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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.
ResearchBlogging.org
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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USGS Sign, Anchorage, Alaska

One hundred years ago today, one of the biggest volcanic eruptions in recorded history took place in southwestern Alaska. The volcano, known as Novarupta, is located in what is now Katmai National Park, which was established in 1918 as a direct result of the eruption and its effects on the landscape. As a result, this anniversary is a big deal for the National Park Service in Alaska, which has a special issue of its journal Alaska Park Science devoted to the eruption as well as a special webpage of information on volcanoes in the region. The main institution involved in Alaska volcanology, however, is the Alaska Volcano Observatory, a joint program of the US Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the State of Alaska Division of Geological and Geophysical Surveys. They are spearheading much of the commemoration of Novarupta and have their own website listing events and other information on it.

The eruption of Novarupta began on June 6, 1912 and continued for three days. There are various contemporary reports of the eruption from people who were in the area at the time, including one by I. M. Dailey of the US Coast and Geodetic Survey, who was stationed 150 miles away in Seldovia at the time, which was soon published in the Bulletin of the American Geographical Society and is now available free through JSTOR. Other reports come from the larger town of Kodiak, even closer to the eruption, where a foot of ash fell in the course of sixty hours of darkness. A fuller picture of what had happened at the site of the eruption itself didn’t emerge until a series of expeditions over the next few years sponsored by the National Geographic Society traveled to the vent site and undertook a variety of studies that had an enormous impact on the emerging field of volcanology. In an article in the aforementioned special issue of Alaska Park Science Judy Fierstein, a USGS volcanologist who has done extensive research at Novarupta and other volcanoes at Katmai, summarizes both the early reports and studies and more recent work that has clarified the reconstruction of exactly what happened over those three days in 1912.

Many of the early National Geographic expeditions were led by the botanist Robert Griggs, who would be quite influential in shaping interpretations of Novarupta. He discovered and named Novarupta itself, although Fierstein notes that he actually concluded erroneously that the main vent for the eruption was not there but at Mt. Katmai six miles away, which collapsed dramatically into a huge caldera during the event. Subsequent research has revealed, however, that while most of the magma that erupted was indeed stored in a chamber under Mt. Katmai, it actually erupted through Novarupta. Understanding exactly how this complicated internal “plumbing” system of the two volcanoes worked is one of the continuing challenges in ongoing research on the eruption.

Griggs also discovered and named the famous “Valley of Ten Thousand Smokes” where flows of ash from the eruption filled a large valley downslope from Novarupta. At the time Griggs visited just a few years after the eruption, this valley was filled with steaming fumaroles where the still-hot ash met various water sources, and the astonishing sight prompted the poetic name. Within a few more years, however, most of the fumaroles had stopped steaming, and they’re pretty much all dead now. Still, the name remains, as does the strikingly barren landscape with little vegetation having recovered even a hundred years later. The area is so otherworldly that it was actually used as a training ground in the 1960s for astronauts preparing to go to the moon.

Remarkably, despite the scale of Novarupta, which ejected more than three cubic miles of magma in the form of a cloud of ash thousand miles wide and 100,000 feet high that wind currents eventually carried as far as Algeria, there were no deaths from the eruption. The inhabitants of the three Native villages near the volcano had fled after a series of earthquakes in the days leading up to the eruption indicated that a major catastrophe was likely, and the few other communities in this sparsely populated area were far enough away that the levels of ash fall they received were substantial but not deadly. Even Kodiak, which was the hardest hit community due to both proximity and wind direction, managed to get through the initial period of fear and panic during which the whole population took refuge on a Coast Guard cutter docked in the harbor, and it soon recovered its earlier prosperity. The residents of the three closest villages were unable to return to their homes, of course, and were resettled in other communities elsewhere on the Alaska Peninsula, where their descendants reside to this day. All this is in striking contrast to the death toll of over 36,000 people from the eruption of Krakatoa in 1883, which was of a similar magnitude but occurred in a much more densely populated area.

Indeed, the lack of major cultural or long-term environmental effects from Novarupta (outside of the immediate area, of course) initially led one prominent archaeologist, Don Dumond of the University of Oregon, to initially discount the role of volcanic eruptions in general as a force shaping the culture history of the Alaska Peninsula. Dumond conducted long-term excavations primarily in the Brooks River area of Katmai National Park from the 1950s to the 1980s, and his interpretations based on that work have been enormously influential in shaping interpretations of the region’s prehistory. Initially he saw no particular correlation between the numerous volcanic ash layers in his Brooks River sites, which he assumed came from eruptions of the numerous local volcanoes, and the cultural changes visible in the archaeological record. More detailed geophysical work on the ash itself, however, led one volcanologist to suggest that some of the larger ash layers at Brooks had come from various known eruptions at Aniakchak, a very large volcano about 150 miles further south on the Peninsula. If eruptions had deposited ash that far away, they must have been much larger than Novarupta, which would therefore not necessarily be a good guide to their ecological or cultural effects. Dumond therefore decided to look over the record of ash deposits and culture history in other parts of the peninsula to determine if these ash layers really were as widespread as they should be if they came from Aniakchak or another very large volcano.

