The Teozacoalco Archaeological Project has undertaken work around San Pedro Teozacoalco in the Mixteca Alta of the Mexican state of Oaxaca (Figure 1) for two decades. Initial exploration of the area occurred in early 2000 (Shoemaker Reference Shoemaker2000). In 2002 and 2004, work involved non-systematic settlement surveys (Whittington Reference Whittington2002, Reference Whittington2003; Whittington and Gonlin Reference Whittington, Gonlin, Gonlin and French2016). In 2008, it focused on stratigraphic test-pitting at various prehispanic sites encountered in previous years (Whittington and Workinger Reference Whittington, Workinger, Zborover and Krofeges2015). From 2013 to 2017, teams used GPS devices to map Iglesia Gentil on Cerro Amole, the largest and most complex site in the area and a prehispanic capital for several centuries (Whittington Reference Whittington2017; Whittington et al. Reference Whittington, Vicente Cruz, López Zárate and Escamilla2018).
The state of Oaxaca, its capital, and settlements discussed in the text.
Kowalewski and others (Reference Kowalewski, Balkansky, Stiver Walsh, Pluckhahn, Chamblee, Pérez Rodríguez, Heredia Espinosa and Smith2009) stated that archaeologists have studied the household scale and regional settlement patterns, but future research should examine activities and institutions at the middle level between the household and the state. This paper evaluates three GIS-based methods for their ability to define middle-level neighborhoods for Iglesia Gentil and places Teozacoalco and Cerro Amole within the context of archaeological and documentary evidence from the Mixteca Alta.
Archaeological Context
The extensive settlement surveys and excavations of the Central Mixteca Alta Settlement Pattern Project and other projects published in Origins of the Ñuu (Kowalewski et al. Reference Kowalewski, Balkansky, Stiver Walsh, Pluckhahn, Chamblee, Pérez Rodríguez, Heredia Espinosa and Smith2009) occurred in areas adjacent to the Teozacoalco Archaeological Project's territory to the north and east. In what follows we paraphrase that publication's conclusions, based on archaeological and ethnographic research, to help contextualize Teozacoalco and Cerro Amole.
The Mixteca experienced two major evolutionary transformations. Beginning around 1300 BC there was a shift from hunting and gathering to agricultural villages. During the Early Formative period (1600–900 BC) the pattern was of head villages and smaller satellite settlements. New hierarchical settlement levels and regionally important centers arose during the Middle Formative (900–300 BC). Starting in 300 BC and the following centuries, urbanism and the state developed. During the Late and Terminal Formative (Table 1), warfare increased throughout Oaxaca, and the Mixteca Alta became militarized and fragmented. People abandoned most settlements and moved to fortified hill-towns. In the Terminal Formative many areas were devoid of occupation, but centralized, internally complex, urban states, such as Huamelulpan, existed that may have absorbed formerly dispersed populations. These early states lacked the complexity of later ones.
Chronology Relevant to Cerro Amole.
Sources: From Kowalewski and others (Reference Kowalewski, Balkansky, Stiver Walsh, Pluckhahn, Chamblee, Pérez Rodríguez, Heredia Espinosa and Smith2009), Lind (Reference Lind1987), Winter and Sánchez Santiago (Reference Winter, Santiago, Winter and Sánchez Santiago2014).
Beginning in the Classic, polities had a four-tiered settlement and civic-ceremonial hierarchy. Each valley had a polity comprising one to multiple communities, with one generally being the primary center. Classic single-valley population sizes varied from 2,000 to as many as 20,000. As in many parts of Mesoamerica, there was a dramatic demographic collapse in the Mixteca Alta at the end of the Classic period. During the Late Classic and Epiclassic many areas were devoid of occupation, possibly because the region was too dangerous or access to markets was not assured, although some Late Classic occupations did exist (e.g., Yucuñdahui and Yucuita).
After AD 1200, the Mixteca Alta experienced its greatest population growth and prosperity. Postclassic polities continued to have a four-tiered settlement and civic-ceremonial hierarchy. Sites varied from dispersed “rancherías” to many medium- to high-density settlements with residential terraces. Some of the latter hill-town sites were reused from earlier times, but many saw new and expanded construction. More than half the population lived in such sites, which included some of the most important cabeceras and other centers of regional economies based on intensive agriculture. Single-valley populations varied from 2,000 to 40,000 people.
Documentary Context
The Mapa de Teozacoalco (Figure 2) was sent with the Relación de Teozacualco to the viceroy of New Spain in January 1580, in response to 50 questions distributed to municipalities by mandate of King Philip II of Spain (Acuña Reference Acuña1984). The answers and the associated maps submitted by municipal authorities are known as Relaciones Geográficas.
The Mapa de Teozacoalco. Its size is 138 × 176 cm. East is at the top (image used with permission of Nettie Lee Benson Latin American Collection, University of Texas Libraries, University of Texas at Austin). (Color online)
Using the conventions of European maps and Mixtec codices in a synthetic way, the Mapa represents the core landscape and history of the lords of Teozacoalco (Anders et al. Reference Anders, Jansen and Pérez Jiménez1992a; Caso Reference Caso1949, Reference Caso1960). Painted by a Mixtec artist in the late 1570s, the Mapa indicates that the capital (cabecera) of San Pedro Teozacoalco had 13 subject communities (sujetos or estancias).
The left side of the Mapa is significant because it has two long sequences of dynastic rulers associated with two large Mixtec glyphs and Spanish glosses. Alfonso Caso (Reference Caso1949) used the sequences as a sort of Rosetta Stone to interpret surviving codices that depict the histories of various Mixtec polities. He realized that one glyph and its associated sequence related to the nearby polity of Santiago Tilantongo, whereas the second referred to Teozacoalco. “Teozacualco” is a corrupted version of the Nahuatl “Hueyzacualco,” a translation of the native name of the polity, “Chiyo Cahnu,” meaning gran solar o sitio (large piece of land or site [translation by the authors]; Acuña Reference Acuña1984:142–143).
Chiyo Cahnu and its rulers appear as political players in various prehispanic and early colonial period codices, including the Bodley (Caso Reference Caso1960; Jansen and Pérez Jiménez Reference Jansen and Pérez Jiménez2005), Egerton (König Reference König1979), Muro (López García Reference López García1998), Selden (Caso Reference Caso1964), Tulane (Smith and Parmenter Reference Smith and Parmenter1991), Vindobonensis (Anders et al. Reference Anders, Jansen and Pérez Jiménez1992b), and Zouche-Nuttall (Anders et al. Reference Anders, Jansen and Pérez Jiménez1992a; Nuttall Reference Nuttall1902; Williams Reference Williams2013), as well as other documents, including the Mapa de Macuilsuchil (Mundy Reference Mundy1996), confirming that the polity was a powerful center during the Postclassic period. Chiyo Cahnu existed as a named place as early as 1030—when the ruler of Topiltepec visited it, according to the Codex Selden (Caso Reference Caso1964)—but apparently had no royal ruler. It later participated in political alliances with other important Mixtec and Zapotec settlements; Pohl (Reference Pohl2002) placed it in a widespread alliance network. Royal women and second-born sons of royal couples from Chiyo Cahnu went to other polities to marry and rule. Royal men and women from other important Mixtec and Zapotec polities came to Chiyo Cahnu to marry local royal persons. The codices and Mapa document a fluid political situation.
On various occasions, royal individuals or couples from other polities arrived to found new dynasties and rule Chiyo Cahnu. There is disagreement about some early dates in the dynastic history painted on the Mapa and in the codices (e.g., Byland and Pohl Reference Byland and Pohl1994; Jansen and Pérez Jiménez Reference Jansen and Pérez Jiménez2005, Reference Jansen and Pérez Jiménez2007; Rabin Reference Rabin and Plunket2003; Williams Reference Williams2013). Based on available evidence, it seems most likely that Lord 5 Dog, second-born son of the ruler of “Tiger/Jaguar Town” (Ñuu Ñaña, today Asunción Cuyotepeji; Jansen and Pérez Jiménez Reference Jansen and Pérez Jiménez2007; König Reference König1979), and Lady 6 Wind, also of Ñuu Ñaña, were married in 1073 or 1085 and founded the first dynasty of Chiyo Cahnu. In 1321, Lord 2 Dog of Zaachila and his wife, Lady 6 Reed of Tilantongo, arrived to establish the third dynasty. They are represented in two places on the Mapa. In one, they are walking on the road from Tilantongo and are being met by seven named nobles. In the other, they are sitting atop the ruler's palace in the current town of San Pedro Teozacoalco. Subsequent members of Chiyo Cahnu's dynasties are positioned above that palace. We argue that this change in the location of the dynastic history on the Mapa is significant for Chiyo Cahnu's settlement history.
Most of the Mapa shows San Pedro Teozacoalco's territory in 1580 in the form of a mappa mundi, a convention from the European Middle Ages in which the territory is warped to fit into a circle and east is positioned at the top (König Reference König and Van Doesburg2008). Mixtec glyphs are arrayed around the circumference of the territory, identifying geographic features defining the border. Inside the map proper are rivers, mountains, roads, and settlements. San Pedro Teozacoalco is depicted in some detail, showing a church, plaza, and ruler's palace (Figure 3). Teozacoalco's 13 subject communities are depicted as chapels with red crosses on top. Spanish glosses provide the names of the subject communities and their distances from San Pedro Teozacoalco.
San Pedro Teozacoalco and environs on the Mapa de Teozacoalco. Churches are marked with red crosses. Cerro Amole, on the right, also bears a red cross, identifying it as a sacred place. The founders of the third dynasty and subsequent rulers sit atop the royal palace, shown in plan view (image used with permission of Nettie Lee Benson Latin American Collection, University of Texas Libraries, University of Texas at Austin). (Color online)
Initial research into the territory painted on the Mapa focused on identifying the sujetos and borders of the colonial municipality of 1580 (Anders et al. Reference Anders, Jansen and Pérez Jiménez1992a; Coffman Reference Coffman1982; Mundy Reference Mundy1996). These researchers identified, at least tentatively, the locations of the majority of the sujetos and border features. Their work suggested that the symbols for the subject communities were positioned relatively accurately throughout the territory and that the actual territory was somewhat pear-shaped and extended approximately 70 km north to south and 30 km east to west (around 2,100 km2; Figure 4). Teozacoalco had controlled a larger territory between the Spanish conquest and 1580 (Gerhard Reference Gerhard1993), and various documents from the early colonial period state that San Pedro Teozacoalco was the cabecera of a large territory, one of the three main administrative areas of Spanish authority in the Mixteca Alta (Spores Reference Spores1984). Today, the municipality of San Pedro Teozacoalco encompasses only 93 km2 (INEGI 2023a).
Boundaries of the municipality of San Pedro Teozacoalco in 1580 reconstructed from the Mapa de Teozacoalco and the municipality's current boundaries.
