Bipolar Lithic Technology at Post-Classic Calixtlahuaca?!

By Dr. Bradford Andrews

P1: Bipolar technique

Analysis of the Calixtlahuaca stone tools has revealed that bipolar percussion was used to make stone tools in the city. So, what exactly is the bipolar technique (BP)? BP involves striking the top of a piece flakable stone placed on an anvil stone (see picture P1). As such, it enables the knapper to transmit force from both “poles” of a “focal” piece (Flenniken 1981). It is also effective for making implements out of small pieces of stone that are difficult to flake because the knapper is able to securely support them allowing for efficient flaking.
BP as a common technique for making stone tools is usually associated with the early Formative period (2000 B.C. to A.D. 250). By the late Formative, prismatic blade technology began to emerge, becoming the most important source of slicing, cutting and scraping tools in Mesoamerica in the centuries that followed (Clark 1981; Parry 1987). Hence, many people tend to think BP was largely absent in Mesoamerica after the Formative. So, the simple fact that the Calixtlahuacans were using it is somewhat of a surprise.
Of more than 6000 technologically diagnostic artifacts (those with features that indicate how they were produced), 11 percent were flaked with BP technology. This figure is not a majority, but it is significant. The BP artifacts we have identified include BP-flakes, “Scalar cores,” and bipolared blade sections. The BP-flakes (see picture P2) are variously shaped and have flake scars with ripples of force trending in opposite directions. Some were presumably flaked to make smaller tools - some were also used because they have use-wear on one or more edges.

P2: Bipolar flakes

The scalar cores are an odd, somewhat controversial artifact
because of the debate over their function (see picture P3). The term we use for this artifact is barrowed from Clark’s (1981) work in Formative period Chiapas. Artifacts similar to this one include the “scaled flake” (Parry 1987) and the piéce esquillées (Hayden 1980). One question is whether these three items were functionally different or had overlapping uses. They could have been used as 1) “bipolar cores” that yielded flakes, 2) and/or “chisels” or “wedges” used for some specific task, perhaps woodworking. My guess is that they had both functions.

P3: Scalar core, front and
back views

The bipolared blades are sections of prismatic blades (made with the blade technology), which were later “smacked” with bipolar percussion (see picture P4). Note the ripples of force coming from both ends towards the center of the segments. Also, some have a “burinated” fracture surfaces – what Clark (1981) calls bipolar corner flakes - along their lateral edges. These fractures are distinct in form. Similar features are visible on segments of experimentally bipolared blades (see pictures P5, P6). Archaeologists sometimes try to replicate the technological characteristics of archaeological artifacts, something called experimental archaeology. In this way, archaeologists are better able to interpret how tools were made. Other “bipolared” blade sections have been reported from Formative San Lorenzo (De León 2008) and the Valley of Oaxaca (Parry 1987:figure 22).

P4: Bipolared blades -top
dorsal, bottom ventral view

So why was bipolar technology used at Calixtlahuaca? The general perspective is that bipolar technology was a simple “non-specialized” way of making tools, and was primarily used in places where obsidian was relatively scarce (Clark 1981; Parry 1987). Therefore, it has been viewed as a means by which knappers worked or recycled tool stone (nodules, “used-up cores,” or used-up implements like bifacial knives, etc.) to maximize the amount of cutting edge available. Recent research, however, has shows that bipolar technology was present in areas of Formative Mesoamerica where obsidian was relatively abundant (De León 2008). Its use probably had less to do with scarcity, and more to do with the size of raw material available; in particular, it seems to have been used a lot when tool stone was available in small pieces. This interpretation may be consistent with its use at Calixtlahuaca.

P5: Experimental
bipolar flaking

As my previous post on stone tools indicates, 75% of the obsidian was gray. We still have yet to chemically source the gray obsidian, but we think much of it came from West Mexico. It is also the case that most of the obsidian artifacts are not large pieces (<10 cm maximum dimension, most are much smaller) and we have no evidence of blade production in the city; we think ready-made blades and blanks used to make bifaces arrived in the city, perhaps via the market system. As such, many of these imports were relatively small – if the inhabitants of the city wanted to flake any of this material further still, bipolar technology would have provided an efficient means for doing so.

