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Sandia Mountains from Kuaua Pueblo, Coronado State Monument, Bernalillo, New Mexico

Sandia Mountains from Kuaua Pueblo, Bernalillo, New Mexico

Given the diversity of languages spoken by the modern Pueblos, and the diverse archaeological “cultures” of Pueblo prehistory (as described in the previous post), one obvious line of inquiry in making connections between past and present focuses on language. Specifically, the fact that some Pueblo languages are part of larger families and others are not seems to open the possibility of some Pueblo groups being relative newcomers to the Pueblo lifestyle, which leaves others as more likely to be the direct descendants of the prehistoric groups who inhabited sites like Chaco and Mesa Verde.

There have been several attempts to reconstruct Pueblo culture history along these lines, but I’m not going to discuss them in detail because I think the whole approach is unlikely to work. A closer look at the specifics of the relationships involved shows why.

There are two Pueblo language groups whose languages are part of larger families: Hopi and Tanoan. The Hopi language belongs to the very large Uto-Aztecan family, stretching from the Great Basin south into Mexico and beyond. The Tanoan family is part of the Kiowa-Tanoan family, along with the single language Kiowa, spoken on the Great Plains. The other two Pueblo languages, Keres and Zuni, are isolates not known to be related to any other language (including each other).

Starting with Hopi, at first glance this seems like a good candidate for a language spoken by a mobile hunter-gatherer group, like the modern Numic speakers of the Great Basin, who only settled down to a sedentary agricultural lifestyle relatively recently. However, it’s important to note that Hopi forms its own branch of the Uto-Aztecan family (or possibly of the Northern Uto-Aztecan subfamily, the existence of which is a matter of dispute). It is no more closely related to Numic than it is to, say, the Piman languages spoken by the O’odham agriculturalists of southern Arizona. Depending on how the overall Uto-Aztecan family is reconstructed, it may even be equally close to Nahuatl, the language of the Aztecs. It’s not possible to assign specific dates to divisions of language families, but on a qualitative level, Hopi is sufficiently divergent from the rest of its family that it is very unlikely that its speakers entered the Pueblo culture area in the past few centuries. Archaeologically, there is abundant evidence that modern Hopi society emerged from the amalgamation of many different groups from different parts of the Southwest who migrated to the Hopi mesas in the post-Chacoan period, and the same impression is given by Hopi oral history. Which of these groups spoke the language ancestral to modern Hopi is impossible to determine from archaeological evidence, of course, but it’s reasonable to think at least one of them did, and had been speaking it while practicing a basically Pueblo lifestyle for many centuries before that.

Turning to Tanoan, the archaeology is a lot murkier but the general point still stands. The relationship to Kiowa suggests the possibility that the Tanoan-speakers only entered the Southwest fairly recently, presumably from the Plains. In a small language like this is it is even harder to quantify divergence than it is in large language like Uto-Aztecan, but again, the Tanoan languages are quite different from Kiowa. They are so different, in fact, that it wasn’t until the 1950s that the relationship between the two was established to the general satisfaction of historical linguists. The oral history of these groups is also murky, but what is known of Tanoan traditions doesn’t seem to point to origins outside the Southwest, and Kiowa traditions also don’t seem to record any knowledge of a relationship to any of the Pueblos. Who moved where when is hard to determine in this case, but nothing about the linguistic evidence points to a particularly recent adoption of Pueblo culture by Tanoan speakers. The eastern Pueblos, including the Tanoans, do show a lot of evidence of Plains cultural traits, but this is most likely a result of close contact with the Plains during the late prehistoric and early historic period, for which there is plenty of evidence.

That leaves Keres and Zuni, about which nothing can be said about external relationships. It is likely that both groups have been culturally Pueblo for a very long time, but there is no way to tell based on the linguistic evidence whether they have been so for longer than their neighbors to the east (Tanoan) and west (Hopi).

So basically, I think linguistic relationship is a dead end in determining historical connections between ancient sites and modern Pueblos. That’s not to say that linguistics is entirely useless, however. There are other, more subtle aspects of the linguistic relationships among Pueblo groups that may well have historical value. That’s a topic for another post, however.

Hopi Buttes from Homol'ovi Ruins State Park

Hopi Buttes from Homol’ovi Ruins State Park

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Northwest Corner of Pueblo del Arroyo

Northwest Corner of Pueblo del Arroyo

As a first step in evaluating the connections between prehistoric and modern Pueblo societies, it’s necessary to define exactly which societies we’re talking about here. This post is a brief overview of the prehistoric cultures and modern ethnolinguistic groups in question. As noted below, these are not necessarily equivalent units, and failing to recognize this has been a frequent problem with previous reconstructions of Southwestern culture history.

On the ancient side, we are primarily dealing here with  a handful of “branches” within the overall Anasazi “root.” (See my previous post on lesser-known prehistoric Southwestern societies for more on the “root and branch” system that has traditionally been used to organize Southwestern prehistory.) These branches inhabited various parts of the drainage of the San Juan River prior to AD 1300; how far back they go before that is unclear. These are the traditional branches:

  • Chaco Branch: The primary center of this branch is of course Chaco Canyon in northwestern New Mexico, but it extended over the entirety of the southern San Juan Basin and further south into the drainage of the Rio Puerco of the West. There are various distinctive characteristics of this branch prior to about AD 1200, when it seems to converge with the Mesa Verde branch before disappearing entirely.
  • Mesa Verde Branch: While Mesa Verde proper is historically the area of main research focus for this branch, recent research has shown that it was much more widespread, extending thoughout much of southwestern Colorado and southeastern Utah. The exact nature of its relationship with the Chaco branch is still unclear, but there has been increasing evidence for cultural similarity and historical connections between the two. There is a clear pattern of alternating population concentration implying migration between north and south on a scale of centuries prior to the depopulation of the entire area before AD 1300.
  • Kayenta Branch: Located in northeastern Arizona, this branch shows some clear cultural differences from Chaco and Mesa Verde, but certain sites do show evidence of influence from Mesa Verde especially during the Tsegi Phase from AD 1250 to 1300. The cliff dwellings of Navajo National Monument and Canyon de Chelly are probably the best known Kayenta sites.

On the modern side, there are 19 Pueblos in New Mexico, plus several on the Hopi Reservation in Arizona and a few communities of Pueblo ancestry in the vicinity of El Paso, Texas. They belong to six known linguistic groups, listed below.

