Sunday, 27 December 2015

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:
 
2. Image from:
 
3. Image credit Ruth Gotthardt in Beringian Research notes no. 19.
 
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:
 
7. Photograph from The Mammoth Trumpet Vol 1 no. 1. Winter 1984
 
8. Data retrieved from:
 
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.


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