A summary by Balkansky and others (Reference Balkansky, Kowalewski, Pérez Rodríguez, Pluckhahn, Smith, Stiver, Beliaev, Chamblee, Heredia Espinosa and Santos Pérez2000) of archaeological projects in the Mixteca Alta indicated an absence of work in the territory depicted on the Mapa de Teozacoalco. No archaeologists had attempted field confirmation of the identifications made by Anders and others, Coffman, and Mundy. That changed with the advent of the Teozacoalco Archaeological Project in early 2000.
Cerro Amole
Red crosses appear on the Mapa atop San Pedro Teozacoalco's church and the chapels of the 13 subject communities and on depictions of piles of stones known as mojoneras that mark the territory's border. Like churches, mojoneras are sacred places where offerings are made. Only one other cross appears on the Mapa: on top of the mountain today known as Cerro Amole (Figure 3). Atop the depiction of Cerro Amole is a tiered structure surmounted by a red cross, undoubtedly marking a sacred place known to the Mapa's artist. No Spanish gloss explains the structure or cross, and it is not mentioned in the Relación Geográfica. Perhaps this indicates that detailed information about the place was withheld from the Spanish authorities in a subtle act of resistance more than a half century after the conquest.
Beginning in 2000, the Teozacoalco Archaeological Project undertook exploration of Cerro Amole, which looms south of the town. Cerro Amole's elevation is 2,366 m, more than 750 m higher than the town, at 1,585 m. Large structures near the summit and some outlying concentrations of structures were sketch-mapped in 2002 and 2004. Significant architectural features near the summit include a 51 m long ballcourt with three partial sculptures in the court, a pyramid-like structure, a large palace-like structure, and a large platform with many buildings and mounds on top. Downslope from the summit is an ancient road running around the circumference of much of the mountaintop that defines most of the extent of architecture on the upper part of the mountain.
The focus of fieldwork from 2013 to 2017 was the complete mapping of structures between the summit of Cerro Amole and the circumferential road using GPS devices. This methodology was adopted based on discussions with personnel from the Cerro Jazmín project (Neff Reference Neff2010; Pérez Rodríguez and Martínez Tuñón Reference Pérez Rodríguez and Martínez Tuñón2020; Pérez Rodríguez et al. Reference Pérez Rodríguez, Anderson and Neff2011 ). The Cerro Jazmín project used a total station to map structures in an area of 263 ha (2.63 km2) in 10 months of work (Neff Reference Neff2010). The density of vegetation and the steepness of Cerro Jazmín's slopes required moving the total station multiple times, necessitating multiple error corrections. Margaret Neff (personal communication 2012), who oversaw mapping Cerro Jazmín, suggested that high-accuracy GPS devices would provide results as accurate as a total station under similar conditions. Cerro Amole has even denser vegetation and steeper slopes than Cerro Jazmín.
Mapping Cerro Amole was done with Ashtech ProMark 100 and 120 GPS devices with ArcPad 10 software, complemented by Ashtech ASH111660 L1/GLONASS antennas to improve data capture and satellite signals under trees. During 12 weeks of fieldwork from 2013 to 2017, teams mapped architecture and artifact locations in an area of 794,158 m2 (79 ha, or 0.79 km2; Figure 5). Mounds, building walls, patios, platforms, ancient roads, 2,624 residential and agricultural terraces, and 371 “architectural units” consisting of one or more of 629 buildings were mapped. Within the 629 mapped buildings were 320 complete rooms: those with four adjacent walls whose areas could be determined.
Data collected with GPS devices during three field seasons permitted creation of a map of the buildings, terraces, roads, and artifact locations in the site of Iglesia Gentil using ArcGIS.
Teams also mapped 367 artifact locations, from which we collected and analyzed 1,099 ceramic artifacts (Supplemental Table 1). Many ceramics were small body sherds with eroded surfaces, but in some cases Cerro Amole's ceramics could be related to those in other areas of Oaxaca (Supplemental Text 1). In addition to ceramic sherds, teams found 134 nonceramic artifacts: sculptures; pieces of obsidian, chert, and quartz; pieces of bone; manos and metates; other utilized stones; and burned clay. Fragments of obsidian and chert were collected. Green obsidian fragments were common; based on previous XRF testing, they are known to originate from the Pachuca source, some 500 km northwest of Cerro Amole. Other nonceramic artifacts, including metate fragments, were identified and photographed.
ArcGIS Pro software (ESRI 2023a) was used to integrate (1) the coordinates of architectural elements and artifacts recorded with the GPS units; (2) observations of ceramic sherds; (3) locations of architectural units; and (4) data on topography, elevation, and sources of water from the GIS database of the Instituto Nacional de Estadística, Geografía e Informática (INEGI 2023b). At this time, we have little temporal data such as diagnostic artifacts or carbon dates from Cerro Amole. We hope that future excavations at the site will add nuance to our understanding of Cerro Amole's settlement history. In the generation of our three hypothetical neighborhood models, we treated all structures as contemporaneous.