P6: Experimental blade
sections - top ventral,
bottom dorsal

What is particularly interesting is that after Calixtlahuaca became part of the Aztec Empire in 1474, the amount of green obsidian from Pachuca rose significantly. Preliminary figures from dated houses indicate that from the Dongu (A.D. 1100-1300) to the Yata (A.D. 1470-1530) phases green obsidian increased from 11% to 48%. This shift is coincident with an increase in blade-core artifacts, more than 60% of which were green. This shift is also coincident with a decrease in the amount of bipolar artifacts, which dropped from a high of 17% in Dongu to a low of 7.6% by the Yata phase.
Calixtlahuaca’s incorporation into the Aztec Empire meant more Pachuca green obsidian reached the city. Moreover, if prismatic blades were preferred and were more readily available in the Yata phase, then perhaps there was less pressure to recycle using bipolar technology. Ongoing research, including a chemical study of the gray obsidian artifacts will be evaluating these trends and what we think they indicate about life at Post-classic Calixtlahuaca.

References
Clark, John E.
1981 The Early Preclassic Obsidian Industry of Paso de al Amada, Chiapas, Mexico. Estudios de Cultura Maya 13:265-283.

De León, Jason
2008 The Lithic Industries of San Lorenzo-Tenochtitlán: An Economic and Technological Study of Olmec Obsidian, Penn State University.

Flenniken, J. Jeffrey
1981 Replicative Systems Analysis: A Model Applied to the Vein Quartz Artifacts from the Hoko River Site. Washington State University Laboratory of Anthropology. Submitted to Reports of Investigations. Copies available from 59.

Hayden, Brian
1980 Confusion in the Bipolar World: Bashed Pebbles and Splintered Pieces. Lithic Technology 9(1):2-7.

Parry, William
1987 Chipped Stone Tools in Formative Period Oaxaca, Mexico: Their Procurement, Production, and Use. Memoirs of the Museum of Anthropology. University of Michigan, Ann Arbor.

Day of Archaeology, 2011

Angela Huster

Last Friday, the Day of Archaeology 2011 project collected blog entries from archaeologists around the world about their day. While not that different than my last posting on this blog, my description of a day in the Calixtlahuaca lab can be found at:

http://www.dayofarchaeology.com/aztec-archaeology-at-calixtlahuaca-or-not-one-of-my-better-days/.

Lab Reorganization

By Angela Huster

Having finally worked out both context and chronology for most of our excavated lots, we’re now in the process of separating the material that we want to keep from that which will be discarded once we have permission from INAH. Ceramics currently fall into one of four categories – Already classified, to keep; Already classified, to discard; To classify, then discard; and To briefly skim, then discard. We are keeping classified material from the domestic context sample and a handful of other contexts, while most of the lots that are being skimmed and tossed are from plowzone, slopewash, modern terrace fill, or other mixed contexts. Like all archaeological collection storage, deciding what to keep is a fine balance between the available storage space (and cost), the research potential of the material, and the odds that anyone will actually get around to looking at it in the future.

This process has resulted in two simultaneous sets of activities. Judith, Delfina, and Janeth are consolidating the lots in each of the first three categories. They’re moving the lots that we’re keeping to the shelves against the back wall of the lab at the same time that they’re moving the lots to be discarded toward the front of the lab so that the boxes will be easier to haul out of the lab.

At the same time, Julia, Shelia, and I are skimming the lots from very marginal contexts for miscellaneous items (figurines, spindle whorls, pipes, molds, etc), and good examples of decorated types to add to the type reference collection. This has been unexpectedly productive, considering that the lots were skimmed once when they were originally washed. We have found three spindle whorls, at least four figurines, a ceramic lip plug, and a reconstructible (if highly eroded) tripod bowl, among other things.

