiga tatarica), muskox (Ovibos moschatus), bear (Ursus), wolf (Canis lupus) and lion (Panthera).”

 

The authors also noted that the humus-rich rubble showed an impoverishment in the megafauna characteristic of the continent-wide mass extinction event

 

Next the authors move on to explain their early radiocarbon dates in the Chronological context section:

“As we have seen, the sedimentological, palynological and palaeontological data enable us to place the cave deposits on a chronological scale that definitely includes the Holocene (humus-rich rubble) and the end of the late Pleistocene, or Late Glacial (loess). Several 14C measurements made early in the research (Cinq-Mars 1979;⁹ Morlan and Cinq-Mars 1982¹⁰) roughly confirmed this chronostratigraphic estimate and even gave some indication of precision. We were able to date an episode of forest fire, definitely Holocene, in the (cryoturbated) upper sediments of Cave I. We also obtained a date of 12,900 BP from the femur of a horse, collected in the upper level of the lower loess of Cave I; and a date of 15,500 BP from a mammoth scapula found in the lower loess of Cave II, where the palynological signs of the herbaceous tundra were identified.”

 

However at this point news of the finds and their dates seems to have spread throughout the archaeological community thus when new Accelerator Mass Spectrometry (AMS) had been run by R.M. Brown (Atomic Energy of Canada) and E. Nelson (Simon Fraser University) Cinq-Mars and Nelson simply could not get their data published! In fact the site results were quietly ignored for 8 long years!!

 

However, in 1997 with the acceptance of Monte Verde site as pre-Clovis Cinq-Mars was able, once again to obtain funding. To allay all doubts from the archaeological community he had his best samples re-tested using exclusively AMS technology. The results were stunning, even the mammoth scapula described above tested older that previously.

 

Cinq-Mars’ samples of human modified bone ranged from 17000 to nearly 25000BP.

 

The authors however do not give a summary of the dating results, but refer readers to the Canadian Archaeological Radiocarbon Database (CARD). Although this website is not particularly user friendly, once the site designation for the Blue Fish Caves is found (MgVo I-III), the results can be accessed. I have collected the results⁴ together in a table for ease of viewing:

 

Whilst these dates for human modified megafaunal bones was impressive in itself, the authors felt that some of their paleoecological data are equally if not MORE important. Here is what they say: “More importantly, these results demonstrate that the mammoth steppe fauna mentioned above, in a combination that remains to be precisely determined, constituted an essential element of the Glacial Maximum biotope of eastern Beringia (between about 17,000 and 25,000 BP).” Basically what they are saying is that their data show that as mammoth step did exist at the time of the sediment formation over height of the last glacial maxima (ca. 22000BP). In other words their data refute the “productivity paradox” of Schweger et al.¹¹ (1982) and the position of Cwynar and Ritchie (1980)¹² and support the position of Guthrie (1985)¹³ and Matthews (1982)¹⁴ that the environment was extremely rich and capable of supporting an extensive megafaunal assemblage.

 

In their next section Cultural Manifestations the authors present their lithic and other finds. They explain their discoveries thus:

 

“Like other Beringian sites that have yielded very ancient archaeological material, the cultural remains found in the Bluefish Caves are exasperatingly sparse. They consist of three classes of lithics, some butchering marks found on various megafaunal remains and some examples of simple bone tools. With a few rare exceptions,, these were all found in the loess layer of Caves I and II, and in a context which, once again, is not always easy to read.”

The lithic artefacts included cores, microblades, angle burins on truncated blades or flakes, burin spalls, notches, etc. and, various flakes and flake fragments that may be debitage. Examples are shown in Cinq-Mars’ Fig 4 below:

 

 

The raw materials were primarily high-quality cherts, usually blue, but occasionally speckled or more rarely, black, and definitely exotic to the region. “So far, such artefacts have been recovered only in Caves I and II.” Cinq-Mars later notes: “Bluefish limestone does not contain chert. The few examples of this material found in the region (in several rocky outcrops to the east of the caves or in the form of pebbles on the river bars) are of very poor quality. We also know that cherts similar to those found in Caves I and II occur in a number of archaeological sites located about 100 kilometres to the north, in the Cordilleran foothills (Brooks, British and Barn mountains).”