He published his findings in a 2004 paper, and the results were intriguing but inconclusive. Many other sites on the Peninsula did have ash layers that could potentially be from the same eruptions as the major Brooks River ones, but difficulties in precisely dating these layers and relating them to the dating of the known eruptions at Aniakchak left the issue largely open. While this particular study was largely inconclusive, I find the general idea of trying to determine the relationships between volcanoes and human history very interesting (as longtime readers will recall), so hopefully more research along these lines in this exceptionally volcanically active area will shed more light on the question, which is potentially of great importance in explaining certain cultural and linguistic phenomena.

Regardless of whether volcanic eruptions were major factors in the prehistory of Alaska, it’s clear that they are a major risk factor for us today because of a new development since 1912: the rise of air travel. We need only recall the havoc wreaked by the eruption of Eyjafjallajökull in 2010 (a vastly smaller eruption than Novarupta) to realize how big an effect a major eruption can have on aircraft, and southwestern Alaska is one of the most heavily traveled air routes in the world for both passengers and freight. Indeed, one of the main reasons the Alaska Volcano Observatory was established was to monitor Alaska’s volcanoes for their risk to air traffic. One study using simulations based on the scale of the Novarupta event found that a similar event today could potentially shut down essentially all air traffic throughout the northern hemisphere (and, in the unlikely event that ash moved into the southern hemisphere as well, even the whole world). And note that this is by no means an extremely unlikely occurrence; eruptions of this scale happen regularly, and while there hasn’t been one since Novarupta, there’s every reason to think another one will happen at some point. The only thing to do is to keep watching the volcanoes and studying their past eruptions to try to glean insights for the future. This hundredth anniversary of one of the most important such eruptions is an excellent opportunity to remember that.
ResearchBlogging.org
Dailey, I. (1912). Report of the Eruption of Katmai Volcano Bulletin of the American Geographical Society, 44 (9) DOI: 10.2307/200811

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Earthquake Park, Anchorage, Alaska

On this date in 1964, which happened to be Good Friday, the largest earthquake in US history struck Southcentral Alaska. With its epicenter in Prince William Sound and its magnitude measured as 8.6 or even higher on the Richter Scale, the Good Friday earthquake caused massive destruction throughout the region. The nearby town of Valdez was completely destroyed and later rebuilt on a different, less seismically vulnerable site. Other towns such as Seward and Whittier didn’t suffer that fate, but 13 of the 70 residents of Whittier died in the quake and the following tsunami, and port facilities both there and in Seward suffered so much damage that they have never fully recovered their economic importance.

Anchorage, which was a bit further away, suffered somewhat less, although it was still hit hard. Indeed, its port managed to stay open in the aftermath of the quake and tsunami, which was one of the factors making Anchorage become the main economic center for the region and the whole state in the following years. This is not to say that the earthquake wasn’t a major disaster for Anchorage as well, however. The city was built on sediments that turned out to be pretty vulnerable to shifting when hit with an impact of that scale, and parts of the downtown were literally torn apart. An upscale residential area known as Turnagain Heights suffered a landslide so devastating that the city, rather than attempt to rebuild, designated it as a park. It is now aptly named Earthquake Park, and while there isn’t much obvious evidence of the effects of the earthquake anymore, there are interpretive signs that tell the story quite effectively.

Sign Describing Turnagain Heights Landslide, Earthquake Park

Earthquakes are a fact of life in Alaska, which just north of the area where the Pacific Plate slides under the North American Plate (known as the Aleutian Trench). This movement is continual, but it only occasionally occurs in the form of massive slips of the sort that cause earthquakes on the scale of the one in 1964. The more usual effect is to warp and compress the land of Southcentral Alaska. This warping, along with other factors such as glaciation, leads to complicated changes in sea level over time, changes which can vary substantially in areas only a few miles apart.

And that, in turn, greatly complicates study of the archaeological record of Alaska. Rising sea level typically destroys archaeological sites (although in certain very specific circumstances it may instead preserve them in excellent condition), and changes in sea level over time may make sites from a given time period difficult to locate even if they haven’t been submerged. Furthermore, cultures of coastal Alaska have generally been oriented toward the sea, with settlements typically located fairly close to wherever the coastline was at the time. This means that sea-level fluctuations have even more profound impacts on understanding the archaeological record here than they might in some other areas.

Interpretive Signs at Earthquake Park

These factors are illustrated dramatically in a 1996 article by Aron Crowell and Daniel Mann reporting on research in Kenai Fjords and Katmai National Parks attempting to carefully document sea-level changes and their effects on the archaeological record. These two parks are not very far from each other, being about 200 miles apart and both located on the coast of the Gulf of Alaska, but their geological and cultural histories differ dramatically. Kenai Fjords, as its name implies, is dominated by coastal fjords created when rising sea level inundated glacial valleys. Its archaeological record is sparse and limited to the past few centuries.

