Papers by Alejandro Serna
Nuevos aportes sobre el uso mortuorio de la laguna del Juncal: el caso del sitio arqueológico San Javier (Valle Inferior del río Negro, Río Negro, Argentina), 2025
El área en torno a la antigua laguna del Juncal (valle inferior del río Negro, Río Negro, Argenti... more El área en torno a la antigua laguna del Juncal (valle inferior del río Negro, Río Negro, Argentina)
concentra una gran diversidad y abundancia de restos arqueológicos. En la década de 1970, en
sus inmediaciones se excavó el sitio San Javier, pero su información permaneció inédita. Este
trabajo tiene por objetivo generar una primera caracterización del conjunto bioarqueológico del
sitio, con énfasis en la estructura sexo-etaria, cantidad de individuos inhumados, rasgos
tafonómicos y cronología, evaluando su relación con otros contextos mortuorios del noreste de
Patagonia. En San Javier se inhumaron al menos 22 individuos de ambos sexos y diferentes
edades, la muestra presenta excelente estado de conservación, huellas antrópicas y pigmentación
rojiza, producto del tratamiento postmortem de los cuerpos. La frecuencia en que se observan
huellas antrópicas y pigmento entre elementos óseos de adultos y subadultos presenta diferencias
significativas, sugiriendo prácticas rituales diferenciales según la edad o limitaciones en la
muestra. Los fechados radiocarbónicos (1710 ± 60 a 340 ± 40 años AP) aportan evidencia para
cerrar el vacío de información sobre la ocupación humana de la laguna entre ca. 2500 y 750 años
AP y confirman la persistencia de su uso mortuorio durante el Holoceno tardío. Además, San
Javier proporciona evidencia clara de entierros secundarios con pigmento rojizo en el valle
inferior del río Negro, ampliando la distribución espacial conocida de estas prácticas. El sitio
refuerza el rol de la laguna del Juncal como punto neurálgico de actividades mortuorias y rituales
integrando prácticas compartidas a escala regional.
International Journal of Paleopathology, 2025
To evaluate the social implications of traumatic injuries in non-sedentary hunter-gatherers by an... more To evaluate the social implications of traumatic injuries in non-sedentary hunter-gatherers by analysing osteological remains through models based on the Bioarchaeology of Care. Materials: Human skeletal remains from North Patagonia (Late Holocene). 3179 anatomical elements from 189 individuals of both sexes and different age categories. Methods: Macroscopic analysis of all bones to identify two injury types (dislocations and fractures) to apply the Index of Care to each case. Results: About 20 % of individuals suffered injuries, mostly mild, requiring short-term care. Severe cases needed intensive care, likely disrupting the normal routines of daily life in the group. Conclusions: Despite logistical costs and disabilities that led, in some cases, to social reorganisation of daily or planned activities, these groups ensured their peers' survival and recovery through care. Significance: The Index of Care was expanded by defining categories based on care intensity, applicable to any context, and offers new information about interpersonal care in Patagonia. Limitations: Only osteological remains are available to assess interpersonal care. Suggestions for further research: Incorporate other pathological conditions (e.g., bone infections) and more samples on a larger spatial-temporal scale to evaluate interpersonal care in the region.
R. Soc. Open Sci. , 2025
Strontium isotopes (87 Sr/ 86 Sr) are increasingly used as a provenance tool in multiple discipli... more Strontium isotopes (87 Sr/ 86 Sr) are increasingly used as a provenance tool in multiple disciplines. Application to biological materials requires knowledge of the variation in bioavailable 87 Sr/ 86 Sr across the landscape, potentially in the form of an isoscape (a quantitative model of spatial isotopic variability). This paper summarizes and provides advice on our current understanding of the main concerns in creating and interpreting isoscapes of bioavailable 87 Sr/ 86 Sr. Isoscape creation approaches include domain mapping, geostatistical contour mapping and machine learning, the last becoming more readily achievable with the availability of software packages. It is critically important to develop isoscapes at a resolution appropriate for addressing the research questions. Choice of sample materials depends on the research questions and availability: plants or fauna with small ranges are favoured, with some analytes (snails, soil leachates) posing challenges. Interpreting 87 Sr/ 86 Sr in biological tissues requires considering Sr metabolism and the timing of tissue formation, thus far underappreciated. The numerous sources of error involved in developing and applying isoscapes must be recognized to avoid over-interpreting data and spurious provenance precision. We hope this paper will help researchers investigating provenance, mobility, landscape use and migration to develop the most appropriate isoscapes for their purposes, and possible future use by others.