Reconstructing Hypothetical Neighborhoods
Although intermediate levels of social organization—above the household but below the entire settlement, city, or polity—are notoriously difficult to pinpoint in archaeological contexts (Marcus Reference Marcus, Canuto and Yaeger2000), they nevertheless represent a crucial frontier for building new archaeological theory to understand daily social life in the past. Ethnographic research demonstrates that informants recognize units such as the “neighborhood” and consider them important to daily life (Talen Reference Talen2019; York et al. Reference York, Smith, Stanley, Stark, Novic, Harlan, Cowgill and Boone2011). Critical to forming social identities (Chase Reference Chase2023; Peeples Reference Peeples2018), integrated communities—those where recurrent face-to-face interaction occurs—also have high potential for productive collaboration or what is called “collective action” (Blanton and Fargher Reference Blanton and Fargher2008, Reference Blanton, Fargher, Charlotte Arnauld, Manzanilla and Smith2012; Carballo and Feinman Reference Carballo and Feinman2016). In Mesoamerica, organizational units such as the Mixtec siqui, Aztec calpulli, and Maya cuchcabal were often formally recognized in social, military, and economic (especially tribute) systems.
The best information about the composition and nature of Postclassic Mixtec settlements comes from ethnohistorical records (Spores and Balkansky Reference Spores and Balkansky2013; Terraciano Reference Terraciano2001). Mixtec codices and Spanish accounts reveal that the ñuu was the Late Postclassic form of the state, a multicommunity grouping that was an integral autonomous unit or integral component of a larger polity: “The closest approximation of the landholding corporate group would be the residential barrios and subject communities (siqui) extending outward from the capital centers . . . small-scale versions of the ñuu, with their own noble rulers” (Spores and Balkansky Reference Spores and Balkansky2013:118–119).
However, these models become less reliable the further back in time they are projected. Archaeological and ethnographic data have important roles to play in reconciling ethnohistoric data with earlier time periods. Again, we paraphrase Origins of the Ñuu about the characteristics of middle-range social organizations based on archaeological and ethnographic research. By the Early Classic, groupings like the ñuu were present. Below the level of the ñuu were groups of households, siqui or barrios, that had land rights and could be thought of as local communities. Siqui or local communities were not self-sufficient. Those bound together into a ñuu might have a population of several thousand, large enough to be an autonomous state with its own ruling family and palace. Barrios and communities engaged in symbolic activities and had material features such as temples and boundary shrines.
Intermediate levels of social organization clearly existed in prehispanic societies, but is it possible to identify, investigate, and conceptualize these ethnohistorically documented social units archaeologically? According to Kowalewski and others (Reference Kowalewski, Balkansky, Stiver Walsh, Pluckhahn, Chamblee, Pérez Rodríguez, Heredia Espinosa and Smith2009), a siqui might be visible archaeologically. At the site of Nicayuju, people who lived on hillside residential terraces had a temple and plaza at the top of the hill. Many Classic and Postclassic barrio centers, including at Cerro Amole, have small structure arrangements like those at Nicayuju.
We now turn to GIS modeling for further insights. We experimented with three distinct approaches to neighborhood reconstruction at Cerro Amole: average nearest neighbor and kernel density (KD) analysis, least cost analysis (LCA), and watersheds. Cerro Amole provides a reasonably sized and significant mountaintop settlement to explore and evaluate neighborhood analyses.
Kernel Density Analysis
Recently, a group of Mayanists applied average nearest neighbor and kernel density analyses to 23 ancient centers across the Maya Lowlands to see how well potential neighborhood identification methods from one area lined up between different subregions (Thompson et al. Reference Thompson, Walden, Chase, Hutson, Marken, Cap and Fries2022). The method seemed to work better at smaller sites than at the largest ones, prompting us to test the model here. Using their workflow in ArcGIS Pro, we generated a similar set of potential “neighborhoods” for Cerro Amole. In simple terms, KD analysis locates spatial clusters of points—in our case, the 629 buildings on Cerro Amole—based on a ratio between the average distance between those points and the expected mean distance (EMD) for an identical number of points scattered randomly across the same space.
After eliminating clusters that contained no complete rooms (these were mainly groups of single-wall features), the KD analysis identified 76 groupings of varying size and shape (Figure 6; Table 2). Many clusters contained as few as two complete rooms, although several outliers presented more than 20 and up to 50. As seen in Table 2, the coefficient of variation (the standard deviation divided by the mean) for this model is 1.2, indicating wide variance and suggesting that the clusters do not represent comparable units. For this reason, it probably is not the best-fitting neighborhood model for the site. Nevertheless, the workflow produced spatially discrete clusters that may have been socially meaningful to the residents. For example, the smaller groupings of structures may represent extended family compounds, whereas the largest ones may approximate the size of a typical siqui.
Kernel density analysis resulted in 76 structure clusters of greatly varying sizes.
Descriptive Statistics for the Three Neighborhood Reconstruction Methods.
Least Cost Analysis
KD is a robust spatial clustering technique, but it is most suitable for flat terrain. Cerro Amole's site, however, is topographically variable because it is a settlement on a mountain. If neighborhoods are places of recurrent face-to-face interaction (Smith Reference Smith2010), the effects of extreme topography on mobility and accessibility need to be considered (Chase Reference Chase2021). Following the methodology of White (Reference White2015), we drew on Tobler's hiking function (Tobler Reference Tobler1993)—an empirical model that calculates hiking time over the landscape by adjusting walking speed based on the slope angle encountered in the direction of travel—to generate a second neighborhood model based on least cost analysis.
Least cost analysis (LCA) has its origins in graph theory, the models of which create algebraic matrices that represent relationships between objects (Peeples Reference Peeples2019). An LCA model called least cost paths (LCP) creates networks of connections between physically bounded “nodes” and “edges” by quantifying measures like centrality and embeddedness. Typically, these models rest on the premise that people have complete knowledge of a landscape and always choose to minimize travel time through it. In general, LCPs can reveal potential patterns of movement not visible to the naked eye and otherwise provide hypotheses that can be tested against archaeological data, historical records, or both (e.g., White and Barber Reference White and Barber2012). Tobler's hiking function informs our LCA/LCP model.
