Facultad de Ciencias Exactas y Naturales

Se presenta un estudio sobre disponibilidad y explotación de recursos líticos en un área
de la Cordillera de los Andes (NO de San Juan, Argentina) que incluye un gradiente altitudinal
comprendido entre el límite internacional argentino-chileno (5.600 msnm) y el valle del río de las
Taguas (3.700 msnm). Se evalúa la disponibilidad y la calidad de rocas aptas para la talla lítica
mediante la caracterización de fuentes de materia prima y de talleres líticos ubicados en tres
franjas altitudinales. Las materias primas son caracterizadas macroscópica y petrográficamente.
Se discute la implementación de sistemas de producción lítica secuenciales (sensu Ericson 1984)
en función a las características de las fuentes y sus emplazamientos en ambientes con ofertas
diversas para la ocupación humana. Se elabora una base regional de recursos líticos y una carta
geológica digitalizada mediante un SIG, con el fin de ajustar los datos arqueológicos sobre fuentes
y recursos líticos con la información geológica del área.

We have carried out long-term comparative in a wide latitudinal range of the Andes (29 e37 south), encompassing selected areas that differ in ecology and biogeography. This latitudinal span shows diversity in subsistence modes across time and space, ranging from Andean agro-pastoralists in the north to Patagonian hunter-gatherers in the south. As part of this research, a program of geochemical and archaeological characterization of obsidian sources and distributions is being developed, attempting to assess connections between different biogeographical contexts. This work has allowed recognizing five Andean sources with different geological and topographical properties. Stemming from this macro-regional endeavor, in this paper we present a comparative analysis of the human use of two sources that, based on the intensity of human use on a macro-regional scale, can be interpreted as 'minor' sources. This study is framed on GIS least-cost models for human circulation across rugged landscapes allowing access to the sources. We assess temporal and spatial patterns of human occupation of high-altitude Andean deserts and neighboring areas comparing two of obsidian sources: Laguna del Diamante (34 S) and Cerro Huenul (36 S). The results indicate the existence of asymmetric distributions, particularly in the case of Laguna del Diamante. This evidence is used to assess the existence of dominant geographic vectors of human access and use of the Andean highlands. On this basis, we explore the analytical potential of minor sources for the study of human biogeography and organization of technology.

Resumen El análisis de los espacios internodales en escala arqueológica ofrece un marco adecuado para la integración de preguntas generadas desde distintos ámbitos teóricos, con un gran potencial de complementariedad. El objetivo de este trabajo es evaluar, desde una perspectiva biogeográfica, el rol desempeñado por los espacios internodales en la dinámica de interacción social intergrupal en Pata-gonia septentrional. En primer lugar, presentamos los lineamientos teórico-metodológicos que guían nuestra propuesta, en la cual la biogeografía constituye el marco de referencia para identificar distintos tipos de Ei en la región de estudio. Existe una impor-tante variación geográfica y ecológica en los sectores del paisaje que pueden haber constituido internodos en el pasado, la cual debe ser caracterizada como un primer paso para evaluar su dinámica sociodemográfica. Planteamos que hay dos variables ecológicas claves que establecen la base geográfica de los internodos: a) gradiente de variación en la disponibilidad de recursos; y b) escala espacial de los espacios internodales. En segundo lugar, sobre la base de información en escala etnográfica, describimos en forma muy simple los mecanismos sociales de interacción que regulan el acceso y uso de este tipo de espacios. Con ello, buscamos comenzar a modelar arqueológicamente la dinámica relacionada al uso de los internodos en Patagonia septentrional. En tercer lugar, exploramos el rol de dos líneas de evidencia que informan sobre interacción social y circulación de información/objetos: las representaciones rupestres y la geoquímica de obsi-dianas. Para finalizar, reflexionamos sobre el alcance de los aportes generados y proponemos líneas futuras de trabajo que permitirán profundizar la comprensión de la dinámica humana de circulación de información/objetos implementada en el noroeste de Patagonia, así como de las redes de interacción que vincularon grupos de cazadores recolectores en distintas escalas espaciales. Palabras claves: Biogeografía humana – interacción social – distribución de representaciones rupestres – geoquímica de obsidianas – noroeste de Patagonia. Abstract The analysis of internodal spaces in archaeological scale offers a frame useful for integrating questions produced from different theoretical stands, which are actually complementary. The goal of this paper is to assess the role of internodal spaces for inter-group interaction in northern Patagonia from a biogeographical perspective. First, we present the theoretical-methodological frame that guides this proposal. There is important geographical and ecological variation in those parts of a given landscape that can be considered as internodes during the past, which should be characterized as a first step to assess their socio-demographic dynamics. We suggest that there are two key ecological variables that make up the basis of internodes: a) gradient of ecological variation in resources; b) spatial scale of the internodes. Secondly, based on ethnographic information, we describe in a simple manner the possible social mechanisms of interaction that structure and regulate the access to and circulation across internodes. By using this frame, we intend to model the archaeological dynamics of the human use of internodal areas in northern Patago-nia. In third place, we explore the role of two lines of research that may constitute proxies on social interaction and circulation of information/objects in space: rock art and obsidian geochemistry. Finally, we consider the preliminary contribution of this research, suggesting paths for future development of these ideas.

