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Archive for the ‘Salvage’ Category

Looking South from Kin Ya'a

One of the most notable examples of an assemblage of highly mutilated human remains from the Southwest being attributed to witchcraft execution rather than cannibalism, in accordance with J. Andrew Darling’s theory discussed in the previous post, is Ram Mesa, southwest of Chaco Canyon near Gallup, NM.  This site was excavated by the University of New Mexico as a salvage project, and the relevant assemblage was reported by Marsha Ogilvie and Charles Hilton in 2000.

The Ram Mesa assemblage, consisting of 13 individuals, is pretty similar to many other assemblages in the Southwest attributed to cannibalism, but Ogilvie and Hilton make a plausible case that while the remains are clearly highly “processed” there isn’t a whole lot tying this dismemberment and mutilation to actual consumption of the remains.  Few of the bones showed any evidence of burning, a condition which applies to several other cases of alleged cannibalism as well.  The few cut marks, which were mostly found on children’s skulls and lower jaws, weren’t particularly indicative of the removal of large muscles that might be expected if consumption were the object.  On the other hand, however, relatively few of the bone fragments were sufficiently large to be identified to body part, and any diagnostic evidence from these tiny fragments was clearly destroyed by the thoroughness of the processing.  It’s not clear, therefore, how representative the larger fragments with surviving evidence of burning and cutting are of the entire assemblage.  The most I would say about this site is that the evidence is not sufficient to make a positive diagnosis of cannibalism, and other explanations are therefore plausible.

However, as I noted before in discussing Darling’s arguments, witchcraft execution and cannibalism are not necessarily mutually exclusive.  Indeed, the execution of suspected witches may well have involved some level of cannibalism among some Southwestern groups in prehistoric times, thought there is certainly no evidence that it did in historic times as documented by ethnographers.  There are some other oddities about the Ram Mesa site that suggest that it might not be expected to pattern with the majority of the suspected cannibalism assemblages, so it is certainly possible that it represents a variation on the same behavior that may not have included cannibalism.

For one thing, this is an odd place for one of these assemblages.  Although some early excavations at Chaco Canyon and in northern Arizona have been proposed as showing evidence of cannibalism, the vast majority of the well-documented cases are in southwestern Colorado, especially around the modern town of Cortez.  This includes the Cowboy Wash site, the site with the best evidence for cannibalism of any of them.  Given the known cultural differences between prehistoric populations at the northern and southern edges of the San Juan Basin (the San Juan and Cibola Anasazi, respectively), it’s quite possible that the cultural activities resulting in similar assemblages in these two areas may have been somewhat different, with the San Juan groups practicing cannibalism and the Cibola groups not.

Furthermore, there may be differences in the dating of the sites.  Most of the well-documented Cortez-area sites date to right around AD 1150, and they may all represent part of a single event at that time, which was in the midst of a severe drought when social structures were likely under extreme stress.  The Ram Mesa site is dated by six radiocarbon dates to a period that Ogilvie and Hilton describe as “AD 978 to 1161.”  They do clarify that these are calibrated dates, which is helpful, but it would have been better if they had shown the ranges for the individual dates, as well as the materials that were dated, which would give a better idea of the most likely dating for the human remains.  On the assumption that the remains date to the latest period of occupation, which seems plausible based on comparison to similar assemblages elsewhere, this puts the latest date at 1161, which is interestingly close to the dates for the similar Cortez sites.  Due to the lack of information of the dates, however, it’s not clear is this is an intercept (i.e., most likely) date or the late end of a range; if the latter, it’s possible that the assemblage dates to somewhat earlier than the Cortez sites.  In that case it would not be part of the same phenomenon, whatever that was, and the postulated lack of cannibalism may be related to that.

In any case, this site definitely seems to have been within the Chacoan sphere of influence, which makes the interpretation of the remains there important for understanding the relationship of alleged cannibalistic events to the rise and fall of Chaco.  Christy Turner has famously argued that they represent the expansion of the Chacoan system and the use of brutal force by the rulers of Chaco (hypothesized on very dubious evidence to be Toltec immigrants from central Mexico) to ensure that outlying communities were incorporated into the system and supplied tribute to the canyon.  This idea is pretty implausible based on the evidence from the Cortez area, where most of the assemblages date to the period of Chaco’s decline rather than its rise.  If Ram Mesa dates to the same period it would support that evidence, whereas if it dates to earlier it could conceivably either support Turner’s ideas or point to a different interpretation, perhaps having something to do with the well-known fact that the outlying Chacoan communities to the south of Chaco seem to have been abandoned beginning much earlier than those in other directions.  There are a lot of outlying Chacoan great houses in this area, including Casamero and Kin Ya’a, but they seem to have rather different histories than those to the north, such as Aztec Ruins and Yellow Jacket.

Like most research related to Chaco, this paper ultimately raises more questions than it answers.  That’s not necessarily a bad thing, however, especially when it comes to a topic as controversial and poorly understood as these assemblages suggesting cannibalism.
ResearchBlogging.org
Ogilvie, M., & Hilton, C. (2000). Ritualized violence in the prehistoric American Southwest International Journal of Osteoarchaeology, 10 (1), 27-48 DOI: 10.1002/(SICI)1099-1212(200001/02)10:13.0.CO;2-M

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Train Station, Dolores, Colorado

Southwestern archaeology, especially in the Chaco area, is structured chronologically primarily by the Pecos Classification.  This system was initially worked out at the first Pecos Conference in 1927, and it was originally interpreted as a series of stages in cultural development, with the assumption that sites with similar characteristics and material culture were roughly contemporaneous.  Once tree-ring dating became available, however, it became clear that this wasn’t quite true, and furthermore that different sub-regions of the Southwest went through the stages at different times.  There have been a variety of approaches developed in the decades since to either redefine the Pecos system or abandon it.  In the Four Corners, the main approach has been to just recast the Pecos stages as chronological markers without any inherent cultural content.  The exact dates used for each stage vary by specific area and specific researcher, but here’s a rough outline of how they are often defined:

  • Basketmaker II: 500 BC to AD 500
  • Basketmaker III: AD 500 to 750
  • Pueblo I: AD 750 to 950
  • Pueblo II: AD 950 to 1150
  • Pueblo III: AD 1150 to 1300
  • Pueblo IV: AD 1300 to 1540

There’s no Basketmaker I.  The Pecos Conference attendees were unsure what, if anything, came before Basketmaker II, and they provisionally included an earlier stage in case there did turn out to be earlier sites.  As it turned out, there were, but they were sufficiently different from Basketmaker sites that they ended up being considered part of the Archaic period of hunter-gatherer societies predating the introduction of agriculture.  (Recent discoveries have begun to muddle this picture, at least for certain areas, but while not everyone still uses the term “Archaic” for the period just before Basketmaker II no one has yet begun to call it “Basketmaker I.”)

Camping at McPhee Campground for 2009 Pecos Conference

Although the stages are generally interpreted as chronological rather than developmental these days, there is still a general sense of what sorts of sites are “typical” or expected for each stage, and this has driven a lot of the variation in specific date ranges.  Basketmaker II sites are generally associated with corn and squash agriculture, a scattered settlement pattern, lots of basketry but no pottery, and the use of the atlatl.  In Basketmaker III this pattern was adjusted by the introduction of the bow and arrow, pottery, and beans, and people began to cluster in some cases into pithouse villages, although there were still many isolated hamlets in some areas.  Pueblo I was something of a transition between Basketmaker III and Pueblo II, with the first construction of significant above-ground architecture in addition to pithouses.  Pueblo II was associated with masonry roomblocks and kivas, generally organized as “unit pueblos” of a few rooms with a kiva and trash mound in front and loosely grouped into “communities.”  The height of Chaco dates to this period, and within the area of Chacoan influence these communities typically had great houses in addition to the unit pueblos but separate from them.  In Pueblo III people began to aggregate into larger, denser communities more like the “pueblos” of historic times.  The cliff dwellings at Mesa Verde and elsewhere date to this period and are the best known of these aggregated sites, but there were many others in a variety of locations.  At the end of the Pueblo III period almost all of the Four Corners area was abandoned and people aggregated further into even larger pueblos in the Rio Grande Valley and the Zuni and Hopi areas to the west, in addition to a few other areas.  The Pueblo IV period is marked by the increasing concentration of population into ever-larger sites and the clustering of these sites in particular areas separated from other clusters by uninhabited “buffer zones.”  This period also saw the apparent introduction of the kachina cult and various other novel social phenomena, and it continued until the Spanish showed up and smashed everything.

That’s the picture in a nutshell, but some periods are better-known than others.  Pueblo II and III have been particularly well-researched in the Chaco and Mesa Verde areas, although there is still plenty that remains unknown about them.  In contrast, Pueblo I was very poorly understood until the Dolores Project in the 1980s totally revolutionized our knowledge of it.  This project was a massive cultural resource management (CRM) salvage project in advance of the damming of the Dolores River and the creation of McPhee Reservoir.  At the time it was the largest CRM project ever, and it might still have that distinction.  Numerous sites in the Dolores River Valley were excavated carefully and thoroughly documented.

McPhee Reservoir from McPhee Campground, Site of 2009 Pecos Conference

It’s impossible to overstate how much our current knowledge of the Pueblo I period is based on the discoveries made at Dolores.  What the project found was that the Dolores Valley, although sparsely occupied both before and after Pueblo I, during Pueblo I contained numerous large, dense villages, most of which only existed for a very short period of time during the AD 800s.  As research continued throughout southwestern Colorado, it became more apparent that these villages were just part of the story of the incredibly dynamic Pueblo I period.  People were moving all over the place, very rapidly, and forming and dissolving villages within the space of one or two generations.  Abundant evidence for drought and conflict at certain key points during the period provided some explanation for why, but the really important thing that came out of the Dolores Project specifically was the detailed study of some of the specific villages that allowed reconstruction of their short histories with remarkable precision.

On a larger scale, it appears that the Pueblo I period involved the movement of people into higher elevations than they had occupied during Basketmaker III, followed by movement back down after 900 and into Pueblo II.  While areas with Pueblo I villages typically didn’t have substantial earlier or later occupations, many other areas (including Chaco) had major Basketmaker III and Pueblo II occupations but little evidence of use during Pueblo I.  This probably had to do with climatic changes, but there were clearly also a lot of social processes going on as well.  Since the rise of Chaco as a regional center began right after all of this, Chacoan specialists have been realizing recently that the evidence from Dolores is very important as background for understanding Chaco.