At this point, the entire process has been going incredibly smoothly, and we owe the fact that we are ahead of schedule to the lab ladies.

The 1563 Calendrical Relief

In talking about the 1563 calendrical relief shown in my previous post, Angela suggested that it could be a foundation monument. In 1561 the town of San Francisco Calixtlahuaca was founded following Spanish law (a decree from the Viceroy). If there were Nahuatl speakers among the new residents who retained a notion of ancient altepetl ceremonies and procedures, perhaps they had the relief carved to give the new town a measure of traditional legitimacy.




I was in the village Saturday, delivering copies of our reports to various people, and I realized that I wasn't sure where my photos were of the cemetery church and the relief. So I went over and took some new photos. The light was very good on the relief. Why is it incorporated into the church wall? When was it put there? What does it tell us? Wish I knew.



I'm not sure what year this church dates to. Its probably discussed in one of the books on Franciscan church architecture in the State of Mexico, but my copies are back home in Arizona. Here are some images of the front of the church. If you can date the church stylistically, let us know! My guess is 17th or 18th century.

And finally, here is a view of the site from in front of the cemetery:

What happened to the people of Calixtlahuaca after the Spanish conquest?

Most Aztec-period cities and towns continued on as Spanish-colonial cities after the Spanish conquest of 1521. From Mexico City to Cuernavaca to Xochimilco to Texcoco, and many others, these towns were settled by Spaniards (sometimes only a few, sometimes many).. Christian churches were built and the towns flourished in the Colonial economy and on into modern times, where they still exist today.

But not Calixtlahuaca. This Matlatzinca city went from a populated urban center and political capital to an abandoned ruin within a few decades after the Spanish conquest. The city of Toluca, on the other hand, was either nothing or a small village in pre-Spanish times -- no credible archaeological site has been found for pre-Spanish Tollocan. But by the mid-1500s Toluca had a large Franciscan church and convent, and the city went on to become capital of the state of Mexico, and the country's fourth major industrial center today.

We know that the occupation of at least some of the houses at Calixtlahuaca continued for a couple of decades after 1521, because we find ceramic figurines with Spaniards in Spanish dress and poses (see photo). These are in the final occupation layers  of the site. But we don't think the occupation continued much beyond a few decades, because we did not find colonial middens with cow and horse bones, glazed ceramics, iron nails, etc. This lack of 16th century colonial debris is not a definitive indication of abandonment, however. In the Teotihuacan Valley, Tom Charlton reported years ago that rural Aztec villages continued functioning for up to a century after 1521 without obvious colonial material remains like these. But Calixtlahuaca was not a rural village - it was the most powerful capital between Tenochtitlan and the Tarascan Empire. So if it HAD continued to be occupied, we would expect to find things like: (1) a sixteenth century church; (2) these kinds of Spanish colonial artifacts.

So, what happened? Most likely, the residents of the city were forcibly moved into Toluca. The Spanish authorities instituted a practiced called "congregación" in which they moved native peoples into towns and cities (the better to control them, to con vert them, and to tax them). Many of the congregaciones left evidence in Spanish official archives, but any documents describing a congregación to Toluca have unfortunately not survived (Jarquin 1994).

But the abandonment of Calixtlahuaca is likely, given that in 1561, the Spanish crown granted land to found the village of San Francisco Calixtlahuaca, which was the origin of the modern town of the same name. I looked at the official decree today in the Archivo General Agrario in Mexico City. The text is accompanied by a crude map, showing the lands granted to the new town. Not being a paleographer, I had trouble reading the sixteenth century handwriting. There is a brief description in a catalog of the archive, however (Olmedo 1998:84).  If the residents of Calixtlahuaca had kept living at the site, or if they had moved down off the hill to the site of the historical town, one would not think that the crown would issue a decree founding the town.

This area was part of the "Marquesado del Valle" estate of the conqueror Hernando Cortés. Soon after 1521 he started raising cattle and pigs in the vicinity of Calixtlahuaca, and the new town in 1561 was probably populated by his employees or subjects.