 

This is an important finding. Only humans could have moved these artifacts to the cave. On the dating of these stone artifacts, the authors say this:

“Most of them occurred mainly in the interior and at the entrance of Cave II, both at the bottom and the upper limit of the (lower) loess level where were also found most of the faunal remains. Several technological characteristics of the burins (all angle burins on truncated supports) may indicate that much of the assemblage represents either a specific episode in the use of the cave, or consecutive visits by a particular group. Although the context does not allow us to date these lithics with precision, we know that they considerably predate the end of the period in which the loess was deposited; i.e., before 10,000 BP. Their provenance and association with the remains of extinct species suggest that they may have been incorporated into the deposit around 12,000 BP or perhaps even earlier.”

 

The detrital debitage come from older layers of the site “Their distribution inside the cave parallels that of the tools described above and is also suggestive of some cultural sedimentation in that portion of the loess unit whose pollen is characteristic of the herbaceous tundra which dates, as noted above, from between 25,000 and 13,500 BP.”

 

Lastly the authors found a number of small cobbles at the very base of the loess near bedrock. Although unsure of their origin the authors note: “several of the larger specimens that could, after all, have been used as hammerstones”.

 

Now we come to the really juicy bit of the paper: Cut or butchering marks, the details were given as:

 

“The evidence consists of a variety of cut marks, incisions, scrape marks, chopping marks and striations resulting from the intentional butchering and defleshing of animals with stone tools, and penetrating, more or less deeply and in various places, the external walls of the bones. (Morlan and Cinq-Mars 1982: Fig. 10)¹⁶. It is important to note that we refer here to undeniable cultural indicators and not to similar marks made by carnivores, rodents, various geological processes or even excavators. Thus far, we believe that we have been able to identify examples on numerous elements of the skeleton of nearly every large mammal species, with the possible exception of wolf, moose, wapiti and saiga. Almost all were found in Caves I and II.”

 

They conclude:

 

“This type of data also enables us to refine the time frame of the cultural content of the deposit. As there are no such markings on the faunal remains found in the humus-rich rubble, it is evident that this type of evidence and its causes date to the Pleistocene. This is confirmed by the 14C dates mentioned earlier and which were obtained from some of the specimens exhibiting such modifications. These dates suggest that cultural activities relating to the exploitation of the Bluefish fauna occurred sporadically between about 25,000 BP and 10,000 BP.”

 

Whilst objections were raised at the time, a subsequent publication by Morlan⁵ in 2003 with analysis of some of the human modified bones by the world renowned taphonomic specialist Pat Shipman, have silenced most critics of the site’s authenticity.

 

The authors also found objects worked from bone into tools.

These included fleshers for processing hides, one shaped from a caribou tibia, initially dated 24,820 BP but recently found to be much younger, and secondly and more importantly a human worked mammoth long bone.

The bone tool made from the mammoth long bone is explained in some detail by the authors: “...obtained through a relatively complex sequence of actions or “chaîne opératoire”, which can be summarised as follows:

  

•the raw material, namely a mammoth long bone, was first reduced to a fragment consisting of an epiphysis and the contiguous portion of the diaphysis;

 

•what could be described as a rough striking platform was then prepared at the end of the diaphysis segment;

 

•from this platform, a series of three flakes, ranging from 7 to 10 cm in length, were subsequently detached by percussion from the cortical face of the diaphysis segment;

 

•finally, one of these flakes, the longest one, was further worked and/or retouched bifacially and reduced diagonally, from its proximal end, by more than a third of its original size.”