McPhee Reservoir, Dolores, Colorado

Particularly influential in shaping understandings of Chaco has been one of the Dolores villages in particular, known as McPhee Village.  Like the other Dolores villages, McPhee was founded around 840 as people began to move out of earlier villages further south around Mesa Verde and Durango.  Not everyone from these earlier villages went to Dolores (an important point), but many did, and the Dolores villages grew rapidly, only to decline just as rapidly as people moved out starting in the 870s and continuing until around 900, at which point there was only a very small remnant population in some of the villages.

The remarkable thing about McPhee Village was the presence of some roomblocks there that bore an uncanny resemblance to the early “great houses” that would arise in the San Juan Basin to the south, including at Chaco, shortly afterward.  Not all of the roomblocks were like this; most were small, linear unit pueblos typical of those in most other villages.  Two roomblocks in particular, however, known as McPhee Pueblo and Pueblo de las Golondrinas, looked astonishingly like the early form of Pueblo Bonito.  They were arc-shaped rather than linear, with two arcs making up McPhee Pueblo and Pueblo de las Golondrinas consisting of one larger arc.  (Note that “McPhee Pueblo” refers to a specific roomblock within “McPhee Village.”  The terminology is confusing.)  Furthermore, these roomblocks were made up of room suites consisting of three rooms, with one large room facing the “plaza” within the arc backed by two smaller “storage” rooms.  The “plaza” area within each arc contained pit structures presumably associated with these suites.  Again, this is much like the layout of Pueblo Bonito and other early Chaco great houses.  These roomblocks were also made largely of masonry rather than adobe, in contrast to most earlier sites as well as many other Dolores villages, which again linked them to the later Chaco sites.

Dolores Medical Center, Dolores, Colorado

A variety of studies have been done of these sites, particularly focused on what differentiated them from other roomblocks at McPhee Village.  James Potter did a study of animal remains at McPhee Pueblo and Pueblo de las Golondrinas, looking for evidence that the residents of these sites might have hosted community-wide feasts and/or conducted special rituals, either of which could have been ways for them to gain social power within the community.  Both sites contain, in addition to the standard residential pitstructures common at all sites in the village, special “oversized” pitstructures with more formal, elaborate features that could have served as special locations for feasts or rituals.  He found that McPhee Pueblo did indeed have a much higher number of different types of animal remains present, including many “non-economic” species such as carnivores and certain birds that may have had important ritual uses.  Furthermore, it had a higher proportion of rabbits than most other roomblocks, which is significant because among the modern Pueblos rabbits are often hunted communally and eaten in ritual feasts.  Interestingly, Pueblo de las Golondrinas, despite its size and the presence of an oversized pitstructure, did not have these characteristics, suggesting that its inhabitants may not have been as successful as those at McPhee Pueblo at hosting communal rituals and increasing their power.

Another take on this question comes from an analysis of ritual architecture by Gregson Schachner.  Starting from the assumption that times of significant environmental and social change, such as those that surely accompanied the rapid founding and dissolution of the Dolores villages, offer opportunities for ambitious individuals or groups to gain power and influence by taking control of ritual practices or introducing new ones, he noted that unlike some other Dolores villages McPhee Village doesn’t have a great kiva, the standard community ritual structure both before and after the Pueblo I period.  Instead, roomblocks like McPhee Pueblo and Pueblo de las Golondrinas have the oversized pitstructures that might have been used for special ritual practices that the inhabitants of those sites may have tried to introduce to their communities. Schachner assumes that these pitstructures were primarily ritual rather than residential, which I think is dubious, but otherwise his arguments make sense.  He basically sees the process as having involved certain individuals or groups having tried to introduce new rituals that gave them increased status and power in the context of the convulsions of the Pueblo I period.  Those rituals might have been adopted because they offered a new way forward during the drought that coincided with the founding of the Dolores villages in the 840s, but they might have lost their appeal as a new drought in the 880s led people in the village to reject the innovations of these would-be leaders.  As the village dissolved, construction seems to have begun on a new great kiva over the oversized pitstructure at Pueblo de las Golondrinas.  This great kiva was not completed, however, and the whole village was soon abandoned.  Great kivas continued to be a key part of the new villages further to the south that appear to have absorbed many of the people leaving Dolores after 880, but the oversized pitstructure does not seem to have continued as a recognizable architectural form.

Mac's Plumbing, Dolores, Colorado

The great house form, however, which began to proliferate in the San Juan basin starting in the tenth century, seems to have some connection to the arc-shaped roomblocks at Dolores.  Recently, a model for the rise of Chaco incorporating the insights of the Dolores Project has begun to gain increasing acceptance.  Under this model, the frustrated would-be elites from the Dolores villages moved south into Chaco and other communities and began to build similar structures to those they had lived in at Dolores.  This time, however, circumstances were better, and they were able to gain more control over their communities.  These communities were spread throughout the basin, but those in Chaco Canyon specifically eventually gained ascendancy over the others, and the Chaco Phenomenon was born.

There is a certain logic to this, and parts of it are likely true, but it’s important to note that the timing isn’t quite right for frustrated elites from Dolores to have founded the first great houses at Chaco.  The earliest parts of Pueblo Bonito are now thought to have been built by 860 and perhaps considerably earlier, while the Dolores villages didn’t start to dissolve until the 870s.  It’s quite possible that later additions to the site in the 890s and early 900s involved immigration from Dolores, and indeed it is these room suites that are particularly similar to those at McPhee Pueblo.  It’s worth considering, however, the possibility that the early history of Chaco involved people moving in from the south as well as the north, and we don’t know nearly as much about the Pueblo I period in that area.  Were there large, unstable villages with ambitious families or individuals there too, or was something totally different going on that led people to head north at the same time people were heading south from Dolores?  We can only guess at this point, but it’s important not to let our greater knowledge of developments at Dolores lead us to focus too much on it to the exclusion of other important areas.  Dolores was very important, no question, but it wasn’t the only important place at the time.
ResearchBlogging.org
Potter, J. (1997). Communal Ritual and Faunal Remains: An Example from the Dolores Anasazi Journal of Field Archaeology, 24 (3) DOI: 10.2307/530690

Schachner, G (2001). Ritual Control and Transformation in Middle-Range Societies:
An Example from the American Southwest Journal of Anthropological Archaeology, 20, 168-194 DOI: 10.1006/jaar.2001.0379

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Kiva E, Aztec West

In July 1914 Earl Morris, the pioneering Southwestern archaeologist who would later become famous for his excavations at Aztec and other sites in the region, happened to visit one Eudoro Córdoba, who owned a farm on the Animas River a short distance upstream of the major ruins at Aztec.  On his mantelpiece were various artifacts which immediately attracted Morris’s attention, and when Morris asked about them Córdoba told him that he had collected them in the course of plowing over a series of small ruins that were obstructing the cultivation of his fields.  He was at the time working on the last of these sites, and gave Morris permission to excavate the remaining portion of it in a more rigorous manner.  There wasn’t a whole lot left, but Morris did manage to excavate six rooms and a small area to the east of the roomblock which contained several burials.  He published a short article describing the excavation and artifacts the next year.  This was one of the earliest examples of what would later become known as “salvage archaeology.”

There are several interesting statements in Morris’s article on the site.  For one thing, while this was the last of the “seven or eight small ruins which had obstructed [Córdoba's] fields,” Morris noted that there had been many more sites in the area:

Roughly three quarters of a mile east of the great pueblos the river swings obliquely across its narrow valley from northeast to southwest. The broad bench thus left north and west of the river was till recently dotted upon all sides of the large ruins with the remains of many cobblestone and adobe structures. Within the last few years a number of these lesser sites have been destroyed in order that the owners of the land might increase the tillable area of their fields.

Córdoba was one of these landowners, of course.  It appears from Morris’s statement that a large number of what we would now call “small houses” existed in close proximity to the great houses at Aztec, much like at Chaco.  This is particularly relevant to the question of the extent to which the Totah was densely inhabited before the Chacoan immigration that many have posited as being behind the founding of Aztec and Salmon.  People have generally agreed that Salmon, which is on the San Juan rather than the Animas, was founded in a previously uninhabited or sparsely inhabited area, and some people claim the same for Aztec.  Since we don’t know when the sites Morris mentions near Aztec were inhabited, his statement doesn’t provide direct evidence either way, but it does point out the dangers of making judgments about prehistoric habitation based on currently visible site distributions.  The San Juan valley has been just as heavily developed in modern times as the Animas valley, and the larger size of the San Juan also implies that more sites are likely to be buried under sediment there.  I remain skeptical about claims that the Salmon area was uninhabited before 1090.

South Wing of Aztec West, Looking East

The site Morris excavated, however, seems to have clearly been contemporaneous with the Aztec complex rather than predating it.  There was no way for Morris to know this in 1915, of course, which was before he even started excavating at Aztec West, but it’s clear from the artifacts he shows in his article that the site was inhabited in the 1200s, and perhaps a bit earlier.  Most of the illustrated ceramics seem to be Mesa Verde Black-on-white, which is typical of this period.  The site itself was made of adobe with occasional cobbles, which is standard local architecture, and it was apparently two stories high in places.  This is unusual among small houses (though standard for great houses), and it suggests that this site may be a residence of local inhabitants of some distinction or, perhaps, a somewhat larger aggregated site comparable to those known from the Mesa Verde region to the north during this period.  The site was mostly gone before Morris got to it, so he couldn’t tell how large it had been originally.  We know so little about sites in this region other than Salmon and Aztec that it’s hard to say what this site may have originally been like, but the sites excavated on the Bolack Ranch on the south side of the San Juan by the Totah Archaeological Project may provide a useful point of comparison.

As was apparently the case for some of the Bolack Ranch sites, the Córdoba site contained many burials.  In addition to five adults and two infants buried a short distance to the east of the roomblock, nineteen people were buried in three of the six rooms Morris excavated.  Morris suggested that “calamitous circumstances such as siege, pestilence, or famine overtook the inhabitants and caused great mortality among them,” leading to the unusually high number of burials in so few rooms and the oddities of the way some of them were buried.  The site appeared to Morris to have been burned, which might indicate warfare in the region during the late 1200s.  This would not be surprising, as there is abundant evidence for warfare in many other nearby regions at this time.

South Wing of Aztec West, Looking West

Another interesting thing about this site was the burial of a badger just north of the human burials east of the roomblock.  According to Morris “the animal had been put away with all the care ordinarily bestowed upon a human being.”  Animal burials like this are pretty common at Pueblo sites.  They are most often of dogs or turkeys, but occasionally of other animals.  As far as I know no one has looked at the spatial and temporal patterns in which animals are buried where, but that might be one way of getting some evidence for possible migrations of specific groups that might have had particular attachments to different animals.

Overall, this is an interesting paper, with quite a bit of interesting information despite its short length and emphasis (typical for the time) on artifact description rather than discussion of larger issues.  It doesn’t seem to get cited very much, which is unfortunate because it provides a useful point of comparison for more recent excavations in the region.
ResearchBlogging.org
Morris, E. (1915). The Excavation of a Ruin near Aztec, San Juan County, new Mexico American Anthropologist, 17 (4), 666-684 DOI: 10.1525/aa.1915.17.4.02a00040

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Durango, Colorado

The best-known of the various instances of alleged cannibalism in the prehistoric Southwest are a set of several that occurred around AD 1150 in the area around the modern town of Cortez, Colorado.  There are also scattered examples of similar assemblages dating to both before and after this and located both in southwestern Colorado and elsewhere, but most of them are not as well documented and they are therefore not easily comparable to the well-known assemblages.  One exception, so far the only known example of possible cannibalism dating to the period in the late thirteenth century when the Four Corners region was abandoned, is Castle Rock Pueblo at Canyons of the Ancients National Monument west of Cortez.  Earlier assemblages, in particular, are very rare, and the few known are generally not very well documented at all.  Cannibalism has thus generally been discussed in the literature as something that appears rather suddenly in the Southwestern archaeological record around 1150, perhaps indicating Mesoamerican influence that may or may not have had something to do with the rise and fall of the regional system centered on Chaco Canyon between about AD 1030 and 1130.  There have been some scattered references in the literature to earlier instances, but without good documentation they have not gotten much attention compared to the later ones.

That may now change, however.  An article published very recently reports on an astonishing assemblage recently documented in detail at Sacred Ridge, part of Ridges Basin south of Durango, Colorado (east of Cortez).  This site dates to around AD 700 to 800, during the Pueblo I period.  As part of salvage excavations in preparation for a reservoir project in the basin, archaeologists discovered one of the largest assemblages of intensively processed human remains known from the Southwest.  At least 35 people were represented in the assemblage, although the actual number present is exceptionally difficult to determine because the remains were fragmented to an enormous degree even compared to other heavily processed assemblages.   The ages of identifiable individuals ranged from infancy to adulthood.  The conditions of the deposition of the remains indicates that most were processed, possibly in connection with cannibalism, then dumped into one of the residential pithouses at the site.  Several artifacts found associated with the remains tested positive for human hemoglobin and/or myoglobin, indicating that they had come into contact with human blood and/or muscle tissue.

Francisco's Restaurante y Cantina, Durango, Colorado

This is a very large assemblage.  The well-documented assemblage at site 5MT10010 at Cowboy Wash, for example, consisted of only 7 individuals, and the other three sites in the Cowboy Wash community that have been excavated (all of which also showed evidence of cannibalism) ranged from 2 to 13 individuals.  Castle Rock had at least 41 individuals, but that was a large, aggregated community from a later period when the regional population was both larger and more concentrated in aggregated sites.  Finding 35 people killed at a Pueblo I village is extraordinary.

So who were these people?  The circumstances of the assemblage suggest that they were probably the inhabitants of the Sacred Ridge site, which contained several residential pithouses and constituted a relatively large portion of the overall Ridges Basin community.  Biometric analyses of the remains suggested that the individuals in the assemblage were both related to each other and distinct from the other people in the community.  This raises the possibility that they were recent immigrants who had attempted to move into the area, perhaps at a time when environmental conditions were difficult and some parts of the region had become less suitable for habitation, forcing their inhabitants to move into already-occupied areas where the local residents may not have been friendly.  This is similar to what some have proposed for Cowboy Wash, where ceramics indicate that the residents had strong ties to the Chuska Mountain region to the south and may have been recent immigrants into an area where they were not welcome.  The early AD 800s, when the Sacred Ridge massacre apparently occurred, does indeed seem to have been a time of difficult environmental conditions, as was the mid-1100s when the well-known cannibalism events such as the one at Cowboy Wash occurred.  The migration hypothesis thus seems fairly plausible to explain Sacred Ridge.

Railroad Station, Durango, Colorado

Not so fast, however.  In addition to doing the biometric analyses, the researchers in this case also did strontium analyses of the tooth enamel found in the assemblage.  Strontium isotope analyses can be used to determine where a person (or a tree) lived, which makes this type of analysis a useful way to directly test migration hypotheses.  Tooth enamel has a strontium ratio that reflects where a person lived as a child, since enamel is preserved throughout life after initially forming in childhood.  The strontium ratio of bone, on the other hand, reflects where a person lived shortly before death, since bone cells are continually being replaced throughout life.  In this case only tooth enamel was tested, but I’ve seen other studies comparing tooth and bone enamel to determine if a person lived in the same place at the beginning and end of life, which is just about the best way to test a migration hypothesis that I can imagine.  In the case of Sacred Ridge only tooth enamel was analyzed for some reason, but it still provides a way to determine if the individuals at Sacred Ridge had grown up in the Ridges Basin area or had moved at some point in their lives from somewhere else.

What the analysis showed was that all the analyzed individuals had likely grown up either in the immediate Ridges Basin area or nearby.  None could be conclusively identified as having grown up anywhere else.  This effectively falsifies the immigration hypothesis and requires a different explanation for the massacre.  It appears that the people who lived at Sacred Ridge were both local to Ridges Basin and distinct from the other inhabitants of the area, which the authors interpret as an “ethnic” difference.  They point to a variety of other indications in architecture and material culture suggesting that the area was quite diverse ethnically during this period, and they argue that the massacre represents ethnic violence within the community during a period of environmental deterioration likely leading to social stress.  The inhabitants of Sacred Ridge appear to have had greater access to large game animals than other members of the community, which may indicate that they were relatively well-off compared to others, who may have become resentful when times turned bad and taken out their frustrations through intensive violence, possibly involving cannibalism, which may have been so intense in part as an attempt to erase the identity of the victimized group.  The authors run through and discount a number of other explanations that have been offered for cannibalism assemblages, including warfare, social control, starvation, and witchcraft execution.  They reject these based on specific criteria they identify as the plausible archaeological correlates of each theory.  The specific correlates they offer strike me as dubious, and they do acknowledge that their “ethnic violence” theory is not necessarily incompatible with some of the others, but the approach is interesting.

Gaslight Theater, Durango, Colorado

There has been a recent trend in Southwestern archaeology toward trying to reconstruct ethnicity in the archaeological record, and there is an increasing sense that the Southwestern past may have been much more diverse ethnically than archaeologists have often assumed.  This paper takes that trend in an interesting direction by combining it with the contemporaneous trend toward greater interest in violence and warfare in the prehistoric Southwest.  The authors suggest that some of the later cannibalism assemblages might be profitably reexamined with the ethnic violence idea in mind, which is a good idea.  That said, “ethnicity” is a problematic concept when it comes to archaeological data, which is necessarily material in nature and not necessarily reflective of such an abstract concept.  It would be unreasonable to expect a short paper like this to address the issue at length, of course, and it appears that other publications from this project deal with it in more detail.  The innovative use of biodistance and strontium analyses to address these issues is a worthwhile development regardless of whether the trends identified correspond to ethnicity, however, and this paper makes for a very interesting contribution to the literature on violence and cannibalism in the Southwest that may require some adjustments to existing theories.
ResearchBlogging.org
Potter, J., & Chuipka, J. (2010). Perimortem mutilation of human remains in an early village in the American Southwest: A case for ethnic violence Journal of Anthropological Archaeology, 29 (4), 507-523 DOI: 10.1016/j.jaa.2010.08.001

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Sleeping Ute Mountain and Surrounding Landscape from Four Corners

If you stand at the Four Corners monument and look in the direction of Colorado you will see Sleeping Ute Mountain dominating the view.  From this direction you are looking at the southwest side of the mountain, and in front of it you see the southern piedmont.  On the right side of the piedmont, though not visible from this distance, is Cowboy Wash.  It’s one of several ephemeral streams running from the mountain itself across the piedmont to the San Juan River.

One thing that might strike you about the view from this perspective is that it looks like an awfully dry, desolate, uninhabitable wasteland.  And you would be correct to think that.  The southern piedmont of Sleeping Ute Mountain is an extremely arid and inhospitable environment even by the standards of the Southwest, which is saying something.  It’s only a few miles from Mesa Verde to the east and the Great Sage Plain to the north, both areas that get relatively abundant rainfall and supported large and prosperous prehistoric communities, but it is worlds away from them environmentally.  While those areas get sufficient rainfall to support dry farming, and the Great Sage Plain is commercially farmed even today, the southern piedmont does not, and any type of agriculture there would have to rely on some sort of irrigation.  Today the Ute Mountain Ute tribe has a large irrigation project in the area, using water brought in from McPhee Reservoir, 45 miles to the north, via the Towaoc Canal.  The construction of the reservoir and the canal was part of the Dolores Project, which involved substantial archaeological excavation of the inundated area that significantly improved archaeological understanding of the prehistory of the region.  This work took place from 1978 to 1985 and was known as the Dolores Archaeological Project, the largest salvage archaeology project in US history.

McPhee Reservoir, Dolores, Colorado

The creation of the irrigated fields on the piedmont resulted in further salvage excavations in the 1990s.  Among the sites excavated was 5MT10010, which contained considerable evidence of a gruesome incident of probable cannibalism around AD 1150.  It is not the only site in the area to show evidence of cannibalism during this period; in fact, three other sites in the same community, excavated slightly earlier in connection with the construction of the canal, also showed evidence of having been destroyed in an incident involving extensive processing of human remains in a way suggesting cannibalism, and there are several other sites in the area showing similar assemblages, most from the same period but at least one from a later period.  It is at 5MT10010 that the most solid evidence for actual cannibalism, as opposed to processing of bones in a way that may or may not indicate actual consumption of human flesh, in the form of a coprolite that tested positive for the presence of human muscle tissue.