Katmai, on the other hand, has a relatively stable coastline and an enormously rich and well-documented archaeological record dating back several thousand years. Much of what is known about the archaeology of southwestern Alaska is based on long-term research in various parts of Katmai by Don Dumond of the University of Oregon from the 1950s through the 1980s, and there has been considerable additional research since then. The cultural sequence in this area closely parallels that of the nearby Kodiak Archipelago, which was one of the most densely populated parts of Alaska when the Russians arrived in the eighteenth century. The Kenai Fjords area, on the other hand, had a much lower density at this time, as did Prince William Sound further east, with which it has many similarities. This lower density has been plausibly attributed to lower resource productivity in these areas, but Crowell and Mann point out that the extremely low density of prehistoric archaeological sites in Kenai Fjords is perhaps also due to geological processes and seal level change.

Welcome Sign, Earthquake Park

To investigate the differences between the two parks, Crowell and Mann intensively investigated certain parts of each, with intriguing results. One of the areas investigated in Kenai Fjords was a narrow sand spit with a series of beach ridges containing a total of four archaeological sites (most dating to the eighteenth and nineteenth centuries and the earliest about 500 years old) and a small tidal pond surrounded by trees killed when the 1964 earthquake caused the land to drop about one meter, exposing their roots to the seawater that permeates the sandy soil. This same seawater also fills the pond, so the sediments in and around it could be interpreted as a record of changes in relative sea level over time. Digging down in search of radiocarbon-datable material, the archaeologists found a series of buried tree stumps 1.8 meters below the present surface that seemed to have been killed in a sudden cataclysm surprisingly similar to what happened in 1964. Six radiocarbon samples taken from the bark of these stumps gave dates that were statistically identical and averaged out to about AD 1170.

This strongly suggests that there was a major earthquake at least as strong as the Good Friday one in or around 1170. This is consistent with evidence from several other parts of the region, where other studies have found less precise evidence for major geological changes around this time. The implication for the issue of archaeological site preservation is that any coastal sites in this area predating 1170 would have been destroyed by the earthquake. Since the geomorphology of Kenai Fjords means that the only usable settlement locations here are on low coastal sand spits like this one, this earthquake probably completely destroyed the previous archaeological record. This would explain why there are so few sites in the park, and why they basically all date to the late prehistoric period or later. The relatively low productivity and other drawbacks of the area may well have limited population earlier as well, but with the earthquake having destroyed any evidence of what was going on previously there’s no way to know for sure.

Sign Describing the Good Friday Earthquake, Earthquake Park

Katmai was a different story, however. Crowell and Mann discovered 22 new sites there in the course of this project (as compared to 16 sites total in Kenai Fjords documented by this and other projects), suggesting that further survey along the coast will likely reveal even more as yet unknown sites in this very productive area. Interestingly, many of the sites they found were located away from the present coastline, often in uplifted areas that may have been coastal at times of higher sea level than at present. Radiocarbon dates from these sites and from peats in the intertidal zone allowed Crowell and Mann to reconstruct a tentative sea level curve for much of the past several thousand years, with the main conclusion being that sea level has been pretty consistent over the past 4000 years, with a slight rise sometime in the past couple hundred years, possibly as a result of subsidence of land in the 1964 earthquake. (Crowell and Mann don’t discuss the possibility that global sea level rise as a result of climate change may be another explanation for this, but it strikes me as plausible.) In any case, whatever the source of this slight recent rise in sea level, it had few apparent effects on archaeological site preservation beyond contributing to the exceptional preservation of one waterlogged site. The subsidence from the 1964 earthquake was very slight in this area, and this appears to have been true for the 1170 one as well. The rich archaeological record of the Katmai coast, then, appears to be in part a function of the relative stability of sea level in this area over thousands of years, in striking contrast to areas just a few hundred miles away.

The archaeological record is always incomplete, and any conclusions drawn from it have to be tempered by knowledge of that incompleteness. As this paper demonstrates very effectively, however, the factors determining just how much of the past is left for us to study vary a lot, especially in places like Alaska where the forces of the earth are exceptionally active. The modern population of Alaska learned just how active those forces can be in 1964, and it stands to reason that the ancient population learned the same lesson in 1170.

"Living with Earthquakes" Sign, Earthquake Park

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Delaney Park at Noon on the Winter Solstice, Anchorage, Alaska

Today is the winter solstice, which means two things: the anniversary of the beginning of this blog (three years now), and the shortest day of the year.  Up here in Alaska, the second is particularly noteworthy.  We had about five and a half hours of daylight today; officially, the sun rose around 10:15 and set around 3:45.  In Anchorage, however, which has mountains to the east, the sun didn’t actually appear until about 11:00.  The state likes to emphasize the converse of this phenomenon in summer in their promotional material, of course, hence the idea that Alaska is the “Land of the Midnight Sun,” but in the winter the “Twilight Noon” is equally appropriate.  Indeed, for the parts of the state that are below the Arctic Circle (most of it), it never gets completely dark or completely light for 24 hours straight, so the Midnight Sun never strictly appears even on the summer solstice.  Noon on the winter solstice definitely does start to look pretty similar to twilight, though.

I’ve talked a lot about archaeoastronomy in the Southwest on this blog, which is why marking events like the solstices has been such an important part of it, but as far as I can tell there is no evidence that the native people up here paid much attention to astronomical phenomena.  (It’s quite possible that they did and I just haven’t found the documentation of it, of course.)  This could be because of the lack of an indigenous agricultural tradition, since calendar-making has generally been linked to agriculture, although of course seasonal events like salmon runs are often very important to non-agricultural people and it would presumably be helpful to have a means of marking them.  I believe navigation by the stars was pretty well developed among some of the more maritime-oriented societies of the North, which makes sense given the general lack of landmarks along the Arctic Ocean coastline, but use of the sky to tell time doesn’t seem to have been as important.  Presumably people just paid more attention to other time markers.  This is a topic I should definitely look into.  Anyway, happy solstice, and thanks for reading.

Captain Cook Statue at Noon on the Winter Solstice, Anchorage, Alaska

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Room 38, Pueblo Bonito

In a recent post, I noted the limited distribution of macaw remains within Pueblo Bonito.  While this site has a much higher number of macaws than any other Chacoan site, and more than almost every other site in the prehistoric Southwest, within the site macaw remains were highly concentrated.  All macaws were found in the eastern half of the site, and most were in the eastern part of “Old Bonito” at the northern end of the overall site, particularly in Room 38, which had twelve.  This suggests to me that macaws were closely associated with whatever social group lived in or used that part of Pueblo Bonito.

It’s hard to say what that social group was, but it’s possible that the burials in a complex of four rooms in the northern part of Old Bonito were associated with it.  Associating these burials with the eastern rooms in Old Bonito is perhaps a bit of a stretch, since the burial rooms are actually in the western half of the Old Bonito arc, but they’re just barely on the west side, and there is a separate set of burial rooms at the far western end of Old Bonito that could be plausibly associated with whatever social group lived in or used those rooms.  There is no equivalent set of burial rooms in the eastern part of the arc, although there are a few isolated burials of infants and fetuses.  (Two of the infant burials, in Rooms 306 and 309, were associated with macaws.)  The eastern end of Old Bonito was covered over by later construction and is poorly known, but there is no evidence that it ever held a mortuary complex comparable to the one at the western end.  Given the circumstances, I think it’s plausible that the northern burial complex was associated with the group (or one of the groups) associated with the eastern part of Pueblo Bonito, perhaps in addition to the group associated with the immediately adjacent room suite at the west end of the northern part of Old Bonito, if this was indeed a different group.

Western Burial Rooms in Old Bonito

Analysis of the Pueblo Bonito burials by Nancy Akins for the Chaco Project found that, judging from cranial attributes, the northern and western burial groups were distinct from each other but internally homogeneous.  This suggests that they probably represented kin-based social units, and that the site consisted of at least two of these units, perhaps occupying or using different areas.  Akins couldn’t find a very large sample of burials from other sites in the canyon for comparison, but she was able to compare burials from three small sites in the canyon.  One of these, Bc 59, is across from Bonito on the south side of the canyon near Casa Rinconada, while the other two, 29SJ299 and 29SJ1360, are in Fajada Gap, a few miles east and the location of a substantial community of small houses and two great houses (Una Vida and Kin Nahasbas) in close proximity to Fajada Butte.

While the two burial populations in Pueblo Bonito weren’t particularly similar to each other, they more closely resembled the small site samples.  Specifically, the western burial population was similar to the one from Bc 59, while the northern burial group was more similar to the Fajada Gap group.  Importantly, the two Bonito groups were both more similar to these small-house populations than they were to each other.  This suggests that kinship connections among different sites in the canyon were complicated and didn’t break down on straightforward great house v. small house lines.

Bc 59 from Casa Rinconada

What does all this have to do with macaws?  Well, there is only one small house site at Chaco (as far as I know) that has produced macaw remains, and that site is… 29SJ1360, one of the sites with burials that patterned with the northern burial group at Bonito!  As reported by Peter McKenna in his report on this site, which was excavated by the Chaco Project, a few macaw bones were found in the fill from one of the pit structures.  While there were only a few bones found, they were all unique, suggesting the presence of only one macaw, and from various parts of the body, suggesting that the whole macaw was present.  This fill was only casually screened for artifacts and was later used to backfill the pit structure, so the rest of the macaw is probably still there.  This site also had an unusual architectural feature, a small bin attached to the outside of one of the roomblocks, that according to McKenna looked “remarkably like a parrot bin.”  One important feature that appears to have led to this conclusion was the presence of an adobe “plug” in the north wall, presumably reminiscent of the stone plugs used with “cage stones” at macaw pens at Casas Grandes, where there is substantial evidence for the keeping and breeding of macaws a few hundred years later.

This is all pretty tentative, of course.  Very few sites at Chaco have been excavated, so we have very little sense of the overall distribution of rare finds such as macaw remains.  Still, two separate lines of evidence (biological relationship and association with macaws) seem to point to a strong connection between the northern/eastern part of Pueblo Bonito and at least some sites in the Fajada Gap community, which is not particularly close to Bonito.  Given the rarity of macaws, especially, this seems significant.

Fajada Butte with Green Vegetation

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

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Room 38, Pueblo Bonito

Pueblo Bonito is the best-known and most-studied site at Chaco, but there’s still a lot we don’t know about it.  Because it was excavated early in the history of Southwestern archaeology, provenience information for the vast numbers of artifacts found at Bonito is not nearly as precise as would be expected today.  We do generally have information about what was in each excavated room, and often where in the room specific artifacts were, but the careful stratigraphic approaches used today were either totally unknown or in their infancy during the excavation of various parts of Bonito, so interpreting the field notes and site reports can be a challenge.  Partly for this reason, a lot of recent interpretations of Chaco have been based mainly on the more recent and better-documented excavations by the Chaco Project in the 1970s.  This makes Pueblo Alto in particular, the only great house extensively excavated by the Chaco Project, enormously influential in recent interpretations, not always in beneficial ways.  The Pueblo Bonito data has been incorporated into most theories to varying extents, but this often just takes the form of vague gesturing at the elaborate burials and huge quantities of high-value artifacts found there, and sometimes it basically amounts to discounting the importance of Bonito because it is so unlike the other sites.

Still, Bonito is important!  The problematic nature of the documentation notwithstanding, there’s still a ton of data available, and the Chaco Archive has been doing excellent work lately in making it more widely accessible.  Their cool interactive map of the site even allows you to click on a room and see a list of all the features, artifacts, tree-ring dates, and pictures associated with that room.  I’ve been playing around with it a lot lately, and there’s really a ton of interesting stuff in many of the rooms that we don’t hear so much about.

Room 309, Pueblo Bonito

Building on what I was saying earlier about a badger burial at a small site excavated by Earl Morris near Aztec, I decided to look for unusual animal burials or remains that might suggest some patterns in ritual practices or group identities at Bonito.  Many modern Pueblo clans are named after specific animals, and it seems reasonable that some Chacoan social groups (which may or may not be equivalent or ancestral to the modern clans) might have had similar identities that would lead them to leave animal remains in certain contexts that could indicate connections through time between different rooms or sites.  The Chaco Archive database allows you to search for specific types of artifacts, and it even has a special option for non-human burials.  The database doesn’t have all the sites included yet, but it does have all of Bonito, and it’s a powerful tool for finding information about the sites that are included.

Starting with the non-human burials, the ones at Bonito seem to all be of macaws and parrots.  The close connection between Bonito and macaws has long been noted, and Room 38 is particularly known for its large numbers of them, but one thing I hadn’t realized is that, like so much else at Bonito, the distribution of macaws is highly concentrated, not just in a few rooms, but specifically in a few rooms on the east side of the site.  The macaw burials, in addition to the two in Room 38, are in Rooms 71, 78, and 306, all of which are in the eastern part of Old Bonito.  Not all of these are actually formal burials, but they are all complete skeletons.  Extending the search to individual bones adds Rooms 249, 251, 309, and 312, as well as Kiva J and the east mound in front of the site.  Again, these are all on the east side of Bonito, although not just in Old Bonito this time.  Rooms 309 and 312 aren’t technically in Old Bonito, but they are among the rooms added right in front of it, and are very close to Rooms 306, 71, and 78, which also had macaws.  Rooms 249 and 251 are in the block of rooms added onto the southeast part of the site over an earlier extension that apparently built over part of the eastern end of Old Bonito (this part of the site is very complicated and its construction sequence is poorly understood).  Kiva J is one of the six blocked-in kivas between this block and the plaza.  And, of course, the east mound is the easternmost of the two mounds.

Kiva J, Pueblo Bonito

What does all this mean?  Many have suggested that the number of macaws at Bonito indicates the possible presence of a macaw clan like the one known today at Zuni.  If this is indeed the explanation for all the macaws, and it seems plausible given the restricted distribution of them to just a few sites at this time and the contexts in which they are found, it seems that this clan probably lived in or had claims on the eastern part of Pueblo Bonito, and that this association held not just in the earliest stages of the site but even after it was expanded.  Perhaps members of this clan were the initial residents of the eastern suites in Old Bonito, then when those rooms were converted to other uses as the site was expanded they moved into the new southeast wing.

