Where They Got the Obsidian

Mt. Taylor from Chaco

As I’ve discussed before, the patterns of use and importation of chipped stone at Chaco are somewhat puzzling. Unlike many other commodities, such as wood, corn, and pottery, which were imported from specific distant locations within the Chacoan sphere of influence in astonishing quantities during the height of Chaco’s regional power, chipped stone seems to have been largely a mundane, utilitarian concern. Throughout all periods of Chaco’s occupation most chipped stone was local. At Chaco’s peak of power and influence between AD 1020 and 1130 there was a slight uptick in imports of stone, particularly a distinctive pink chert from the Narbona Pass area to the west.

As I noted in the earlier post, however, obsidian follows a different pattern from the other imported stones. It is most common not at the height of Chaco’s regional power in the eleventh century but much earlier, in the Basketmaker III period between AD 500 and 750, when it is the most common nonlocal type of chipped stone. This was a time when Chaco may have seen an earlier period of regional importance, although figuring out what was going on at this time is very difficult for several reasons. By the Pueblo I period the amount of obsidian seems to drop precipitously, and it doesn’t start to recover until the very end of Chaco’s period of Pueblo occupation after AD 1120. This pattern puts obsidian decidedly out of phase with most other material culture imports to the canyon, which tend to correlate with the well-known evidence for social complexity and monumental architecture that we associate with the Chaco Phenomenon.

A recent paper by Andrew Duff, Jeremy Moss, Tom Windes, John Kantner, and Steven Shackley tries to put the obsidian evidence on a firmer footing by using geochemical sourcing to identify the source outcrops for a broad sample of obsidian found at Chaco and at various Chacoan outlier communities in the San Juan Basin. As they note, this is the latest chapter in a complicated story. Way back in the 1980s, the Chaco Project did an extensive sourcing study of obsidian found in its excavations in the canyon using X-ray fluorescence (XRF), a non-destructive sourcing technique that was then relatively new in archaeology. Their results, reported by Cathy Cameron in a number of publications, were surprising. They seemed to show that the closest source of obsidian, Mt. Taylor, provided very little of the obsidian found at Chaco (about 4%), while a distant source, Red Hill in Catron County, New Mexico, provided a very high proportion, especially in the assemblages from earlier sites. Also well-represented was obsidian from the Jemez Mountains, the second-closest source, with the proportion of Jemez obsidian increasing over time, a common pattern in the northern Southwest.

This seemed to indicate that there were substantial early ties between Chaco and the Red Hill area, far to the south but still just barely adjacent to some known Chacoan outliers. This result was mentioned in many publications on Chaco over the years, although many people didn’t really seem to know what to think of it. However, it soon began to be questioned. After this initial sourcing study had been done, Tom Windes submitted some samples of obsidian from Pueblo Alto and the Spadefoot Toad site for obsidian hydration dating, which involved a sourcing analysis as an intermediate step in the dating process. These analyses were inconclusive when it came to dating the artifacts (not uncommon in the Southwest, where obsidian hydration has a poor record as a dating technique), but the sourcing portion suggested strongly that the samples that had previously been sourced to Red Hill instead came from Mt. Taylor. Windes mentioned this anomaly in his site reports, as did Cameron in her subsequent publications on the subject, but a full published account didn’t appear until this new study.

The new study also used XRF to do the sourcing analysis, but both analytical techniques and source characterizations have improved considerably since the 1980s, so the results were quite different from the first effort. For some reason this study was unable to do a complete reanalysis of the earlier samples (although it implies that this may be possible in the future), so there was only limited overlap and the focus was mostly on recent samples collected by Windes at Basketmaker III and Pueblo I site in and around Chaco, as well as outlier sites studied by Kantner in the Red Mesa Valley near Mt. Taylor and by Duff at the southern edge of the Colorado Plateau near Red Hill.

The results were not really surprising, in that they have been known in broad outline since Windes submitted his samples for dating and reported on the sourcing anomalies, but it’s nice to see them formalized in a peer-reviewed paper. Basically, this study found that no samples from Chaco came from Red Hill, although a few came from other sources in the same general area, and that the most common source found at Chaco was Mt. Taylor. Over time there was a trend in the Chaco data showing a shift from Mt. Taylor to Jemez sources, accompanied by the well-known trend toward less obsidian in assemblages overall. The sample from the Blue J site near Mt. Taylor, in contrast, showed high proportions of Mt. Taylor obsidian increasing over time, in marked contrast to the Chaco pattern. The southern sites showed assemblages of obsidian almost entirely composed of Red Hill and other nearby sources.

Basically, the overall pattern was a classic distance-decay distribution, where the prevalence of a given source at a given site was mostly predictable by the distance between the source and the site. This is in sharp contrast to the pattern for many other imported goods at Chaco, which are present in high quantities in the source areas and at Chaco but not in between. This suggests strongly that obsidian was not part of any general Chacoan exchange system(s) but was procured by individual communities in accordance with their own needs, mostly using the closest sources. This is in keeping with the general tendency for chipped stone to be a relatively low-priority commodity in these societies.

The paper mentions the decline in overall abundance of obsidian after the Basketmaker III period at Chaco, but doesn’t spend much time discussing it beyond saying this:

The overall decrease in obsidian use noted at Chaco sites may reflect a shift in technological focus away from hunting and a subsequent focus on grinding technology as agriculture becomes the dominant subsistence strategy.

As I’ve noted before, this is almost certainly wrong; the decrease in question occurs at the end of the Basketmaker III period, at which time there is considerable evidence that Southwestern populations were already heavily dependent on agriculture. The decrease in obsidian is still odd, though. One thought I’ve had to explain it is that maybe the obsidian from after this period isn’t actually missing at all, but is at Pueblo Bonito, which had lots of obsidian but was excavated a long time ago using techniques that aren’t really comparable to the modern techniques used by the Chaco Project and later efforts that resulted in the collections being analyzed here. I would suggest that an XRF sourcing analysis of the Bonito obsidian would be interesting. As it is, there’s a huge shift in the proportions of the different sources at Chaco between Basketmaker III and Pueblo I. The earlier samples (dominated by the huge samples from the major villages of Shabik’eschee and 29SJ423) show a predominance of Mt. Taylor obsidian, while the later ones show mostly Jemez sources. The sample size is so much smaller for the later period, however, that I’m skeptical about taking this flip at face value. Including the Bonito assemblage might help to bridge this gap, or at least explain it.

Finally, it’s again noteworthy how unimportant obsidian appears to have been to the Chaco system. Even if the Pueblo Bonito evidence ends up indicating a more important role at Chaco itself, the various outlier communities appear to have used local sources and to have followed their own priorities in acquiring this commodity rather than getting it through any Chaco-controlled or -oriented system. This is one of the ways that Chaco appears to diverge from Mesoamerican societies, despite recent evidence that it may have had more contact with them than was previously believed. Obsidian was hugely important symbolically in Mexico, and control of major sources was a major source of power and wealth for various Mesoamerican polities. In the Southwest, however, nobody seems to have cared that much about controlling major obsidian sources, and obsidian seems to have been distributed as a fairly ordinary commodity without any particular symbolic importance. I think this is one of the strongest pieces of evidence suggesting that whatever influence Mesoamerican societies may have had on Chaco was indirect and mediated by Chacoan elites rather than imposed directly from Mexico, as some have argued.

In any case, while this isn’t really the most exciting paper, it’s still an important one in straightening out a part of Chacoan archaeology that had become pretty confused. Obsidian may not have been all that important at Chaco, but it’s still worth studying in part precisely because of its mundanity.

Duff, Andrew I., Moss, Jeremy M., Windes, Thomas C., Kantner, John, & Shackley, M. Steven (2012). Patterning in procurement of obsidian in Chaco Canyon and in Chaco-era communities in New Mexico as revealed by X-ray fluorescence Journal of Archaeological Science, 39 (9), 2995-3007 DOI: 10.1016/j.jas.2012.04.032

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The Figurines of Cahokia

Welcome Plaque, Spiro Mounds

Among the rarest and most fascinating artifacts associated with Mississippian sites are figurines made of carved stone. These are most numerous in the Cahokia area, although they have also been found in various other parts of the Mississippian world, most notably at the Spiro site in Oklahoma. Regardless of where they are found, however, many of these figurines show striking similarities in raw material and iconography, and they have accordingly been the subject of considerable study.

Most of the known examples of these figurines were excavated a long time ago under conditions that are poorly documented. This is most notoriously the case at Spiro (on which more later), but it is also true of many of the Cahokia-area specimens. A reevaluation of all these early finds was spurred largely by the discovery of new examples through carefully controlled excavations as part of the FAI-270 highway salvage excavations in the 1970s by the University of Illinois. Probably the most famous of these new finds was the Birger Figurine, found at the BBB Motor site northeast of Cahokia in 1979. The context of this and other figurines discovered during this project indicated that they dated to the Stirling Phase (AD 1050 to 1150). During this period the BBB Motor site appears to have functioned as a rural ceremonial center devoted primarily to the processing of human remains for burial, so the presence of figurines there at this time may have some relevance for interpreting their function.

A few years after the discovery of the Birger Figurine Guy Prentice published an article analyzing its iconography in relation to the mythology of various Native groups of the Eastern Woodlands. The figurine depicts a woman using a hoe on the body of a snake that encircles her, the tail of which bifurcates into two vines bearing what appear to be gourds or squashes. As Prentice notes, this seems to pretty clearly symbolize agricultural fertility, and the woman may therefore represent some sort of “Earth-Mother” figure. Various Native groups in the East did in fact worship such a goddess, and the more specific attributes of these deities shed further light on the symbolism of the figurine. They typically had strong associations with serpents, hence the snake, as well as agriculture and fertility more generally. Additionally, and not at all obvious from the figurine itself, they tend to have associations with the moon and with death (with which snakes are also associated). There is typically a sort of “circle of life” motif tying together the Earth-Mother, fertility, agriculture, death, and rebirth. Prentice makes a convincing case that the Birger Figurine fits well into this motif.

One of the issues Prentice has to deal with in his article, however, is which groups are most relevant for interpreting these figurines. Recall that they are found both in the Cahokia area and at Spiro. It was long assumed that they were manufactured at or near Spiro, since they are made of a type of stone that resembles a bauxite known to occur in Arkansas. However, as Prentice points out, similar types of stone are found in various other areas, including the Ozark Highlands of southeast Missouri, near St. Louis (and therefore quite close to Cahokia). He deals with this issue by analyzing myths from throughout the Eastern Woodlands along with those of the Caddoan tribes of the Spiro area.