There are many questions that arise from these findings, but one of the most puzzling is also one of the simplest: what were people doing living at Cowboy Wash in the first place, and how did they manage it?  After all, they weren’t building giant dams and canals of the sort involved in the Dolores Project.  In many parts of the Southwest, especially upland areas like Mesa Verde, dry farming using only rainfall was standard during this period, and water control techniques were generally used only for domestic water if a nearby spring or other reliable source was not available.  There are a few springs on the southern piedmont that probably would have supplied sufficient domestic water for the small number of people living there, but the rainfall would definitely not have been sufficient to farm with.  The only source of water at all sufficient for agriculture would have been the occasional floods, from spring snowmelt and summer thunderstorms, that would flow through Cowboy Wash itself and the other drainages on the piedmont.  None of these flows permanently today, and there is no evidence that they ever did.  As at Chaco Canyon, then, which is similarly dry, farming would have to have been based on some sort of technique for capturing the floodwater.

Flowing Chaco Wash and Cliffs below Peñasco Blanco

There are a variety of ways this might be done, including diverting the rainwater from cliffs, as was done at Chaco, planting along the sides of the drainage where the floods would regularly overflow the banks, and what is known as “ak-chin” farming, as practiced by the O’odham of southern Arizona, which involves planting right in the path of the runoff at places where the velocity of the water is relatively low, as at the mouths of tributaries to main arroyos.  There are no sheer cliffs on the southern piedmont like the ones at Chaco, so probably a mix of overbank and ak-chin farming would have been practiced at Cowboy Wash.

A paper by Gary Huckleberry and Brian Billman addresses the nature of farming at Cowboy Wash, and also addresses a related issue, which is whether periodic entrenchment of arroyos due to drought played a role in the patterns of abandonment and migration that characterize Southwestern prehistory.  It is pretty clear by now that the paleoclimatological record shows periods of drought corresponding to periods of abandonment of certain parts of the Southwest, and one proposed mechanism for how this would have worked is that drought would have led to increased erosion and/or hydrological changes in the water table that led to the entrenchment of arroyos, which would have been disastrous for populations dependent on certain types of floodwater farming (especially overbank), as the broad floodplains of the local drainages would have been replaced by deep channels that took the water away quickly instead of letting it overflow to water the crops.  Ak-chin farmers would not necessarily have been affected to the same degree, but if the side drainages they used became entrenched as well they would not have been able to use their techniques either.  Thus, drought would lead to arroyo-cutting, which would lead people to leave formerly productive areas for others that were less affected.  This theory has been proposed as an explanation for certain events at Chaco, with the idea being that some of the social changes late in the Chacoan occupation were due to degradation of the Chaco Wash and the need to change agricultural strategies.  The phenomenon of arroyo-cutting in general is richly illustrated in historic times at Chaco.  The early reports of the Chaco Wash from the nineteenth century indicate that it was a shallow, meandering drainage, much like the current condition of the Escavada Wash to the north and the “Chaco River” that is formed by the confluence of the two at the western end of the canyon and flows north to the San Juan.  By the early twentieth century, and accelerating since then, however, the Chaco Wash through the canyon has cut down significantly and there is a very deep arroyo channel apparent today.

Entrenched Arroyo at Chaco

The drought-downcutting-abandonment theory makes sense as far as it goes, but as Huckleberry and Billman point out there are some problems.  For one thing, the extent to which arroyo-cutting is actually linked to drought, rather than other factors including the specific geology of the area, is hotly debated and there is no consensus.  The idea that while drought may be one factor causing arroyo-cutting there are other factors involved as well is supported by the fact that in different drainages in the Southwest that have been studied in depth the periods of arroyo-cutting do not necessarily correspond to region-wide droughts or other climatic changes.  In some areas they do, but in other areas they don’t.  At Cowboy Wash specifically, the available evidence indicates that the wash began to entrench sometime before AD 950, and that it began to refill with sediment sometime between AD 1265 and 1400.  If abandonment does in fact correspond to arroyo-cutting, then presumably the Cowboy Wash area should have been abandoned between 950 and 1265, and possibly occupied before and after this.  If downcutting results from drought, there should also be evidence of drought during the 950 to 1265 period.

The basic upshot of the Huckleberry and Billman paper is that neither of these expectations is met.  The evidence for drought conditions at Cowboy Wash generally matches that for the rest of the region, with the major droughts in the mid-twelfth century and late thirteenth century AD and several smaller droughts at irregular intervals before then.  This doesn’t show any particular relationship to the stratigraphic evidence for arroyo-cutting, which seems to have been going on to some degree throughout the period from AD 950 to at least AD 1265.  Furthermore, the evidence for settlement doesn’t line up either.  The marginal nature of the Cowboy Wash area implies that it would probably not have been occupied for most of prehistory, and this was indeed the case.  There were a few ultimately unsuccessful attempts to colonize the southern piedmont, however, and they don’t show any particular relationship to the periods of arroyo-cutting (although they do perhaps relate to periods of drought).  The first agricultural occupation of the area came during the Basketmaker III period, when a few pithouses were apparently used seasonally as summer fieldhouses, presumably associated with nearby fields, from about AD 600 to 725.  After these were abandoned, at a time which may correspond to a drought, the area does not seem to have been occupied again for more than three hundred years.  Then, around AD 1050, a few permanent, year-round sites were built.  These seem to have been occupied for only a few years, however, as there was no significant buildup of trash associated with them.  After they were abandoned, three larger villages, including one at Cowboy Wash, were established around AD 1075.  These had extensive trash deposits and seem to have been occupied for one or two generations.  These communities were apparently abandoned, however, when the next occupation began in the 1120s by a population with apparent links to the Chuska Mountain area to the south.  This occupation at Cowboy Wash is the community that was apparently destroyed around AD 1150 (again coincident with a major drought) when its inhabitants were mutilated and cannibalized.  After this event, the area was once again abandoned until about AD 1225, when two new communities were founded, including one again at Cowboy Wash.  Within a few decades the population at Cowboy Wash appears to have aggregated at Cowboy Wash Pueblo, following a typical pattern for the region.  Also typical of the region, the whole southern piedmont seems to have been abandoned by AD 1280, at the time of the “Great Drought” that coincides with major changes throughout the Southwest.

Entrenched Chaco Wash from Cliff Top near Pueblo Bonito

So basically, all of the attempts at year-round occupation of the southern piedmont seem to have occurred during the period that Cowboy Wash was being downcut.  While these were all ultimately unsuccessful, some lasted for a few decades, so clearly they were able to grow some food at some times.  This strongly implies that at least in this case, arroyo-cutting was not particularly linked to abandoned, although drought probably was.  Huckleberry address the issue of how farming could have been done during periods of downcutting by looking at Cowboy Wash and its tributaries today.  They find that while some portions of the main wash, especially, are indeed heavily downcut, other portions are not, and they label this type of drainage a “discontinuous ephemeral stream,” which is to say, a normally dry wash with some portions that are severely downcut and others that are not.  On the uncut portions, which include much of the length of the tributaries, overbank or ak-chin farming could easily be done today, and this was presumably the case in antiquity as well.  The hydrology of the area is such that the areas of downcutting would not have been stable, and would have tended to migrate upstream, but the complexity of the system is also such that this would not have made the entire system unusable; while some parts were being newly cut, others would be filling in, and prehistoric farmers would merely have to move their fields around a bit rather than abandoning the area entirely.

All that being said, however, the question of why people were trying to settle this quite harsh and difficult area in the first place.  It is interesting to note that the attempts at settlement generally came during periods of relatively favorable environmental conditions, which would have made this area a bit less forbidding than usual, as well as during times of increased regional population, when all the good land may well have been taken and some people were forced to seek out the more marginal areas.  The violence that appears to have accompanied the drought of the twelfth century, especially, suggests that when the good times came to an end social relations got very bad very fast.  Huckleberry and Billman suggest that the reason people did end up abandoning Cowboy Wash, the times when they were not attacked, was merely drought itself, which they were unable to cope with as well as other populations, even those who also used floodwater farming techniques, because the size of the watershed was relatively small and the amount of rainfall feeding the washes was also small, so the total amount of water they had to work with was much smaller even in good times than at place like Chaco with large watersheds.  In that context, even a small decrease in annual precipitation could be devastating, leading to failed harvests and the need to move away.

Non-Entrenched Escavada Wash from New Mexico Highway 57

Indeed, there is evidence that the time of the massacre at Cowboy Wash was very difficult for the people there.  Archaeobotanical studies of pollen and other plant remains showed that there was apparently little or no maize in or around 5MT10010 at the time of abandonment, which is quite surprising for a Pueblo site.  The plant remains that were there were mostly from wild plants such as chenopod, amaranth, and tansy mustard, all of which would have been available in the spring and likely would have been intensively collected if there were no stored corn available due to a failed harvest the previous fall.  In addition to pinpointing the season in which the incident occurred, this implies that times were very tough for the inhabitants of 5MT10010, and perhaps for their attackers too.  The coprolite showed no sign of having plant material in it, which suggests that whoever left it had not just eaten some corn at home before setting out to attack 5MT10010.

Another paper associated with the project, by Patricia Lambert, suggests another problem the Cowboy Wash inhabitants apparently had: disease.  In this paper Lambert reports on analyses of ribs of individuals at 5MT10010 and other sites in the Cowboy Wash area dating to various periods of occupation that had lesions on them suggestive of those seen in modern collections of individuals known to have died of tuberculosis and (to a lesser extent) other respiratory diseases.  These lesions were found in 11 of 32 individuals from Cowboy Wash that had enough of their ribs left to examine.  One of the individuals with lesions was from 5MT10010.  This was an adult woman who was not one of the victims of the attack at site abandonment but who had instead died earlier and been formally buried.  Lambert also examined comparative collections of remains from Pueblo Bonito at Chaco and Elden Pueblo near Flagstaff Arizona.  Only 3 of the 45 individuals from Pueblo Bonito and 2 of the 20 from Eldon Pueblo had similar lesions, suggesting that this disease was much more prevalent at Cowboy Wash than at these other sites, even though it was not absent at them.  Lambert notes that tuberculosis is an opportunistic disease that tends to strike people whose systems are compromised by other problems such as hunger and stress.  The evidence for physical violence in the Cowboy Wash sample, even setting aside the cannibalism assemblages, was much greater than in the other two samples as well.  Combined with the harsh environment, this suggests strongly that Cowboy Wash was a difficult place to live for several reasons.  Farming was possible but risky, and when conditions turned bad both hunger and violence from other hungry people were constant threats.