Although spatial clustering is not a goal of LCA, and distances are fairly modest on Cerro Amole, the analysis nevertheless reveals natural groupings in various locations based on travel time between buildings with complete rooms. Figure 7 is a raster image where the 3 m cells of Cerro Amole's digital elevation model represent the travel time, in minutes, to the closest building with complete rooms. More than 95% of these buildings cluster with at least one other building within a 5- to 10-minute range, suggesting that neighborhoods may have coalesced—likely organically—around this threshold of travel time.
Raster image where the three-meter cells of Cerro Amole's digital elevation model represent the travel time between structures with complete rooms. Seven neighborhoods are delineated based on least cost paths modified by Tobler's hiking function, where structures with complete rooms are within a 10-minute walk of each other.
We identified seven neighborhoods that may represent discrete, socially meaningful units in Figure 7. If the inhabitants of Cerro Amole commuted and interacted with other households purely on an accessibility basis—in terms of 5- to 10-minute walks—these would be the most integrated social clusters. The coefficient of variation value for this model is much lower (0.71; Table 2), indicating more consistently sized neighborhood reconstructions.
Watershed Model
In our final GIS model, we factor rainwater runoff—and the natural and cultural features that channeled it—into a model of prehispanic social organization. Archaeological, ethnohistorical, and ethnographic data suggest that terrace agriculture has played an integral role in livelihood in the Mixteca Alta for more than 2,000 years (Pérez Rodríguez Reference Pérez Rodríguez, Spores and Robles García2014). Because they lacked flat, arable land, Mixtec communities invested large amounts of time and energy constructing and maintaining agricultural systems, particularly the check dam terraces called lama-bordos that are still ubiquitous in the Mixteca. This form of land management, which is also present on Cerro Amole, would have produced important relationships between people who inhabited and cultivated adjacent terraces and common watersheds. Although the specific forms of land-tenure ownerships remain unknown from the archaeological record, farmers still would have depended on the rainwater and soil runoff from others’ tracts of land, as well as on the upkeep of their physical infrastructure.
The model's northern (and north-facing) “hydrological” neighborhood—the largest and most productive watershed on Cerro Amole—may offer insights into how watersheds organized local society (Figure 8). The group of large buildings situated at the top of the drainage likely pertained to elites, and the model suggests that these powerful residents could have administered and materially benefited from this critical agricultural zone (per Wittfogel Reference Wittfogel1957, Reference Wittfogel and Johnson1972). However, the archaeological and historical records largely do not support the idea that most preindustrial systems of water management were administered through the “top-down” mechanisms often associated with autocratic governance. Rather, they indicate that smallholders were not only the most common but also the most successful organizers of local water infrastructure (Lansing and Kremer Reference Lansing and Kremer1993; Ostrom Reference Ostrom1992, Reference Ostrom1993; Pérez Rodríguez Reference Pérez Rodríguez, Spores and Robles García2014).
Watersheds based on Cerro Amole's ridges and slopes define eight areas that cut through the seven neighborhoods based on LCPs and travel times.
The hydrology model presents the smallest CV value of the three methods (0.65; Table 2) and therefore the most consistent number of structures across all reconstructed neighborhoods. A close look at the northwestern and northeastern ridges of the mountain reveals, however, that watersheds split several zones of dense occupation right down the middle. If we are to believe the model, we would interpret that adjacent neighborhoods butt up against each other on ridgelines, leaving the narrow terraces in the middle of steep hillside drainages purely for agriculture. This interpretation is possible, but we find it more likely that there would have been social cohesion in these compact ridgeline concentrations—despite spreading into two drainages—making distinctions between neighborhoods based on the watershed model difficult to support.
Comparing Neighborhood Models
An overlay of all three models (Figure 9) suggests social organization at different physical scales. Where there is overlap between the LCA and KD models, such as in the northwestern or northern drainages, evidence for socially meaningful units is more robust. Indeed, if GIS clustering produced worthwhile results, it should be possible to distinguish between a similar number of neighborhoods based on structure size and characteristics, density of architecture, artifacts, and topography. Preliminary statistical analysis and physical descriptions show that this is true.
Overlay of the three models defining neighborhoods.
Characteristics of Neighborhoods Defined by GIS Modeling
Hot spot analysis is a tool available in ArcGIS Pro (ESRI 2023b). It calculates the Getis-Ord Gi* statistic for each feature in a dataset, in the context of neighboring features. It produces z-scores and p-values that point out where high or low values cluster spatially. The sum for a feature and its neighbors is compared to the sum of all features. If the local sum is different from the expected sum and the difference is too large to be the result of random chance, the z-score is statistically significant.
A statistically significant hot spot is a feature with a high z-score that is surrounded by other features with high values. The higher the z-score, the more intense the clustering of high values, or hot spots. A statistically significant cold spot is a feature with a low z-score that is surrounded by other features with low values. The smaller a statistically significant z-score is, the more intense the clustering of low values, or cold spots. Hot spot analysis based on the areas and locations of 320 complete rooms whose sizes can be determined because they have at least four connected walls (Figure 10) helps in visualizing which neighborhoods have statistically significant clusterings of large or small rooms.
Hot and cold spots based on the sizes of complete rooms in buildings.