One question that might be raised at this point is whether this distribution is actually specific to macaws.  Maybe all exotic birds and animals are concentrated in this part of the site, which would suggest that there might be something special about the eastern half of the site but not necessarily anything tied to a specific clan.  Some research into the layout of the rooms has shown that the southeast corner is unusual in not being divided into obvious room suites, whereas the southwest corner seems to be.  Maybe instead of the macaw clan living in the eastern half, everyone lived in the western half and they used the eastern half for macaw-related (and other) ritual.

Room 330, Pueblo Bonito

One way to test this would be to look at other unusual animals.  Finding animals of ritual importance beyond obvious exotics like macaws is tricky, because many animals were certainly used for mundane purposes and their remains are therefore all over.  Dogs and turkeys were kept domestically, so their remains probably wouldn’t indicate anything special about social groupings, and game animals such as rabbits and deer might have interesting implications for access to different kinds of meat but, again, not necessarily specific symbolic implications.  That basically leaves animals that don’t serve a clear subsistence or other utilitarian purpose but are nevertheless found in sufficient numbers to suggest something more than mere chance is behind their presence.  The best example I’ve found: bears.

You basically never hear about bears in discussions of Chaco.  They are not present in the area now and probably weren’t in antiquity either, and their remains are certainly rare at Chaco but not entirely absent.  At Pueblo Bonito, bear remains are mostly concentrated on the west side of the site, in stark contrast to the macaw remains on the east side.  There are some artifacts made of bear bone, including two apparent gaming pieces, one each from Rooms 267 and 290 (both on the east side), but there are also unworked bear bones, especially jaws and feet, particularly concentrated in Rooms 92, 102, and 109, which are part of the same suite of rooms in the west wing of Old Bonito.  Room 92 also had a bear hide and mass of hair that is probably also from a bear.  Another room in this part of the site, Room 330, had a grizzly bear jaw.  Another bear jaw was in Room 66 and a claw was in Room 10; both these rooms are on the east side of the site.  So not as clear-cut as the macaw evidence, but still a strong suggestion that people with some sort of connection to bears lived in the western part of the site.  The “bear-paw” motif is well-known in rock art, and George Pepper, who excavated these rooms, reported that Room 97 (the room under Room 92) had similar “bear paws” drawn on the smoke-blackened plaster.  Finally, Kiva Q, the great kiva in the west plaza, contained a (dedicatory?) cache of objects that included bear paws.  This is all very suggestive, though of course not totally dispositive.

Kiva Q and West Plaza, Pueblo Bonito

There may be other examples of these sorts of patterns that could give us a better sense of who exactly was living at Pueblo Bonito and what other people at which other sites they had particularly close ties to.  Despite the fact that this information has been available for a long time, it’s only now that it’s starting to become widely available in a useful form.  New analytical techniques are revolutionizing our understanding of Chaco in all sorts of ways, but one of the most important contributions technology can make is just to make existing information available so it can be assembled, analyzed, and compared to information from elsewhere.

Bear Paw at Three Rivers Petroglyph Site

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Metate Incorporated into Wall Capping, Pueblo Bonito

I’ve written a bit about the recent research, spearheaded by Larry Benson of the USGS, into the sources of the corn found at Chaco.  These studies continue to refine the techniques used to identify source areas, but so far they have shown that corn was almost certainly being imported to Chaco both during and after the florescence of the Chaco system between AD 1030 and 1130.  As they begin to test more potential field areas, of course, the number of matches for the strontium isotope ratios in the corn at Chaco has increased.  While early studies indicated that much of it likely came from the Chuska Valley, it now looks much more likely that it instead came from the area along the Chaco River between there and the canyon.  This is an area with numerous outlying great houses, and it was probably the main route for the many commodities from the Chuska area that were brought to the canyon, and it’s also generally a better area for agriculture than the canyon itself, so this all makes sense.  There has also been some evidence that at least some corn was also coming from the Totah area to the north, again a more productive agricultural area with many Chacoan outliers.

Based on the proveniences of the corncobs from Pueblo Bonito that were tested early on, one tentative suggestion emerging from this research was that the main sources of imported corn changed over time.  The cobs that came from the lower Chaco River were from Rooms 3 and 92 in the northern part of Old Bonito, one of the earliest parts of the building to be built, while the one cob of possible Totah origin came instead from Room 170, in the southeast corner, one of the newest parts of the site.  Since there does seem on other grounds to have been a shift in the emphasis of the Chaco system from south to west to north over time, it would make sense that the early rooms contained early cobs from the west while a later room contained a later cob from the north.