Given this context, the occurrence of extreme events such as cannibalism incidents at Cowboy Wash starts to make some sense.  Cowboy Wash is a place of extremes.
ResearchBlogging.org
Huckleberry, G., & Billman, B. (1998). Floodwater Farming, Discontinuous Ephemeral Streams, and Puebloan Abandonment in Southwestern Colorado American Antiquity, 63 (4) DOI: 10.2307/2694110

Lambert, P. (2002). Rib lesions in a prehistoric Puebloan sample from southwestern Colorado American Journal of Physical Anthropology, 117 (4), 281-292 DOI: 10.1002/ajpa.10036

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Sleeping Ute Mountain from Cortez, Colorado

In comments to the previous post, Graham King raises an important question: assuming that the assemblages of broken, burned, and otherwise unusually treated bones at sites like 5MT10010 at Cowboy Wash represent incidents of cannibalism, what does this mean culturally and historically?  After all, cannibalism has occurred in various contexts in many societies, including our own, and it can arise from a variety of causes.  One of the most obvious is starvation, seen most often in situations like the plane crash in the Andes made famous in the movie Alive and incidents during the settlement of the American West such as the Donner Party and the Alferd Packer case, all of which involved small groups being trapped in mountains under harsh conditions and resorting to cannibalism to survive.

So were the events at Cowboy Wash around AD 1150 the result of survival cannibalism, perhaps of members of the community who had died due to disease or starvation by other members of the community?  The excavators of 5MT10010 argued that they were not, but the evidence they gave for this conclusion is not particularly convincing.  They basically had two arguments against survival cannibalism:

  • If the individuals at Cowboy Wash had died natural deaths, the demographics of the dead should reflect the differing susceptibility to harsh conditions of different age groups, which generally means a higher death rate among infants and a lower one among older children and adolescents.  Since the 5MT10010 assemblage contained no infants but a higher than expected number of older children, it is unlikely to have resulted from natural death.
  • Unlike in the historically documented cases, the people at Cowboy Wash were not physically trapped.  There was nothing preventing them from moving away from the area if there were insufficient resources.  The southern piedmont of Sleeping Ute Mountain is pretty flat and open, rather than mountainous, and the abandonment of the sites there apparently took place in the spring, when snow would not have been an issue.

Neither of these arguments is very convincing.  The assemblage of cannibalized individuals at 5MT10010 looks demographically unusual, sure, but then again it apparently consists of only seven people.  That’s a minimum number, of course, but since the whole site was excavated and it wasn’t a large site to begin with it seems likely that the recovered bones represent most or all of the people involved.  If the assemblage represents the inhabitants of the site, which the excavators claim and I see no reason to doubt, they likely represent a family or other social unit, and it’s quite possible that they just didn’t happen to have any infants in the group at the time of the event.  In any case, with a population this small there is no reason to expect any sort of “normal” demographic profile.

The second argument is better, but still somewhat unconvincing.  It’s definitely true that the inhabitants of Cowboy Wash wouldn’t have been snowed in at the time of the abandonment event, which apparently took place in the spring, but it’s not necessarily true that they would have had somewhere else to go.  This was a time of drought and resource shortages throughout the northern Southwest, and there is considerable evidence for violence (even leaving aside the alleged cannibalism incidents) throughout the region, including at other sites in the Ute Mountain area, at the time.  Indeed, Cowboy Wash is a very marginal area for agriculture to start with, so the fact that they were there in the first place, and that they had not already left when the harvest failed, implies strongly that they had nowhere else to go.  Under those circumstances, it is certainly conceivable that some community residents might have begun to succumb to hunger or disease and others in the community may have resorted to eating them.  That’s not to say that it’s likely or the best explanation, of course.  One piece of evidence arguing against this interpretation, which the excavators mention but don’t go into much detail on, is that all the processing seems to have taken place at the same time, rather than drawn out over a period of weeks or months as might be expected if people were gradually dying and being eaten.

Sleeping Ute Mountain from Lowry Pueblo

Instead of survival cannibalism, the Cowboy Wash excavators prefer a scenario of intercommunity violence to explain the 5MT10010 assemblage.  This implies that the people who ate the residents of 5MT10010 also killed them.  This sort of explanation does fit well with the other evidence for violence short of cannibalism in the region during this period, but it is tricky to show any correlation between violent death and cannibalism because the processing of the bodies would likely eliminate any skeletal evidence of violent death.  That does seem to be the case in this assemblage, as in most other alleged cases of cannibalism.  There’s plenty of evidence of skeletal trauma, of course, but most of it seems to be directly related to the processing of the bodies shortly after death, and much of the rest seems to represent injuries incurred during life that had healed before death.  In this case, then, there is no direct evidence linking alleged cannibalism to violent death.

One piece of evidence supporting the “raid by other group” theory is that three other sites in the Cowboy Wash community, contemporary with 5MT10010, have also been excavated and all three show similar signs of cannibalism.  Since there are only ten sites in the whole community, the fact that four of them seem to have been rapidly abandoned at the same time that many people in them were eaten seems to imply that the abandonment was the result of a single event.  As the authors of the 5MT10010 paper point out there and in more detail in another article, however, there are some differences among the four assemblages and even between the assemblages in the two pitstructures at 5 MT10010 containing large numbers of bones.  Although all four sites show evidence of processing for consumption, the specific body parts that are most prevalent and the way they were processed suggest that the processing was done separately at each site and not in accordance with a common technique.  For example, at 5MT10010 the bodies found in one pitstructure appeared to have been cut into small pieces and cooked in a pot on the surface, with the bones thrown down the ventilator shaft after consumption.  At the other pitstructure, however, the bodies seem to have been cut into fewer pieces and roasted directly on a fire in the hearth inside the structure.  All this suggests that if in fact the Cowboy Wash community was destroyed by a raid, the raiders who attacked each part of it seem to have acted fairly autonomously in deciding how to deal with the inhabitants, even though they all apparently had the common goal of eating them.

This is actually rather odd, and does seem to undermine the idea that warfare was behind the cannibalism at Cowboy Wash.  It is possible, however, that raiding and survival cannibalism aren’t mutually exclusive, and that the raiders of Cowboy Wash may have attacked it specifically in order to eat the people there because they themselves were starving.  The excavators do mention that the meat from a cannibalistic attack may have been a valued “spoil of war” during harsh environmental times like this, but they generally downplay this aspect and focus more on the idea that cannibalism would have served as a terroristic tactic to strike fear in the hearts of enemies and perhaps scare them away from the area.  (The two are not necessarily mutually exclusive, of course.)  The fact that the people in the different parts of the Cowboy Wash community were apparently prepared differently does seem more compatible with the idea that the attackers were focused on eating them because they were hungry than with the idea that they were concerned with striking fear into any survivors or other nearby villages.  The terroristic theory seems to imply a ritualistic approach to the cannibalism, which is not particularly apparent in this or any other Southwestern cannibalism assemblage.  Any type of ritual cannibalism would likely have been more standardized in execution, as in Mesoamerica where ritual cannibalism was widespread.  In the Southwest, by contrast, the execution seems rather haphazard.

So, tentatively, I think the best explanation at least for Cowboy Wash specifically, and perhaps for other cases as well, is that certain communities in the Mesa Verde area during the extended drought of the mid-twelfth century AD hit upon the idea of compensating for their poor harvests by attacking other communities, not to take their stored food (since they likely didn’t have any either) but to eat their residents.  Which communities these might have been and where they got the idea remain open questions.  This idea led to a rash of cannibalism incidents around AD 1150 which subsided soon thereafter, perhaps as climatic conditions improved (or, alternatively, as other communities got better at defending themselves).  When the next major drought came, in the late thirteenth century, the idea of cannibalistic raiding does not seem to have been taken up again.  The authors of the Cowboy Wash articles take pains to note that there is no evidence of cannibalism in the Mesa Verde area after AD 1200.  Although there is plenty of evidence of violence during the late 1200s preceding the total depopulation of the region by 1300, none of this involved cannibalism.

Or did it?  There is actually some evidence from at least one site suggesting that the idea of cannibalism did not totally disappear from the Mesa Verde area after 1200.  But that’s a matter for another post.
ResearchBlogging.org
Lambert, P., Billman, B., & Leonard, B. (2000). Explaining variability in mutilated human bone assemblages from the American Southwest: a case study from the southern piedmont of Sleeping Ute Mountain, Colorado International Journal of Osteoarchaeology, 10 (1), 49-64 DOI: 10.1002/(SICI)1099-1212(200001/02)10:13.0.CO;2-B

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Sleeping Ute Mountain from Mule Canyon, Utah

In their critique of the article reporting evidence for alleged cannibalism at site 5MT10100 near Cowboy Wash on the southern piedmont of Sleeping Ute Mountain, Kurt Dongoske, Debra Martin, and T. J. Ferguson challenged many of the conclusions and lines of evidence presented in the article.  Among these was the evidence of consumption of human flesh from a coprolite found in a hearth at the site, which could potentially serve as the “smoking gun” offering physical proof of cannibalism, if the analysis is correct.  The authors of the critique found the presentation of this evidence in the initial article unconvincing, however, describing the data as “sketchy” and implying a lack of scientific rigor in the analysis.  They concluded this section of the critique by saying:

We are not microbiologists, and therefore before accepting the claim that the coprolite contains human myoglobin, we await peer review and publication of the fecal study by Science or another scientific journal specializing in biomolecular research.  As presented in the Cowboy Wash study, the fecal evidence is suggestive but not convincing. More work pursuing this line of evidence is warranted in future studies.

In their response to the critique, the authors of the original paper added more detailed information on the coprolite analysis, but they also did as the critique authors recommended and published a short article in Nature (Science‘s main competitor) giving more specific details on the analytical techniques used to detect human myoglobin both in the coprolite and on some potsherds from a cooking vessel found in the same pitstructure.  There isn’t actually much in this paper that wasn’t in the response to the critique, aside from the laboratory procedures, which I am not in a position to evaluate.  It’s not actually clear to me if this article was peer-reviewed; it doesn’t explicitly mention any reviewers or any details of the review process, but this doesn’t necessarily mean it wasn’t reviewed.  It’s also not clear to me if the authors submitted it in response to the critique or if they had already intended to.  Both the original article and the critique were published in January 2000, and this article was received by Nature on March 7,  accepted on June 6 (which does seem to imply some sort of review process), and published on September 7.  Meanwhile, the response to the critique was published in April.  In any case, whether or not the authors of the initial paper were spurred by the critique to submit additional publications (and this is not the only one to appear after the critique was published), they certainly can’t be accused of shrinking from the challenges it set for them.

Mentioning this paper also allows me to go into a bit more detail about the myoglobin analysis, which I didn’t in the previous post.  Basically, to determine if the coprolite resulted from the consumption of human flesh the researchers needed to find something to test for that would be present in parts of a human body likely to be consumed but not in parts of the consumers body likely to end up in the coprolite during the digestion process  (e.g., blood or intestinal lining).  They decided on myoglobin, which is a protein molecule in the skeletal and cardiac muscles that transports oxygen from the outer membrane of muscle cells to the interior parts of the cells where it is used to generate energy.  Importantly, this protein is not found in the smooth muscles of the digestive system or in the blood, so it is unlikely to end up in fecal matter as part of the digestive process.  The researchers used a variety of controls to establish this, including coprolites from Salmon Ruin and modern fecal samples from “normal individuals,” people with blood in their stool, and people who had recently eaten beef.  None of these ancient or modern samples tested positive for human myoglobin, but the beef ones did test positive for bovine myoglobin, establishing that myoglobin can indeed be found and identified to species in fecal material.  These controls were mentioned in the original article, and when I read it I had wondered where they had gotten the modern samples.  The Nature article explains that they came from leftover material from clinical samples that was turned over for research use, which makes sense.  For the sherd testing, the controls were other sherds from the same site, sherds from another site in Southwestern Colorado dating from the same period but without evidence of cannibalism, and sherds from a Plains site near Denver also dating to roughly the same period.  None of these control sherds tested positive for human myoglobin either, although some tested positive for deer or rabbit myoglobin.  Thus, since the coprolite from Cowboy Wash and the sherds found near it were the only samples to test positive for human myoglobin, the hypothesis that they were associated with ingestion of human flesh was not disproven, and it remains the most plausible explanation of the Cowboy Wash assemblage.

It’s certainly possible that problems may be found with this analysis that cast doubt on the result, but I haven’t seen any, and until I do I’ll provisionally accept it as indicating very strongly that broken and burned bone assemblages like the one at Cowboy Wash most likely result from cannibalism.  What that might mean culturally and historically, of course, is a different and more difficult question.
ResearchBlogging.org
Marlar RA, Leonard BL, Billman BR, Lambert PM, & Marlar JE (2000). Biochemical evidence of cannibalism at a prehistoric Puebloan site in southwestern Colorado. Nature, 407 (6800), 74-8 PMID: 10993075

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Peñasco Blanco

Near the very end of his report on the excavations at Pueblo Bonito by the Hyde Expedition in the 1890s, George Pepper wrote the following:

The finding of cracked and calcined bones in some of the rooms brings up the question of the eating of human flesh by the people of this pueblo.  There was no evidence of human bodies having been buried in rooms above the first floor and only portions of skeletons were in evidence in Rooms 61 and 80 which contained broken and charred bones.  During the period of our work in Pueblo Bonito some of our Navajo workmen cleaned out a number of rooms in Penasco Blanco and in one of these a great many human bones were found.  Some of these including portions of the skull, were charred, and the majority of the long bones had been cracked open and presented the same appearance as do the animal bones that have been treated in a similar way for the extraction of the marrow.  It would therefore seem that these Pueblo Indians, either through stress of hunger or for religious reasons, had occasionally resorted to the eating of human flesh.

The report was published in 1920, and ever since then the question of cannibalism has hung over Chaco Canyon like a giant question mark.  In the 1920s Frank Roberts found some additional bones at another site at Chaco that were in a similar condition, but these and the ones mentioned by Pepper constitute the entire sample of bones from Chaco itself that have been proposed as evidence for cannibalism.  On its own, this is pretty weak stuff, especially since it comes only from sites that were excavated early in the history of archaeological research at Chaco and information on the context of these bones is very limited.  Most archaeologists have therefore generally been content to conclude that whatever these bones represent, they don’t have much relevance to explaining Chaco as a whole.

Over the decades since Pepper wrote his report, however, a growing number of other sites throughout the northern Southwest have revealed human bones that are broken, burned, and otherwise suspiciously unlike typical burials.  As archaeological techniques have improved, the amount of information about the context of these finds has increased, and as physical anthropologists have gained experienced and added new techniques more information can be gained from both these new finds and the early ones now in museums.  One physical anthropologist in particular, Christy Turner of Arizona State, has put an enormous amount of effort into analyzing evidence for cannibalism in the prehistoric Southwest.  His overall interpretation of the evidence has led him most recently to propose, particularly in the 1999 book Man Corn, coauthored with his wife, that cannibalism was a core part of the Chaco system, which he sees as a militaristic state led by some sort of sociopathic Toltec leader who came up from Mexico and attempted to institute a Mesoamerican state based on tribute and human sacrifice, or something (I haven’t read the book).

Sleeping Ute Mountain from Anasazi Heritage Center

Obviously this theory depends heavily on attempts to equate the evidence for cannibalism across the Southwest with the rise of Chaco, and here it immediately runs into problems.  While there is the evidence from Chaco reported by Pepper and Roberts, most of the evidence for cannibalism in the Southwest comes from contexts that are rather distant from Chaco both spatially and temporally.  Some are earlier, particularly in the AD 800s and 900s, when the Chaco system may have been gearing up but was certainly not yet in the culturally dominant role it attained by the late 1000s.  More are later, mostly in the AD 1100s, after Chaco’s influence declined.  Spatially, most of the well-documented examples from recent examples are from southern Colorado, which was certainly under Chacoan influence at one point but probably was not at the times the events apparently occurred.  Indeed, most of these well-documented examples are from a strikingly specific time and place: around AD 1150 in the area around Sleeping Ute Mountain, west of the modern town of Cortez, Colorado.  There are other examples known from New Mexico and Arizona, but like the Chaco examples they mostly come from poorly documented early excavations and can’t be placed very well temporally.

According to one count, there are 32 sites in the Southwest that have yielded bones that may indicate cannibalism.  Of these, 18 are in the greater Mesa Verde region in southwestern Colorado and southeastern Utah and can be dated with some certainty.  Fully half of these sites, 9 out of 18, date to between AD 1125 and 1175.  This striking spatial and temporal patterning has led some to suggest that these may reflect a single event of some sort that occurred in the context of the multidecadal drought of that period and the social disruption caused by the decline of the Chaco system at the same time.  This idea was proposed in a talk I attended at the 2009 Pecos ConferenceSeveral names were on the talk, including Turner’s (although he didn’t seem to actually be there), but much of the actual talking was done by David Breternitz, an archaeologist with long experience with the region.  In addition to proposing that these assemblages indicating cannibalism or at least “folks treated inconsiderately” represented a single event that may have taken place over the course of mere weeks, days, or even hours, Breternitz noted the problematic connotations of using the word “cannibalism,” which has made the study of these sites a lightning rod for controversy as well as an irresistible temptation for sensationalistic treatments in the popular press.  He referred to it as the “C word” and analogized it to the “N word,” which is not appropriate to use in talking to the NAACP (or, I would add, most other audiences).

Sign at Border of Ute Mountain Indian Reservation

Both the puzzling and the controversial aspects of the cannibalism issue are present in the case of one of the best-documented of these assemblages in the Cortez area.  This is that found at site 5MT10010 near Cowboy Wash on the southern piedmont of Ute Mountain, which was excavated as part of a salvage operation in connection with an irrigation project of the Ute Mountain Ute tribe, on whose reservation the site is located.  This site, which was described in an article in American Antiquity in 2000, was located in an area that was slated to be completely covered by a new irrigated field and was therefore completely excavated.  It consisted of three pitstructures, like kivas but of clearly residential function, with associated surface masonry rooms, which do not seem to have been used residentially, outdoor activity areas, and trash middens.  Two of these pitstructures contained assemblages of human bones that were heavily damaged and broken into hundreds of small pieces, some of which showed burning, cut marks, and other evidence of cannibalism similar to that found at other sites.  These apparently represented the remains of seven individuals: two adult males, one adult female, one adult of uncertain sex but probably male, and three youths of uncertain gender aged approximately 14, 11, and 7.  Their bones were strewn all over the two pitstructures and showed no grave goods or evidence of formal burial, in striking contrast to five individuals who had been formally buried in the trash mounds (which is a typical burial location for this area and period).

From the way the bones were broken and burned the authors concluded that all of the individuals in the pitstructures had been killed in a sudden attack at the same time, after which they were cooked and eaten and the site was totally abandoned and not reoccupied.  In addition to the cut marks and burning on the bones themselves, two stone tools found in one of the pitstructures tested positive for human blood, implying that they had been used to chop up the bodies.  Evidence for the sudden nature of the attack and the resulting abandonment consisted largely of the large number of artifacts left in place in all three pitstructures; normally when a site would be abandoned the people would take most of the usable artifacts with them, but in this case they were left in place.

As if all this wasn’t enough, the third pitstructure, which didn’t contain any bones except two which were heavily weathered and appeared to have been deposited naturally from the surface at some point after abandonment, did contain something even more interesting: a coprolite, unburned, in the hearth.  Analysis revealed that the coprolite was human, apparently resulted from a meal consisting entirely of meat, and tested positive for the presence of a human muscle protein.  This is about as close to smoking gun as it is possible to get in trying to establish if cannibalism took place in a given instance.  Cut marks on bones can be and have been explained in various other ways, which are not generally very convincing but hard to disprove.  This coprolite, however, seems to establish clearly that at least in this one instance, cannibalism did take place.

Sleeping Ute Mountain from Hovenweep National Monument

The authors, having established to their satisfaction that this assemblage does in fact represent an episode of cannibalism, went on to situate it in the context of both the local community and the larger region.  The regional analysis basically pointed out the rash of likely cannibalism episodes around AD 1150, which may have been associated with the drought of that period, although it also noted the earlier episodes and the likelihood that this behavior constituted a longstanding pattern that for some reason became briefly intense and then subsided.  They note that there is no evidence for cannibalism in the Mesa Verde area after AD 1200 (though this may not actually be true; more on that later) and very little evidence anywhere else in the Southwest after that date either.  Whatever this event represents, it was clearly pretty temporary.