  • Hopi: This language belongs to the Uto-Aztecan family, one of the more widespread and well-documented families of North and Central America. As the name implies, the family includes both the Great Basin hunter-gatherers of the Numic subfamily (Ute, Paiute, and Shoshone) and the complex agricultural Aztecs of the Basin of Mexico, as well as many groups in between. As a result, this family is among the best examples in the world of a lack of correlation between language family and economic orientation. The Hopis fall in between the extremes of the Numa and the Aztecs, and their language forms its own branch of Uto-Aztecan sufficiently different from the others to make it very difficult to draw any culture-historical conclusions. The three Hopi mesas (unimaginatively named “First,” “Second,” and “Third” in English) have distinctive dialects that further complicate the situation.
  • Zuni: Today this is just a single pueblo, speaking a language generally considered an isolate unrelated to any other. Prior to the Pueblo Revolt of 1680 there were several Zuni pueblos, however. In addition to language, there are several other aspects of Zuni culture that tend to distinguish it from the other pueblos, although there are also enough similarities to Hopi to distinguish the two as “western” pueblos in contrast to those further east.
  • Keres: This is another language isolate, but spoken by several historically autonomous pueblos that still retain separate identities and speak slightly different dialects of a single mutually intelligible language. The Keres pueblos form a “bridge” in some respects between the western and eastern pueblos. Acoma and Laguna tend to pattern more with Hopi and Zuni, while Zia, Santa Ana, San Felipe, Cochiti, and Santo Domingo are located further east and tend to have more similarities to the Rio Grande Pueblos.
  • Tanoan: This (sub)family is located entirely in the Rio Grande Valley and is divided into three languages/subfamilies, which are in turn related to a fourth language, Kiowa, spoken on the Great Plains. The Tanoan subfamilies are:
    • Tiwa: This subfamily is in turn divided into Northern and Southern divisions, which occupy the extreme north and south portions of the modern Pueblo domain. Northern Tiwa is spoken in Taos and Picuris, while Southern Tiwa is spoken at Sandia and Isleta in the vicinity of modern Albuquerque. Tiwa was also spoken historically at Ysleta del Sur near El Paso, Texas, which was founded by Southern Tiwas displaced during the Pueblo Revolt of 1680. There is some evidence that the Piro pueblos south of the Southern Tiwa also spoke a language closely related to Tiwa, although this language is poorly documented and is now extinct.
    • Tewa: This subfamily occupies the portions of the northern Rio Grande valley near modern Santa Fe, in the pueblos of San Juan, Santa Clara, San Ildefonso, Nambe, Tesuque, Pojoaque. A closely related dialect was also spoken further south in the Galisteo Basin until approximately 1700, when the remaining residents of that area moved to the Hopi area of Arizona and founded the pueblo on First Mesa known as Hano (or Tewa), which continues to speak a dialect of the Tewa language to this day.
    • Towa: Today this language is spoken only at Jemez Pueblo on the western edge of the Rio Grande region, but until the 1830s it was also spoken at Pecos on the eastern edge. When the pueblo of Pecos was abandoned its remaining inhabitants moved to Jemez, where their descendants still form a distinctive segment of the population.

So that’s the present situation. The picture is complicated, and it’s hard to figure out what the historical events that resulted in this arrangement would have been. The fact that Tiwa occupies both the northern and southern ends of the Rio Grande culture area, while Towa occupies the eastern and western peripheries and Keres occupies both a core part of the center of the region and an area further west that is more similar culturally to Hopi and Zuni, makes it difficult to fit the known facts into a simple scheme of migration or cultural diffusion. Clearly the story must be more complicated, and digging into those complexities will be the purpose of the following posts in this series.

Kuaua Pueblo, Coronado State Monument, Bernalillo, New Mexico

Kuaua Pueblo, Coronado State Monument, Bernalillo, New Mexico

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Kivas in East Plaza, Pueblo Bonito

Kivas in East Plaza, Pueblo Bonito

It’s quite clear that, in a general sense, the modern Pueblo people of New Mexico and Arizona are the cultural descendants of the ancestral Pueblo (Anasazi) groups of Chaco Canyon and other parts of the northern Southwest no longer occupied by people of Puebloan culture. Indeed, as the previous post explains, the descendants of the Chacoans are much easier to identify than those of pretty much any other prehistoric society in the Southwest. Nevertheless, the modern Pueblos are quite diverse in many ways. While they all have similar material culture, which is what most clearly shows their relationship to prehistoric sites like Chaco, the Pueblos speak six different languages belonging to four completely unrelated language families, and the linguistic divisions correspond generally (but not perfectly) to differences in other aspects of culture, such as kinship systems, sociopolitical structures, and religious practices.

With so much diversity, it’s reasonable to hypothesize that some modern Pueblo groups have closer connections to particular ancient sites than others. Demonstrating any specific connections has been frustratingly difficult for scholars so far, however. The immense upheavals of the Spanish colonial period led to significant changes in many Pueblos that make it difficult to trace their histories back into the prehistoric period, and archaeology has demonstrated considerable evidence for prehistoric upheavals that similarly obscure continuities of culture and population. Adding to the difficulty are the facts that the Pueblos have long had very similar material culture to each other, which makes it difficult to tell different ethnolinguistic groups apart archaeologically, and that the extensive migrations of the late prehistoric period seem to have involved rapid change in material culture as well, obscure whatever small differences had existed among different Pueblo groups.

On account of these difficulties, for a long time Southwestern archaeologists and anthropologists were often reluctant to try to reconstruct culture history in enough detail to connect specific ancient sites with specific modern Pueblos. In recent years this reluctance has decreased, however, and there is now a fair amount of interest in these questions, spurred in part by the requirements under NAGPRA for demonstrating cultural affiliation of modern groups in ancient sites. It’s interesting to compare this trend to the last period of considerable interest in this topic, which was similarly spurred by the effort in the 1950s to settle Indian land claims. In any case, archaeologists today have proposed various models of Southwestern prehistory to account for the distribution of modern Pueblo peoples.

With this context, and inspired in part by some interesting questions asked by commenter J. R. Barnett, I’ve decided to do a series of posts addressing this issue and the types of evidence available to address it. I’ll be focusing heavily on linguistic evidence, which is of particular interest to me personally as well as being of considerable importance in defining cultural differences among the Pueblos. I will, however, also discuss the evidence from archaeology, physical anthropology (including DNA studies), sociocultural anthropology, and oral traditions. In doing some reading on these topics recently, it’s been apparent that there really is quite a lot of relevant evidence out there. While we will surely never be able to recover every detail of the story, it’s worth taking a serious look at the available evidence to see what we can find out.

Apparent Kiva at Abo Pueblo, Salinas Pueblo Missions National Monument

Apparent Kiva at Abo Pueblo, Salinas Pueblo Missions National Monument

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Montezuma Castle, a Sinagua Village

Montezuma Castle, a Sinagua Village

As I’ve mentioned before in reference to the Fremont culture of what is now Utah, while the Anasazi of the Four Corners region are by far the most famous of the prehistoric southwestern societies, and particularly famous for their allegedly mysterious disappearance, there’s actually very little mystery about what happened to them. They very obviously became the modern Pueblos of New Mexico and Arizona. It has not been possible so far to trace connections between any specific prehistoric site and any specific modern pueblo (beyond obvious cases like the Zuni and Hopi pueblos that were abandoned in very late prehistory or very early historic times when the inhabitants moved to nearby communities that are still extant today). However, the general connections between the Anasazi and the modern Pueblos in material culture are quite clear and no one disputes them.

When it comes to the other prehistoric cultures, however, the situation is much less clear. While a few seem to have clear modern descendants, most show few if any obvious similarities to the modern indigenous cultures inhabiting their areas, and the extent of any continuity is controversial at best. A recent comment on my Fremont post mentioning the Gallina culture of north-central New Mexico reminded me of this. I may expand on some of these cultures in future posts, but for now I just want to list them so that people who are not familiar with the diversity of southwestern culture history get a sense for the range of cultures known from the archaeological record and the very limited extent to which it is correlated with the equally extensive ethnographic record of this region.