 

Cinq-Mars Fig 5 showing the tool preparation sequence detailed above.

A number of different photographs of worked bone artifacts exist from the Old Crow Basin, adjacent to the Blue Fish Cave site and from the Blue Fish cave itself. A selection is shown below:

 

Morlan⁵ 2003 Fig 3, dated 33700 ± 800⁶

Bison rib with human made, cut mark SEM photograph by P. Shipman⁷, sample dated

42000 ± 1200 BP⁸

Taphonomic experiment, 1980’s by Morlan, showing replication of fracture types on found archaeological material ONLY with green bone and thus confirming human working of mammoth bone. From Ice Age Old Crow².

Verdict:

·         Blue Fish caves used by man to butcher megfauna at ca. 25000BP and possibly as early as 31000BP

·         Humans hunting and butchering animals in the Old Crow Basin from 42000BP - wow that’s old!

References

1. Revista de Arqueología Americana, No. 1, (1990): pp. 9-32.

Translation retrieved from:

http://www.historymuseum.ca/learn/research/resources-for-scholars/essays/significance-of-the-bluefish-caves-in-beringian-prehistory/

 

2. Image from:

www.tc.gov.yk.ca/publications/ice_age_old_crow.pdf

 

3. Image credit Ruth Gotthardt in Beringian Research notes no. 19.

Retrieved from: http://www.tc.gov.yk.ca/publications/Blue_Fish_Caves_2008.pdf

 

4. Accelerometer Mass Spectrometer (AMS) dates for Blue Fish Cave II

Most records retrieved from: http://canadianarchaeology.ca/sites/1339

 

5. Morlan, R. E. 2003. Current perspectives on the Pleistocene archaeology of eastern Beringia. Quaternary Research Volume 60, Issue 1, July 2003, Pages 123–132.

 

6. Data retrieved from:

http://canadianarchaeology.ca/samples/4873

 

7. Photograph from The Mammoth Trumpet Vol 1 no. 1. Winter 1984

 

8. Data retrieved from:

Retrieved from: http://canadianarchaeology.ca/samples/4742

 

9. Cinq-Mars J.1979 “Bluefish Cave 1: A Late Pleistocene Eastern Beringian Cave Deposit in the Northern Yukon”, Canadian Journal of Archaeology No. 3, pp. 1-32.

 

10. Morlan, R.E. and J. Cinq-Mars. 1982 “Ancient Beringians: Human Occupation in the Late Pleistocene of Alaska and the Yukon Territory.” In: Paleoecology of Beringia, ed. D.M. Hopkins et al. (New York, Academic Press) pp. 353-381.

 

11. Schweger, C.E., J.V. Mathews, Jr., D.M. Hopkins and S.B. Young (eds.)

1982 “Paleoecology of Beringia – A Synthesis.” In: Paleoecology of Beringia, ed. D.M. Hopkins et al. (New York, Academic Press) pp. 425-444.

 

12. Cwynar, L. and J.C. Ritchie. 1980. “Arctic steppe-tundra: A Yukon perspective”, Science Vol. 208, pp. 1375-1377.

 

13. Guthrie, R.D. 1985 “Woolly Arguments Against the Mammoth Steppe – A New Look at the Palynological Data”, Quarterly Review of Archaeology Vol. 6.

 

14. Matthews, J.V., Jr. 1982 “East Beringia During Late Wisconsin Time: A Review of the Biotic Evidence.” In: Paleoecology of Beringia, ed. D.M. Hopkins et al. (New York, Academic Press) pp. 127-150.

 

15. Ritchie J.C., J. Cinq-Mars and L. Cwynar. 1982 “L’environnement tardiglaciaire du Yukon septentrional, Canada”, Géographie physique et Quaternaire Vol. XXXVI, pp. 241-250.

 

16. Cinq-Mars J.1982 “Les grottes du Poisson-Bleu”, Geos Vol. 11, pp. 19-21.