Talus Unit with Snow

A paper published in 2008 by a group of big names in Chacoan studies sought to look at this directly by radiocarbon dating the cobs.  This is an interesting paper which goes beyond that narrow topic to also look at the characteristics of the corn found at the various great houses and other sites.  One of the co-authors is Mollie Toll, a specialist in archaeobotany who has done a lot of research on Chacoan corn.  As part of that research, she had long noted that the corn at Pueblo Bonito generally had bigger ears with more rows of kernels than most other corn known from the prehistoric Southwest.    It was bigger than earlier and later corn, for one thing, but it was also bigger than most other corn from the same period.  Corn from the Chacoan occupation of Salmon Ruin was also unusually large, as was corn from the Talus Unit behind Chetro Ketl, but corn from Pueblo Alto and Pueblo del Arroyo, other contemporary great houses at Chaco, was smaller and more in line with that from earlier and later sites.

Toll came up with three possible explanations for the difference.  Pueblo Bonito corn could be a different variety or “landrace” from the others, which is plausible but not directly testable with current technology.  It could also have been grown outside of the canyon where conditions were better for agriculture, while the corn from other great houses was grown in the canyon where conditions were poorer.  Finally, and problematically, the corn at Bonito might not have been Chacoan at all!  Since modern corn is generally bigger than ancient corn, Toll (when she was first looking at this in the 1980s) couldn’t exclude the possibility that the corn found at Pueblo Bonito had actually been put there by Navajos in the nineteenth century.  Much of it was from George Pepper‘s excavations in the 1890s, so it couldn’t be newer than that, but there was no way for Toll to tell how much older it was.

Room 3a/92/97, Pueblo Bonito

We still can’t tell different ancient landraces apart (although the recent sequencing of the maize genome may make this more feasible in the future), but the strontium isotope testing is giving us a sense of where the corn was grown, and accelerator mass spectrometry now makes directly dating the corn relatively easy.  Seven cobs from Pueblo Bonito that had been used in the strontium studies were dated for this paper.  One was the cob from Room 170 that possibly came from the Totah, one was from Room 92, and the rest were from Room 3.

The results were illuminating, but also challenging.  All the cobs clearly dated to ancient times, so the possibility that the size of Pueblo Bonito’s corncobs represents recent deposition is effectively quashed.  Three of the Room 3 cobs had closely clustered dates with intercepts around AD 1000, which offered some partial support for the idea that the corn in the early rooms was relatively early, but the other two were widely spaced, one at 870 and at 1170.  This is problematic for the idea that the date of corn in a room can be predicted from the date of that room’s construction, but it makes sense that the deposits in a room may date to well after its construction.  Since Room 3 dates very early, probably to the 900s, it’s likely that the deposits there resulted from much later trash dumping once it was no longer used for its original purpose.  Room 3 has a firepit, so it was probably originally a residential room, and it is likely one of those “big square rooms” that I have argued began to take the place of kivas in Chacoan room suites of the tenth century.  Room 92 is part of the maze of confusing rooms next to Room 3.  It had a well-preserved floor with corn and bean bushes on it (it’s not clear from Pepper’s description if this was the second or third floor), which suggests that it was used as a storeroom at the end of the period of occupation in this part of the building.  The cob from this room had the latest date of any in the study, with an intercept of AD 1220, which is consistent with the idea that this room was in use as a storeroom at the end of occupation.

Room 170, Pueblo Bonito

The biggest surprise, however, was the cob from Room 170, which dated to AD 1010.  This is particularly odd, since Room 170 was probably built around 1080 or even later.  Looking at the probability curve for this date, there is some chance that the actual date was around 1100, but the curve as a whole has a much more prominent peak around the intercept at 1010 than any of the other reported dates, which suggests that the probability is quite high that the intercept does in fact represent the true date or close to it.  The authors give various possibilities for why the cob might have been placed in this room long after it was grown, including the idea that it was put there as some sort of ritual offering of continuity with the occupation of earlier parts of the building.  I prefer another explanation they also suggest, which is that it was part of an earlier trash deposit that was redeposited in Room 170 for some reason.  There is very little information on what the deposits in this room were actually like, but many of the rooms in this part of the building were full of trash when excavated, and I think it’s most likely that this one was too.  The trash could have been put there for any number of reasons; if it was redeposited from somewhere else, it may have served as structural fill to support an upper story.  In any case, this puts a damper on the idea that the overall sources of corn changed over time.  Indeed, the sources seem to have been pretty constant through time for cobs left in different areas of the site, which suggests that the real story is much more complicated.

One nice thing about this paper is that the authors do a very good job of properly reporting their radiocarbon dates, particularly in giving point estimates as intercepts, which are meaningful, rather than midpoints, which are not.  Many papers make this mistake, including some of Benson’s reporting these and other dates on corn.  This paper also shows the probability curves for the dates, which give even more information.  This seems to be pretty common these days among Mesoamerican archaeologists, but it’s still quite rare in the Southwest, where radiocarbon dating has only recently become a major focus.  The availability of tree-ring dates, which are much more precise, has generally led Southwestern archaeologists to neglect radiocarbon, but it’s becoming increasingly obvious from studies like this one that the ability to date things other than trees is very useful in interpreting sites.