Before I get to the list, though, I should give a brief introduction to the “root-and-branch” system of southwestern archaeological taxonomy, which is necessary to understand what these archaeological units are and are not. This system was originally developed by Harold Gladwin, a New York stockbroker who moved to Globe, Arizona in the 1920s and established a nonprofit archaeological research institute known as Gila Pueblo that was immensely influential in the development of southwestern archaeology in the 1930s and 1940s. Gladwin’s conception of southwestern culture history was based on an analogy to trees, with “roots” as the basic units, which in turn were divided hierarchically into “stems” and “branches.” The data on which these units were based was mainly ceramic, as pottery is the most useful artifact class for distinguishing among the various cultural manifestations of the prehistoric Southwest. The “branches” were considered roughly equivalent to the “tribes” of the ethnographic record, but given the historical focus of archaeology at this time they were further divided into chronological “phases.” Gladwin’s scheme was revised by Harold Colton of the Museum of Northern Arizona in Flagstaff, who renamed some of the roots to avoid Gladwin’s association of them with specific modern linguistic groups, given the uncertainty involved in this kind of identification. Colton also generally downplayed Gladwin’s intermediate “stems” in favor of a simpler system of “roots” and “branches” (which he still analogized to modern tribes). The system that emerged from this interplay of Gladwin’s and Colton’s ideas has remained in use ever since as the main taxonomic scheme for southwestern archaeology.

Within this system, “Anasazi” refers to one of the roots, with “Chaco,” “Mesa Verde,” Kayenta,” etc. as branches. Note that I have avoided using the term “Ancestral Puebloan” in place of “Anasazi” in this post so far; there’s a reason for that. While the term “Anasazi” has been criticized based on its Navajo etymology, it refers to a very specific unit in a taxonomic system, and “Ancestral Puebloan” is a problematic replacement because most or all of the other units in that system are also likely ancestral to the modern Pueblos. For want of a better term, then, I’m sticking with “Anasazi” for this purpose.

With that prologue out of the way, below are the roots and branches currently recognized by most archaeologists that don’t have obvious modern descendants. Note that while the Chaco, Mesa Verde, Kayenta, and Rio Grande branches of the Anasazi root are not listed here since they are clearly ancestral to the modern Pueblos, some other Anasazi branches are included since it is much less obvious what happened to them. They may have ended up as part of one or more modern Pueblo groups, but it is also possible that they changed their culture so much as to become unrecognizable archaeologically, or died out altogether. The branches belonging to other roots may have contributed to the formation of the modern Pueblos as well, or they may have developed into other cultures or disappeared entirely as well.

  • Anasazi Root:
    • Gallina Branch: Inhabited north-central New Mexico until about AD 1300. Late Gallina sites exhibit extensive evidence of violent death, implying conflict with other groups, perhaps those entering the area from the north and west around this time. While the Gallina are generally considered a branch of the Anasazi, their material culture shows many similarities to Plains groups to the east and their actual ethnic and linguistic affiliation remain unclear.
    • Virgin Branch: Inhabited the Virgin River valley and adjacent areas of southern Nevada, southwestern Utah and northwestern Arizona from Basketmaker times until approximately AD 1150 (or possibly a bit later). They seem to have been part of the overall Anasazi culture area from early on, but the Virgin region was abandoned significantly earlier than other Anasazi areas further east, and it is unclear what this means.
  • Fremont Root: Inhabited most of modern Utah for centuries until fading away in the late prehistoric period. The relationship of the Fremont to modern Pueblo and Numic populations remains unclear, and it is also unclear just how coherent a cultural unit “Fremont” ever was.
  • Hohokam Root: Inhabited southern and central Arizona (below the Mogollon Rim) for millennia from the initial development of agriculture until the fifteenth century AD. Famous for their elaborate canal systems and distinctive pottery, as well as their apparently Mesoamerican-influenced ballcourts, the Hohokam remain one of the most mysterious of prehistoric southwestern cultures despite also being one of the best-studied. They may have been ancestral to the modern O’odham (Pima and Papago) peoples who inhabited the same area in historic times, but this is hotly disputed as there are many differences in material culture. There have also been suggestions that some Hohokam may have been ancestral to modern Pueblo groups (especially the western Pueblos of Hopi and Zuni) and Yuman-speaking groups west of the Hohokam heartland.
  • Mogollon Root:
    • Jornada Branch: Occupied south-central New Mexico until about AD 1400. Possibly descended in part from the Mimbres to the west and possibly ancestral to some of the Rio Grande Pueblos further north, the Jornada are among the less studied southwestern groups. Based on rock art, they have been proposed as the originators of the kachina cult that later became widespread among the Pueblos.
    • Mimbres Branch: One of the most talked-about, but not one of the most-studied, groups of the prehistoric Southwest, the Mimbres are known mainly for their unique pottery featuring naturalistic decoration. This area showed a long developmental sequence under apparent Hohokam influence followed by a brief period of possible (but disputed) Anasazi influence including aggregation into large, nucleated villages, followed by regional abandonment in the twelfth century AD.
    • Mountain Branches: There are several branches of the Mogollon proposed to have existed in the mountains of western New Mexico and eastern Arizona until around AD 1400 when this whole region was abandoned. There are many continuities between these settlements (which often took the form of large aggregated pueblos) and modern Hopi and Zuni, but the connection is not totally unambiguous.
  • Patayan Root: By far the least studied of any of the southwestern roots, the Patayan occupied the harsh deserts of western Arizona and are generally considered to be ancestral to the modern Yuman-speaking tribes of that area. (Gladwin even called the root “Yuman,”  which Colton changed to “Patayan” to avoid relating it quite so obviously to a modern ethnolinguistic group.) Despite the fairly straightforward relationship of at least some Patayan branches to modern Yuman groups, the root as a whole remains poorly understood, and the northern branches in northwestern Arizona (especially the Cohonina and Prescott branches) have seen very little research and their attachment to the root at all has been challenged by some archaeologists.
  • Sinagua Root: This group, occupying the area around modern Flagstaff, Arizona, shows clear evidence of influence from both the Kayenta Anasazi to the east and the Hohokam to the south (and possibly the Cohonina to the west as well). It is not at all clear that they form their own root, but if they don’t it’s equally unclear which root they belong to. This may be more a flaw of the classification system than a real mystery about the people. Whether they belong on my list is dubious as well, as they are probably ancestral to certain Hopi “clans.” Still, enough doubt remains about their origins and fate that I thought it was worth mentioning them.