Plaque at Brown Mound Showing Figurine, Spiro Mounds

A research program led by Thomas Emerson of the Illinois State Archaeological Survey has sought to address this issue more directly, by chemically sourcing the figurines to determine where they were made. They began by analyzing figurines from the Cahokia area, including the Birger Figurine, and determined that they were in fact made of flint clay from the Ozarks and not from Arkansas bauxite. They followed this up by analyzing figurines from other areas to the south and southeast of Cahokia, including Spiro. This involved developing a new, non-destructive method for analyzing figurines, as these specimens were mostly museum pieces that were not available for any sort of destructive testing. The results of this study indicated that all of these examples also came from the Missouri Ozarks. Basically, all of the tested figurines appear to have come from the same source area (possibly even the same quarry), which was in the Cahokia area, and it is most plausible to think that most or all of them were also sculpted in or around Cahokia regardless of where they ended up.

There are several implications of this finding. For one, there is a striking difference in subject matter between the figurines found in the Cahokia area and those found in areas to the south, especially at Spiro. The former largely depict female figures and themes related to agriculture and fertility, while the latter more often depict male figures and themes related to warfare, violence, and the chunkey game. It was once thought that this might reflect a difference between Cahokian and Caddoan worldviews, but since all the figurines now seem to be Cahokian in origin it seems more likely that all of these themes were important in Cahokia but that only the more masculine, warlike figures ended up traveling to the southern centers, which may indicate something about the nature of Caddoan societies in the relevant period.

Another issue is just when that relevant period was. As noted above, the recent finds of figurines at the BBB Motor site and others in the Cahokia area indicate a time frame of AD 1050 to 1150 for most examples, and it is very unlikely that any were being made in the American Bottom after around 1200. This is around the time Cahokia starts to decline in influence, though it wasn’t totally abandoned until a while later, and it seems likely that some major changes made figurine-making a much less important activity than before. Outside of the Cahokia area, however, figurines don’t start to appear until even later, after around 1250, and mostly in burial contexts. This suggests to Emerson and his colleagues that it was only after the decline of Cahokian power that figurines began to be exported in significant numbers to the Caddoan and other southern centers, which were increasing in power and influence at that time.

Craig Mound, Spiro Mounds

When the Caddoans and other rising stars in the Southeast began to acquire Cahokian figurines, it appears that they strongly preferred the masculine warrior styles rather than the feminine Earth-Mother ones, although it is also quite possible that the Cahokians themselves refused to part with the latter, which tended to be ritually broken and buried at religious sites like BBB Motor. In any case, it was mostly the warrior figures that ended up moving south, and once they arrived (probably), many were drilled to be used as pipes rather than as static figures. The Cahokians seem to have made some figurine pipes, with the pipe mouthpiece and bowl incorporated into the design, but these Caddoan examples were clearly made secondarily out of non-pipe figurines, since the drill-holes interfere with the original design. This change is significant; as Emerson and colleagues put it in their 2003 paper:

This was a critical transition (i.e., from figurine to pipe) from an object of elite or religious sacra that was “observed” and to which obeisance was due to an instrument with which an individual “interacted.” There is a vast difference between bowing to an ancestral being and smoking one. For this transition to have occurred it seems reasonable to assume that either fundamental changes occurred in local religious or social practices or that the figurine had moved into a different cultural context where its original meaning was not comprehended or was irrelevant. We have no evidence for this type of transformation of a figurine into a pipe in the American Bottom. Conversely, at present, we have no large undrilled figurines in areas outside of Cahokia. The production of large flint clay icons or idols was a uniquely Cahokian phenomenon. The conversion of such figurines to pipes seems to have been a uniquely Caddoan practice.

The discovery that these figurines were apparently all manufactured in the Cahokia area in the eleventh and twelfth centuries is a very important piece of evidence for untangling the importance of Cahokia for the development of Mississippian iconography and other cultural features. Interpreting that evidence is of course difficult, but this research shows the importance of archaeometric techniques for providing a baseline from which rich cultural interpretations can proceed.

Emerson, T., & Hughes, R. (2000). Figurines, Flint Clay Sourcing, the Ozark Highlands, and Cahokian Acquisition American Antiquity, 65 (1) DOI: 10.2307/2694809

Emerson, T., Hughes, R., Hynes, M., & Wisseman, S. (2003). The Sourcing and Interpretation of Cahokia-Style Figurines in the Trans-Mississippi South and Southeast American Antiquity, 68 (2) DOI: 10.2307/3557081

Prentice, G. (1986). An Analysis of the Symbolism Expressed by the Birger Figurine American Antiquity, 51 (2) DOI: 10.2307/279939

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Where Did the Cahokians Come From?

Monks Mound Sign at Cahokia Mounds

Regardless of exactly how many people lived at Cahokia, it’s clear from recent research that the population of the site and its immediately surrounding area grew immensely in a short period of time in the eleventh century AD. As Timothy Pauketat points out in the 2003 article that I was discussing earlier, the scale of this growth is much too great to be due to natural increase of a local population. Thus, even though there was a local population of some size in the American Bottom in the immediately preceding period that presumably contributed to the growth of the Cahokia site, it’s pretty clear that there must have been quite a bit of immigration in addition to account for the huge influx of people.

Who were these people, and where did they come from? It can be fiendishly difficult to untangle migrations in the archaeological record, even in conditions like this where it seems clear that there must have been some migrating going on. Archaeology depends mainly on the remains of material culture, which can change quite rapidly under conditions of change and stress such as those that often obtain during and immediately after migrations. Nevertheless, there do seem to be some clues to where at least some of the immigrants into the American Bottom may have originated. These clues mostly revolve around the type of material culture on which archaeologists most often rely to understand prehistoric societies: pottery.

Pots can’t automatically be equated with people, of course, but certain types of pottery are sufficiently distinctive and limited in distribution that they may serve as markers for population movements. In the case of Cahokia, Pauketat and others have pointed out that one of the many pottery types found in deposits dating to the period of population growth bears a striking resemblance to a type known as “Varney Red Filmed” found in northeast Arkansas and southeast Missouri around the same time. Importantly, these pots are often tempered with ground shell. Shell-tempering would later become one of the defining traits of Mississippian societies throughout the South and Midwest, but it appears particularly early in the area where Varney Red Filmed was made, starting around AD 800. According to another study reporting on evidence of Varney-like ceramics found at sites in Wisconsin, examples of Varney wares have been found in the American Bottom starting shortly before AD 1000. While these early finds are considered trade wares, by the time Cahokia emerges about 50 years later similar ceramics are apparently being made there, as shown by analysis of the clays in them, and some shell-tempered sherds that seem to be made from American Bottom clays were identified at the aforementioned Wisconsin sites, attributed to a short-lived influx of immigrants from the American Bottom, perhaps those who lost out in the struggles that led to the rise of Cahokia.

Cahokia Interpretive Center from Monks Mound

Returning to Pauketat’s 2003 article, he finds that not only are locally produced but clearly Varney-influenced pots being made at Cahokia itself in the mid-eleventh century, some of the sites in the rural Richland Complex to the east, which was settled rapidly around the same time, show the same high proportions of Varney sherds as some areas of Cahokia itself, implying that at least some of the people who established the Richland Complex came from the American Bottom. The relationship between these people and those at Cahokia remains difficult to entangle.

One of the hallmarks of the American Bottom in the period immediately preceding the rise of Cahokia is remarkable diversity in ceramic style. Varney is only one of the many local and “foreign” ceramic styles present in sites during this period, and it seems clear that people were coming to the area from all over. Nevertheless, the important similarities between Varney ceramics and those that soon begin to spread along with other attributes of Mississippian culture implies that northeast Arkansas and southeast Missouri may have played an important role in developing the complex of ideas that we today call “Mississippian” and that an increasing body of research suggests initially spread through the influence of Cahokia. Studying the archaeology of these areas during the period before and during the rise of Cahokia is therefore potentially important.

Ceramic sourcing using Instrumental Neutron Activation Analysis has been one line of evidence applied to sites in southeast Missouri during this period, not least because the University of Missouri happens to have a research reactor that has been widely used for sourcing of ceramics and other archaeological artifacts. One paper from this effort, published in 2000, showed that this technique can indeed distinguish among sherds made from clays from three major physiographic regions of southeastern Missouri: the Ozark Highlands and the Western and Eastern Lowlands in the Mississippi Valley. The results showed in addition that there was extensive movement of vessels, including shell-tempered Varney wares, between the Western Lowlands and the Ozark Highlands. It can’t be determined from this data if this reflects trade or migration, but it certainly shows interaction between the two. There is also some limited evidence, in the form of possibly transitional sherds tempered with a mix of shell and sand or limestone, that the shell-tempering technique may have developed here rather than being imported from elsewhere. Given the importance of shell tempering later on, the idea that it may have been an indigenous development among Varney potters may have important implications for lines of cultural influence.

This is all very suggestive of the idea that some of the people who immigrated to the American Bottom around AD 1050 came from the Varney area and brought with them some ideas that they had developed there or perhaps borrowed from other groups. People were certainly coming from other directions too, and their ideas may have been just as influential even if they were less visible archaeologically. In addition, there was a longstanding local population in the American Bottom that surely played a role as well. All of these people likely contributed to the unique flowering of the greatest cultural and political center north of Mexico that began soon afterward. Untangling exactly what contributions each group made, and figuring out in more detail who they were, are bigger challenges than simply tracing where they may have come from and what their pots looked like, of course.

Lynott, M., Neff, H., Price, J., Cogswell, J., & Glascock, M. (2000). Inferences about Prehistoric Ceramics and People in Southeast Missouri: Results of Ceramic Compositional Analysis American Antiquity, 65 (1) DOI: 10.2307/2694810

Pauketat, T. (2003). Resettled Farmers and the Making of a Mississippian Polity American Antiquity, 68 (1) DOI: 10.2307/3557032

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The Alaska Highway and Its Past

How Far West? Plaza, Beaver Creek, Yukon Territory

On this date in 1942, US Army engineering crews working east from Delta Junction, Alaska and west from Whitehorse, Yukon met up near Beaver Creek, Yukon, completing the Alaska Highway.  For the first time, Alaska was accessible from the Lower 48 by road.  This was a remarkable achievement, especially since it was done in only a few months; construction had begun in March and accelerated in June when the Japanese invaded the Aleutian Islands, making the need for a military route to Alaska seem more pressing.  Also noteworthy about the construction effort was that about a third of the soldiers who worked on the project were black, and their impressive accomplishments apparently played a role in the total integration of the military a few years later.