The main church in San Francisco Calixtlahuaca today dates to the nineteenth century. But the small church at the cemetery, just outside of town, is much older. Perhaps this was the main church from the sixteenth century, or perhaps an older church was torn down to build the modern one. The cemetery church has a fascinating carved stone relief embedded in its wall. This drawing is by Hanns Prem from 1970 (see Prem 1980).. The relief shows the Christian date at top "1563 año", and the date for that year in the Aztec calendar at the bottom (6 Reed). We have no idea whether this relief is from the village or from another place entirely. It would be fascinating if 2years after the founding of the new colonial town, someone put up a carving in both the Spanish and Aztec calendars. By the 1700s, there were at least some Nahuatl speakers in San Francisco Calixtlahuaca, as evidenced by a will published by Caterina Pizzigoni (2007).

This model is still somewhat speculative. We would love to have more data on what happened to all those people in the early to mid sixteenth century. According to published catalog, the Archivo General Agrario supposedly has another map and document from San Francisco Calixtlahuaca, from 1575 (Esparza et al. 2000:160-161), but they could not find it at the archive today (even when I showed them the published catalog entry). Maybe we will find additional sixteenth century documentation. But for now, the outline sketched above makes sense out of both the archaeological and the historical data.

Two years ago, the newspaper Milenio published a nice article on Calixtlahuaca and our project. It was called "Calixtlahuaca: La nostalgia del poder," referring to the fact that the positions of Calixtlahuaca and Toluca were reversed during the colonial period. Before 1521, Calixtlahuaca was a big capital city and Tollocan (if it existed at all) was a small village. Today, Toluca is the state capital, and Calixtlahuaca just a village. But that village has some great ruins (our site!) and the big city has none.

References

Esparza, René, Rita Reséndez, and Arnulfo Embriz Osorio (editors)
    2000    Catálogo de mapas, planos, croquis e ilustraciones históricas de restitución y dotación de tierras y ampliación de ejidos del Archivo General Agrario. CIESAS, Mexico City.

Jarquín Ortega, María Teresa
    1994    Congregaciones de pueblos en el Estado de México. Colegio Mexiquense, Toluca.

Olmedo Gaxiola, Regina (editor)
    1998    Catálogo de documentos históricos del Archivo General Agrario. CIESAS, Mexico City.

Pizzigoni, Caterina
    2007    Testaments of Toluca. UCLA Latin American Studies, vol. 90. Stanford University Press, Stanford.

Prem, Hanns J.
    1980    Chronolgische Miszellen I. Mexicon 2(2):20-21.

*** Check out Wide Urban World for a post on Calixtlahuaca ***

Visit to the site

Structure 16 cleaning

Angela and I showed Jennifer Burley around Calixtlahuaca today. Jennifer is a student of art history at the University of Arizona, studying Aztec sculpture with Emily Umberger, our project art historian. In case we got lost there is a nice new blue pyramid sign pointing up the hill. One new development is that many of

Catalino surveying

the temples and public buildings are being cleared off and cleaned up. The biggest change is in structure 16, the big rectangular platform on the plain, east of the royal palace at the edge of the modern town. José García Payón did some superficial clearing of the structure, but did not really excavate much of it.  The photo shows the south side of the structure, where two walls are visible. It wasn't clear to us whether these are two different construction stages, or else a two-step profile of the building. I'm sure that the archaeologist in charge, Arqueóloga María del Carmen Carbajal, will sort this out.

Angela & Jennifer on Str. 16

The work crew is headed by Calixtlahuaca resident Catalino Estrada Monte de Oca. Catalino was one of our best workers during the excavations in 2007. He spent much of the time helping out mapper, Max Farrer (see photo). If you visit Calixtlahuaca, be sure to stop in at Catalino's store, on the road up to the site, and say hi.

The work crew has cleared off part of a small platform on top of structure 16 (photo at right). The purpose of structure 16 remains a mystery. Was this a ballcourt? The form does not seem to fit. Perhaps a calmecac (school)? García Payón had labeled the royal palace as a calmecac, but that is an error; perhaps the school was here instead. We did notice a slab support from an Aztec III black-on-orange bowl in the fill of structure 16, suggesting that it was built (or enlarged) in either the Ninupi or Yata phases (Late Postclassic).

The site museum

The Calixtlahuaca bird

Another nice development at the site is that the small site museum has re-opened. It was closed in 2007 for repairs. The plan was to re-do the exhibits with new objects, new text, and a better exhibit. I was asked to participate, and I gladly agreed, but then no one ever contacted me! The leaks in the roof were fixed quickly, but the museum remained closed for several years. Then the old objects were simply put back, with minimal signs or explanation, and the museum opened again.

It's nice to see the materials back in the site museum. One is a nice stone relief of the Calixtlahuaca bird. As discussed in an earlier post, this seems to have been some kind of emblem of the city or dynasty, back before it was called Calixtlahuaca (that is, prior to the Mexica conquest of the 1470s, when the name Calixtlahuaca first appears in the historical sources), and perhaps even before the city was called Matlatzinco (its name during much of the Middle and Late Postclassic periods). Emily Umberger and Maëlle Sergheraert identified a number of examples this turkey-looking bird on stone reliefs recovered at the site in the 1930's by José García Payón.

Here is an old photo of García Payón's crew working on structure 4, the Tlaloc temple. Someone could do a seriation of old Mexican excavation photos, and date the photo by the size and shape of the workers' hats.

Restoring structure 4 in the 1930s

Neighborhoods at Calixtlahuaca

How can we understand the social organization of an ancient city? One important way is by looking at the neighborhood. Neighborhoods are geographic areas within a city where people engage in daily face to face interaction (Smith 2010; Smith and Novic n.d). This definition works particularly well for archaeologists, because we can identify neighborhoods as a groups of houses based on the spatial proximity of the houses to each other. More interesting then simply identifying neighborhoods is finding it out what the people were like within in them.

Neighborhoods come in a wide variety of social forms. Throughout history, neighborhoods have shown various degrees of social clustering (of which social segregation is a type). Neighborhoods can be clustered along variables such as class, religion, place of origin, race, occupation, and position within the political hierarchy (Rapoport 1980; Garrioch and Peel 2006). Social clustering in many instances is viewed as a problem in modern urban environments. The ideal neighborhood is thought of as being one that contains a mixture of social and economic statuses (Congress for the New Urbanism 1996). A common assumption is that preindustrial cities were organized in such a way as to fit the neighborhood ideal. Whether or not this is true is yet to be determined through more research and analysis.

At Calixtlahuaca, we have twenty probable neighborhoods. I identified these by looking at the distribution of sherds across the landscape. Areas with a sherd density of three sherds per square meter or greater were assumed to be areas of more intense occupation. Here households would have been in close proximity to other households and formed the foundation of a neighborhood.

How were neighborhoods at Calixtlahuaca organized? Were they clustered or did they fit the modern neighborhood ideal? These are the questions that my research addresses. I'll look at 1) whether neighbors were procuring goods from the same production source, 2) whether they had shared tastes for the same styles and forms of ceramics, 3) whether they shared domestic ritual practices, and 4) whether there was similarities in wealth among people in the same neighborhood. I'll be sure to let you all know my results when I get them!

Congress for the New Urbanism

1996 Charter of the New Urbanism, Vol. 2008: Congress for the New Urbanism.

Garrioch, David, and Mark Peel

2006 Introduction: The Social History of Urban Neighborhoods. Journal Of Urban History 32(5):6

Rapoport, Amos

1980 Neighborhood Homogeneity or Heterogeneity: The Field of Man-Environment Studies. Architecture and Behavior 1(1):65-77.

Smith, Michael E.