There are other groups as mysterious as these, including some whose very existence as cultural units is controversial (most notably the Salado of southeastern Arizona and adjacent areas). This list should give a general sense, however, of how much diversity there was in the prehistoric southwest and how little we know about the relationships among the various groups and their relationships to modern tribes. In this context, the Anasazi of the Four Corners don’t look particularly mysterious, and I suspect the unusual attention paid to them stems mostly from the picturesque nature of the remains they left behind, which certainly does distinguish them from most (though not all) of the other groups, which left less impressive architecture behind.
ResearchBlogging.org
Colton, HS (1938). Names of the Four Culture Roots in the Southwest Science, 87 (2268), 551-552 DOI: 10.1126/science.87.2268.551

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Rio Grande from Coronado State Monument, Bernalillo, New Mexico

Rio Grande from Kuaua Pueblo, Coronado State Monument, Bernalillo, New Mexico

Today is the winter solstice, which also makes it the fifth anniversary of this blog. I tend to like to post about archaeoastronomy on these occasions, and as I mentioned in the previous post I’m currently in Albuquerque and have been reading up on the archaeology of the Rio Grande Valley. Luckily, a recent article I read has a very interesting archaeoastronomical proposal specific to this region, which makes everything come together nicely. Getting to that point requires some explanation of the context first, however.

Today the northern Rio Grande Valley is one of the main centers of Pueblo population, and this was also true at the time the Spanish arrived in the sixteenth century. It’s been clear to archaeologists since the late nineteenth century that the modern eastern or Rio Grande Pueblos belong to the same overall cultural tradition as both the modern western Pueblos (Laguna, Acoma, Zuni, and Hopi) and the prehistoric Pueblo sites found all over the northern Southwest. Within this overall cultural tradition, however, there are noticeable differences in certain aspects of culture between the Rio Grande Pueblos and those further west, as well as between both groups and the prehistoric sites. The long and complicated history of interaction between the Rio Grande Pueblos and the Spanish has both led to cultural changes in this region and made the modern Pueblo residents very reluctant to reveal information about their cultures to anthropologists. Both of these phenomena make understanding the background of Pueblo diversity exceptionally difficult.

As a result, archaeological research in the northern Rio Grande area has proceeded along a somewhat different course from research further west. While extensive early research at well-preserved abandoned sites at places like Chaco Canyon and Mesa Verde led to the formulation of a robust and well-supported relative chronological scheme by the late 1920s that was soon anchored by the absolute dates provided by tree-ring dating, fitting the Rio Grande sites into this sequence proved to be a challenge. Alfred Vincent Kidder’s extensive excavations at Pecos provided clear evidence of continuity between prehistoric and historic Pueblo culture, which allowed the historic Pueblos to be easily placed at the end of the sequence, aligning earlier developments in the east and west proved to be a challenge. Pecos itself was founded quite late in prehistory, and very few other prehistoric sites had been excavated in the Rio Grande area. The so-called “Pecos System” of chronology and culture history was actually based primarily on western sites, and over time it became clear that it didn’t fit the emerging picture of Rio Grande prehistory pretty well. That picture, based primarily on survey and excavation work done by the Laboratory of Anthropology at the Museum of New Mexico starting in the 1930s, by the 1950s resulted in a new framework for eastern Pueblo prehistory.

The main architect of the new system was Fred Wendorf, an archaeologist at the Museum of New Mexico who had done a lot of the work of documenting sites in the region. He published a paper in American Anthropologist in 1954 describing his proposed system, which consisted of five periods:

  • Preceramic: Before AD 600
  • Developmental: AD 600 to 1200
  • Coalition: AD 1200 to 1325
  • Classic: AD 1325 to 1600
  • Historic: AD 1600 to present

Contrast this to the Pecos System, as presented by Joe Ben Wheat in a paper published in the same journal in the same year:

  • Basketmaker II: Before AD 400
  • Basketmaker III: AD 400 to 700
  • Pueblo I: AD 700 to 900
  • Pueblo II: AD 900 to 1100
  • Pueblo III: AD 1100 to 1300
  • Pueblo IV: AD 1300 to 1600

The most obvious difference between the two systems is that the Pecos System contains more periods. A more subtle difference is that in the Pecos System all of the periods are associated with agriculture, which appeared quite early in the Four Corners area. Exactly how early was not quite clear in 1954; Wheat says it was “about the time of Christ.” In the Rio Grande, on the other hand, the Developmental was the earliest agricultural period in Wendorf’s scheme as well as the first ceramic one, preceded by a Preceramic period that was totally undated at the time but that Wendorf suggested may have lasted quite late, even after the beginning of the Developmental.

This pattern of delayed appearance of typical “Anasazi” cultural phenomena in the Rio Grande persisted throughout Wendorf’s scheme. He defined the beginning of the Coalition period by the switch from mineral to organic pigment in pottery decoration, a trend which had been gradually diffusing east from Arizona over the past few hundred years. Similarly, the beginning of the Classic was defined by the appearance of glaze-decorated ceramics, which had appeared a few decades earlier in the Zuni area. The Historic period began with the onset of Spanish colonization. In general Wendorf’s period definitions depended heavily on trends in pottery decoration, in contrast to the Pecos periods which were defined by a broad suite of material culture changes, with architecture especially important. One reason for this was that architecture and other cultural traits were bewilderingly diverse within each of these periods, especially the Developmental, and this diversity was apparent even with the very small number of excavated sites at that time.

Palace of the Governors, Santa Fe, New Mexico

Palace of the Governors, Santa Fe, New Mexico

Wendorf’s scheme was in conflict on various points with a different scheme for Pueblo culture history as a whole developed by Erik Reed of the National Park Service. After Wendorf’s paper was published, discussions between the two led to an updated version of it published under both their names the next year in El Palacio. This paper has been extremely influential and the framework it established has been used by most archaeologists in the Rio Grande area since. The basic outlines of the framework are the same as those in Wendorf’s 1954 paper, with the changes involving the correction of the numerous typos in that paper, the addition of data from more recent excavations, and a somewhat different discussion of attempts to correlate archaeological phenomena with the complex distribution of modern linguistic groups. The latter was a particular interest of Reed, whose theories on it had been criticized by Wendorf in the earlier paper. I find it interesting as well, but I won’t get into it here.

Instead my focus here is on Wendorf and Reed’s Developmental period. Wendorf originally defined this period based on extremely limited information as a time of low population, diverse architectural styles and settlement patterns, and evidence of cultural influence from the San Juan Anasazi to the west. Population was extremely limited until about AD 900, when many more sites appear to have been inhabited and sites began to appear in the northern part of the region for the first time. This is the time of the rise of Chaco, and local Rio Grande ceramics show clear similarities to Chacoan types. Some archaeologists, including Reed, had argued that this rise in population came from an actual immigration of people from the Chaco area, but Wendorf doubted this, pointing out that other cultural traits showed considerable differences from Chacoan patterns. He suggested that while there could well have been some immigration from the west at this time, it was more likely from somewhere like the Mt. Taylor area that was part of the general Chacoan sphere of influence but closer to the Rio Grande, and that the number of people was likely small.

Architecture during the Developmental period was varied, with site sizes ranging from ten to 100 rooms and one to four kivas. The kivas were round and lacked most of the typical Chaco/San Juan features such as benches, pilasters, and wall recesses. They also usually faced east, in strong contrast to Chaco kivas, which usually faced south or southeast, even when they were associated with east-facing surface roomblocks (a common pattern for small houses at Chaco).