Two years after the highway was completed, while it was still under US Army control, Frederick Johnson of the Peabody Foundation (now the Peabody Museum of Archaeology at Phillips Andover) conducted an archaeological survey along the route as part of a multidisciplinary expedition that had begun the year before with biological and geological studies.  Johnson published a short article in 1946 describing the survey and illustrating some of the artifacts found.  The main importance of this (apparently largely forgotten) article was just to preliminarily describe the archaeology of a large region that, because it had been so difficult to get to before the construction of the highway, was almost completely unknown.  Johnson says as much in the article, while also noting the theoretical importance of gaining an understanding of this region because of its potential role in the peopling of the New World as a migration corridor.  He doesn’t press the latter point, however, and it’s pretty clear that the artifacts he describes are much too recent to have had anything to do with the initial migrations into North America (although there’s no way he could have known this at the time and he doesn’t say anything about it).

White River, Yukon Territory

The presence of geologists in the group was useful for Johnson’s purposes, as it meant that the stratigraphy of the sites he excavated could be evaluated with an expert eye.  Most or all of the artifacts from the sites he discusses in detail, and perhaps of all the sites he found, came from what appeared to be a single layer of reddish-brown soil under a layer of volcanic ash over five inches thick in some places but much thinner in others and apparently absent entirely in some.  This ash is presumably the so-called White River Ash from the eruption(s) of Mt. Churchill, which is in this general area; these eruptions may have been pretty important in the prehistory of this region and beyond.  The artifacts therefore predate the eruption(s), but not necessarily by very long.

The artifacts themselves, all of stone and almost all chipped rather than ground, consist of projectile points, scrapers, gravers, and a variety of miscellaneous forms.  Johnson notes that the assemblages from all the excavated sites are quite similar, which is noteworthy because the area covered was so large.  This implies they probably date to about the same period (as does the similar geology of the strata in which they were found) and may have been made by people from the same cultural tradition.  The sites themselves all appear to represent the same kind of occupation, which Johnson terms a “workshop” where stone tools were made or repaired.  Only one site had a firepit, and none had anything suggesting the presence of structures.  Beyond that there isn’t much Johnson can say, since the state of knowledge of subarctic prehistory was so rudimentary at the time and the area he was discussing had essentially no prior information at all.

Kluane Lake, Yukon Territory

As it happens, the part of the Alaska Highway I drove on my way up to Anchorage is near some of the sites Johnson mentions, many of which are in the Kluane Lake area of the southwest Yukon.  It was interesting to see placenames I recognized in this article.  I’ve been reading quite a bit about Alaska archaeology recently, and it’s really quite fascinating.  I’m not sure quite where Johnson’s findings fit into the overall picture, since his article seems to be virtually forgotten by now and recent work basically never cites it.  His pictures of artifacts are probably good enough to tell where they would fall in currently understood culture sequences, however, and I have an idea of where that might be but I’ll have to look into it a bit more before discussing it further.  I’m still not sure if this blog will be the best venue for discussing Alaska stuff, but it’s what I’ve got for now and I figured I should mark the occasion of the highway’s anniversary by talking a bit about its much deeper past.

Johnson, F. (1946). An Archaeological Survey along the Alaska Highway, 1944 American Antiquity, 11 (3) DOI: 10.2307/275560

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The Mysterious Mimbres

United Country Mimbres Realty, Silver City, New Mexico

Inspired by my recent visit to the Gila Cliff Dwellings, I’ve been reading about the Mimbres Mogollon culture of southwestern New Mexico.  As I noted earlier, the cliff dwellings themselves aren’t actually Mimbres, instead belonging to the Tularosa Mogollon culture more common to the north, and they postdate the “Classic” Mimbres period (ca. AD 1000 to 1150, exactly contemporary with the florescence of Chaco further north) by over a century.  They do, however, fall well within the area occupied by the Classic Mimbres, and there is in fact a Mimbres village, the TJ Ruin, within the monument boundaries.  The upper Gila River valley was a major area of Mimbres settlement during the Classic period, and it had some of the largest Classic villages, although it is not nearly as well understood as the Rio Mimbres valley which is often considered the Mimbres “heartland” and which gave the culture its name.  A review article by Michelle Hegmon from 2002 provides a good and relatively recent overview of the major issues in Mimbres archaeology.

The Mimbres are best known for their pottery, some of which features elaborately painted naturalistic designs unlike anything else known from the prehistoric Southwest.  This pottery was painted with black paint on a white slip, as was Anasazi pottery from Chaco and other areas at the time, and many of the abstract geometrical designs that form the bulk of the decorated pottery are reminiscent of Anasazi styles.  There’s no equivalent among the Anasazi to the naturalistic designs, however, which show elaborately detailed people, animals, possible mythical scenes, and much else.  No two designs are exactly alike.  Most of the figurative designs were on bowls which were placed with burials, usually with a “kill-hole” through the center of the vessel, which was then placed over the face of the buried individual.  Iconographic study of Mimbres pottery dates back nearly a century, starting with the work of Jesse Walter Fewkes of the Smithsonian in the 1910s, but in the past 20 years it has been supplemented by studies taking a more technological approach.  Particularly important has been a series of studies using instrumental neutron activation analysis (INAA) to determine the sources of the clay used in the pots and untangle patterns of production and exchange.  The results of these studies have generally been consistent with widely distributed production of pottery throughout the region, which is in contrast to other documented cases of community-level specialization in pottery production known from other parts of the Southwest at various times.  Design analysis has led some to suggest that the finest of the black-on-white bowls were made by a very small number of potters, however, which implies that perhaps a few specialists in villages scattered across the region made almost all of the well-known naturalistic vessels.

Tune Town Music Exchange, Silver City, New Mexico

Speaking of villages, one of the most interesting things about the Mimbres is that theirs were quite different from communities found throughout the rest of the Southwest during the Classic period.  While most areas, including the Chaco region, had communities of loosely clustered small house sites, the Mimbres were aggregated into large, dense villages made up of roomblocks very similar to those that would become increasingly common in Pueblo sites to the north starting in the thirteenth century and continuing into the historic period.  Indeed, some have argued that the Classic Mimbres invented the “Pueblo” as a type of community, and even that many of the social institutions of the modern Pueblos, such as the kachina cult, derive ultimately from Mimbres precursors.  There is definitely a clear continuum in artistic style from Mimbres pottery through Jornada Style rock art to the Rio Grande style of rock art and mural painting that appears among the northern Pueblos beginning around AD 1300.

After the decline of Chaco around AD 1130, the northern Southwest witnessed a pattern of ever-increasing aggregation eventually resulting in the modern Pueblos with their very Mimbres-like plans and institutions.  There have been various explanations offered for why this occurred, and I think those that attribute it largely to increased warfare are among the most persuasive.  There is definitely much more direct evidence for violence after about AD 1150 than before then.  Whatever was causing trouble in Pueblo societies at this time, it seems very likely that solutions drawn from the Mimbres experience became increasingly attractive further north.

But what was that experience?  Why did the Mimbres aggregate into large Pueblos at a time when everyone else lived in scattered small houses?  The Classic Mimbres period coincides with a time of remarkable peace throughout most of the Southwest, so defense seems less likely as an explanation here than it does later on.  Some of the Mimbres pots do show scenes of violence, including a well-known beheading, but it’s not at all clear that these show actual events rather than myths.  In general, there doesn’t seem to be any more evidence for warfare among the Classic Mimbres than anywhere else at the same time, which makes their much denser settlement pattern particularly mysterious.  It may have had something to do with irrigation agriculture, which the Mimbres had probably adopted somewhat earlier under the influence of the Hohokam in southern Arizona, who were by far the most accomplished irrigators of the prehistoric Southwest.  Among the Mimbres, as among other Mogollon groups, there was extensive Hohokam influence early on, which seems to have largely ceased by AD 1000, possibly replaced by increased influence from the Anasazi to the north (although this is controversial).  Steve Lekson, who has done a lot of work in the Mimbres area in addition to his work at Chaco, has argued that the Classic Mimbres consists of “an Anasazi lifestyle supported by Hohokam infrastructure,” and I think there may be something to that.  The labor demands of irrigation may have led to residential aggregation, although it’s important to note that the Hohokam themselves never aggregated to anything like the same degree despite their much more elaborate irrigation systems.

Welcome Sign, Truth or Consequences, New Mexico

What’s even more puzzling about the Mimbres, however, is what they did after the end of the Classic period.  The large villages and figurative pottery seem to come to a rather sudden end around 1150, about the same time that Chaco declined and the northern Southwest entered a long, difficult period of warfare, aggregation, and regional abandonment.  It used to be thought that the Mimbres just “collapsed” at this time, with their ultimate fate unknown, but more recent research, especially in the eastern Mimbres area along the Rio Grande near the modern town of Truth or Consequences, has shown that the real story is more complicated.  Margaret Nelson has been researching settlement patterns in the eastern Mimbres area, and she has found that one notable shift after the end of the Classic period involved the dissolution of the aggregated Classic villages and the dispersal of people into small hamlets, often built on the sites of Classic fieldhouses.  She also sees continued production of Mimbres pottery, although apparently without the distinctive naturalistic designs, for a long time after the end of the Classic.  Hegmon, who has collaborated with Nelson on much of this work, has proposed calling these occupations “Postclassic Mimbres.”  They show much more extensive trade of pottery with surrounding areas than during the Classic period, as well as more variable architecture, implying that whatever social controls had held the large Classic villages together had broken down and been replaced by a more flexible social system.

What’s remarkable about this is that it’s basically the opposite of what was happening everywhere else in the Southwest, where the dominant trend during this period was aggregation.  The Mimbres, at least in the east, were instead dispersing.  The picture is less clear in the Mimbres and Gila valleys further west, but at least some of the Classic villages seem to have continued to be occupied at lower population levels (similar to what was going on at Chaco), while a new type of occupation seen at some sites in the area, known as the Black Mountain Phase, may or may not represent a change in Mimbres culture.  There is debate over whether the Black Mountain Phase actually shows continuity with Classic Mimbres or not.  It’s also possible that some people headed south, to the rising center at Casas Grandes, in which case they would be participating in the trend toward aggregation.

It’s becoming increasingly clear, then, that the Mimbres didn’t really collapse or totally abandon their region in 1150.  Instead, they seem to have sort of splintered, with some scattering to hamlets on the sites of former field houses, others possibly reorganizing their communities into Black Mountain Phase sites, and still others migrating away from their region either south to Casas Grandes or east to the Jornada area, where the very Mimbres-like Jornada petroglyph style seems to appear around this time.  This process of dispersal when everyone else was aggregating, combined with their earlier aggregation when everyone else was sprawling across the landscape, gives a distinct “out of phase” feel to Mimbres cultural dynamics.

I certainly don’t have any solutions to propose to the mysteries of the Mimbres, and as far as I can tell no one else really does either.  They’re among the most fascinating of the many peoples who inhabited the prehistoric Southwest, and while they are by no means the most obscure, outside of specialist circles they are known almost exclusively for their pottery.  The pottery is amazing, of course, and quite deserving of attention, but there’s much more to the Mimbres than their pots.

Fewkes, J. (1916). Animal Figures on Prehistoric Pottery from Mimbres Valley, New Mexico American Anthropologist, 18 (4), 535-545 DOI: 10.1525/aa.1916.18.4.02a00080

Gilman, P., Canouts, V., & Bishop, R. (1994). The Production and Distribution of Classic Mimbres Black-on-White Pottery American Antiquity, 59 (4) DOI: 10.2307/282343

Hegmon, M. (2002). Recent Issues in the Archaeology of the Mimbres Region of the North American Southwest Journal of Archaeological Research, 10 (4), 307-357 DOI: 10.1023/A:1020525926010

Hegmon, M., Nelson, M., & Ruth, S. (1998). Abandonment and Reorganization in the Mimbres Region of the American Southwest American Anthropologist, 100 (1), 148-162 DOI: 10.1525/aa.1998.100.1.148

Nelson, M., & Hegmon, M. (2001). Abandonment Is Not as It Seems: An Approach to the Relationship between Site and Regional Abandonment American Antiquity, 66 (2) DOI: 10.2307/2694606

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Chipped Stone

Stone Tools at Chaco Visitor Center Museum

When it comes to stone tools, archaeologists make a basic distinction between “chipped-stone” and “ground-stone” tools.  Chipped-stone tools are generally those that need to be sharp, such as projectile points, knives, scrapers, and drills, and are typically made of hard stone that keeps an edge.  Some ground-stone tools, such as axes, are also sharp, but for the most part ground-stone tools rely on other qualities of stone for purposes like hammering and grinding.  In the Southwest, ground-stone tools are usually made of sandstone, basalt, or other types of stone that are plentiful in the area immediately around a site.  These tools are heavy, and it generally wouldn’t have made any sense to import special types of stone to make them when, as is the case throughout the Southwest, there were plenty of rocks around.  The types of stone used for ground-stone tools are also generally those used for masonry in areas where masonry construction was typical, including at Chaco, where sandstone was the usual material.

Chipped-stone tools are a different story.  They are usually small and highly portable, and the best materials to make them are often scattered and not convenient for every habitation site.  Thus, widespread trade in chipping stone has very early origins.  Hunter-gatherers need very good stone for their projectile points, and also tend to be very mobile, so their chipped-stone tools tend to be very well-made and to be made of high-quality material from a wide variety of sources.  Settled agriculturalists such as the Chacoans don’t rely so heavily on chipped-stone tools for their subsistence needs (ground-stone tools like metates are much more important), and they typically put much less effort into both procuring stone for chipped-stone tools and making the tools themselves.

Flake of Narbona Pass Chert at Pueblo Alto

When it comes to Chaco specifically, chipped-stone shows a much more muted form of the pattern of massive imports of other goods such as pottery, wood, turquoise, and even food.  Cathy Cameron summarizes the patterns revealed by the chipped-stone assemblages from Chaco Project excavations in the 1970s in an article from 2001.  The basic pattern is that most chipped stone was from local sources throughout the occupation of Chaco, although “local” really refers to a wider area here than the canyon itself.  Good chipping stone is not plentiful in the canyon itself, but abundant sources of good chert and petrified wood occur a few miles to the north and would have been easily accessible to canyon residents in the course of their daily lives (i.e., special trips to gather stone would probably not have been necessary).  These local sources always dominate assemblages from Chaco.  Imported stone types do increase during the Chaco era from AD 1030 to 1130, especially at great houses such as Pueblo Alto.  The most abundant import at this time is Narbona Pass chert, a distinctive pinkish type of stone that comes from a very restricted area in the Chuska Mountains to the west.  The Chuskas are also the source of many other imports to Chaco, including huge amounts of pottery and wood, but the relative proportions of Narbona Pass chert in the overall chipped-stone assemblages are much more modest.  It comprises 21.1% of the total Chaco Project sample for AD 1020 to 1120 and 18.9% of the sample for AD 1120 to 1220.  This is much higher than any other type of imported stone ever reaches, and even higher than any single type of local stone for these periods (though much lower than the total proportion of local stone).

Other imported materials found in notable numbers include Brushy Basin chert from the Four Corners area, a type of yellow-brown spotted chert and a special type of petrified wood, both from the Zuni area, and obsidian.  Brushy Basin chert (along with other materials from the same formation) and Zuni petrified wood reach relatively high proportions of the overall assemblage at the same time that Narbona Pass chert does, and Zuni chert does too but at a much lower level.  The pattern of obsidian is different, and hard to understand.  It’s the most common exotic type of stone before AD 920, rising to as high as 7.6% of the assemblage in the seventh century.  Sourcing studies seem to show that most of the obsidian coming it at this point came from the area around Grants, New Mexico, near Mount Taylor, during this period.  Once the Chaco system really gets going, though, the proportion of obsidian plummets to less than 1%.  From 1120 on, however, it rises again, comprising 7.3% from 1120 to 1220 and 2% after 1220, still less than Narbona Pass chert but respectable.  This obsidian seems to come mostly or entirely from sources in the Jemez Mountains to the east of Chaco.

Log of Petrified Wood at Chaco

So what were the Chacoans doing with this imported stone?  Not much, as it turns out.  One of the oddest things about the amount of Narbona Pass chert, particularly, is that it doesn’t appear to have been used for anything special.  Like all other types of stone, both local and imported, it was used primarily for expedient, informal tools.  The Chaco Project found 2,991 pieces of Narbona Pass chert, and only 18 of these were formal tools.  This pattern is typical for most material types, though obsidian seems to have been more often used for formal tools, many of which were probably imported as finished tools rather than made in the canyon.  Of the formal tools the Chaco Project did find, of all materials, about half were projectile points, and the rest were various types of knives, scrapers, and drills.

So what’s going on here?  Hard to say.  Cameron evaluates the chipped-stone data in the context of the models for the organization of production proposed by other participants in the conference from which this paper originated, and she decides that Colin Renfrew’s pilgrimage model fits best, with some adjustments.  This conclusion is driven largely by the fact that so much of the Narbona Pass chert came from the Pueblo Alto trash mound and the idea that this indicates that it was deposited there as part of communal rituals.  I find claims like this dubious, and I think it’s more likely that people in Chaco were just importing this type of stone either because it is so visually striking or because of their strong social connections to Chuskan communities (or both).

Chuska Mountains from Tsin Kletzin

The thing I find most puzzling is the obsidian.  Obsidian was hugely important in Mesoamerica, and in view of the appropriation and importation of many aspects of Mesoamerican culture by the Chacoans, most recently dramatized with evidence for chocolate consumption, it seems very odd that the rise of the Chacoan system would coincide with a steep decline in the amount of obsidian imported.  This is particularly odd since the Grants area was very much a part of the Chaco world, and there were numerous outlying great houses and communities near Mt. Taylor.  If the Chacoans had wanted obsidian, they could easily have gotten it.  And yet, it seems they didn’t.

Or did they?  Keep in mind that this data is based mostly on Chaco Project excavations, although Cameron does incorporate some insights from a study of formal chipped-stone tools done by Steve Lekson that incorporated other data as well.  Lekson’s study noted that Pueblo Bonito in particular had an astonishing number of projectile points relative to most other sites, and I can’t help but wonder if part of the lack of obsidian at other sites was a result of more of it flowing to Bonito.  The excavations at Bonito were done a long time ago without the careful techniques of the Chaco Project, so the data isn’t totally comparable, but I’m going to look at the artifact records from Bonito (conveniently made available at the Chaco Archive) to see how common obsidian was there.

Arrowheads at Chaco Visitor Center Museum

Speaking of projectile points, another thing Cameron mentions is that many of them seem to have been imported to Chaco, some of them apparently embedded in meat.  Others were particularly finely made and left in burials and caches, suggesting that they may have been specially made for votive purposes.  That’s probably the case for many of the points Lekson identified as being particularly numerous at Bonito, but what I want to know is why arrowheads were such common grave goods and offerings there.  Was there a particular association between Chaco and hunting?  The great house residents do seem to have eaten a lot more meat than other people in the canyon and elsewhere.

On the other hand, arrows weren’t only used for hunting.  Cameron notes that one projectile point found by Neil Judd at Pueblo Bonito was embedded in a human vertebra, and the Chaco Project also found a woman at the small site 29SJ1360 near Fajada Butte who had two points inside her.  We often talk about how peaceful Chaco was and how little evidence there is for warfare during the Chacoan era, but I’m starting to wonder about that.  It’s certainly true that Chaco itself and most other sites occupied during its florescence show less obvious evidence for violence than sites afterward do, but there are still some signs that things may not have been totally peaceful throughout the Southwest in Chacoan times.  Arrowheads in vertebrae don’t get there on their own, after all.  Who shot those arrows?

