But what were they doing...

One of the ongoing questions at Calixtlahuaca has been the degree of specialized production at the site. This could either take the form of particular households that focused on producing high quantities of a particular type of good, or the entire site specializing in producing something for trade on a regional scale. We know that specialization at both of these levels occurs at sites in both the Basin of Mexico and in Morelos. Among many other cases, the site of Otumba included specialized workshops to produce obsidian tools, and a neighborhood that made clay figurines and spindle whorls (Charlton, et al. 1991; Parry 1990). Cuexcomate and Capilco in Morelos has site-wide specialization in cotton production, and some households also made amate-bark paper (Fauman-Fichman 1999; Smith and Heath-Smith 1993).

Calixtlahuaca has been frustrating in this regard – most of the standard lines of evidence for craft production have come back negative (Huster 2016:Chap. 5). Neither the survey nor the excavation located areas of intensive obsidian working. The INAA and petrographic data for ceramics showed a wide range of variation within the broader local groups, a pattern consistent with many small producers. We only located a couple of molds for making figurines or other small clay objects, and there are very few duplicates among the finished molded items among our collections. There are a few spindle whorls for cotton spinning, but the frequencies are far lower than in other areas where it was too also too cold to grow cotton.

I’m currently evaluating whether maguey (agave) production might be sitewide or regional-scale specialty. I had previously discarded it a household-level specialization, because pretty much all of the households had some evidence for maguey textile production and none of them stood out as unusual when compared within the site. However, when compared on a regional scale, some lines of evidence suggest that the amount of maguey processing was similar to sites such as Cihuatecpan or Tepetitlan (Cobean and Mastache 1999; Evans 2005), which researchers have argued were sites specializing in maguey products. This would be an interesting finding, because the usual explanation is that people in Central Mexico focus on growing maguey (and other cacti) in areas where it is too dry to reliably grow corn (Parsons and Darling 2000), and the number of cornfields I flailed through while surveying Calixtlahuaca would suggest that this is not the case there. The Codex Mendoza tribute lists for the provide also include both maguey fiber textiles (a fairly uncommon item, limited to a single geographic cluster of provinces) and unusually high quantities of corn (2 bins, rather than the usual one), which would suggest that the two crops were both economically important in the region.

One of the 2006 survey crews trying to figure out how to lay out a surface collection in the middle of a modern cornfield at the site.

References:

Charlton, Thomas H., Deborah L. Nichols and Cynthia Otis Charlton

                1991       Aztec craft production and specialization: archaeological evidence from the city-state of Otumba, Mexico. World Archaeology 23:p. 98-114.

Cobean, Robert H. and Alba Guadalupe Mastache

                1999       Tepetitlán: A Rural Household in the Toltec Heartland / Tepetitlán: Un Espacio Doméstico Rural en el Area de Tula. Serie Arqueología de México. University of Pittsburgh, Pittsburgh PA and Instituto Nacional de Antropología e Historia, Mexico City.

Evans, Susan Toby

                2005       Men, Women and Maguey: The Houshold Division of Labor Among Aztec Farmers. In Settlement, subsistence, and social complexity : essays honoring the legacy of Jeffrey R. Parsons, edited by R. E. Blanton. Cotsen Institute of Archaeology, University of California, Los Angeles.

Fauman-Fichman, Ruth

                1999       Postclassic Craft Prodution in Morelos, Mexico: The Cotton Thread Industry in the Provinces. Doctoral Dissertation, Department of Anthropology, University of Pittsburgh, Pittsburgh.

Huster, Angela C.

                2016       The Effects of Aztec Conquest on Provincial Commoner Households at Calixtlahuaca, Mexico. Doctoral Dissertation, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ.

Parry, William J.

                1990       Analysis of Chipped Stone Artifacts from Otumba and Neighboring Rural Sites in the Eastern Teotihuacan Valley of Mexico. In Preliminary Report of Recent Research in the Otumba City-State, edited by T. H. Charlton and D. L. Nichols. vol. 3. University of Iowa, Department of Anthropology, Research Report, Iowa City.

Parsons, Jeffrey R and J Andrew Darling

                2000       Maguey (Agave spp.) utilization in Mesoamerican civilization: a case for precolumbian" Pastoralism". Boletín de la Sociedad Botánica de México (66):81-91.

Smith, Michael E. and Cynthia Heath-Smith

                1993       Rural Economy in Late Postclassic Morelos: An Archaeological Study. In Economies and Polities in the Aztec Realm, edited by M. G. Hodge and M. E. Smith, pp. 349-376. Institute for Mesoamerican Studies, Albany.

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.

Calixtlahuaca Obsidian

By Bradford Andrews

At Calixtlahuaca (like most prehispanic societies in Mesoamerica), obsidian was the most common type of stone used to make tools for a wide variety of domestic, militaristic, and ritualistic purposes. More than 94% of the tools and debitage (byproducts of stone tool manufacture and use) from the site are composed of obsidian. Analysis of the obsidian materials was initiated by me and two of my Pacific Lutheran University students, Elisa Hoelter and David Treichel, during the summer of 2009. To date almost 9,000 artifacts have been analyzed.


Obsidian is a volcanic stone made of silica that is created by the rapid cooling of volcanic ejecta. Because it cools so rapidly, it lacks a true crystalline structure (Cobean 2002). This quality makes obsidian ideal flaking sharp implements used for numerous slicing, cutting, and scraping activities. Most of the obsidian found on Aztec sites comes from relatively recent volcanic deposits scattered across Central Mexico, stretching from Veracruz on the Gulf to the western Mexican state of Michoacan bordering the Pacific Ocean (Glascock et al. 1988).

The Calixtlahuaca obsidian artifacts show some interesting variation concerning flaked stone tool production and use in Aztec period Central Mexico. Here are three patterns that stand out:

First, the collections are composed almost exclusively of gray obsidian (75%). Although data are limited, this contrasts with has been reported for other Aztec sites outside the Basin of Mexico, the location of modern day Mexico City and the heartland of the Aztec Empire. In Morelos more than 90% of the artifacts are made of obsidian from the Pachuca source in the modern state of Hidalgo, northwest of the Basin. Pachuca obsidian is typically green in color. We think, therefore, that Calixtlahuaca was supplied with obsidian by means of a different system than was the case for some of the other Aztec dominated sites in Mesoamerica. It is probable that much of it came from sources west of Calixtlahuaca, many of which are located in Michoacan. Future chemical analysis will be conducted to evaluate this proposition.

Second, most of the tools (66%) were derived from obsidian blades that do not appear to have been produced by craftsmen who lived at Calixtlahuaca. The Mesoamerican blade technology consisted of shaping a cylindrical “core” from which blades were then removed by “pressing” them off with a wooden implement (Hirth and Andrews 2002). Such a process results in byproducts of blade production that are minimally represented at Calixtlahuaca. This finding is interesting because at numerous Mesoamerican sites evidence suggests that blades were made in workshops by resident craftsmen. It seems likely, therefore, that blade tools arrived at the site ready-made for use, or were produced by traveling craftsmen who periodically visited the site and plied their wares in the market.

Third, many of the artifacts that were made using a biface technology (23%) do appear to have been shaped into various tools in Calixtlahuaca households  Biface technology entails the removal of flakes from two sides, or “faces” of a relatively flat piece of obsidian to make items such as projectile points (arrowheads) and other scraping and chopping tools. This finding is interesting because in Central Mexico evidence for the production biface tools in the majority of a city’s households is the exception rather than the rule.

These preliminary observations on the obsidian artifacts from Calixtlahuaca provide important new comparative information on flaked stone tool production and use in the provinces of the Aztec Empire.

I presented these observations at the recent Society for American Archaeology meetings:

Andrews, Bradford W. (2010)  Calixtlahuaca Obsidian: Initial Reflections of Lithic Technology on the Western Aztec Periphery. Paper Presented at the 75th Annual Meeting of the Society for American Archaeology, St. Louis, Missouri.

Artist’s reconstruction of Biface production in a Calixtlahuaca Household, illustration by Michael Stasinos.

References cited

Cobean, Robert H. (2002) A World of Obsidian: The Mining and Trade of a Volcanic Glass in Ancient Mexico. Serie Arqueología De México. Pittsburgh: Instituto Nacional de Antropología e Historia/University of Pittsburgh.

Glascock, Michael D., J. Michael Elam, and Robert H. Cobean. (1988) Differentiation of Obsidian Sources in Mesoamerica. Archaeometry '88. Eds. R. M. Farquhar, G. V. Hancock and L. A. Pavlish. Toronto: University of Toronto Press, 245-51.

Hirth, Kenneth G., and Bradford W. Andrews (2002) Introduction." Pathways to Prismatic Blades: A Study in Mesoamerican Obsidian Core-Blade Technology. Eds. Kenneth G. Hirth and Bradford W. Andrews. Los Angeles: The Cotsen Institute of Archaeology, University of California, 1-14.