While the Wendorf and Reed system has remained in general use among Rio Grande archaeologists, the Developmental period in particular has seen much more data emerge from subsequent research, much of it associated with cultural resource management salvage projects. Cherie Scheick argued in a 2007 article that the period was much more diverse and complex than Wendorf and Reed had portrayed it as, illustrated by two nearby and contemporaneous sites in what is now Santa Fe that nevertheless had quite different ceramic assemblages which would place on in the Developmental period and the other in the Coalition period based on the Wendorf and Reed system. (This sort of thing is a major flaw with chronologies based mainly on ceramic styles, since time is by no means the only factor affecting differences in pottery.) Basically there seems to have been a long transitional period between the Developmental and Coalition in which communities with a variety of ceramic styles existed in close proximity. In particular, the introduction of carbon pigments seems to have been more variable than Wendorf and Reed realized, and they coexisted with mineral pigments for a substantial period. Scheick also points out that, contrary to what some earlier researchers had thought, there are no particular patterns over time in the architecture, such as larger villages developing later in the Developmental period.

Lurking in the background of all this research is the question of the abandonment of the Mesa Verde region and whether any of the apparent increases in population in the Rio Grande correspond to an influx of people from that area. Wendorf and Reed placed this migration in the middle of their Coalition period, with the appearance of a ceramic type, Galisteo Black-on-white, that is very similar to late Mesa Verde Black-on-white, and various other changes in material culture in the region that accompanied a population increase. However, recent research in the Mesa Verde region itself has suggested that the depopulation was a longer-term process beginning much earlier than previously thought, so some of the changes in the early Coalition period, could also be due to immigration. The basic problem is that while there are plenty of individual examples of similarity between San Juan/Mesa Verde culture and Rio Grande culture over a long period of time, there are no sites showing a complete package of San Juan cultural traits. There seems to be an emerging consensus that this is because the migration was primarily not of entire communities moving as units but of smaller units (families or lineages) that joined existing communities in the target region, perhaps ones that they had had earlier contact with through trade or other activities.

Round Kiva at Kuaua Pueblo, Coronado State Monument

Round Kiva at Kuaua Pueblo, Coronado State Monument, Bernalillo, New Mexico

An additional piece of evidence for this idea comes from the paper I mentioned at the beginning of this post, published by Steven Lakatos in 2007. Lakatos did an analysis of features in Rio Grande pit structures (kivas) during the Developmental period. He looked at size, orientation, and presence or absence of a hearth, an ash pit, a deflector, and a ventilator in a total of 131 excavated pit structures in the Rio Grande Valley dating to AD 600 to 1200. He looked at specific types of each of these features and came up with a wide variety of statistical comparisons. The sample sizes for most of the subsamples he looked at are so small, however, that I doubt many of these comparisons are meaningful. His overall conclusions, however, are probably reliable.

Lakatos found that there is a consistent pattern of features in pit structures throughout the Developmental period: hearth, ash pit, deflector, and ventilator, sometimes accompanied by sipapu and/or ash grinding stone, in a row aligned to the east-southeast (average azimuth from true north of 118 degrees for the Early Developmental period and 123 degrees for the late developmental). This is in strong contrast to the San Juan (Chaco/Mesa Verde) kiva pattern, where ash pits are rare, other features like benches and pilasters are common, and orientation is usually to the south or south-southeast. Lakatos notes that this Rio Grande kiva pattern continues into the Coalition period and later, as kivas become more formalized community-scale integrative structures, and while all the features in the complex potentially had originally mundane uses, the formalization of the pattern and its persistence over time suggest that at some point it acquired ritual significance. He notes the ritual importance of ash to modern Rio Grande Pueblos as a way of explaining the ash pit and ash-grinding stone as ritual features. The persistence of the pattern into the Coalition period and beyond suggests to Lakatos that immigrants to the Rio Grande from Mesa Verde and elsewhere not only joined existing communities, but largely assimilated to existing religious and cultural practices in an area that had developed a distinctive identity already. Thus, the reason it is so hard to pinpoint continuity between San Juan and Rio Grande archaeological sites is that the San Juan immigrants changed their culture to conform to Rio Grande practices.

I’m not sure I buy that there was quite as much continuity in the Rio Grande as Lakatos and other Rio Grande archaeologists tend to think. Looking at it from the outside, the ceramic evidence certainly seems to imply at least some continuity with Mesa Verde culture, and a close examination of what little ethnographic information is available on the Rio Grande Pueblos may reveal other traits of western or northern origin. Still, Lakatos’s evidence for continuity in kiva form looks convincing to me, and the patterns he identifies are certainly quite different from those of Chaco and Mesa Verde. The fact that his interpretation meshes well with other research suggesting migration by small groups into established communities is also encouraging.

So what does all this have to do with the winter solstice? Well, Lakatos also calculated the azimuth of winter solstice sunrise for the Albuquerque area in AD 1000, and it was 119 degrees east of north. This is strikingly similar to the average azimuths of the kiva alignments he analyzed, which have small standard deviations indicating strong clustering around the average values. The variation that does exist could easily correspond to local horizon variation in this rugged, mountainous region. Lakatos expresses surprise at this finding, but it makes perfect sense to me. The winter solstice is an enormously important event for the modern Pueblos, as Lakatos discusses, and pointing their kivas toward it would be a natural response to that importance. And with that in mind, I wish all my readers a happy solstice.

ResearchBlogging.org
Lakatos, SA (2007). Cultural Continuity and the Development of Integrative Architecture in the Northern Rio Grande Valley of New Mexico, A.D. 600-1200 Kiva, 73 (1), 31-66

Wendorf, F (1954). A Reconstruction of Northern Rio Grande Prehistory American Anthropologist, 56 (2), 200-227 DOI: 10.1525/aa.1954.56.2.02a00050

Wendorf, F, & Reed, EK (1955). An Alternative Reconstruction of Northern Rio Grande Prehistory El Palacio, 62 (5-6), 131-173

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Palace of the Governors, Santa Fe, New Mexico

Palace of the Governors, Santa Fe, New Mexico

I’m currently in Albuquerque visiting my mom, and while I’m here I figured I read up on the archaeology of the Rio Grande Valley and do some posts on it. I’ve read some interesting articles from the journals I have access to, and I’ll have some substantive posts soon based on that, but one thing that has limited me so far is that so much of the early archaeological literature on this region was published in El Palacio, the magazine of the Museum of New Mexico (named after the Palace of the Governors, the original location of the museum). Today this is basically a glossy (but serious and substantive) magazine aimed at a popular audience, but in its first few decades it functioned more like a scholarly journal and was the primary venue for publication of research on the archaeology, anthropology, and history of northern New Mexico.

The problem with this for someone like me had been that, unlike other major publication venues for this kind of research that have evolved into (or been created as) peer-reviewed scholarly journals, El Palacio is not included in any of the major academic databases, and it could only be found on paper in libraries that happened to subscribe to it. This made it effectively impossible for me to access it, given geographic and time constraints, so I was at a distinct disadvantage in understanding the archaeology of this region.