Cameron, C. (2001). Pink Chert, Projectile Points, and the Chacoan Regional System American Antiquity, 66 (1) DOI: 10.2307/2694319

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Where They Got the Pots

Whiteware Sherd at Una Vida

Pottery is the most important type of artifact for archaeology in the Southwest.  This is because the agricultural societies of the prehistoric Southwest made huge numbers of pots and often decorated them in distinctive ways that differed both from place to place and over time, often within quite short periods.  With the precision available from tree-ring dating, certain pottery types can be dated to remarkably short periods, in some cases consisting of less than 100 years, and those types in turn can be used to date unexcavated sites with no tree-ring dates of their own.  Differences in decoration over time are more obvious than differences among places for most periods, which is an interesting fact that probably deserves more attention than it has gotten.  Ceramic design styles changed at roughly the same times over amazingly large areas that in some cases don’t show any other evidence of substantial contact.  During the Chaco era, from about AD 1030 to 1130, the dominant design style throughout the northern Southwest used a lot of hachure, for example.  The specific types have different names, assigned to them by archaeologists working in different regions, and despite the general similarity in design these can be distinguished by distinctive aspects of their manufacture.  These include the type of clay used for the vessel (known as the “paste”), the presence and nature of an additional type of clay (the “slip”) put on top of the paste especially for painted types, the type of paint used, and the material used to temper the clay.  Tempering is the addition of some material to the paste to make it easier to work.  Almost all Southwestern pottery types are tempered, and the type of tempering material is one major way different regional wares are distinguished.

To make this more concrete, let’s look at the Cibola pottery tradition, to which Chaco’s pottery belongs.  There are two “wares” within this tradition: Cibola white ware and Cibola gray ware.  The gray ware is the “utility ware” used for cooking pots and other mundane vessels.  It is never painted, and when it has any type of decoration this typically consists of some sort of corrugation.  Types of corrugation vary over time.  During the height of the Chaco era, the dominant type was corrugation all over the vessel, whereas in earlier times only the neck would be corrugated.  Corrugated sherds are very common at Chacoan sites, because these vessels were made in large numbers, broke frequently from heavy use, and were mostly large jars that broke into many pieces.  Vessels forms are almost entirely jars rather than bowls.  Temper is typically either sand (in some cases probably from ground-up sandstone) or ground-up sherds.

Black-on-white Sherd at Pueblo Alto

Cibola white ware is more complicated.  This is the main “decorated” ware made at Chaco and in the area to the south of it.  These vessels have the same sand- or sherd-tempered gray paste as the gray wares, but the decorated surface also has a white slip that gives vessel a white appearance from the exterior.  The slips are thin and often applied in a sort of “washy” manner, and in some cases the gray paste can be seen beneath them.  Designs are painted on with mineral-based paint (usually made with iron oxide), at least until about AD 1100.  Forms are both jars and bowls.  Jars are decorated on the exterior, while bowls are usually decorated on the interior.

Similar gray and white wares are present for most other regions during the same period.  San Juan gray and white wares were made north of the San Juan River and are distinguished primarily by the use of crushed volcanic rock rather than sand or sherds as temper.  The white slips on the white ware are also thicker and often highly polished.  To the west, in the Kayenta area, white wares were generally painted with organic (carbon-based) paints, and over time this practice spread eastward, until after 1100 it was common in the Cibola and San Juan areas as well.

Chuska Mountains from Peñasco Blanco

A particularly important ceramic area for understanding the Chaco system is the Chuska Mountain area to the west, along the Arizona-New Mexico border.  In regional ceramic terms this area basically separates the Cibola and Kayenta traditions, and in some ways it was transitional between the two.  Chuskan potters adopted carbon paint earlier than those in the Cibola and San Juan areas, so imported white wares from the Chuskas to Chaco are typically carbon-painted although the designs on them are generally the same as local types.  The thing that really distinguishes Chuska pottery, though, is temper.  Chuskan ceramics are nearly universally tempered with trachyte, a rare and very obvious type of volcanic rock that outcrops only in a small area in the Chuskas.  Trachyte-tempered pottery is therefore virtually guaranteed to have been imported from the Chuskas.

Why is this?  Because potters are generally thought to have used local materials for temper (and for clay, but pinpointing clay sources is much more difficult).  Designs might be similar over a wide area, but if the temper in a vessel is a material only found in a very restricted area, it’s virtually certain that the vessel was made near there.  Unfortunately, most of the materials used for temper in the Southwest are very widespread; there’s sand everywhere, sherds would be present wherever anyone had broken pottery (so, again, everywhere), and the types of volcanic rock used in the San Juan region were quite widespread.  Luckily, however, trachyte-tempered Chuska pottery is an exception to this, which makes it very easy to identify imports from the Chuska area at Chaco and elsewhere.

Corrugated Grayware Sherd at Wijiji

There are other ways to determine the source areas for pottery.  X-ray fluorescence (XRF) and instrumental neutron activation analysis (INAA) are two widely-used methods of determining clay sources by the concentrations of trace elements in sherds, but they are very expensive and the results can be difficult to interpret.  Some studies using these techniques have been done in the Southwest, and a database of element concentrations for different source areas is beginning to develop.  At Chaco, however, analysis of pottery sources has so far depended primarily on the more traditional techniques of looking at paint, slip, and especially temper.  The biggest study was that done in connection with the Chaco Project, the results of which were presented in a 1997 publication by Wolky Toll and Peter McKenna (available on the Chaco Archive website).  Some of the data from this study was also used by Toll in his 2001 article that I have discussed before.

In brief, what Toll and McKenna found was that the Chacoans imported a lot of pottery.  The amounts of imports and their sources varied over time, however.  Imports were relatively rare before AD 800, making up 16.6% of the sample, but they came from a variety of sources, including the Chuskas, the San Juan region, and the Mogollon region to the south, which has very distinctive brownwares that are obvious imports when they appear.  Trachyte temper is only present in 3.6% of the total sample.  The period from 800 to 920 has a rather small sample from the Chaco Project excavations, but an increase in imported ceramics is apparent, with 28.1% imports and 9.7% trachyte-tempered.  The most common non-local temper, however, was chalcedonic sandstone, thought to come from the area to the south of Chaco, which comprised 13.2% of the ceramics from this period.  This is consistent with other evidence for intense contact with the area to the south at this time.

Pots from Early Periods at Chaco Museum

From 920 to 1040, overall imports drop slightly to 25.1%.  Chalcedonic sandstone drops to 7.9%, while trachyte rises to 12.3%, the highest percentage for any specific type of import.  This trend continues in the following period, from 1040 to 1100, which corresponds to the height of the Chaco system and the construction of most of the great houses in the canyon.  The overall percentage of imports rises to 39.8%, with almost all of that (30.7%) being trachyte-tempered.  It’s well-known that many other goods were being imported from the Chuskas at this time, especially wood, so it’s not surprising that Chuskan pottery would also have been popular.  There were a lot of Chacoan great houses and communities in the Chuska area, which seems to have been closely integrated into the overall Chacoan system, perhaps to a greater degree than other “outlying” areas.  The shift from south to west in the focus of the system seen in the pottery data is echoed in other types of evidence from this period.

The trend toward higher imports reaches a peak in the 1100 to 1200 period, which includes the end of Chaco’s regional dominance (but perhaps also its peak).  Imports constitute an astonishing 50.4% of all the ceramics from this period, and trachyte-tempered pots comprised 31.3%, a gain in overall percentage from the previous period but a loss relative to other imported types.  Chalcedonic sandstone continued to decline, while Kayenta wares increased to 4.8% after never having exceeded 1% before.  It’s important to note, however, that the sample from this period is much smaller than that for the previous period and it may not be totally representative.  The last period, from 1200 on, has a very small sample but continues to show a high percentage of overall imports (45.7%).  Trachyte drops to 21.6%, and San Juan wares skyrocket to 16.4% after never having exceeded 5% before.  This shift to the north for ceramic sources surely has to do with the relative decline of Chaco in this period and the rise of centers to the north, especially Aztec, which probably succeeded Chaco as the center of whatever Chaco had been the center of.  This is also the period during which Mesa Verde became a major population center, but despite the fact that the main decorated white ware type is known as “Mesa Verde Black-on-white” it’s unlikely that many of the San Juan wares found at Chaco came from Mesa Verde itself.  It’s much more likely that they came from Aztec or elsewhere in the Totah area, which had much closer ties to Chaco than Mesa Verde proper ever had.

Pots from Later Periods at Chaco Museum

So basically, the pattern that emerges from the ceramic data is of a shift in imports from the south to the west as the Chaco system really got going, followed by a shift to the north as it faltered or changed.  This is paralleled in other types of artifacts, as well as in settlement patterns.  The outlying communities to the south in the Red Mesa Valley were being abandoned in the late eleventh century even as new outliers like Salmon were being built to the north.  There are enough lines of evidence pointing in this direction to suggest that it corresponds to something real, but it’s hard to say what exactly was going on and why.

It’s also important to note the weaknesses in this analysis.  Remember, this is Chaco Project data.  It doesn’t include any of the pottery excavated from Pueblo Bonito, Chetro Ketl, Pueblo del Arroyo, or any other sites excavated prior to the 1970s.  It also has a heavy bias toward data from Pueblo Alto, which as I’ve mentioned before can be problematic in overall interpretations of Chaco.  However, at least the heavy importation of Chuska wares does seem to be supported by data from Pueblo Bonito.  Anna Shepard, the ceramic analyst who pioneered many of the techniques that are now standard in the Southwest, analyzed the sherds from Neil Judd’s excavations at Bonito in the 1920s and concluded that many of them were imported from the Chuskas based on the presence of trachyte temper.  Judd, who was heavily devoted to the currently prevailing notion that Pueblos were self-sufficient for utilitarian goods like pottery, was so skeptical of this finding that he actually wrote a rebuttal to Shepard’s analysis and published both in his report.  As it turns out, however, Shepard was right, and ahead of her time, in seeing substantial importation of pottery to Chaco.

Corrugated Grayware Sherds at Kin Ya'a

Of course, this leaves open the question of why the Chacoans would have imported so much pottery.  Was it due to a shortage of materials?  Surely there was no shortage of clay or sand; Chaco may be lacking in most resources, but it has virtually inexhaustible supplies of clay and sand.  Wolky Toll is inclined to think that a shortage of fuel for firing may have been a factor, and that the heavily forested Chuskas may have been a better place to find fuel and thus to make pots.  Certainly local wood resources in the sparsely wooded area around Chaco would have run out quite quickly what with all the monumental construction, but I don’t really buy this.  Wood isn’t the only type of fuel you can use to make fires.  There is plenty of evidence that the Chacoans burned corncobs and other material in their domestic hearths, and Toll and McKenna refer in their report to an apparent pottery production location in the Chuskas, dating to Basketmaker III times, that was not near wood sources but did have “complex hearths with substantial fuel waste build up (primarily corn stalks).”