The upper Taguas river valley is rich in high-quality lithic sources and humans have used these sources continually over the last 10,000 years. A multi-year project of survey and excavation revealed a material signature dominated by lithics and analyzed 32,622 lithic artifacts, almost exclusively made from sources within the valley. The representation of lithic sources varied between sites and stratigraphic levels, suggesting shifting preferences for different source. To better understand these preferences, we ranked each the quality of the raw material of each source. Next, we ranked the time required to travel from each site to all sources with anisotropic least cost paths. This GIS analysis was based a surface elevation model and Tobler’s cost for movement on slopes. This step was particularly important given the abrupt topography of this high-altitude area. These two factors allowed us to evaluate differences in preferences between sites and stratigraphic layers. The results show that people were willing to travel to more distance sources in order to acquire higher quality materials. This is likely because all of the sources are within an eight-hour walk of the valley bottom, where most of the sites are located. The time required to walk to each sites was also an important factor in explaining the variable use of sources.

A B S T R A C T We studied the organization of mobility of hunter-gatherers groups of northwestern Patagonia (Argentina) from an interdisciplinary perspective. We combined geochemical and technological characterization of obsidian assemblages from surface and stratigraphic contexts spanning the Holocene, and a preliminary geoarchaeolo-gical study of the sources. The goals were to assess the provenance, mode of supply, use, and discard of obsidian artifacts on the basis of information on the structure of the two main regional sources: Cerro Huenul, located in the lowlands, and Laguna del Maule, located in the Andean highlands. We conducted geoarchaeological field sampling at different altitudes of the Barrancas River fluvial deposits to study the geomorphic impact on the secondary structure of the highland source. Preliminary geoarchaeological results allow extending the area of availability up to 90 km towards the lowlands from the outcrops. In addition, we performed non-destructive XRF analyses on 266 lithic artifacts, which were placed along a continuum of reduction. 89% of the artifacts corresponded to the local Cerro Huenul source, while 11% to Laguna del Maule. While the artifacts made on Cerro Huenul obsidian were represented by the full reduction sequence, those from Laguna del Maule are only represented by advanced stages. We integrate these results with information on the frequencies of projectile points, ceramics, and rock-art motifs for the two main archaeological sites in the region: Cueva Huenul 1 and Cueva Yagui. These proxies indicate that the sites have different place use histories, providing a scheme for the analysis of human use of the regional landscape.

The Andes mountain range is one key physiographic feature of South America with the potential to have acted as a barrier and corridor for human societies. The goal of this paper is to assess from where and how were the highlands utilized during the last 2000 years, which is a key period witnessing the development of productive economies and changes in the organization of mobility. We develop a regional case study focused on the highland wetland Laguna del Diamante (3300 masl), which is a highly productive ecosystem only accessible during summer. This case is based on a multidisciplinary approach combining: a) geochemical characterization of obsidian sources located in the highlands and artifacts; b) isotopic approach to ranges of paleomobility of individuals by means of 87 Sr/ 86 Sr; and c) stylistic study of ceramic assemblages. The two main obsidian types from the highlands have restricted and decaying spatial distribution, suggesting that these archaeological distributions track part of human circuits of mobility instead of indirect transport acquisition. Their archaeological distribution is heavily skewed towards the western Andean slope. We present strontium isotope values for four teeth and bone samples from two individuals recovered in the area, which are interpreted in reference to a preliminary baseline of biologically available strontium. We infer that these individuals had ranges of paleomobility systematically connecting the western slope with the highlands. The analysis of the ceramic assemblages shows that most of the diagnostic sherds can be assigned to styles that have distributional cores in the Central Valley of Chile up until the time of Inca presence, while only a minimum portion of the sample can be assigned to distributional cores on the eastern slope. By integrating the patterns in the transport of obsidian and ceramic artifacts and the paleomobility of individuals, we find support for the existence of dominant access to the highlands from the western Andean slope. A GIS-based analysis of the seasonality of precipitation shows that the western slope presents more pronounced and drier summer months, providing a context that contributes to explain these patterns. These results contradict previous interpretations suggesting that the archaeological record from the highlands is more directly tied to human groups inhabiting the eastern lowlands during most of the year. Beyond the geographic debate, this issue has an impact on the subsistence organization of the incoming groups, on the socioeconomic role of the highlands, and on the demographic contexts leading to trajectories of economic intensification in both Andean slopes. This research contributes to build a framework for comparative research on human use of highland environments.

Objectives: The goal of this paper is to assess the scale of human paleomobility and ecological complementarity between the lowlands and highlands in the southern Andes during the last 2300 years. By providing isotope results for human bone and teeth samples, we assess a hypothesis of ‘high residential mobility’ suggested on the basis of oxygen isotopes from human remains.
Methods: We develop an isotopic assessment of human mobility in a mountain landscape combining strontium and oxygen isotopes. We analyze bone and teeth samples as an approach to life-history changes in spatial residence. Human samples from the main geological units and periods within the last two millennia are selected.
Results: We present a framework for the analysis of bioavailable strontium based on the combination of the geological data with isotope results for rodent samples. The 87Sr/86Sr values from human samples indicate residential stability within geological regions along life history. When comparing strontium and oxygen values for the same human samples, we record a divergent pattern: while δ18O values for samples from distant regions overlap widely, there are important differences in 87Sr/86Sr values.
Conclusions: Despite the large socio-economic changes recorded, 87Sr/86Sr values indicate a persisting scenario of low systematic mobility between the different geological regions. Our results suggest that strontium isotope values provide the most germane means to track patterns of human occupation of distinct regions in complex geological landscapes, offering a much higher spatial resolution than oxygen isotopes in the southern Andes.

Resumen El análisis de los espacios internodales en escala arqueológica ofrece un marco adecuado para la integración de preguntas generadas desde distintos ámbitos teóricos, con un gran potencial de complementariedad. El objetivo de este trabajo es evaluar, desde una perspectiva biogeográfica, el rol desempeñado por los espacios internodales en la dinámica de interacción social intergrupal en Pata-gonia septentrional. En primer lugar, presentamos los lineamientos teórico-metodológicos que guían nuestra propuesta, en la cual la biogeografía constituye el marco de referencia para identificar distintos tipos de Ei en la región de estudio. Existe una impor-tante variación geográfica y ecológica en los sectores del paisaje que pueden haber constituido internodos en el pasado, la cual debe ser caracterizada como un primer paso para evaluar su dinámica sociodemográfica. Planteamos que hay dos variables ecológicas claves que establecen la base geográfica de los internodos: a) gradiente de variación en la disponibilidad de recursos; y b) escala espacial de los espacios internodales. En segundo lugar, sobre la base de información en escala etnográfica, describimos en forma muy simple los mecanismos sociales de interacción que regulan el acceso y uso de este tipo de espacios. Con ello, buscamos comenzar a modelar arqueológicamente la dinámica relacionada al uso de los internodos en Patagonia septentrional. En tercer lugar, exploramos el rol de dos líneas de evidencia que informan sobre interacción social y circulación de información/objetos: las representaciones rupestres y la geoquímica de obsi-dianas. Para finalizar, reflexionamos sobre el alcance de los aportes generados y proponemos líneas futuras de trabajo que permitirán profundizar la comprensión de la dinámica humana de circulación de información/objetos implementada en el noroeste de Patagonia, así como de las redes de interacción que vincularon grupos de cazadores recolectores en distintas escalas espaciales. Palabras claves: Biogeografía humana – interacción social – distribución de representaciones rupestres – geoquímica de obsidianas – noroeste de Patagonia. Abstract The analysis of internodal spaces in archaeological scale offers a frame useful for integrating questions produced from different theoretical stands, which are actually complementary. The goal of this paper is to assess the role of internodal spaces for inter-group interaction in northern Patagonia from a biogeographical perspective. First, we present the theoretical-methodological frame that guides this proposal. There is important geographical and ecological variation in those parts of a given landscape that can be considered as internodes during the past, which should be characterized as a first step to assess their socio-demographic dynamics. We suggest that there are two key ecological variables that make up the basis of internodes: a) gradient of ecological variation in resources; b) spatial scale of the internodes. Secondly, based on ethnographic information, we describe in a simple manner the possible social mechanisms of interaction that structure and regulate the access to and circulation across internodes. By using this frame, we intend to model the archaeological dynamics of the human use of internodal areas in northern Patago-nia. In third place, we explore the role of two lines of research that may constitute proxies on social interaction and circulation of information/objects in space: rock art and obsidian geochemistry. Finally, we consider the preliminary contribution of this research, suggesting paths for future development of these ideas.

The Andes mountain range is one key physiographic feature of South America with the potential to have acted as a barrier and corridor for human societies. The goal of this paper is to assess from where and how were the highlands utilized during the last 2000 years, which is a key period witnessing the development of productive economies and changes in the organization of mobility. We develop a regional case study focused on the highland wetland Laguna del Diamante (3300 masl), which is a highly productive ecosystem only accessible during summer. This case is based on a multidisciplinary approach combining: a) geochemical characterization of obsidian sources located in the highlands and artifacts; b) isotopic approach to ranges of paleomobility of individuals by means of 87 Sr/ 86 Sr; and c) stylistic study of ceramic assemblages. The two main obsidian types from the highlands have restricted and decaying spatial distribution, suggesting that these archaeological distributions track part of human circuits of mobility instead of indirect transport acquisition. Their archaeological distribution is heavily skewed towards the western Andean slope. We present strontium isotope values for four teeth and bone samples from two individuals recovered in the area, which are interpreted in reference to a preliminary baseline of biologically available strontium. We infer that these individuals had ranges of paleomobility systematically connecting the western slope with the highlands. The analysis of the ceramic assemblages shows that most of the diagnostic sherds can be assigned to styles that have distributional cores in the Central Valley of Chile up until the time of Inca presence, while only a minimum portion of the sample can be assigned to distributional cores on the eastern slope. By integrating the patterns in the transport of obsidian and ceramic artifacts and the paleomobility of individuals, we find support for the existence of dominant access to the highlands from the western Andean slope. A GIS-based analysis of the seasonality of precipitation shows that the western slope presents more pronounced and drier summer months, providing a context that contributes to explain these patterns. These results contradict previous interpretations suggesting that the archaeological record from the highlands is more directly tied to human groups inhabiting the eastern lowlands during most of the year. Beyond the geographic debate, this issue has an impact on the subsistence organization of the incoming groups, on the socioeconomic role of the highlands, and on the demographic contexts leading to trajectories of economic intensification in both Andean slopes. This research contributes to build a framework for comparative research on human use of highland environments.

A B S T R A C T We studied the organization of mobility of hunter-gatherers groups of northwestern Patagonia (Argentina) from an interdisciplinary perspective. We combined geochemical and technological characterization of obsidian assemblages from surface and stratigraphic contexts spanning the Holocene, and a preliminary geoarchaeolo-gical study of the sources. The goals were to assess the provenance, mode of supply, use, and discard of obsidian artifacts on the basis of information on the structure of the two main regional sources: Cerro Huenul, located in the lowlands, and Laguna del Maule, located in the Andean highlands. We conducted geoarchaeological field sampling at different altitudes of the Barrancas River fluvial deposits to study the geomorphic impact on the secondary structure of the highland source. Preliminary geoarchaeological results allow extending the area of availability up to 90 km towards the lowlands from the outcrops. In addition, we performed non-destructive XRF analyses on 266 lithic artifacts, which were placed along a continuum of reduction. 89% of the artifacts corresponded to the local Cerro Huenul source, while 11% to Laguna del Maule. While the artifacts made on Cerro Huenul obsidian were represented by the full reduction sequence, those from Laguna del Maule are only represented by advanced stages. We integrate these results with information on the frequencies of projectile points, ceramics, and rock-art motifs for the two main archaeological sites in the region: Cueva Huenul 1 and Cueva Yagui. These proxies indicate that the sites have different place use histories, providing a scheme for the analysis of human use of the regional landscape.

En este trabajo se analizan y se comparan aspectos de la organización tecnológica de grupos cazadores-recolectores, transicionales y pastores que ocuparon los ambientes de altura del NO de San Juan. En una escala meso espacial y a partir del estudio de la base regional de recursos líticos se realizan análisis de procedencia, secuencias reductivas, variabilidad artefactual y clases técnicas de un registro correspondiente a tres segmentos temporales del Holoceno. El análisis lítico correspondiente a cazadores-recolectores indica la implementación de estrategias expeditivas y conservadas, caracterizadas por predominio de rocas locales, de actividades de formatización de artefactos y de instrumentos con baja y alta inversión de trabajo. El registro de grupos con economías diversificadas indica el desarrollo fundamentalmente de estrategias expeditivas, caracterizadas por el predominio de rocas locales, de actividades para la obtención de soportes y de artefactos con baja inversión de trabajo. Además, se incrementan rocas de procedencia indeterminada, hay mayor variabilidad artefactual, disminuyen las tareas de formatización y las piezas con alta inversión de trabajo. Se detectó la continuidad de la caza como actividad económica y de sistemas de producción lítica secuenciales y regionales que involucran el desarrollo de tareas diversas en tres sectores altitudinales. Palabras clave: Holoceno; ambientes de altura; NO de San Juan; organización tecnológica; sistemas de producción lítica. Abstract: This paper analyzes and compared aspects of technology organization in hunter-gatherers, transitional groups, and herders who occupied high-altitude environments in northwestern San Juan. We present meso-scale analyses of lithic sources, reductive sequences, artifact diversity, and material classes from three temporal segments of the Holocene. For the hunter-gatherers, the lithic analysis show expeditious and conservative strategies, predominance of local lithic sources, tool shaping and a low and high investment of labor. The record of groups with more diversified economies display a predominance of expeditious strategies with prevalence of local rocks, knapping designed to acquire blanks and less time investment in making lithic tools. Furthermore, there is an increased of undetermined lithic sources, more artifact diversity, less time investment in making lithic tools and more time investment in making lithic tools. We detected a continuity in hunting as an economic activity and sequential and regional lithic production systems that involve various tasks at three different altitudes.

En este capítulo se estiman, de manera preliminar, las posibles vías de circulación/contacto que existieron en el área del río de Las Taguas Superior (en la frontera entre Chile y Argentina) durante los 290 años ac y los 670 años dc. Mediante un Sistema de Información Geográfica se realizan análisis de rutas de menor costo con el objeto de evaluar la posible integra-ción del valle de Las Taguas a un circuito de rutas entre ambas vertientes cordilleranas y de comparar rutas modeladas a partir de las curvas de Tobler y de Tripcevich. En función de los resultados obtenidos se propone que las sociedades de ambas vertientes cordilleranas, asociadas a las denominadas Fase Cultural Punta del Barro en San Juan y El Complejo Cultural el Molle en el Norte Semiárido Chileno, habrían ocupado el área del valle del río de Las Taguas pudiendo generar fuertes lazos económicos e ideológicos, y así impor-tantes influencias en la organización social y económica a través del tiempo. Abstract This chapter presents preliminary estimates of possibles routes of circulation/contact that existed in the Upper Taguas River Valley (near the Chile-Argentine border) between 290 bc and ad 670. Utilizing a Geographic Information System, least cost path analysis is used to evaluate the integration of the Taguas Valley along routes that crossed the Andean cordillera, modeled with Tobler's and Tripcevich's curves. Based on the results, we propose that the two societies on different sides of the cordillera, the culture Punta del Barro in San Juan, and the El Molle cultural complex in the semiarid northern Chile, would have occupied the Las Taguas River Valley area. They may have generated strong economic and ideological ties, and in turn, significant influences on social and economic organization over time.