The community analysis was particularly interesting.  This community on Cowboy Wash, which was established around AD 1125 and consisted of 10 sites, four of which have been excavated.  Strikingly, all four of the excavated sites showed the same sort of evidence of cannibalism, strongly implying that they were all attacked and destroyed at the same time around AD 1150.  This is in contrast to the earlier community at Cowboy Wash, which existed from about AD 1075 to sometime in the 1120s and was abandoned before the new one was established, probably by new people.  Another striking characteristic of the newer Cowboy Wash community was the prevalence of ceramics made in the Chuska Mountain area to the south along the Arizona-New Mexico border.  Chuska pottery was common at Chaco during its prime and has been found in various other areas as well, but it is extremely rare in the Mesa Verde region and the prevalence of it at Cowboy Wash strongly suggests that the inhabitants were either immigrants from the Chuskas themselves (pretty plausible in the light of the disruptions likely associated with the fall of the Chaco system, with which the Chuska communities were strongly associated) or maintained strong trading ties to Chuska communities rather than other local communities.  Either way, the inhabitants of this community would likely have been easily identified as “outsiders” in the area, which may explain why they were targeted by others during this time of scarce resources, extended drought, and increased violence.  The Cowboy Wash community was not in a defensive location and does not appear to have had any defensive features such as walls.  Its fate may explain why such locations and features became so common not long afterward.

Chuska Mountains from Peñasco Blanco

Of course, with something like this there will always be objections, and a critique of the claim of cannibalism by two archaeologists who have been closely identified with the interests of the modern Pueblos, Kurt Dongoske and T. J. Ferguson, along with physical anthropologist Debra Martin, accompanied this article when it was first published.  The three of them basically criticized everything they could about the presentation of data and argumentation in the article on the Cowboy Wash site.  Some of the criticisms were reasonable, including a caution about being too quick to talk about cannibalism and to keep in mind the likely effect of this in the popular press and on modern Native Americans.  Others basically amounted to nitpicking about the presentation of data, often appearing to demand a level of information more appropriate for a full site report than a journal article.  In a response, the authors gave more information on the analysis and tried to counter accusations that the blood residue and coprolite analyses in particular may have been contaminated or otherwise problematic.  They also conceded some of the points raised in the critique, especially about the importance of thinking about the effect of this kind of research and the way it is presented in public discourse.  This response seemed pretty convincing to me.  I’ve heard that the coprolite evidence in particular has been challenged, but I’m not sure if any more substantial objections than the easily defused ones in the initial critique have been raised.

Another interesting thing about the critique and response, to me, is the way the critique basically accuses the authors of the initial article of being insufficiently “scientific” in not rigorously testing alternative hypotheses.  This is interesting largely because it clearly falls on the “anthropology is and should be a science” side of the “is anthropology a science?” debate, even though these particular anthropologists are coming from a perspective that is usually associated with the other side in their close association with the modern Pueblos and appreciation of their viewpoints.  In this context they seem to be mostly raising the science issue as a club with which to (rather ineffectively) attack the initial article, but the use of this approach is still noteworthy.  The response basically runs with this assumption and argues that, no, the analysis really was very scientific and they didn’t include all the data and hypotheses because of the space constraints of the journal article, but it’s all in the full report.  Both seem to think of “science” mostly as a methodology, particularly associated with hypothesis testing, rather than a body of knowledge, which is also interesting.

Another thing the critique mentions is the desirability of more comprehensive approaches to the issues of violence, migration, warfare, and so on.  The critique authors say this in the context of criticizing the initial report for focusing too narrowly on cannibalism specifically, which sits oddly with their criticisms of it for not being specific enough in describing the physical evidence, but this is one of their better points.  They specifically mention the possible role of ethnicity in structuring some of these dynamics, and cite the paper on ethnicity at Wupatki by Glenn Davis Stone and Christian Downum that I recently discussed.  I know of at least one recent paper that has done just that; I’ll have more on it later.

Sleeping Ute Mountain from Four Corners

So what does all of this imply for Chaco? Not much, really.  The authors of the initial Cowboy Wash paper note that to the extent that the Cortez-area spate of cannibalism episodes around AD 1150 has anything to do with Chaco, it is most likely in representing one aspect of the social chaos that may have followed the decline of the Chaco system after AD 1130 or so.  They also note that Cowboy Wash is about as far from a Chacoan outlier as it was possible to get in the region during this period.  The closest proposed outlier is Yucca House, on the other side of Sleeping Ute Mountain toward Cortez, the outlier status of which is rather questionable since it is unexcavated and also has a large later occupation that makes it difficult to identify any Chacoan parts.  And speaking of the location of Cowboy Wash, it is important to note that the southern piedmont of Sleeping Ute Mountain is remarkably desolate even by Southwestern standards and would have been very marginal for agriculture.  It doesn’t get enough rain for dry farming, so any farming the people at 5MT10100 would have done would have to have been floodwater farming using the wash itself, which would be very vulnerable to fluctuations in rainfall and other climatic conditions.  This probably explains why the area was colonized and abandoned several times during prehistory.  The time of the attack appears to have particularly bad for the inhabitants, as there was minimal evidence of domestic plants and most of the plant remains found at the site were of wild plants that would have been gathered in the spring to compensate for a poor harvest in the fall.

And what about the bones mentioned by Pepper at Chaco itself?  Hard to say.  Turner has reexamined some of them and concluded that they do in fact represent evidence of cannibalism, but then again he would conclude that.  The fact that we don’t really have any more detailed information about their contexts within the site than the minimal information given by Pepper makes it very difficult to place them within the context of Chacoan prehistory as we know it today.  Judging from the better information we now have from Colorado, I think one possibility is that the Chaco bones represent something similar that happened around the same time.  The canyon was not totally abandoned after it declined in regional importance around 1130, and it might have participated in some way in the cannibalistic warfare that apparently took place after that, though whether as victim or perpetrator is hard to say.  Whether or not this is the actual explanation, it is important to remember that the fact at a big, complex site like Pueblo Bonito not everything found somewhere in the is necessarily closely connected to the original purposes for which the site was built.  Things change, after all.  Furthermore, Pueblo Bonito has hundreds of rooms, almost all of which have been thoroughly excavated, and possible evidence of cannibalism has been found in two.  That’s a pretty thin reed on which to hang a theory postulating that Chaco was all about cannibalism.  Some cannibalism may well have taken place at Chaco, but there is really no reason to think that it was a major part, or indeed any part, of the reason Chaco was built or became so influential.  At least, that’s the way I see it.  Merry Christmas.
ResearchBlogging.org
Billman, B., Lambert, P., & Leonard, B. (2000). Cannibalism, Warfare, and Drought in the Mesa Verde Region during the Twelfth Century A.D. American Antiquity, 65 (1) DOI: 10.2307/2694812

Dongoske, K., Martin, D., & Ferguson, T. (2000). Critique of the Claim of Cannibalism at Cowboy Wash American Antiquity, 65 (1) DOI: 10.2307/2694813

Lambert, P., Leonard, B., Billman, B., Marlar, R., Newman, M., & Reinhard, K. (2000). Response to Critique of the Claim of Cannibalism at Cowboy Wash American Antiquity, 65 (2) DOI: 10.2307/2694066

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Looking East from the Pueblo Alto Trail

In my earlier post about Stephen Hall‘s recent paper reporting on maize pollen at Chaco Canyon dating as early as 2500 BC, I said briefly that this really shouldn’t be surprising to anyone who’s been following this kind of research closely, and also that I would discuss the context for it later.  Basically, the context is that there has been a considerable amount of evidence accumulating in the past twenty years or so firmly placing maize in the Southwest much earlier than most archaeologists had previously thought.  Much of this evidence has been gathered in a recent paper criticizing Jane Hill‘s arguments for the spread of maize having occurred as part of a migration of Uto-Aztecan speakers from Mesoamerica.  The earliest directly dated maize seems to be from the Los Pozos site in the Tucson Basin, with a date range of 2860 to 2470 BC (this represents the calibrated 95% confidence interval, as do all subsequent radiocarbon dates in this post unless noted otherwise).  According to the text of the paper, however, this date has been questioned, and the earliest uncontroversial direct date on maize comes from the aptly named Old Corn site near Zuni, with a range of 2460 to 2060 BC.  Note that the earliest date Hall found at Chaco (2567 to 2332 BC) has an upper bound slightly earlier than this, although the ranges overlap considerably.  Similarly early dates occur at some Tucson Basin sites and at Three Fir Shelter in northern Arizona, although the Three Fir Shelter date has a particularly large confidence interval.  The considerable geographic extent of these early maize dates implies that the initial introduction of maize to the Southwest may well have been quite a bit earlier than the earliest archaeological evidence for it.  It also suggests that at least in most areas, with some possible exceptions such as the Tucson Basin, maize was initially integrated into a hunter-gatherer lifestyle without causing major changes to either the subsistence system or the social structure of the groups adopting it.  This challenges many of the traditional assumptions about the effect of the introduction of agriculture on hunter-gatherer societies, including the idea that farming necessarily leads to an immediate shift to settled village life.  There is little to no evidence in most areas of any such shift for thousands of years after the earliest evidence for maize agriculture, suggesting that the impetus for such a transition (which did indeed happen in almost all parts of the Southwest eventually) must be sought elsewhere.

Una Vida from Petroglyph Area

Okay, so there’s plenty of evidence for agriculture as early as the pollen dates at Chaco in many parts of the Southwest, but Chaco ain’t Tucson.  The high, dry, harsh environment of the central San Juan Basin seems particularly unsuitable for agriculture compared to a lot of the other areas with early evidence for maize.  So surely this is a surprising finding at least for the local area, right?

Actually, no.  Evidence for the early use of maize in the general area of Chaco, though until now not within the canyon itself, has actually been out there for over twenty years, although it doesn’t seem to have gotten much attention in the subsequent literature.  It is described by Alan Simmons in an article from 1986, reporting on research done initially as a cultural resources management (CRM) project in connection with plans for coal mining in the area directly to the east of Chaco.  This project, known as ADAPT I, found many typical Archaic sites in the area, some of which were excavated as mitigation activities because of the expected impacts of mining.  (I believe this mining operation never actually happened, but I don’t know any of the details.)  These Archaic sites were typical for the San Juan Basin, which is to say that they were mostly lithic scatters with few diagnostic artifacts or datable materials, but a few of them ended up being very surprising in having more under the surface than was apparent at first, including possible hearths or ovens, some of which contained maize pollen associated with charcoal that was radiocarbon dated to the Archaic period and one of which even contained maize macrofossils that were directly dated to the late Archaic.  (The dates Simmons relates are apparently uncalibrated and are therefore not directly comparable to the calibrated date ranges given above, but they are comparable to the uncalibrated dates given by Hall for the pollen samples, including at the early end.)

Looking North from New Alto

This very unexpected result led to a new project, known as the Chaco Shelters Project, to try to get more data on the Archaic period in the Chaco area through intensive study of the type of site most likely to contain well-preserved material: rockshelters.  Two shelters were excavated, both outside of the park boundaries, one to the east (Sheep Camp Shelter) and one to the west (Ashislepah Shelter).  Neither provided much in the way of artifacts, which was something of a disappointment, but both showed evidence of Archaic use, and Sheep Camp Shelter contained macrobotanical remains of both maize and squash.  Neither contained maize (or squash) pollen.  Both maize and squash remains were directly dated to the late Archaic.  The squash results were more important, as the resulting dates were at the time the earliest evidence for the presence of squash in the Southwest.  Despite the presence of these direct dates, the earliest dates Simmons had were on charcoal associated with the maize pollen at the ADAPT I sites, and these could potentially be questioned given the known problems with this kind of indirect dating.  Now that Hall has come up with direct dates on the pollen itself which cover roughly the same timespan, however, Simmons’s indirect evidence looks more convincing than it may have at the time.

At the time Simmons was writing, there was much less direct evidence of Archaic agriculture in the Southwest than there is now, and the few reported early dates were problematic and disputed.  He therefore has a substantial and quite useful discussion of the general issue in addition to reporting his specific data.  He clearly comes down on the side advocating a gradual shift from hunting and gathering to agriculture, with maize being initially adopted by hunter-gatherers as part of a preexisting subsistence system and only becoming the primary means of subsistence considerably later.  This view was generally associated with arguments for in situ development of Anasazi culture out of the local Archaic tradition, and was opposed by those who preferred to see agriculture as being introduced later and all at once, perhaps as part of a migration of agriculturalists from the south (a position now maintained by Jane Hill, among some others).  With regard to the Chaco area specifically, Simmons accounts for the differences between the open ADAPT I sites (with maize pollen but little macrobotanical evidence) and Sheep Camp Shelter (maize and squash macrofossils but no pollen) by proposing that maize was initially integrated into a subsistence system involving seasonal mobility, with spring and summer being spent in the ADAPT I area, where the many sand dunes would have fostered the growth of wild plants, and winter being spent in the more protected rockshelters in the canyons to the west.  When maize and squash were added to the seasonal round, they would have been planted on or near the dunes in the spring, harvested in the fall, and taken back to the shelters to provide durable, storable food for the harsh and largely barren winter.  He admits that the shelter evidence, especially, is a bit weak, as it doesn’t really support the idea of extensive winter use of the shelters, but there were apparently many Archaic sites near the shelters that may provide more support for occupation of the general area during the winter.  He therefore concludes that the model he proposes is generally consistent with the data although more research is needed to confirm it.  He mentions Atlatl Cave, in the park and excavated by the Chaco Project, as one possible additional data point in favor of his model.

Pueblo Bonito from Peñasco Blanco

Hall’s new pollen data from within the canyon provides some support for Simmons’s model, especially in backing up the indirect dates with direct ones, but it also suggests some possible modifications to it.  It clearly seems to indicate that the canyon itself as well as the dunes to the east was used to grow corn during the Archaic.  This casts some doubt on Simmons’s proposal of seasonal mobility, at least in the way he frames it.  Growing corn in the canyon would imply occupation of it, perhaps in rockshelters such as Atlatl Cave, during the spring and summer in addition to (or instead of?) during the winter.  That is, Simmons’s seasonal mobility model could perhaps be “condensed” into a similar model of subsistence activities throughout the year, but with year-round residential occupation in the canyon.  People would presumably have still traveled around to gather resources in different areas at different times of year, but this would be “logistical” as opposed to “residential” mobility, with hunting and gathering parties setting out from a more permanent base camp solely to collect resources as opposed to moving the whole group to the location of the resources.  It is of course also possible that Simmons’s model should be modified in some other way, keeping the seasonal mobility but changing the role of the canyon in it, but it’s hard to see where else in the area would have been more suitable for winter occupation.

One of Simmons’s suggestions, that the advent of corn agriculture may have made the Chaco area an easier place to live by providing a fairly reliable food source in a place with limited and unreliable wild food resources, is particularly interesting.  The San Juan Basin is well-known for its considerable Archaic population, which has generally been interpreted as indicating seasonal mobility and specialized adaptations to the region’s sparse resources, but what if that population was actually supported in part by incipient maize (and squash) agriculture?  People often marvel at the apparent barrenness of the Chaco environment and the oddity of the idea that anyone would try to farm there, but this is another way to look at the harshness of the environment.  To put it differently, farming in Chaco is certainly difficult and risky, but can you imagine trying to live there without farming?
ResearchBlogging.org
Merrill, W., Hard, R., Mabry, J., Fritz, G., Adams, K., Roney, J., & MacWilliams, A. (2009). The diffusion of maize to the southwestern United States and its impact Proceedings of the National Academy of Sciences, 106 (50), 21019-21026 DOI: 10.1073/pnas.0906075106

Simmons, A. (1986). New Evidence for the Early Use of Cultigens in the American Southwest American Antiquity, 51 (1) DOI: 10.2307/280395

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Close View of Sunset Crater Volcano

Most research on human-environment interactions focuses on large-scale changes in environmental conditions over long periods of time (by human standards, at least).  There are good reasons for this, especially when applied to prehistory, most importantly that there are a lot of potential data sources for environmental conditions that can be correlated with cultural chronologies to identify possible relationships between the two.  A lot of research in the Southwest along these lines has sought to correlate periods of higher and lower average rainfall, readily apparent in tree-ring records, with population increases, decreases, and movements, as inferred from the number and types of archaeological sites in a given area, which conveniently can be dated with those very same tree-ring chronologies.  Jeff Dean at the University of Arizona’s Laboratory of Tree-Ring Research has been a major figure in this sort of research for a long time, and it’s resulted in a lot of interesting insights and theories about Southwestern prehistory.

"Squeeze-Up" at Sunset Crater National Monument

As we’re seeing right now in Iceland, however, there is another type of environmental event that can affect human societies: a short, intense, unexpected, and uncontrollable catastrophe like an earthquake or a volcanic eruption.  These are generally harder to see in the paleoclimatological record, and as a result they are hard to correlate with cultural changes.  Volcanoes themselves, however, are an exception to this invisibility, since they spew out all kinds of ash and lava that have very visible effects on the local geology.  In many cases these can be dated by radiocarbon or other methods and correlated with events in the societies of the people living in the area.  One very good example of this is found in Alaska among the northern Athapaskans.  Another is closer to home, as it were, from the perspective of this blog: Sunset Crater.

Sign Explaining "Squeeze-Up" at Sunset Crater National Monument

Sunset Crater is northeast of Flagstaff, Arizona.  It is the most recent of the San Francisco Peaks to erupt, and the only one to erupt during the time that humans have occupied the area.  It erupted sometime in the mid-to-late eleventh century AD; the date 1064 AD gets thrown around a lot, based on some tree-ring samples at Wupatki that showed odd ring patterns in the few years after that, but this dating has been questioned and the general consensus is only that the eruption occurred sometime around this time, based on the (often quite large) deposits of ash found in sites from this period.  Note that this is during the height of the Chacoan era.  The eruption may have been visible at Chaco itself, and it was certainly visible at some of the outlying Chacoan sites, so the Chacoans, along with everyone else in the region, would definitely have been aware of the events even though the immediate area shows little to no Chacoan influence.  It’s not clear how long the eruption lasted.  Eruptions of cinder cone volcanoes can potentially go on intermittently for decades, although they can also be much shorter.  Sunset Crater could have kept erupting for as long as 100 years or even 200, but more data are needed to determine this more precisely.

Sandstone and Igneous Masonry at Nalakihu, Wupatki National Monument

One theory about the effect of the eruption on human societies, first formulated by Harold Colton of the Museum of Northern Arizona in the 1930s, is that while the initial eruption was devastating to the small local population, the layer of ash that the eruption laid down turned out to be an excellent mulch, holding in much-needed moisture in this dry area and making agriculture much more productive, which spurred a massive influx of population to places like Wupatki that had been covered by ash and led to substantial cultural changes.  This theory has since been challenged, and there is no real consensus today on what effect the eruption had on cultural dynamics in the area.  It is highly unlikely, however, that it had no effect.  A volcanic eruption is a big disruption to existing patterns of living.

Lava at Valley of Fires Recreation Area, Carrizozo, New Mexico

One interesting and concrete manifestation of the effects the eruption may have had on local people comes from an interesting paper (which is my source for most of the general information about Sunset Crater above) on some building stones found at a nearby habitation site that show clear imprints of corncobs in them.  The authors conclude that this could pretty much only result from people deliberately going to places where lava was coming out, probably small features known as hornitos that would have been easily approachable, and putting in offerings of corn cobs to let the lava run over them, then after the lava cooled taking the rocks back to the site (which is a few miles away) and forming them into building blocks with distinct corncob impressions.  This would have been a lot of work, so it’s pretty apparent that it had a lot of cultural importance in some way.

Post Office, Carrizozo, New Mexico

Another interesting cultural connection to volcanoes is suggested in this article in the Alamogordo Daily News (via Southwestern Archaeology Today) about a salvage archaeology project south of Carrizozo, New Mexico, an area of considerable volcanic activity, that uncovered a large site that seems to probably date to around AD 900 to 1100, again during the Chacoan period.  This era is not very well-understood in this part of New Mexico, which was occupied by the Jornada Mogollon who may have later played an important role in the origins of the kachina cult.  One of the crew members, a woman from Santa Clara Pueblo, mentions that “where the lava comes out … represents the underworld.”  The article is kind of confusingly written, so it’s not clear exactly what she means by that, but it’s a really interesting clue to the importance of volcanoes to Pueblo people.  I don’t know much about the dating of the lava flows around Carrizozo, so I don’t know if the Jornada Mogollon would have been around to see the actual lava come out, but even if they didn’t they may have regarded certain vents and other features with reverence.  They certainly used the resulting igneous boulders as a medium for their extensive and innovative petroglyphs.

Carrizozo Trading Company Sign, Carrizozo, New Mexico

I’m increasingly coming to think that the importance of sudden, catastrophic events like volcanic eruptions has received too little attention among archaeologists.  Certainly long-term climatic changes are important, as are culture, political, and historical factors, but a catastrophe has a way of forcing changes very suddenly that may shed light on some of the more puzzling changes in the archaeological record.  Something to think about as we watch the effects of a volcano in Iceland on people throughout northern Europe and beyond.
ResearchBlogging.org
Elson, M., Ort, M., Hesse, S., & Duffield, W. (2002). Lava, Corn, and Ritual in the Northern Southwest American Antiquity, 67 (1) DOI: 10.2307/2694881

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