Tuesday, August 30, 2011

Have You Seen This Sherd?

By Angela Huster

I think every archaeological project must have a code for “other unidentified type” sherds, as well as box where said type of sherds all end up. This box is then waved in front of visiting archaeologists in the hope that they will go “Oh yes, that’s obviously a ……”

In a virtual version of box-waving, here are a few of our unidentified sherds. Any comments would be greatly appreciated, particularly from people working west of us.

C-2585/122 : The interior is the same color as the exterior undercolor. The vessel has straight, relatively vertical walls. It could be either a bowl or a relatively large copa – there isn’t enough to get a good rim diameter reading. The paste is medium-fine and light buff colored.

C-1028/122: The interior is dark red. The rim diameter measures 14cm and the vessel wall is outflaring and slightly recurve. This is probably a bowl, though a large copa is also a possibility. It has a very fine orangeish paste.

C-2033/122: The design in the picture is on the inside of the support and underside of the bowl base. All the other portions of the sherd are solid shiny brown. While this is clearly a tripod bowl, it is not a molcajete (grater bowl), and the support is hollow with a rattle. The paste is medium-coarse and light buff colored.

C-1504/122: This probably a large, simple hemispherical bowl. The rim diameter measures 27cm, and the exterior is plain. The interior design is negative. The paste is medium-coarse and medium brown colored.

C-2018/38: This is part of the body of an olla or pitcher. The design is probably negative, but the limited number of lines make it hard to tell. The paste is medium-coarse and medium brown colored.

Monday, August 15, 2011

Using an artistic touch to bring Calixtlahuaca to life

By Dr. Brad Andrews

How can art and archaeology work together? Art is one of the humanities and archaeology is a social science – as such, most people do not realize they have the potential to connect in very useful ways. Artists can bring something very important to the archaeological table: the life-like, recreation of ancient human behavior as inferred from the lifeless remains of the archaeological record. Working together then, the archaeologist can inform the artist about what the artifacts indicate about how people lived – subsequently, the artist can apply artistic license to recreate a snap shot of daily life. The compatibility of both disciplines in this regard is an extremely valuable and effective way for the archaeologist to communicate with the public. One problem professional archaeologists have is that they either find it difficult to talk about what they do to the lay-person, or they simply do not think it is necessary to do so (even though public interest and support keep us employed!). Through the artist, the archaeologist can take advantage of pictures that are literally worth a thousand words. The artist benefits by being able to apply their artistic skills to subject matter they rarely get a chance to engage in – prehistory!

Lucky for us we have been able to turn to artist Michael Stasinos of Pacific Lutheran University to help us bring some of Post-classic Calixtlahauca to life. This endeavor is a collaborative process that involves dialog about archaeological information (artifacts, houses, monuments, etc.), use and consultation of ethnographic and ethnohistoric sources of information, and artistic imagination. As most folks probably know lots of pictures of Mexico, both past and present can be found online. Such content can be consulted to fuel artistic imagination, which is important because the responsible artist must fill in lots of blanks with reasonable and realistic content.

I first began chatting with Michael Stasinos about doing a scene of daily life in a Calixtlahuaca household. As mentioned in my first blog, my research on stone tools has revealed that bifaces were actually flintknapped in the city. Hence, I wanted to be able to bring that interpretation to life. Michael and I began by discussing the typical

layout of a Calixtlahuaca household using plan view maps and photographs of the houses that were excavated in 2006 (see P2 & P3). We also discussed how the buildings might have been walled and roofed. The excavations indicated that walls were probably wattle & daub (walls made of interwoven posts or laths and twigs plastered over with mud or clay) and the roofs were probably thatch. Artistic inspiration for these features was sought looking over photographs of modern thatched dwellings (see P4). Michael chose to depict a seated flintknapper and another young man (perhaps a son) and a woman and child focused on grinding corn. Photographs of pottery and baskets were used as inspiration to populate the area with a number of these items. Care was taken to use the photographs of the site as a basis for integrating masonry detail for the retaining wall and plants such as corn and the famous agave (Maguey – from whence comes tequila!). Finally, Michael added a dog and some turkeys (barely visible on the left side of the house) to complete the scene: voila – a day in the life at Post-classic Calixtlahuaca! (see P5).

Michael is now working on a site-wide scene that will show the Calixtlahuaca cityscape populated with house compounds, complete with a market area in the foreground. All of us working on the project agreed that it would be nice to see what Calixtlahuaca might have looked like with people in it. The actual marketplace has not been identified, but itwas an important economic institution at Calixtlahuaca like it was elsewhere in ancient Mesoamerica.

This city scene started by selecting a photograph of Cerro Tenismo, where the site is located, that could be used as a base (see P6). The challenge with projects like this is to chose a photo that shows a “sense” of the whole, but enables the incorporation of some details in the foreground; the tradeoff is that you lose some of the whole the more foreground details you bring in - a happy balance must be achieved. Michael removed the color in Adobe Photoshop and produced a large base sheet (1 m in width) that he could use to populate the hillside with houses (see P7). The market scene is now in the works, inspired by other ancient Mesoamerican market scenes that have been recreated and photographs of modern Mexican markets. Michael first began populating the market foreground by drawing block figures on a mylar overlay placed on the base sheet (see P8). In this way he is easily able to evaluate issues of space and adjust the content as needed. Now he is in the process of adding the details of market-focused daily activities (see P9 & P10).

These types of illustrations are not easy to do. It requires more than talented artistic license to do good reconstructions. There are way too many egregiously inaccurate renditions out there that smack more of fantasy than fact. The responsible collaboration between artists and archaeologist is a must. We consider ourselves lucky that Michael has been so generous with his time and skills, and has done so with an eye to being accurate and realistic. We will be sure to post the final cityscape version when it is finished.

Wednesday, August 10, 2011

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.

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.

Thursday, August 4, 2011

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: