Christina Torres-Rouff

Investigating cultural heterogeneity in San Pedro de Atacama, northern Chile, through biogeochemistry and bioarchaeology

Individuals living in the San Pedro de Atacama oases and the neighboring upper Loa River Valley of northern Chile experienced the collapse of an influential foreign polity, environmental decline, and the appearance of a culturally distinct group during the Late Intermediate Period (ca. AD 1,100-1,400). We investigate cultural heterogeneity at the Loa site of Caspana through analyses of strontium and oxygen isotopes, cranial modification styles, and mortuary behavior, integrating biological aspects of identity, particularly geographic origins, with cultural aspects of identity manifested in body modification and mortuary behavior. We test the hypothesis that the Caspana population (n = 66) represents a migrant group, as supported by archeological and ethnographic evidence, rather than a culturally distinct local group. For Caspana archeological human tooth enamel, mean (87)Sr/(86)Sr = 0.70771 +/- 0.00038 (1sigma, n = 30) and mean delta(18)O(c(V-PDB)) = -3.9 +/- 0.6 per thousand (1sigma, n = 16); these isotopic data suggest that only one individual lived outside the region. Material culture suggests that the individuals buried at Caspana shared some cultural affinity with the San Pedro oases while maintaining distinct cultural traditions. Finally, cranial modification data show high frequencies of head shaping [92.4% (n = 61/65)] and an overwhelming preference for annular modification [75.4% (n = 46/61)], contrasting sharply with practices in the San Pedro area. Based on multiple lines of evidence, we argue that, rather than representing a group of altiplano migrants, the Caspana population existed in the region for some time. However, cranial modification styles and mortuary behavior that are markedly distinct from patterns in surrounding areas raise the possibility of cultural heterogeneity and cultural fissioning.

Dental health in Northern Chile's Atacama oases: evaluating the Middle Horizon (AD 500-1000) impact on local diet.

As one of the few areas apt for horticulture in Northern Chiles arid landscape, the prehistory of the Atacama oases is deeply enmeshed with that of the inter-regional networks that promoted societal development in the south central Andes. During the Middle Horizon (AD 500-1000), local populations experienced a cultural apex associated with a substantial increase in inter-regional interaction, population density, and quantity and quality of mortuary assemblages. Here, we test if this cultural peak affected dietary practices equally among the distinct local groups of this period. We examine caries prevalence and the degree of occlusal wear in four series recovered from three cemeteries. Our results show a reduction in the prevalence of caries for males among an elite subsample from Solcor 3 and the later Coyo 3 cemeteries. Dental wear tends to increase over time with the Late Middle Horizon/Late Intermediate Period cemetery of Quitor 6 showing a higher average degree of wear. When considered in concert with archaeological information, we concluded that the Middle Horizon was marked by dietary variability wherein some populations were able to obtain better access to protein sources (e.g., camelid meat). Not all members of Atacameño society benefited from this, as we note that this dietary change only affected men. Our results suggest that the benefits brought to the San Pedro oases during the Middle Horizon were not equally distributed among local groups and that social status, relationship to the Tiwanaku polity, and interment in particular cemeteries affected dietary composition.

VIOLENCE IN TIMES OF CHANGE: THE LATE INTERMEDIATE PERIOD IN SAN PEDRO DE ATACAMA

Durante el periodo Intermedio Tardio en los Andes (1.000-1.476 d.C.) se advierte una caida de la prosperidad asociada con el Horizonte Medio y con el estado de Tiwanaku (750-1.000 d.C.). Estas disrupciones se manifiestan en la construccion de sitios fortificados y empobrecimiento material. Hemos investigado si estos cambios incidieron en los niveles de violencia interpersonal en los oasis de San Pedro de Atacama, norte de Chile. Se presentan los resultados del analisis de evidencias de traumas en alrededor de 150 craneos del cementerio Intermedio Tardio de Yaye, uno de los sitios funerarios mas pauperizados del area. El 29,2% de la poblacion (42/144), presenta senales de golpes en el craneo. Estos resultados fueron comparados con los de otros sitios de la epoca (Coyo 3 y Quitor 6 Tardio), los que muestran patrones similares. Se analizaron, ademas, craneos del periodo Tiwanaku (Solcor 3) y del periodo Inka (Catarpe). Estas poblaciones demuestran menos traumas que los de Yaye, lo que puede representar importantes cambios culturales en el area. Los resultados indican que es posible que la alta tasa de traumas visto en los craneos de Yaye y otros del Intermedio Tardio se relacione con situaciones de estres social ocurrido en esa epoca

EXAMINING THE LIFE HISTORY OF AN INDIVIDUAL FROM SOLCOR 3, SAN PEDRO DE ATACAMA: COMBINING BIOARCHAEOLOGY AND ARCHAEOLOGICAL CHEMISTRY

Informacion detallada sobre la vida de un individuo, integrando multiples lineas de evidencia que incluye identificacion del origen geografico, condiciones de salud e indicadores de usos funcionales del cuerpo, puede ser utilizada para aclarar el complejo proceso de la aculturacion en los oasis de San Pedro de Atacama, norte de Chile durante el Horizonte Medio. Este trabajo presenta los resultados de analisis bioantropologicos y quimicos de un individuo (tumba 50, numero de catalogo 1948) del cementerio de Solcor 3 (ca. 500-900 d.C.) en San Pedro de Atacama. Las proporciones de los isotopos de estroncio en el esmalte dentario humano revelan informacion acerca de donde una persona vivio durante su ninez, cuando el esmalte se forma. El individuo 1948 muestra proporciones de isotopos de estroncio claramente fuera del rango que caracteriza a las poblaciones locales de San Pedro de Atacama. Estos datos muestran que el individuo 1948 fue originalmente de un lugar foraneo. El analisis de su salud, rol social y contexto mortuorio nos permite conocer el tratamiento social aplicado a los extranjeros en la region de San Pedro de Atacama durante el Horizonte Medio. Nuestros datos sostienen la idea que la condicion de extranjero del individuo 1948 no fue una limitacion para su asimilacion en la sociedad atacamena. El fue enterrado en un cementerio local, a la moda local, sin que se resaltara su posible origen foraneo. Ademas, los datos con respecto a su salud y estilo de vida no lo distinguen del resto de la poblacion local. Por lo tanto, nuestros analisis sugieren una total aculturacion de este individuo en la sociedad atacamena durante su vida adulta, por lo que retuvo poca o ninguna indicacion de suprobable nacimiento en un area foranea

EATING FISH IN THE DRIEST DESERT IN THE WORLD: OSTEOLOGICAL AND BIOGEOCHEMICAL ANALYSES OF HUMAN SKELETAL REMAINS FROM THE SAN SALVADOR CEMETERY, NORTH CHILE

The San Salvador River in northern Chile is a tributary of the Loa, the only river that traverses the Atacama Desert from the mountains to the Pacific. Recent investigations along the San Salvador River revealed the presence of a Formative period village site and associated cemetery approximately 110 km inland from the Pacific Ocean. Bioarchaeological and biogeochemical analyses conducted on human skeletal remains recovered from the San Salvador Cemetery allowed us to better understand the site’s role as an intermediary for coast/interior relations during the Middle Formative (500 B.C.‐A.D. 100). Evidence from material culture and human remains at San Salvador suggests that this population was involved in exchange networks that united the oases of the Atacama Desert with the Pacific Ocean. Isotopic data support this notion, as the population demonstrates great variability in both the protein (marine and terrestrial) and carbohydrate components of their diet. During this period, communal economies produced surpluses used in a network of exchange for foods, prestige goods, and ideas. These ties were not coincidental but, rather, part of a regional economic structure that remains only partly explored. El Rio San Salvador del norte de Chile es un afluente del Rio Loa, el unico curso de agua dulce que atraviesa el desierto de Atacama desde las montanas hasta el Pacifico. Recientes investigaciones en San Salvador revelaron la presencia de una aldea y un cementerio del periodo Formativo emplazados a unos 110 km. de la costa del Pacifico. Analisis bioantropologicos y biogeoquimicos llevados a cabo en restos oseos humanos recuperados del cementerio permitieron comprender el funcionamiento del sitio como intermediario en las relaciones entre la costa y el interior en el Formativo Medio (500 a.C.‐100 d.C.). La evidencia de la cultura material y de los restos humanos en San Salvador indica que esta poblacion estuvo involucrada en las redes de intercambio que ligaban los oasis del desierto de Atacama y el Oceano Pacifico. Los datos isotopicos apoyan esto, pues la poblacion muestra una gran variabilidad tanto en el consumo de proteina (marina y terrestre) como en los componentes de carbohidratos en su dieta. Durante este periodo las economias comunales produjeron excedentes utilizados en una red de intercambio de alimentos, bienes de prestigio e ideas. Estos lazos no fueron circunstanciales, sino parte de una estructura economica regional que hasta ahora ha sido parcialmente explorada.

Hiding inequality beneath prosperity: patterns of cranial injury in middle period San Pedro de Atacama, Northern Chile.

The Middle Period in San Pedro de Atacama (AD 400-1000) stands out as a time of great prosperity that was, in part, associated with high levels of interaction with foreign polities, including the highland state of Tiwanaku. Although previous studies have demonstrated an increase in rates of violence during the subsequent Regional Developments Period (AD 1000-1400), this does not mean that the Middle Period was a time of peace and tranquility. Here, the prevalence of violence in four contemporary cemeteries is analyzed, exploring potential sources of conflict, including social inequality. Cranial trauma was documented through the presence, location, size, and state of healing of all wounds and was found in 14.7% of the sample (61/415; including two cases of perimortem trauma). Skeletal remains were also analyzed for demographic data to investigate differences in patterns of violence related to sex and age. Notably, most of the trauma centered on the anterior portion of the skull, suggesting the prominence of face-to-face confrontations that involved both sexes. Correlations between trauma and items in the mortuary assemblage that may have been associated with prestige or an elevated social standing in two cemeteries from the Solcor ayllu indicate that individuals from the more elite cemetery were subjected to significantly less traumatic injury. These data suggest that people did not share equally in the benefits of this periods affluence and that there were tensions in Atacameño society despite seemingly widespread prosperity.