That’s all changed, however. I discovered today that, apparently as part of the commemoration of the magazine’s centennial this year, El Palacio has put its entire archive online. The interface is a little clunky, and it looks like it’s only possible to download pdfs of entire issues rather than individual articles, but this is still a fantastic resource that has suddenly become vastly more accessible. Given my general interest in open access publishing and making data broadly available, I figured it was worth doing a post to point this out. I’ll have some more posts on the actual archaeology of the northern Rio Grande soon.

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"Supernova" Pictograph

“Supernova” Pictograph

I recently finished reading Living the Sky: The Cosmos of the American Indian by Ray Williamson. This is a classic work on the archaeoastronomy of North America, and it’s the best introduction to the subject I’ve found. (Granted, there aren’t many out there.) Although it was written in the 1980s, the research it discusses is still quite relevant, and Williamson does a good job of giving a pretty comprehensive overview of research in most parts of the US. The 1970s and 1980s were kind of the heyday of archaeoastronomy in the US, and while there has been continuing research since then, it’s striking how few major discoveries have been made since Williamson’s book was published. Virtually all of the major discoveries I knew about before reading the book are included, plus many others I didn’t know about.

Williamson did quite a bit of research himself on astronomical phenomena at Chaco, which gets lots of coverage in the book. There is some discussion of the Sun Dagger on Fajada Butte, as well as of alignments at Pueblo Bonito and Casa Rinconada and the alleged “supernova petroglyph” near Peñasco Blanco. Williamson gives the latter a lot more credence than others, and actually has a whole chapter on alleged representations of the 1054 supernova in rock art, including several other sites I had not heard about. I’m pretty skeptical about the supernova stuff, but it’s interesting to hear about these other sites.

Reconstructed "Woodhenge" at Cahokia

Reconstructed “Woodhenge” at Cahokia

While the Chaco stuff is interesting, I already knew most of it and Williamson’s account doesn’t add a whole lot to anyone who is reasonably well-versed in it. Where this book really stands out for me is in its discussion of archaeoastronomy in other areas that get less attention, especially the Plains and California, which have a lot of archaeoastronomical phenomena despite their lack of impressive well-preserved architectural sites like those in the Southwest. The chapter on the East is also interesting, with discussion of the famous “Woodhenge” at Cahokia and the “SunWatch” site in Dayton, Ohio as well as other lesser-known sites. Even within the Southwest, Williamson devotes space to research at more obscure places like Hovenweep (which turns out to have a lot of interesting potential alignments) as well as major centers like Chaco.

Williamson also does a good job of connecting the archaeological data to ethnographic reports about astronomical practices among modern groups. There has historically been a tendency for archaeoastronomers, many of whom are astronomers or surveyors by training, to focus on identifying alignments without giving much consideration to the cultural context in which they may have existed. Williamson avoids this pitfall by giving extensive attention to ethnographic practices and their potential connections to the evidence from ancestral sites. He does a particularly good job with respect to the Pueblos, for which both the ethnographic and archaeological data are extensive, but he also includes extensive discussion of the Navajo, Pawnee, and Chumash, and some attention to various other groups. His interpretations of the ethnography at times show a tendency toward oversimplification, and some of his general comments about Native American societies are, well, overly general and imply more widespread commonalities among very different societies than is really reasonable, but he’s not an anthropologist and as such I think these flaws are quite forgivable given all the interesting data he presents in accessible form.

Hovenweep Castle, Utah

Hovenweep Castle, Utah

I also read a 2003 review article on archaeoastronomy in the Americas, written by prominent archaeoastronomer Anthony Aveni, to get a sense of research since the 1980s, but it didn’t add much. For one thing, as mentioned above, the pace of archaeoastronomy seems to have leveled off a lot since then, and it’s striking how many of the references in Aveni’s article are to publications from the 1970s and 1980s. Also, while the article does cover North America as one of its three main sections, it spends much more space on the other two sections, Mesoamerica and South America. This is unsurprising, since the major civilizations in these areas have written records (mostly from the contact period but in the case of the Maya precontact as well) to which archaeological data can be compared. In addition, they have just received more attention in general from archaeoastronomers than cultures further north. Aveni himself studies Mesoamerica, so he has a lot to say about research there.

That said, however, Aveni’s account of North American archaeoastronomy is also surprisingly sloppy and riddled with obvious errors. He refers to Cahokia as “part of the Adena-Hopewell culture,” which is just laughably wrong; Cahokia is the preeminent site of the Mississippian culture, which arose centuries after the decline of Hopewell. He also attributes the Poverty Point site in Louisiana to the Adena, whereas it is actually significantly earlier. His discussion of the Southwest doesn’t contain any obvious errors of that magnitude, but it is very brief and superficial, as is the whole North American section of the paper.

Fajada Butte with Green Vegetation

Fajada Butte with Green Vegetation

Overall, then, I guess I would say that Williamson’s book is a much better introduction to North American archaeoastronomy than Aveni’s article, but that is kind of a trivial conclusion since it’s also much easier to find for the general reader. Even academics who have access to the Aveni paper, though, probably won’t get much out of it on this topic.
ResearchBlogging.org
Aveni AF (2003). Archaeoastronomy in the Ancient Americas Journal of Archaeological Research, 11 (2), 149-191 DOI: 10.1023/A:1022971730558

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Utah Welcome Sign

Utah Welcome Sign

The initial discovery of chemical markers for chocolate on potsherds from Chaco Canyon in 2009 was a hugely significant development in understanding Chaco. The evidence for the presence of chocolate, a Mesoamerican product that couldn’t possibly have been locally grown and is very unlikely to have been gradually traded northward through a series of intermediaries, gave a huge boost to the “Mexicanist” school of thought about Chaco, which holds that many of the unusual aspects of the Chaco system are due to influence from Mesoamerica.

The initial study only involved a few sherds, though, and understanding the exact role of chocolate at Chaco and its implications for Mexican contact needs a much deeper understanding of where and when cacao was present in the ancient Southwest. Thus, soon after the initial discovery further research by a different set of researchers (using somewhat different methods) began to test other pots from Chaco and elsewhere. They did find further evidence that at least some of the famous cylinder jars from Chaco were used in the consumption of chocolate, but they also found traces of cacao in vessels of similar form from the later Classic Hohokam period in southern Arizona, and, most surprisingly, also in vessels from the “small-house sites” at Chaco and elsewhere that are thought to have housed the lower classes of Chacoan society. The previous evidence for chocolate came from distinctive vessels at the “great houses” that are the hallmark of the Chaco system and seem to have been used by elites (though exactly what they used them for remains unclear and controversial). This is exactly the kind of setting where it would be unsurprising to find unusual, exotic things, and indeed the great houses clearly contained many such things in addition to the chocolate. Finding this sort of exotic foodstuff in more mundane pots at the small houses implies that it may have been more widely accessible than previously thought, which has important implications for understanding the nature of the Chaco system.