So if not for lack of fuel, why all the imports?  One clue may come from the types of vessels imported.  The Chuska imports were primarily gray ware utility vessels, which were used for cooking.  It has been proposed that trachyte provides better resilience to thermal shock from repeated heating and cooling than other tempers, and Chuska vessels may thus have been higher-quality cooking pots than other local or imported vessels.  (Similar arguments have been made for the superiority of corrugated pots as compared to plainwares.)  This is certainly possible, but in light of the numerous other Chuskan imports it’s not really clear to me that functional considerations were primary determinants of Chacoan trade patterns.  Maybe the Chacoans just had particularly close social and political ties to Chuskan communities, and that led to closer economic ties.  A lot of this depends on the nature of the Chaco system, which of course we don’t know much about.

In any case, the large-scale importation of pottery is one of the most striking examples of how Chaco was very much at the center of a regional system.  We may not know what that system was, exactly, or how it functioned, but we can see that it existed.  The evidence is right there in all those potsherds that litter the ground around the sites in the canyon.

Toll, H. (2001). Making and Breaking Pots in the Chaco World American Antiquity, 66 (1) DOI: 10.2307/2694318

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Chocolate Everywhere!

Display Case at Chaco Museum Showing Cylinder Jar and Canteens

I mentioned earlier that there was a new paper out on chocolate at Chaco that I needed to read.  I read it today, and it’s quite interesting.  One of the most interesting things about it is that it’s by a different group of researchers than the first one and uses somewhat different methods.  As far as I can tell, all the study of chocolate residue in archaeological pottery until this paper has been done by Jeffrey Hurst at Hershey, in collaboration with a variety of archaeologists.  Except for the Chaco paper he did with Patricia Crown, all of Hurst’s work in this area has been on Mesoamerican pottery and in collaboration with Mesoamerican archaeologists.  This makes sense, since Mesoamerica is where chocolate is grown and was used most extensively in antiquity.  Hurst’s methods involve scraping residue from the interior of pots or grinding up potsherds to test them for the presence of theobromine, a chemical compound that serves as a biomarker for chocolate.  They aren’t hugely destructive methods, as analytical methods applied to artifacts go, but there is a certain amount of damage inherent in the scraping (and more in the grinding, of course).

This new paper pioneers a different method, which uses a wash of deionized water on whole vessel interiors (this could presumably be done with sherds too, but these authors used whole vessels) and subsequent analysis of the water with a very sensitive mass spectrometer.  The researchers are not affiliated with Hershey, but instead with Bristol-Myers Squibb, except for the lead author, Dorothy Washburn.  Washburn has for many years now been studying symmetry patterns on pottery and other artifacts and she has come up with a variety of interpretations of social structure and change from the patterns she sees.  The work she has done on Chaco has led her to posit that the “special” vessel forms associated with the Chaco Phenomenon, particularly cylinder jars but also pitchers and shallow bowls, show a very different type of symmetry from that prevailing on Pueblo pottery before and after Chaco.  In publications such as her chapter in the Salmon Ruins synthesis volume, she further contends that this sudden difference indicates an influx of people from elsewhere with a very different social structure, and she points to Mexico as the most likely source given the presence of both similar symmetries and similar vessel forms there.  This puts her in what I’ve called the “hard Mexicanist” camp, not a popular position among Chacoan scholars these days (although this chocolate stuff may start to change that).  I don’t really buy her arguments for physical migration of Mesoamericans to Chaco, and I think she generally goes a bit too far in inferring specific social structures from the abstract symmetries she studies, but her evidence for a big difference between Chacoan and other designs is solid and well-taken.

Cylinder Jar at Chaco Museum from Above

Given Washburn’s theories, it makes sense that she would jump at the chance to look for chocolate residue in Chacoan vessels.  The Crown and Hurst paper that started all this really came out of nowhere; no one in the Southwest was expecting it at all, and it’s likely to end up being one of the major turning points in interpretations of Chaco.  The paper itself, though, was short, and the research behind it was modest in scale.  Crown and Hurst only tested five sherds from the mounds in front of Pueblo Bonito, three of which seemed from their curvature to be from cylinder jars while one of the others was from a pitcher and the final one could have been from either a cylinder jar or a pitcher.  Testing revealed that the three definite cylinder jar sherds showed evidence of chocolate, while the other two didn’t.  This was remarkable, groundbreaking stuff, to be sure, but it was still only five sherds.  The really important thing about that paper was that it opened up the possibility of running tests like this on all sorts of sherds and vessels to determine the extent of chocolate use in the prehistoric Southwest, and it seems Washburn was inspired to take it a step further.

Room 28 at Pueblo Bonito

She and her coauthors, William Washburn, who I presume is her husband, and Petia Shipkova, both of whom work for Bristol-Myers Squibb’s Pharmaceutical Research Institute in Princeton, NJ, apparently developed this new technique for doing the theobromine testing and they applied it not to sherds but to whole vessels.  Not just any whole vessels, either; they went straight for the important ones: the cylinder jars from Room 28 at Pueblo Bonito, along with cylinder jars, pitchers, and shallow bowls from burial rooms elsewhere in Bonito (including Room 33).  They also tested three cylinder jars from Pueblo del Arroyo, at least two of which are of plain redware rather than the whiteware that characterizes all other known cylinder jars (there is some confusion over whether the other jar is red or white, in that the paper says all three are red but the National Museum of Natural History catalog seems to say that one is white).  In addition, they tested a variety of similar forms from the Hohokam site of Los Muertos.  This is interesting, because the Hohokam in southern Arizona showed a wide variety of Mesoamerican influences to a much greater degree than Chaco ever did, and one of the first things I wondered when I read the Crown and Hurst paper was whether a similar study of Hohokam vessels would also show chocolate use.  They picked Los Muertos specifically because it’s a Classic-period platform-mound complex with what appear to be elite burials.  The platform mounds of the Hohokam Classic are the only other phenomenon except for Chaco in the prehistoric Southwest that show clear evidence of social hierarchy, and the authors of this paper clearly chose this set of vessels to see if chocolate use corresponded to increased hierarchy.  In all they tested 57 vessels from Chaco great houses and 10 from Los Muertos, and as a control they also tested eight vessels from small sites at Chaco, on the Little Colorado River in Arizona, and in southwestern Colorado.

Pitchers at Chaco Museum

What they found was that most of the great-house and Hohokam vessels did indeed test positive for theobromine.  Specifically, 80% of the Los Muertos vessels tested positive, as did 65% of the Chaco cylinder jars, 41% of the Chaco pitchers, and 83% of the shallow bowls from Chaco.  The lower percentage for the pitchers may indicate that they were used for a variety of things, not just chocolate, which might in turn explain why Crown and Hurst’s pitcher sherd tested negative.  The very high number of positives for the shallow bowls is very interesting, and suggests that this class of vessels, largely overlooked because they resemble local forms more than the cylinder jars, may be more important than people have thought.  On the other hand, only 12 bowls were tested (versus 23 cylinder jars and 22 pitchers), so this could just be a fluke of sampling size.  These results seem to confirm the Crown and Hurst results and reinforce the idea that the presence of chocolate, a clear sign of ongoing trade and contact with Mesoamerica as well as acceptance of Mesoamerican ideas and practices, may correlate strongly with the evidence for social hierarchy at both Chaco and the Classic Hohokam platform mounds.

But wait, what about the small-house sites?  Here’s where things get really interesting, in an unexpected way.  All eight vessels from the small houses tested positive for theobromine.  This was totally unexpected, and the authors devote quite a bit of discussion to this result.  Apparently concerned that there might be a problem with the whole theobromine-testing enterprise, they went looking for native plants in the Southwest that might contain theobromine.  If there were any, of course, that would call all of these results into question.  They couldn’t find any, so it does seem (unless there’s something amiss with their experimental protocols) that the results for the small houses really do indicate that chocolate was not just confined to the great houses at Chaco and the platform mounds in Phoenix.  They suggest that commoners might have been paid in chocolate for their work for the great-house elites, a very interesting idea.  In Mesoamerica cacao beans were often used as currency, and if something similar was going on at Chaco that would be cause for some serious rethinking of how the Chacoan economy worked.

Bc 51

One issue that the authors don’t really address is that the small houses they picked are all within areas that could plausibly have been part of the Chaco system, so there isn’t really an independent check here on how widespread chocolate was in the region as a whole.  They preferentially selected vessels from early excavations because early excavators usually didn’t wash the vessels they found, which makes sense for this type of project but also means that provenience information for the small sites is not ideal.  Nevertheless, one of the small houses that produced these vessels was Bc 51 at Chaco, which is right across the canyon from Pueblo Bonito and would obviously have been closely incorporated into the Chaco system.  The others included a cluster of sites in the Montezuma Valley of southwestern Colorado, which is an area with several nearby Chacoan outliers, and a site on the Little Colorado River in eastern Arizona that is not located very precisely but could have been relatively close to the far western edge of the Chacoan system.  There are several major outliers along the Rio Puerco of the West, a major tributary of the Little Colorado, and some evidence for at least a small amount of Chacoan influence as far west as Winslow.

Further testing of vessels and sherds from a wide variety of sites and time periods should help to clarify this picture.  The great thing about this chocolate stuff is that it’s all about analyzing pottery, which is by far the most common type of artifact found at sites in the Southwest.  There are vast numbers of vessels in museums throughout the country that could easily be tested using these techniques, and even vaster numbers of sherds collected from sites throughout the region that could potentially produce an unbelievably huge and detailed database of information on the distribution of chocolate in the prehistoric Southwest.  There are a lot of questions still outstanding at this point, but there is also a huge opportunity to try to answer them.  Hopefully this question will keep a lot of archaeology grad students set for thesis and dissertation topics for years to come, and the rest of us will benefit from the information they find and the patterns they discover.