The ceramic sample, although not as well defined temporally as we would desire, contains potentially important data for supplementing neighborhood characterization based on room size (Table 3): χ2 tests of each ceramic form, paste, and special type grouped by neighborhood show that many distributions differ too much to result from chance variations. Hot spot analysis based on counts and locations of sherds permits us to pinpoint neighborhoods with statistically significant high concentrations of forms, pastes, and other characteristics in a way that simply calculating the density of sherds per neighborhood area does not.
Ceramic Sherd Counts per Hectare for Cerro Amole Neighborhoods.
Notes: Excludes sherds outside neighborhoods. Unidentified/uncertain categories were not tested for hot spots.
* p < 0.5 for χ2 values.
** Hot spots with > 95% confidence levels in neighborhoods.
*** Hot spot that is a statistical anomaly.
Civic-Ceremonial Neighborhood (93,353 m2)
The civic-ceremonial neighborhood is at a lower elevation than the summit neighborhood and is remarkable for its 51 m long ballcourt with three sculptures and a 154 × 75 m (maximum dimensions) platform holding multiple large architectural units. Overall, the neighborhood contains several of the largest architectural units on Cerro Amole. Hot spots with 95% or higher confidence levels based on the sizes of complete rooms cluster on the platform and near it to the west and northwest, although there are a few located south of the platform and east of the ballcourt.
The civic-ceremonial neighborhood has hot spots with 95% or higher confidence levels of conical bowls, hemispherical bowls, and pitchers/ollas, as well as fine cream, fine gray, sandy cream, and sandy gray pastes. Based on ceramic characteristics, occupation began during the Transición / Early Las Flores phases and continued into the Natividad phase. Five metate fragments and one mano were found west of the platform and one metate fragment at its extreme northwestern point. In addition to the three ballcourt sculptures, another possible sculpture fragment was found west of the platform. Other artifacts found in the neighborhood were 10 obsidian blades and chips, six chert chips, and one each of the following: hammerstone, possible hammerstone, piece of bone, piece of burned clay, and piece of quartz.
Summit Neighborhood (94,669 m2)
The summit neighborhood has the highest elevation on Cerro Amole and contains monumental architecture, including a pyramid and a large palace-like structure (both badly looted), and architectural units based on raised substructures. A possible uncarved stela was found in front of the palace-like structure. The area of monumental architecture is separated from the civic-ceremonial neighborhood to its north by a high terrace wall. Slightly southwest of the pyramid is an area of crude structure foundations that are not built on mounds and have different orientations from the monumental architecture. Southwest of the area of monumental architecture, and at lower elevations, is a series of large architectural units. Other extensions of the neighborhood occur on lower ridges to the east and west of the area of monumental architecture. Hot spots with 95% or higher confidence levels based on the sizes of complete rooms are spread throughout the neighborhood.
The summit neighborhood has hot spots of comals, conical bowls, and pitchers/ollas, as well as fine gray, sandy café-orange, and sandy cream pastes. There is also an anomalous hot spot of fine cream paste that is related to concentrations of hot spots in the adjacent civic-ceremonial neighborhood and is of no importance. Ceramic characteristics indicate that people lived in the neighborhood from the Transición / Early Las Flores phases into the Natividad phase. In addition to the possible stela, four pieces of obsidian, one piece of chert, and one piece of bone were found. One mano was encountered southwest of the area of monumental architecture.
Northwest Neighborhood (43,812 m2)
The northwest neighborhood is an area of houses and terraces descending three ridges. Terraces are not particularly dense. A possible temple with a relatively impressive substructure is located within the neighborhood. No hot or cold spots with 95% or higher confidence levels based on complete room sizes occur. Along the peripheral road between this neighborhood and the north-central neighborhood is a gateway or guard post that appears to have controlled access from the mountain's steep northern ascent (Supplemental Text 2).
The northwest neighborhood may have been occupied before any other neighborhoods. Although no hot spots based on ceramic forms or pastes occur in it, the only Ramos / Transición Las Flores ceramic sherd identified on Cerro Amole was found in the southeastern area. Occupation apparently was continuous from at least the Transición Las Flores phase until the Natividad phase. Six metates, two manos, and two grinding stones were found in the neighborhood, as well as two pieces of obsidian, six pieces of chert, a polishing stone, and a possible piece of burned bone.
North-Central Neighborhood (18,715 m2)
The north-central neighborhood is located on a north-facing slope shaded for much of each day by the bulk of Cerro Amole. It is separated from the northwest neighborhood by an area almost devoid of architecture and from the northeast neighborhood by an area of terraces but no buildings. It is separated from the civic-ceremonial neighborhood by an internal road and a very steep slope. The neighborhood has relatively few architectural units but the highest density of terraces. Both hot spots and cold spots with 95% or higher confidence levels based on complete room sizes exist. Hot spots are located at the top (south) of the neighborhood closest to the civic-ceremonial neighborhood. Cold spots are toward the bottom (north) of the neighborhood. No hot spots based on ceramics occur in the neighborhood; the only ceramics that could be dated were Early Natividad. Two metates were found in the neighborhood. A possible workshop with 55 chert chips and one obsidian blade was found near the northwestern extremity of the neighborhood.
Northeast Neighborhood (73,656 m2)
This neighborhood has a density of architectural units equal to or exceeding that of the northwest neighborhood. It also has a density of terraces second only to the north-central neighborhood, from which it is separated by an area of dense terraces devoid of architectural units. It is separated from the civic-ceremonial neighborhood by an area of terraces with no architectural units and an internal road. At the northern extreme is an extensive architectural unit containing a large platform with what appears to be a twin temple complex on top; one of the possible temples is round (Supplemental Text 3). Distributed throughout the neighborhood are many cold spots with 95% or higher confidence levels based on complete room sizes.