Issues of affinity: exploring population structure in the Middle and Regional Developments Periods of San Pedro de Atacama, Chile.

The Middle Period (AD 400-1000) in northern Chiles Atacama oases is characterized by an increase in social complexity and regional interaction, much of which was organized around the power and impact of the Tiwanaku polity. Despite the strong cultural influence of Tiwanaku and numerous other groups evident in interactions with Atacameños, the role of immigration into the oases during this period is unclear. While archaeological and bioarchaeological research in the region has shown no evidence that clearly indicates large groups of foreign immigrants, the contemporary increase in interregional exchange networks connecting the oases to other parts of the Andes suggests residential mobility and the possibility that movement of people both into and out of the oases accompanied these foreign influences. Here, we analyze biodistance through cranial non-metric traits in a skeletal sample from prehistoric San Pedro de Atacama to elucidate the extent of foreign influence in the oases and discuss its implications. We analyzed 715 individuals from the Middle Period (AD 400-1000) and later Regional Developments Period (AD 1000-1450), and found greater phenotypic differences between Middle Period cemeteries than among cemeteries in the subsequent period. We argue that this greater diversity extends beyond the relationship between the oases and the renowned Tiwanaku polity and reflects the role of the oases and its different ayllus as a node and way station for the Middle Periods myriad interregional networks.

The Sequence of Human Occupation in the Atacama Oases, Chile: A Radiocarbon Chronology Based on Human Skeletal Remains

Author(s): Torres-Rouff, C; Hubbe, M | Abstract: The San Pedro de Atacama oases have been permanently occupied since ca. 2500 B.P. and over this time developed a rich culture that was intertwined with social developments in the south-central Andes. However, despite decades of archaeological research, the region still lacks a strong chronological framework based on absolute dates. Here we present 53 new AMS ,14C dates from osteological remains from San Pedro de Atacama, in order to contribute to an understanding of the Atacameno cultural sequence. These dates suggest that some cemeteries were occupied for long periods, frequently transcending cultural phases, and that in fact a number of cemeteries within the same ayllu were in use concurrently. We also show that, not surprisingly, population displacement through time primarily follows oscillations in the sources of water. The new information presented here suggests that future work in the region should emphasize detailed analyses that consider intra-ayllu variability, given that diversity within periods is masked by the uniform use of cultural phases to describe human development.

Cultural Diversity and Paleomobility in the Andean Middle Horizon: Radiogenic Strontium Isotope Analyses in the San Pedro De Atacama Oases of Northern Chile

Despite a long history of research, interactions between the Tiwanaku polity of the Andean Middle Horizon (ca.A.D. 500-1100) and the San Pedro de Atacama oases of northern Chile remain controversial. Here, we investigate Middle Horizon interactions through an isotopic identification of the geographic origins of individuals buried in San Pedro de Atacama cemeteries and present the largest radiogenic strontium isotope dataset generated, to date, for the Andes. For individuals in Middle Horizon San Pedro de Atacama cemeteries ofCasa Parroquial, Coyo Oriental, Coyo-3, Larache, Quitor-5, Solcor-3, Solcor Plaza, Solor-3, and Tchecar Tumulo Sur, mean tooth enamel and bone 87Sr/86Sr = .70834 ± .00172 (2σ, n = 273). Overall, the mean 87Sr/86Sr values from Middle Horizon San Pedro de Atacama cemeteries support the idea that interactions between Atacamenos and inhabitants of other regions varied by ayllu, an Andean kin-based community structure, with some ayllus incorporating individuals with a wider variety of geographic origins than others. When our interpretations of the radiogenic strontium isotope data are contextualized with analyses of mortuary behavior and recent biodistance analyses, we argue that the San Pedro de Atacama oases appear to be have been inhabited by culturally and biologically diverse groups, rather than by large numbers of colonists from the Tiwanaku capital and the Lake Titicaca Basin.

Mobility and Exchange among Marine Hunter-Gatherer and Agropastoralist Communities in the Formative Period Atacama Desert

Northern Chile’s Atacama Desert is one of the most unforgiving landscapes on the planet; however, a variety of complex risk-mitigation strategies facilitated long-term human occupation of the region. Using a burgeoning corpus of human, floral, and faunal stable carbon and nitrogen isotope data, the present work examines patterns of mobility, exchange, and social interaction in northern Chile’s Formative Period (1500 BC–AD 400). While the geographic barriers and harsh climatic conditions of the Atacama Desert, in concert with substantial logistic considerations, established constraints on human diet at the site and local levels, regional dietary variation speaks to frequent and possibly even regular interzonal movements of people and/or foodstuffs. Through isotopic analysis of the remains of 86 individuals, we examine regional patterns of dietary variation in light of recently advanced hypotheses concerning the nature of mobility, exchange, and social interaction in Formative Period northern Chile. These data indicate both systematic regional exchange in foods and other goods and the central role of sites in the Calama oases in facilitating this exchange and movement.