Washburn, D., Washburn, W., & Shipkova, P. (2011). The prehistoric drug trade: widespread consumption of cacao in Ancestral Pueblo and Hohokam communities in the American Southwest Journal of Archaeological Science, 38 (7), 1634-1640 DOI: 10.1016/j.jas.2011.02.029

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On the Purported Evidence for Feasting at Pueblo Alto

Trash Mound from Pueblo Alto

Many recent interpretations of Chaco Canyon see it as a site of pilgrimage, and this is often specifically seen as taking the form of regular region-wide ritual events involving communal feasting, construction work on the massive buildings in the canyon, trade involving various mundane and exotic items, and ritual breakage of pottery and deposition of it in the mounds accompanying most great houses.  This idea, which has been incorporated into a wide range of models of Chacoan society both hierarchical and egalitarian (although it is especially important to egalitarian models), is heavily dependent on data gathered in the excavation of Pueblo Alto by the Chaco Project in the 1970s.  In addition to excavating about 10% of the great house itself, Project personnel excavated a trench and several stratigraphic columns in the large trash mound to the southeast.  What they found was a series of well-defined layers.  Some of these, toward the bottom, seemed to consist mostly of construction debris, and others, toward the top, consisted mostly of windblown sand and redeposited artifacts, but the ones in between seemed to show a pattern of large, well-defined deposits.  This was interpreted as being quite different from the expected pattern from the regular deposition of domestic trash from a residential site, and the theory developed, particularly by Wolky Toll, explained it as the result of occasional massive depositional events in which large amounts of pottery and other artifacts were deposited all at once.  Toll estimated that the number of layers approximately matched the number of years during which Pueblo Alto was occupied, and that they therefore accumulated as the result of annual events in which numerous people came from throughout the region to attend events at Pueblo Alto (and presumably at other great houses too).  As part of these events, pilgrims would probably have brought offerings of items from their home areas, thus explaining the huge amount of imported goods at Chaco as well as the lack of apparent exports.  These items would have included mundane items like wood, corn, and pottery, as well as more exotic things like turquoise and Narbona Pass chert.  People may have also worked on constructing the great houses as part of some sort of ritual offering of labor, which would explain the massive scale of these buildings despite the small permanent population of the canyon itself.  While there is a certain amount of evidence for residential use at Pueblo Alto and other great houses, it indicates a pretty small population relative to the size of the buildings, and Toll’s model interprets this as a small “caretaker” population of what were primarily non-residential, public structures with large plazas that could serve as the sites of ritual feasting and other activities during these festivals.

Furthermore, the composition of the artifact assemblage found during the excavations of the Pueblo Alto mound seemed to offer an interesting possibility for another ritual activity.  Basically, there was a huge amount of pottery in it, especially gray utility ware, much of it imported from the Chuska Mountains to the west.  Based on the number of rim sherds in the excavated portion and an estimate of the size of the whole mound, Toll calculated that 150,000 vessels were used during the 60-year period (AD 1040 to 1100) during which Gallup Black-on-white was the predominant decorated type, a period that roughly corresponds to the height of the Chaco system.  This works out to 2500 vessels a year, or 125 for each of the 20 households estimated to have lived at Pueblo Alto at any one time.  This is a huge number compared to ethnographically documented rates of pottery usage and breakage or ratios seen at small sites, and to Toll it suggested that the pottery deposited in the mound was probably not broken in the course of everyday life at Pueblo Alto but was instead broken deliberately in rituals associated with the annual pilgrimage fairs.  Ritual breakage and deposition of pottery is a known Pueblo practice, but this would be on a scale not seen at any other known site.  Nevertheless, this is the model of the formation of the Pueblo Alto mound that has been widely accepted and incorporated into a wide variety of interpretations of the Chaco system that differ wildly in many respects but all have some sort of pilgrimage function for the canyon as part of its regional role.  It’s important to note that this is the only direct evidence for a pilgrimage function known from excavations at Chaco.

Niche at Pueblo Alto

I think it’s pretty plausible that pilgrimage and communal feasting took place at Chaco, but I’ve increasingly come to think that the evidence from the Pueblo Alto mound is extremely weak.  There are a few different reasons I don’t buy it, and a couple of the most important ones are well illustrated by two articles published in American Antiquity in 2001.

One of these, by Toll himself, is part of the same special issue on the organization of production at Chaco that included Colin Renfrew‘s model of Chaco as a “Location of High Devotional Expression” or pilgrimage center.  Toll likes this idea, obviously, and his article, in addition to summarizing the known data on the production and use of pottery at Chaco, attempts to take a closer look at the Alto data to evaluate Renfrew’s model.  This basically involves looking at each of the “event layers” (as distinguished from the construction and post-occupational layers) and calculating the proportions of local and non-local ceramics and lithics (as well as the different types of pottery forms and wares) in each.  These were then compared to the proportions in the mound as a whole, other Chaco Project excavations dating from the same period, and excavations dating earlier and later.  If Renfrew’s theory works, the event layers should show higher proportions of imported ceramics and lithics, as well as possibly higher proportions of ceramic types likely to have been used in feasting, compared to these other data sets.

Flake of Narbona Pass Chert with Ant at Pueblo Alto

Toll does his best to spin the results to be consistent with Renfrew’s model, but looking at the actual numbers in his tables, there’s just nothing there.  The event layers are virtually identical to the whole mound, which isn’t really surprising given that they comprise a large portion of it, and both are very similar to contemporary non-mound contexts in most ways.  Earlier and later contexts are different in interesting ways, but that’s neither here nor there in terms of evaluating Renfrew’s model.  Chuska ceramics are a case in point: they comprise 33.4% of the event layers, 30.8% of the whole mound, and 33.1% of the contemporary non-mound contexts.  That doesn’t look like a meaningful difference to me.  In the cases where the mound layers do differ from other contemporary contexts, they generally have fewer exotic materials.  For example ceramics from the Red Mesa Valley comprise 3.3% of the event layers, 3.8% of the whole mound, and 4.6% of the contemporary non-mound contexts.  The presence of Narbona Pass chert is something of an exception, with the proportions for the event layers, the whole mound, and other contemporary contexts being 26.1%, 26.4%, and 19.5% respectively, but stone from the Zuni Mountains has proportions of 2.2%, 2.4%, and 10.9% (!) respectively, which suggests that there’s just no pattern here in which the event layers or the mound as a whole contain higher proportions of imported material.  Basically, Chaco was awash in all sorts of imported stuff during this period, and it was not particularly concentrated in the mound more than anywhere else.  The mound has lots of imports because there were lots of imports all over the place, not because it was formed as the result of annual pilgrimage feasts.

The biggest difference between the mound and other contemporary contexts comes with the forms of pottery.  Generally, the forms of pottery found at sites in this area at this time are whiteware bowls, whiteware jars, grayware jars, and redware and brownware bowls.  Red and brown bowls were long-distance imports and are found in small numbers at most sites.  The other wares were local, at least in a general sense, and while there was surely some variation, the standard idea about functions is that gray jars were used for cooking food, white bowls were used for serving food, and white jars were used for storage.  Thus, for feasting contexts an unusually high number of white bowls, and possibly gray jars, would be expected.  Since red and brown bowls are likely to have had symbolic or ritual importance, given the distances from which they were imported, they may occur in higher frequencies in feasting or ritual contexts too.

Shell Bead at Pueblo Alto

The pattern in the Pueblo Alto mound, while distinct from other contemporary sites, didn’t really match these expectations.  The most obvious difference was a much lower proportion of white bowls: 27.0% for the event layers versus 32.7% for the whole mound and 33.4% for other contexts.  This was balanced by a higher proportion of gray jars, which Toll interprets as still giving evidence for feasting, but this is mighty weak evidence for pilgrimage and feasting, even though the high proportion of grayware that came from the Chuskas during this period means that the high proportion of gray jars in the mound contributed to a higher level of Chuskan imports.  Red and brown bowls were also much rarer in the mound (both in the event layers and in the whole thing) than in other sites.

So, despite Toll’s efforts to show the data from the Pueblo Alto mound supporting his and Renfrew’s pilgrimage theories, I don’t buy it.  That’s not to say that there was no pilgrimage or feasting at Pueblo Alto, of course, just that this evidence doesn’t show that there was any.  And, remember, this is the only evidence out there for feasting and pilgrimage at Chaco.

Plaza at Pueblo Alto

But what about those unusually large, distinct layers in the mound?  Don’t those indicate unusual depositional events consistent with annual feasting and the deliberate breaking of huge numbers of pots?

Well, no.  To understand why not, we turn to the second paper published in 2001 on this topic, written by Chip Wills.  Wills is a Chaco Project alum who worked on the Pueblo Alto mound excavations, so he knows what he’s talking about here, and what he says is that the layers in the mound aren’t at all necessarily evidence for annual feasts.  Basically, what he says is that there’s nothing special about the layers in the mound.  They’re not really bigger or richer in artifacts than deposits found elsewhere.  He has a lot of specific criticisms of Toll’s interpretations and methodology, but that’s the gist of it.  He says that the unusually well-defined nature of the layers could well be the result of natural processes on layers deposited in various ways, so that it doesn’t necessarily indicate occasional large deposits rather than steady trash accumulation.  Most importantly, he finds that there isn’t actually a clear distinction between the “construction” and “event” layers, and that it’s quite plausible that the whole mound, or at least the vast majority of it, resulted from the deposition of construction debris from the various stages of construction and remodeling at Pueblo Alto.  There would have been other “depositional streams” as well, including the dismantling of earlier architecture below the present site (which is known to have been present from the excavations).  Wills doesn’t deny that ritual may have played a role in the creation of the mound, since the construction of the great house itself may well have been a ritual act, but he does deny that there is any sign that the actual contents of the mound indicate that it resulted from occasional ritual deposits rather than a combination of construction debris and regular trash dumping.

Rim Sherd at Pueblo Alto

Okay, but what about all those smashed vessels?  Basically, Wills doesn’t find Toll’s calculations convincing.  He says that Toll calculated the number of vessels based on the number of rim sherds found, then extrapolated that number to the whole mound based on the excavated portion.  The assumptions here are that each pot is represented in the mound by a single rim sherd, and that sherd density throughout the mound is constant.  Neither of these is really reasonable, although the “one rim sherd per vessel” one is particularly problematic.  It was apparently based on the fact that few rim sherds from the same vessel were found, but what are the odds that only one rim sherd from each pot made it into the mound?  Extrapolating the number of vessels is tricky, of course, and obviously the raw sherd counts can’t be a reliable way to do it (since vessels varied in size), but this rim sherd idea is questionable at best.  The idea of uniform density is really just an example of a reasonable assumption given an unknowable reality, but it’s still not necessarily right.  Wills mentions another estimate of 30,000 vessels for the whole mound, which he also attributes to Toll, and this produces much more reasonable per year and per household numbers suggesting that the observed sherd density could easily reflect regular domestic trash.  He also notes that it was the number of households, based on architectural data, that was held constant when this seemed to conflict with the number of vessels deposited, but he doesn’t elaborate on the implications of this beyond noting the privileged place architecture tends to hold in population estimates at Chacoan sites.