No ceramic hot spots occur in the neighborhood. On the basis of recovered ceramics, occupation began in the Transición / Early Las Flores phases and continued until the Natividad phase. Thirteen metate fragments, six of them in one deposit, were found in the neighborhood. One piece each of obsidian and quartz were also encountered.
South A Neighborhood (21,245 m2)
The South A neighborhood consists of a prominent architectural unit located on the summit of a hill (which we called “Junior”) that is south of the main part of Cerro Amole and of other architectural units to its west and southeast. The neighborhood is separated from the summit neighborhood by a gorge with an artificial ditch dug in its bottom. The hill has its own system of roads that may be independent of the roads on the main part of Cerro Amole. No ceramic hot spots occur in the neighborhood. The neighborhood may have been occupied continuously from the Late Las Flores phase, but the only ceramic sherds that can be confidently dated are from the Natividad phase.
South B Neighborhood (18,524 m2)
The South B neighborhood is centered on a relatively large architectural unit at a lower elevation than the South A neighborhood. Roads run through the neighborhood. Possible Late Las Flores and Natividad sherds were recovered, but dating is uncertain. Two metates and a mano were found.
Discussion
Evidence of warfare is widely reported in the Postclassic and earlier periods across Mesoamerica, and we suspect that defensibility was a central motivation in the selection of Cerro Amole as the site of Chiyo Cahnu's capital. Approaches from all directions to the settlement on Cerro Amole are steep and were made even more difficult in at least two directions. The approach from the north was restricted by a guard post and the approach from the south by an artificial ditch. The top of Cerro Amole provides clear views in all directions, particularly to the north in the direction of Tilantongo. Although they were outside Teozacoalco's territory, Mitlatongo and Tamazola are visible to the north. However, most of the 13 subject communities depicted on the Mapa de Teozacoalco, some or all of which may have existed when Cerro Amole was settled, are not visible from the summit. In addition, there is no permanent water source on the mountain nor any evidence that inhabitants constructed reservoirs for water impoundment. The large percentage of utilitarian ceramic vessels for holding liquids suggests that obtaining water during the dry season was a serious concern.
We hypothesize that Cerro Amole was the location of the capital of Chiyo Cahnu from the founding of the first dynasty in 1073 or 1085 until the founding of the third dynasty in 1321, a period of 236–248 years. Documentary evidence suggests that Chiyo Cahnu existed before the first royal couple arrived, and ceramic evidence shows that people already were living on the mountain at least as early as the Transición Las Flores phase; however, most construction probably occurred during the early part of the Natividad phase. If we assume that the population on Cerro Amole reached its maximum size and occupied all areas of Iglesia Gentil in 1321, then the population size would have been 1,359–2,738 persons (Supplemental Text 4). The founders of the third dynasty, who moved the capital to the current location of San Pedro Teozacoalco, apparently felt that relocating the population to a place with less extreme topography and access to permanent water sources overrode concerns about defense.
Based on our qualitative assessments of Cerro Amole, as well as the locations of hot and cold spots, which indicate changes in the focus of where people settled and functional differences between parts of the site, we found that the model based on least cost paths modified by Tobler's hiking function produces the most viable social-spatial patterning. The seven neighborhoods identified could correspond to territories overseen by the seven nobles who greeted the founders of the third dynasty before they moved the cabecera to the current location of San Pedro Teozacoalco. Indeed, all the neighborhoods have one architectural unit that is substantially larger than the rest, and some also have a structure that may represent a temple.
The summit neighborhood, with its pyramid and large palace structure, was the royal compound, separated from other neighborhoods by a high terrace wall to the north and an artificial ditch to the south. The presence of some Transición / Early Las Flores sherds indicates that this neighborhood was inhabited at an early date.
The civic-ceremonial neighborhood was much more accessible than the summit neighborhood. It combined elite architectural units with significant public architecture: the ballcourt and the huge platform. The eastern end of the platform has a large open space that could have been an assembly area or market. The complex of rooms and patios immediately north of the ballcourt was likely an important noble's compound. This neighborhood was also settled during the Transición / Early Las Flores phases.
North of the platform, commoners resided in three neighborhoods. The northwest neighborhood was possibly the location of the earliest occupation of Cerro Amole in the Transición Las Flores phase (or even earlier). The northeast neighborhood was settled during the Transición / Early Las Flores phases, but the north-central neighborhood was settled later, possibly not until the Early Natividad phase. Teozacoalco Archaeological Project personnel realized during mapping structures that the northern slope—particularly the part that includes the north-central neighborhood, the northern part of the northeast neighborhood, and the area of dense terraces between them—remains shaded by the bulk of the mountain much of the day and is the coolest and most humid area on Cerro Amole. A large watershed incorporates these shaded areas, which were likely the best places for agriculture because of lower evaporation rates. At the top of the watershed is the civic-ceremonial neighborhood's huge platform.
The elite members living on the platform at the top of the drainage may have overseen and administered the productive agricultural zone below, requiring commoners to live on the northwestern and northeastern fringes to provide more land for terrace farming between their neighborhoods. Alternatively, farmers residing on the ridgelines may have facilitated agriculture and water management of the northern drainage in a more collective fashion, with elites less involved in the day-to-day operation of agricultural systems and economic and tribute activities. In the north-central neighborhood, larger structures are upslope and smaller structures are downslope, reproducing on a smaller scale the overall pattern of the entire drainage.