Obviously this paper just reports a handful of dates, and the authors take pains to point out the tentative nature of any conclusions they draw, but it’s an important contribution to the issue of where the Chaco system, whatever its nature, was getting its means of support.  As is often the case with new avenues of research, at this point papers like this pose more questions than they answer, but there are plenty of corncobs out there to date and analyze in other ways, just as there are plenty of potsherds to test for theobromine.  Once we get a bigger database of dates and strontium (and other) ratios, we’ll start to get a clearer picture of the behavior behind these remains.

Metate Fragment at Pueblo Alto

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Shannon Bluffs, South of Farmington, New Mexico

One reason for the relative lack of information available on the prehistory of the Totah is that the presence of all those big rivers leads many sites to be buried under alluvium and/or destroyed by flooding and changes in the courses of the rivers.  As a result, many sites are not visible at all on the surface, and this is particularly the case for small sites, especially since the local architecture for much of the Pueblo period relied heavily on adobe and cobble masonry, which is much less durable than the sandstone masonry typical of Chaco and Mesa Verde.  Thus, aside from really big sites like Salmon and Aztec, many Totah sites are only discovered with very deep excavation or erosion.

Linda Wheelbarger’s chapter in the Salmon synthesis volume, reporting on the findings of the Totah Archaeological Project on the Bolack Ranch just south of Farmington, emphasizes this in pointing out how many of the sites on the ranch were not visible in any way from the surface and were only discovered inadvertently, such as when breaches in irrigation ditches lead to swift erosion, revealing sites well below the ground surface.  The most obvious sites are on the terraces above the river, and these are also some of the largest sites (including some probable Chacoan great houses), but it’s not clear if they are actually the largest or if there are larger ones buried somewhere in the floodplain.   Most of the known floodplain sites are small houses, but they are quite numerous, and Wheelbarger is able to define five “communities” along the southern bank of the San Juan between the confluence of the Animas River to the west and the Gallegos Wash to the east.  These tend to be at the confluences of various side drainages (including the Animas and the Gallegos) with the San Juan, which is a pattern noted elsewhere in the San Juan Basin as well, including to some degree at Chaco itself.

Plaza at Salmon Ruin

This is something to keep in mind when evaluating the conventional wisdom that the area around Salmon Ruin was largely uninhabited when construction of the building began around 1090.  The basis for this very common assertion is an extensive site survey done in the area around Salmon by the San Juan Valley Archaeological Project in the 1970s in conjunction with excavations at Salmon.  This survey revealed only four small sites within 1 kilometer of the great house that might have been contemporary with it, and only 12 such sites within 6 km.  In his chapter on the function of Salmon in the synthesis volume, Paul Reed explains the survey and its limitations:

The survey did not entail 100 percent coverage because of the complexity of land ownership and lack of permission to survey some parcels.  Nevertheless, much of the territory in the 1 km area around Salmon was surveyed.  As a caveat, it is likely that flood deposits from the San Juan River, along with alternating cycles of erosion, may have concealed or removed other sites located on the floodplain below Salmon.  We have no way of knowing how many such sites may have been present.  With the data that are available, however, it is clear that Salmon was not the center of a large community of surrounding small pueblos; rather, Salmon largely comprised the entire community.

Reed is clearly aware that it is likely that any sites that may have existed on the floodplain are no longer visible, but he nevertheless concludes that “it is clear that Salmon was not the center of a large community of surrounding small pueblos.”  Well, no, it isn’t clear, even “with the data that are available,” unless you make the totally unwarranted assumption that the available data do in fact reflect the reality despite their obvious shortcomings.  It’s worthwhile to note that the handful of sites that were identified were mostly on the terraces, rather than the floodplain, which means that they don’t have much relevance to the issue of how many sites there were in the region overall.  It’s certainly possible that Salmon was founded in a vacant area, as Reed concludes, but it’s important to note (as he does) that this would make Salmon quite unusual among Chacoan great houses, which usually were built among contemporaneous small sites both in Chaco Canyon itself and at outlying communities.

West Wing of Aztec West and Terrace to the North

A somewhat comparable situation exists at Aztec, although there is evidence of a fairly substantial residential district on the terrace above the West and East great houses.  Very little is known about the extent of settlement on the floodplain around the main “downtown” district, and some have argued that Aztec, too, was founded in an area without substantial prior settlement (with the terrace-top houses presumed to postdate the initial construction of the great houses), whereas others have argued that there probably was some sort of existing settlement there that is no longer visible because of the river-side location.  In either case it is clear that Aztec was a larger and presumably more important community within the region than Salmon.

There isn’t any way to settle this issue without extensive testing and excavation, which is unlikely to happen any time soon, but I just want to flag it to emphasize that a lot of the ideas that get entrenched in the archaeological literature are not necessarily well founded, and it’s important to understand the evidence behind them and how strong it is.

Terrace North of Salmon Ruin with Salmon Museum at Top

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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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