I originally read both of these articles a couple years ago when I was first starting to work at Chaco, and at the time I found Toll’s more convincing.  Rereading them now, though, I find Wills more convincing, and his arguments have never really been squarely addressed by Toll or anyone else associated with the pilgrimage/feasting theory (although they are occasionally mentioned in passing).  Chaco may well have been a pilgrimage site and the location of communal feasts, but it’s important to note that the Pueblo Alto trash mound doesn’t provide evidence for this idea, and neither does anything else.

Toll, H. (2001). Making and Breaking Pots in the Chaco World American Antiquity, 66 (1) DOI: 10.2307/2694318

Wills, W. (2001). Ritual and Mound Formation during the Bonito Phase in Chaco Canyon American Antiquity, 66 (3) DOI: 10.2307/2694243

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Why Do We Know So Little about the Totah?

Totah Theater, Farmington, New Mexico

In comments to my post on Salmon Ruins, John Barton asks for more discussion of this area, which is surprisingly poorly understood given its obvious importance to Southwestern prehistory as a whole and the Chaco system in particular.  Wolky Toll has a chapter in the Salmon synthetic volume discussing the Totah region (named from the Navajo name for the Farmington area), and particularly the La Plata subregion, which is becoming somewhat better understood due to a major salvage archaeology project along New Mexico Highway 170, which parallels the La Plata River from the Colorado border south to its confluence with the San Juan just west of Farmington.  Toll has played a major role in this project, and his chapter has interesting things to say about the Totah in general and the La Plata valley in particular.  I don’t really buy all of his interpretations of Chaco; he’s one of the major proponents of a view of Chaco as a regional ceremonial center drawing pilgrims from throughout the San Juan Basin, including the Totah, but with a minimal population permanently resident in the canyon.  He’s particularly associated with the view that even the small-house residents at Chaco only lived there for part of the year, having other residences in other communities, especially along the Chuska Slope to the west.  I’m more inclined to see Chaco as some sort of hierarchical system with at least a relatively large permanent population, mostly in the small houses, though I’m not sure which version of this idea (and there are many out there) I find the most convincing.

Still, Toll knows a lot about the Totah.  He even introduced the term to archaeological use in an important chapter in a previous edited volume that he coauthored with Peter McKenna.  One of the important points he makes in the newer chapter is that while this region has historically been treated as part of either the Mesa Verde region to the north or the Chaco region to the south, it really has an independent identity and cultural trajectory that has been obscured by seeing it entirely in terms of migration or influence from north or south.  This is not to say that the Totah was isolated from developments to the north and south; far from it.  It’s really more accurate to see the whole San Juan basin as a single cultural region, with remarkable uniformity in many cultural expressions and changes over time.  The specific manifestations of those cultural processes were not necessarily identical, of course, but there’s more similarity than archaeologists are often inclined to say.

Mesa Verde Museum

Part of the problem here is just the way archaeology developed in the Southwest.  As Toll notes, the activities of the Wetherill family had a huge influence on which areas came to be considered most important to the interpretation of regional prehistory.  They were not the only influential figures, of course, but they definitely did a lot to put Mesa Verde and Chaco specifically on the radar of the archaeological profession as well as the general public.  In any case, the way things developed was that Mesa Verde and Chaco became well-studied, with major excavation projects in the late nineteenth and early twentieth centuries producing huge numbers of artifacts and a general understanding of the chronological sequence of pottery types and other artifacts.  Once tree-ring dating provided an absolute chronology for the whole region, the general outline became clear: Chaco flourished in the eleventh century then declined in the twelfth, while Mesa Verde hit its peak later, in the thirteenth century, shortly before the whole region was abandoned around 1300.

This was a bit of a shift from the more evolutionary approach to culture history encapsulated in the original Pecos Classification, developed at the first Pecos Conference in 1927 and described by Alfred Vincent Kidder in a short article in Science at that time.  This system saw both Chaco and Mesa Verde, with their big, impressive masonry “pueblos,” as belonging to the Pueblo III or “Great Pueblo” period.  The tree-ring dates, however, showed that Chaco’s peak actually occurred earlier, coincident with the widespread small sites that marked the Pueblo II period.

Aztec West Great House, Aztec Ruins National Monument

Turning back to the Totah, the main excavation project there in the early twentieth century was conducted by Earl Morris at Aztec Ruins.  This was the largest site complex in the area, and it clearly indicated some level of social and cultural importance.  What Morris found there, however, instead of a unique and clearly indigenous material culture, was a mix of what seemed to be Chaco and Mesa Verde material culture.  The early deposits showed clear similarities to Chaco, as did the architecture of the site, which Morris interpreted as evidence for a close cultural connection to Chaco.  After this period, however, Morris saw evidence for an extended hiatus with little evidence of any sort of occupation or use.  After that there was another, quite different suite of material culture that looked much more like Mesa Verde.  Morris interpreted this sequence as an initial Chaco-affiliated occupation followed by abandonment and reoccupation by immigrants from the Mesa Verde region to the north.  In an important chapter in the Salmon synthesis volume, Gary Brown, Peter McKenna, and Tom Windes argue persuasively that Morris was actually wrong about this, and that while the construction and early occupation of Aztec does indeed show substantial connections to Chaco, there was probably not any abandonment or hiatus, just a period of somewhat reduced construction activity at a time of widespread drought and environmental hardship in the mid-twelfth century.  This lull was followed by extensive occupation and construction in the thirteenth century, especially at the east ruin (which Morris didn’t excavate).  The occupants at this time did have pottery similar to that used at Mesa Verde, but that doesn’t mean they were immigrants from there, and it’s much more likely that they were primarily local people who had been living at Aztec all along.  Everyone in the region at this point was making the type of pottery now known as “Mesa Verde Black-on-white,” and there’s no particular reason to think that any groups in the Totah had links to Mesa Verde, which itself seems to have been remarkably isolated during this period, with few trade goods found at the many excavated sites in the region despite its large population.  A similar story seems to obtain for Salmon, with an early Chaco-affiliated occupation followed by a period of continued occupation but little major activity, then an increase in population and activity before the final depopulation of the entire region.

So why did Morris get this wrong?  One reason, which Toll emphasizes, is that the mere fact that Chaco and Mesa Verde have been much more extensively studied than the Totah means that ceramic types (and other types of material culture, but pottery is the most important for cultural classification) have become associated with one or another of these areas, so that when they are found elsewhere in the region they are taken to indicate influence or migration from Chaco or Mesa Verde rather than a regionwide stylistic trend uniting all of these areas.  The latter is more likely, however, especially for the Totah, which was a major population and cultural center throughout the Pueblo II and III periods.  In her chapter in the Salmon synthesis volume, Lori Stephens Reed describes the discovery that the ceramic types found at Salmon and Aztec that have traditionally been classified as “Cibola” (Chaco) or “Northern San Juan” (Mesa Verde) types based on temper and design were mostly made within the Totah, judging from the type of clay used for the paste and slip of the vessels.  Rather than define new types, she just adds the qualifier “Animas Variety” to the existing type designations to indicate this local origin.  This makes sense from an Ockham’s Razor perspective, but as Toll notes in his chapter it’s really the type names themselves that have led to the downplaying of the local factor in the prehistory of the Totah.

Mesa Verde Escarpment from 2009 Pecos Conference at McPhee Campground

The best example of this is the very widespread thirteenth-century pottery type known as “Mesa Verde Black-on-white,” which is found all over the place but has tended to be interpreted as indicating some sort of influence or migration from Mesa Verde.  This is highly improbable, however, since Mesa Verde was gaining rather than losing people for most of this period (until the very end), and the people there don’t seem to have been very actively engaged in regional trade.  This strongly suggests that Mesa Verde Black-on-white is probably of local origin wherever it is found, despite the name.  Toll even muses more than once about how interpretations of Southwestern prehistory might be different if it were called “Aztec Black-on-white” instead.  It’s quite clear that Aztec was a very important site during this period, perhaps not as important as Chaco had been earlier but certainly more important than any single site in the Mesa Verde area.  And yet, because Mesa Verde has been more intensively studied, until quite recently it has been accorded an enormously important role in regional dynamics during this period that closer examination is revealing to be mostly undeserved.  Chaco has received a similarly privileged position for its period of florescence for similar reasons, but it seems to have actually been roughly as influential as this assumption implied.  (Something of an archaeological Gettier case.)

But why didn’t the Totah get the early attention that would have gained it the pride of place in Southwestern archaeology occupied by Chaco and Mesa Verde?  Ironically, a big part of the answer seems to be tied precisely to the geographic factors that made it such an important area in the first place.  One of the main reasons Mesa Verde and Chaco attracted early attention from archaeologists and pothunters was that their isolated locations left them unbelievably well-preserved.  The sites were very obvious on the landscape, many had stood relatively well due to either their massive construction (at Chaco) or their sheltered locations (at Mesa Verde), and they were sufficiently hard to get to that subsequent inhabitants and explorers hadn’t done them much harm.

Animas River, Farmington, New Mexico

The Totah, however, is an enormously attractive and productive agricultural area.  This is presumably what attracted people to Salmon, Aztec, and other communities in prehistory, and it definitely attracted huge numbers of Anglo settlers in the late nineteenth century who proceeded to plow over, loot, and otherwise damage the numerous archaeological sites they found before archaeologists had even heard of them.  The really big sites, like Salmon and Aztec themselves, managed to remain in relatively good condition until they could be professionally excavated, but innumerable smaller sites have likely been completely destroyed.

The local environment has also led to decreased visibility for these sites directly, by covering them with alluvial silt that makes them difficult or impossible to see from the surface.  As a result, we have little sense of how many sites are out there today, let alone how many were there initially before the farmers and the pothunters got to them.  Again, this is in contrast to the harsh environments of Chaco especially, and Mesa Verde to a lesser extent, where there are no permanent rivers to bury sites so deeply.  Furthermore, modern development in the Totah has been extensive, and there’s very little information about what lies underneath the rapidly growing modern towns of Farmington, Aztec, and Bloomfield.  For all of these reasons, the Totah remains surprisingly understudied, despite its obvious importance for understanding Southwestern prehistory.  Luckily this is starting to change a bit, at least on the conceptual level, with publications like Toll’s and Reed’s that point out the distinctiveness of this area and its independent identity.  The Totah has stood in the shadow of Chaco and Mesa Verde for a very long time, but it now seems to be finally coming into the light.

Chaco Street in Aztec, New Mexico

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