Well, now things have become even more complicated. The same researchers who did that follow-up study have done another, this time looking at a much earlier period and a different part of the Southwest. They used their same techniques to test for the presence of chocolate in pottery at Alkali Ridge Site 13 in southeastern Utah, a very important early village site dating to the eighth century AD. Site 13 was one of the earliest large villages established in the northern Southwest during the Pueblo I period, and its architecture shows some striking parallels to later Pueblo I villages such as McPhee Village in the Dolores, Colorado area, as well as to some of the early great houses at Chaco and elsewhere that developed even later. The early Pueblo I period in southern Utah is also associated with the introduction of a new type of pottery, San Juan Red Ware, which was widely traded from an apparently rather restricted production area and probably used for ceremonial purposes of some sort. In addition to being a different color from the more common gray and white pottery of the area, San Juan Red Ware also featured a distinctive design system in its decoration, one without obvious local antecedents. Combined with the distinctive architecture, this has led some archaeologists to posit that there was a migration into southern Utah during early Pueblo I from somewhere to the south, bringing these distinctive traits.

In that context, looking for cacao makes sense, as that would be a clear sign of ties to the south and cultural distinctiveness. Dorothy Washburn, who was the lead author on both this and the previous study,  has actually written mainly on design style in ceramics and other handicrafts, focusing on symmetry patterns. Based on the changes she has found in these patterns, she has argued for a very strong Mexicanist interpretation of Chaco, involving actual migration of people from far to the south bringing a distinctive pottery decoration style. She seems to have a similar view about Alkali Ridge, for similar reasons.

In any case, the study found that there was in fact evidence for cacao on several of the vessels found at Site 13, including some (but not all) of the redware ones. The conclusions, understandably, focus on the association between the new ceramic design system and the use of chocolate, but in fact the redware vessels don’t seem to be much more likely to have evidence of chocolate use than the other ones that were tested. It’s quite possible that San Juan Red Ware was associated with consumption of chocolate specifically, but it seems that other types of pottery were also used for chocolate-related purposes.

This is all very interesting, but it’s also confusing and hard to interpret, in a way that the authors of this paper don’t really address. Back when it seemed like chocolate was limited to cylinder vessels at Chaco great houses, that was easy to interpret: chocolate, like many other exotic goods found at these sites, was part of an extensive trading systems for elite goods, probably used for ritual purposes, which the elites of Chaco participated in (and perhaps dominated and directed). Finding it in the Hohokam vessels implied a similar system operating among elites at Classic Hohokam sites, which is consistent with some interpretations of Classic Hohokam society, plus the Hohokam in general show lots of evidence of contact with Mesoamerica in general so the presence of chocolate is much less surprising there than it was at Chaco. Finding it in the small houses at Chaco complicated the story somewhat and implied that the chocolate imported to Chaco wasn’t as restricted as had been thought, but since it was already known to be present at the great houses it’s not too surprising that the contemporaneous small houses had it too.

Alkali Ridge, though, is much earlier and much further north than any of these other sites. Getting chocolate there in significant quantities would have required a pretty elaborate and robust supply chain over a very long distance, much of which was inhabited by societies that are not generally considered to have been capable of this kind of long-distance coordination. Checking some of those intermediate areas (especially the Hohokam region) to see if they too had chocolate this early is necessary to understand the logistics of this.

There’s also the question of time. We now have evidence of chocolate from Utah in the eighth century, New Mexico (and to a lesser extent Colorado and Arizona) in the eleventh, and Arizona in the fourteenth. There are some big gaps there that need to be filled in to determine if these are three snapshots of a long-term and continuous tradition of chocolate consumption in the Southwest (which would have important implications about trade networks and relations with Mexico) or three separate episodes of chocolate being introduced from the south, possibly through population movement (which would have important implications for regional culture history in general). I think the most important place to look for evidence of continuity between Alkali Ridge and Chaco is in the large late Pueblo I villages in southwestern Colorado, especially the Dolores-area ones like McPhee Village. These sites have apparent connections to both earlier villages like Site 13 and later developments at Chaco. If they also reveal evidence for chocolate use, that would be a strong indication of continuity. The most important places to check for continuity between Chaco and the Classic Hohokam would probably be the Pueblo III communities in east-central Arizona, which again show connections in both directions. Both of these sets of sites are among the best-studied in the Southwest and there should be plenty of pots available for these analyses.

Finally, there is a methodological issue here. It’s possible that these tests aren’t actually detecting chocolate at all, but something else. The authors of the recent paper noted this possibility and looked into whether there are any plants native to the Southwest that might have chemical profiles similar to cacao that would throw off the analysis. They didn’t find any, but they note that many plants have not been analyzed in this way and it’s possible there is a different plant that is showing up in these analyses instead. Another possibility is that there is something about their method itself that is leading to false positives. It’s noteworthy that they have been finding much more extensive evidence of chocolate than the team, led by Patricia Crown and Jeffrey Hurst, that did the initial Chaco study found. That team hasn’t published any more about chocolate at Chaco since then, but I hear Crown was able to do some re-excavation in Room 28 at Pueblo Bonito this summer so there may be more from her on this in the future. Ideally I’d like to see a test of both methods on the same vessels to see how they match up.

The ultimate message here is that even important discoveries, like chocolate at Chaco, require many further studies and refinements to interpret properly. We’re nowhere near a full understanding of the true role of chocolate at Chaco or any other site in the prehistoric Southwest, but every study gets us closer.
ResearchBlogging.org
Washburn DK, Washburn WN, & Shipkova PA (2013). Cacao consumption during the 8th century at Alkali Ridge, southeastern Utah Journal of Archaeological Science, 40, 2007-2013 DOI: 10.1016/j.jas.2012.12.017

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Black-on-white Sherd at Pueblo Alto

Black-on-white Sherd at Pueblo Alto

In keeping with what seems to be the recent pattern around here, my previous post led to some interesting discussion in the comments. Frequent commenter marcaeolog provided a link to a pdf version of Anna Shepard’s Ceramics for the Archaeologist, a classic work that challenges some of Florence Hawley’s theories that I discussed in the post. Andy Ward, who has done extensive experimental work attempting to recreate prehistoric pottery-making techniques, then chimed in with some information on his own efforts, focusing specifically on the question of what keeps carbon-based pigments from burning off during firing. Here’s part of his comment:

I have been doing research in just this area by collecting clays and firing them in open mesquite fires. While it is easier to keep carbon based paint on a pot in a reducing atmosphere this doesn’t account for polychromes. To make polychrome with a carbon based paint, like the ubiquitous Gila Polychrome, requires an oxidizing atmosphere. Certain kinds of clays have the ability to hold these carbon paints through a firing, bentonite clay in particular. Modern pueblo potters have used a slip called Cochiti slip which has these properties, ancient potters in cultures such as the Salado had access to similar slips.

As it turns out, Shepard had the same theory, based on her own experiments, which also provided solid evidence against Hawley’s theory, based on experiments with hydrofluoric acid, that it was compounds in the ash of the organic material that reacted with silica in the clay to protect the pigment from burning away. She acknowledged that this was a reasonable conclusion based on the information available to Hawley at the time, but Shepard’s own experiments comparing organic material with and without this sort of ash showed no substantial difference. Instead the biggest factor was clay type:

The most striking fact brought out by these tests is the effect of the type of clay on the permanence of the carbon. Bentonitic and other highly adsorptive clays retained a good black under firing conditions that completely oxidized the carbon on unnadsorptive, sedimentary clays. All of the clays that held the paint well required a high percentage of wafer to bring them to the plastic state and they had high shrinkage. These clays take up much more of the paint solution than the less adsorptive clays, and on drying, the clay plates are drawn tightly together, protecting the film of paint that surrounds them. The effectiveness of hydrofluoric acid in facilitating oxidation of carbon paints is explained by the fact that it attacks the clay, opening the surface and loosening the bond and thus exposing the carbon to air.

The upshot of this in cultural terms is that, contrary to what I said in an earlier post, it seems like the difference between mineral- and carbon-based black pigments is actually technological rather than cultural. Here’s Shepard again:

The relation of the type of clay to the depth of color of carbon paint from a plant extract is not a matter of merely theoretic interest to the technologist. It has a bearing on the distribution of this class of paint because it could not be produced in regions lacking adsorptive clays unless such clays could be obtained in trade. The use of plant extracts is not open to free choice or established merely by custom; it is limited by ceramic resources.

This is particularly interesting given the well-documented expansion of carbon-based pigments at the expense of mineral ones over the course of the late prehistoric period. If special clays were required to make this work, and those clays had restricted distributions, what accounts for the change? In areas that switched from mineral to carbon paint, such as Chaco, was this the result of a change in clay sources? The discovery, perhaps due to increased contact with other areas that had long used carbon, of which local clay sources worked for this? Importation of clay? Importation of finished pots? This raises a lot of questions, which to my knowledge have not received much attention in the archaeology of these areas, despite the fact that it’s now been several decades since Shepard’s research.

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Black-on-white Potsherd at Kin Bineola

Black-on-white Potsherd at Kin Bineola

“Never read the comments” is generally sage advice, so it’s likely that many of my readers have missed the interesting comment thread in response to my previous post. I won’t try to summarize it all here, but the gist is that a potter showed up and took issue with my use of the word “paint” to describe the pigments applied to prehistoric Pueblo pottery. Apparently, while archaeologists routinely refer to these pigments as paints, that’s not actually an accurate characterization and they are instead best described as types of “slip,” a term that archaeologists usually use only for the underlying layer of thin clay that the “paints” are often applied to. There’s a long history of archaeologists appropriating and misusing terminology from other fields, so it’s not surprising that they would have done this in this case too, but I’m not sure how best to proceed with the terminology, as it is pretty useful in practice to be able to distinguish the underlying “slip” from the “painted” designs on top of it. For now I’ll try using the (hopefully) more neutral term “pigment” for the “paint” and continue to use “slip” for the underlying clay.

Another issue that came up in the discussion, however, is separate from the terminology. This is the question of how the carbon-based pigments that are so well known from many parts of the Southwest could have adhered to pots after firing at all. After all, at the temperatures necessary to create usable ceramics any purely carbon pigment would burn right off. As I started to think about it, I realized that this was indeed a puzzle, and I went looking back into the literature to see if it had been addressed anywhere.

As it turned out, it had, and in the very first research on this subject, that of Florence Hawley in the 1920s. Hawley was an important figure in Southwestern archaeology throughout much of the twentieth century, and her early chemical studies of pottery pigments were fundamental in establishing the classification system by which they have been interpreted ever since. The most important aspect of this system was the division between “carbon-based” and “mineral-based” black pigments, although looking back at her initial publication on this topic from 1929, it’s clear that the dichotomy is more subtle than the terms imply. In fact both types of pigment contain both carbon and mineral elements, the difference being the relative proportions and the specific minerals involved. Both involve the boiling of certain plants, usually Tansy mustard or Rocky Mountain beeweed, to create a thick, black substance that can be applied to an unfired pot with a brush. The carbon type consists only of this substance, while the mineral type involves a subsequent step of adding ground iron oxide before applying it to the pot. Hawley also identifies a third type using manganese, which she speculates was used for certain types of pottery made of clay to which the usual carbon pigment wouldn’t adhere properly. (She also identifies a fourth type, so-called “smudged” pottery, that resulted from adding organic material after firing and letting it sink into the clay. This type is generally associated with the Mogollon culture in the highlands of east-central Arizona and west-central New Mexico and is quite different from the others in appearance.)

The chemical tests Hawley suggests to distinguish among these types of pigment are complicated and involve the use of dangerous acids, so they have not caught on as routine methods for archaeological analysis in more recent years. The tests appear to have been worked out and conducted mainly by Hawley’s father Fred Hawley, who was a chemist at a smelter in one of the mining areas of Arizona. Instead of these tests, archaeologists have generally tried to learn to distinguish the more common types by sight. As one of the papers I discussed earlier found in a test of this method, it works pretty well except in more marginal cases that are difficult to interpret using the standard visual criteria. The methods that have been proposed more recently using modern imaging technology have also not yet become very popular. In general the visual criteria seem to work fine.

As I noted in the previous post, the fact that both organic and mineral pigments seem to work to create black designs, but the mineral type is basically the same as the carbon one, raises the question of why there were two types at all. I suggested that cultural tradition rather than technological considerations probably was the main factor. Hawley doesn’t address the question in those terms, but she does argue that the different pigment types correspond to different cultural traditions, and the second half of the paper consists of her conclusions about cultural provinces and their spheres of influence based on pigment types through time. Her basic scheme of carbon pigments predominating in western areas and mineral pigments further east has generally held up, but otherwise her interpretations show how little was known at the time about Southwestern prehistory. She was clearly writing before tree-ring dating had established a firm foundation for the absolute chronology of cultural developments and pottery types, and the assumptions she makes about which sites were contemporary are strikingly wrong in light of that chronology. This makes her conclusions about changing patterns of cultural influence through time basically useless.

All that said, what about the question I mentioned earlier? How does the carbon pigment survive firing? Hawley’s answer, backed up by the chemical tests, was that it actually contains some mineral inclusions in addition to the carbon, especially silica and carbonates that melt in the process of firing and form a very thin film over the carbon that protects it from burning away. She considers this layer too thin to be considered a glaze, but it appears to serve the same basic function. It only works, however, when firing is in a reducing atmosphere, i.e., with oxygen prevented from reaching the surface of the pot. It’s not totally clear from her explanation where these mineral compounds come from, but the implication seems to be that some are from the plants from which the pigment is made and others are perhaps from the clay of the underlying pot. In the case of the mineral pigments, these potential sources are complemented by the trace silica in the iron oxide. As the more recent papers note, this interpretation has been questioned by others, most significantly Anna Shepard (another pioneering ceramic analyst at the same time as Hawley). It seems clear, however, that getting these pigments to survive firing requires some sort of chemical reaction along these lines, involving compounds in the pigment and/or the clay, along with a reducing atmosphere during the firing process itself.

It turns out pottery is pretty complicated! Archaeologists usually use pottery types primarily as a means to date sites and establish trade relationships, but studying potsherds intently with an eye to technological issues can reveal a lot of additional and potentially useful information.
ResearchBlogging.org
Hawley, FM (1929). Prehistoric Pottery Pigments in the Southwest American Anthropologist, 31 (4), 731-754 DOI: 10.1525/aa.1929.31.4.02a00110

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