2010 The Archaeological Study of Neighborhoods and Districts in Ancient Cities Journal of Anthropological Archaeology 29(2):137-154

Smith, Michael E., and Juliana Novic

n.d. Neighborhoods and Districts in Ancient Mesoamerica In Neighborhoods in Mesoamerican Cities: The Assessment of Intermediate Units of Spatial and Social Analysis. L. Manzanilla, M.E. Smith, and C. Arnauld, eds. Tuscon: University of Arizona Press.

Comals and Cuisine

by Angela Huster

Comals are large, round, flat clay (or today, metal) griddles. Ethnographic work shows that comals are usually used for cooking tortillas (with occasional double use for toasting coffee or seeds, or reheating tamales). I’ve never come across a description of traditional tortilla production that didn’t involve a comal; there’s no Mesoamerican equivalent of the piki stones found in the US Southwest. The archaeological distribution of comals is highly variable in frequency across time and space in Mesoamerica (Fournier 1998), suggesting that tortillas weren’t nearly as ubiquitous as you might think based on modern Mexican cuisine.

Back during the excavation season in 2007, we had noted that the overall frequency of comals (tortilla griddles) at Calixtlahuaca seemed to be very low, when compared to comparable sites in Morelos or the Basin of Mexico. As our chronological control at the site has improved, this has proved to be both true and false, depending on what phase of the site’s occupation we are looking at.

During the Dongu Phase (~1100-1300 CE), only a few contexts had comals, and even when present, the frequencies were very low. During the subsequent Yata Phase (~1300-1470 CE), the frequency of comals remains low, but the ubiquity goes up, with a few comal sherds present in most contexts. The big change occurs with the shift to the Ninupi phase (~1470-1530 CE). The average frequency of comals rims quintuples, from just over 1% of all rim sherds, to almost 6%. In addition, the distribution of the frequencies is very strongly bimodal, with half of the contexts looking pretty similar to the preceding phases, and half of them looking more like the 7-10% frequencies found in Morelos or the Basin of Mexico.

Since the Ninupi Phase approximates the period between the Aztec and Spanish conquests of Calixtlahuaca, the change in comals use raises interesting questions. It suggests that some of the residents of Calixtlahuaca started eating way more tortillas after they became part of the Aztec Empire. One possibility is that the occupants of these households were interacting with Aztec officials. Eating a meal together served to officially “seal a deal” in Postclassic Mesoamerica (Rodríguez-Alegría 2005), so maybe these households were trying to produce Aztec cuisine for their Aztec business partners. Alternatively, the households with high comal frequencies might belong to immigrants from the Basin of Mexico, who brought their own ways of preparing maize with them to their new homes. Teasing apart these scenarios will require comparing the changes in comal frequencies to changes in other types of ceramics as well as other artifact types.

Works Cited:

Fournier, Patricia

1998 El complejo nixtamal/comal/tortilla en Mesoamerica. Boletin de Antropologia Americana 32:13-40.

Rodríguez-Alegría, Enrique

2005 Eating Like an Indian: Negotiating Social Relations in the Spanish Colonies. Current Anthropology 46:551-574.

New blog on excavations at Maya city of Ceibal (Seibal)

Takeshi Inomata and Diana Triadan have returned to the Maya city of Ceibal/Seibal, first excavated by Harvard in the 1960s. They are excavating right now, and they have an excellent blog at the New York Times in the series "Scientist at Work: Notes from the Field."

Start with their first entry, from Feb 17, 2011; from that site you can follow the subsequent posts. Or go to the general site, Scientists at Work, for the current post.

There are several posts now. This is an outstanding chronicle of an excavation; check it out.

Ancient neighborhoods

The organization of Calixtlahuaca into neighborhoods is one of the themes of our project. Julie Novic is focusing on this issue in her dissertation project, and maybe she will write a post on her research soon.

For comparative discussion of urban neighborhoods, see my new blog, Wide Urban World.

• There is a post on the universality of neighborhoods
• And there is a post on Mark Twain's description of London neighborhoods.