South A and south B, the two neighborhoods on the hill called “Junior” that were separated from the summit neighborhood by an artificial ditch and had their own road system, are enigmatic. Each has an architectural unit that is larger than the rest of its neighbors, like the pattern on the main part of Cerro Amole. South A may have been occupied as early as the elite neighborhoods, but the earliest ceramics at South B are tentatively identified as belonging to the Late Las Flores phase.
The ancient roads that run around the peripheries of “Junior” and the main part of Cerro Amole and within various areas of the latter generally appear to define boundaries, rather than to provide access routes (Figure 9). Although they certainly could have been useful for traveling between distant parts of the site, their primary purpose may have been as ceremonial routes.
Architectural remains suggest at least two episodes of habitation on Cerro Amole. On the summit, there are mounds and large buildings with well-built walls around courtyards from the era of royal residence, but there are also small buildings with low-quality walls and different orientations located within the area of large buildings. During the Late Natividad phase, after the abandonment of Cerro Amole by the royalty, some commoner families may have remained on or resettled this mountain that would have been sacred for them. Another possibility is that these small and poorly built buildings do not represent long-term occupation, but instead episodes of shelter during times of invasions or wars (Supplemental Text 5). In this regard, Chapter 32 of the Relación de Teozacualco reads: “No hay, de presente, fortalezas cercadas; aunque, antiguamente, las tenían todos estos pueblos en las coronillas de los cerros a donde se hacían fuertes: de las cuales parecen algunas, el día de hoy, cercadas de piedra vana de altor de un estado, poco más o menos” (There are, at present, no walled fortresses; although, formerly, all these villages had forts on the tops of the hills: some of which seem today to be enclosures of piled stone 1.672 m high, more or less [translation by the authors]; Acuña Reference Acuña1984:147).
Conclusions
This analysis showcases the value of comparing multiple methods to try and obtain information about intermediate levels of social organization. We cannot claim that these models reflect emic conceptualizations of social units such as the siqui, but they provide us with concrete comparative units for describing intrasite variation at Cerro Amole. They also offer rich opportunities for hypothesis testing at Cerro Amole when future investigations, especially excavation, are undertaken. Although each of these models offers insights independently, we argue that their interpretive ability is enhanced when considered together and supported by descriptive data and statistical analysis. With future research these “neighborhoods” should yield new insights into other aspects of daily life and face-to-face interactions in ancient Mesoamerican communities.
Widespread test-pitting of architectural units of various sizes on Cerro Amole was scheduled for late 2019 with approval of the Consejo de Arqueología of the Instituto Nacional de Antropología e Historia. Many of these architectural units were targeted for testing because they had hot spots of various types of ceramics. The goals of the test-pitting were to recover larger, uneroded ceramic samples to help overcome the temporal and typological uncertainties described in this article and to identify locations for future extensive excavations. However, when the team arrived, the citizens of San Pedro Teozacoalco refused to give them permission to undertake the project. Subsequent time-intensive attempts to negotiate with the municipality's authorities were unsuccessful by 2021. Unfortunately, the models and hypotheses presented here must remain untested for the foreseeable future.
Acknowledgments
The late David Shoemaker was the driving force behind the first year of fieldwork, on which subsequent years were based. John M. D. Pohl's inspiration and guidance of David Shoemaker; Nancy Troike's strong encouragement and advice; and help from Jeffrey Blomster, Arthur Joyce, Michael Lind, Robert Markens, Cira Martínez López, and Marcus Winter were vital. We also thank Adrian Chase for his guidance in experimenting with neighborhood reconstruction and reviewers whose advice strengthened this publication. Work was possible only with the support and permission of the Consejo de Arqueología of the Instituto Nacional de Antropología e Historia (archaeological permits P.A. 13/02, 05/04, 27/07, 25/12, 14/14, and 07/17). We are grateful for the hospitality and willingness to collaborate of many of the authorities and citizens of the present-day municipalities within the territory of colonial Teozacoalco.
Funding Statement
Fieldwork since 2000 has been supported by the Patterson Foundation; Foundation for the Advancement of Mesoamerican Studies Inc. (FAMSI); Mudge Foundation; Selz Foundation; Social, Behavioral, and Economic Sciences Research Fund and Pro Humanitate Fund at Wake Forest University; LACS Tinker Field Research Grant; and the American Philosophical Society.
Data Availability Statement
Artifacts collected by the Teozacoalco Archaeological Project are stored in the Exconvento San Pedro y San Pablo Teposcolula and the Exconvento de Cuilapan de Guerrero, both in Oaxaca. Copies of data-collection forms, site-recording forms, field notes, and preliminary reports are stored at the Centro INAH Oaxaca. Reports are stored at the Centro INAH Oaxaca and in Mexico City at the Instituto Nacional de Antropología e Historia. Requests for access to original notes, drawings, forms, reports, photographs, and digital mapping files can be made to the corresponding author.
Competing Interests
The authors declare none.
Supplemental Material
For supplemental material accompanying this article, visit https://doi.org/10.1017/laq.2024.23.
Supplemental Table 1. Count of Ceramic Sherds on Cerro Amole.
Supplemental Text 1. Cerro Amole Ceramic Chronology.
Supplemental Text 2. Description of Gateway Structure.
Supplemental Text 3. Description of Possible Twin Temples.
Supplemental Text 4. Calculation of Cerro Amole Population Estimate.
Supplemental Text 5. Hilltop Refuges in Postclassic Oaxaca.