Scientific Reports, 2025
The acknowledgment of plants as signifiant components in hunter-gatherer diets has provided new
i... more The acknowledgment of plants as signifiant components in hunter-gatherer diets has provided new
insights into past interactions between these groups and their environments, as well as between
groups with diffrent economies and social structures. The Patagonia region, South American Southern
Cone, has been traditionally perceived as dominated by game hunting. This perception has changed
by recognizing a broader spectrum of diet, where local wild and exotic domesticated plants, would
have been intertwined in these hunter-gatherer lives. However, the nature of the archaeological record
preservation obscures an accurate assessment of their role. Here, we quantifid the contribution
of plants and other resources to hunter-gatherer paleodiets through biomolecular methods and
statistical analysis (multivariate and Bayesian). We analyzed the carbon and nitrogen stable isotope composition (δ13Ccol, δ15N) of human remains (n = 30) and fauna/flra (n = 52) from Northern Patagonia,
and radiocarbon dated specifi individuals related to exotic domesticated plants (maize). Our results show that one-third of the overall intake was based on the systematic exploitation of local wild plants, while maize appears to have functioned as an imported edible commodity obtained from distant food
producers.
The acknowledgment of plants as significant components in hunter-gatherer diets has provided new ... more The acknowledgment of plants as significant components in hunter-gatherer diets has provided new insights into past interactions between these groups and their environments, as well as between groups with different economies and social structures. The Patagonia region, South American Southern Cone, has been traditionally perceived as dominated by game hunting. This perception has changed by recognizing a broader spectrum of diet, where local wild and exotic domesticated plants, would have been intertwined in these hunter-gatherer lives. However, the nature of the archaeological record preservation obscures an accurate assessment of their role. Here, we quantified the contribution of plants and other resources to hunter-gatherer paleodiets through biomolecular methods and statistical analysis (multivariate and Bayesian). We analyzed the carbon and nitrogen stable isotope composition (δ 13 C col , δ 15 N) of human remains (n = 30) and fauna/flora (n = 52) from Northern Patagonia, and radiocarbon dated specific individuals related to exotic domesticated plants (maize). Our results show that one-third of the overall intake was based on the systematic exploitation of local wild plants, while maize appears to have functioned as an imported edible commodity obtained from distant food producers.
Journal of Forensic Sciences, 2025
The use of isotopic analysis for human mobility, geolocation, and forensic identification has bec... more The use of isotopic analysis for human mobility, geolocation, and forensic identification has become common over the past two decades, yet its effectiveness depends on the availability of well-documented reference data. Many reference data exist in the literature, but the suitability of these data for forensic applications has not been critically assessed. Here, we compile oxygen and strontium isotope data for North American human tissues (hair, nails, bone, and tooth enamel). We review the geo
Maize, one of the primary crops cultivated in South America, has achieved significant interest in... more Maize, one of the primary crops cultivated in South America, has achieved significant interest in regional archaeology. However, the study of maize in regions considered peripheral to major centres of agricultural production, such as Southern Chile, has received minimal attention. Southern Chile is the southernmost point for the dispersal of maize cultivation in the Americas, with archaeological evidence dating back ca. 1000 CE. Despite the manifest presence of maize, our knowledge of its culinary and economic importance for pre-colonial societies from Southern Chile is scarce. In this study, we extracted and analysed organic residues from 188 pottery sherds to explore the potential significance of maize in local foodways over the transition from the Early (ECP: 400-1000 CE) to the Late (LCP: 1000-1550 CE) Ceramic Period. Biomolecular and carbon-stable isotope (δ 13 C) analyses of lipids indicate that maize was not a staple. Instead, our findings suggest that maize had a potentially prominent role in preparing fermented beverages consumed in important socio-political gatherings and feasts. The significance of maize (Zea mays) production in pre-colonial Western South America has traditionally been a major focus of archaeological research. Evidence from the Andean regions and the Pacific coast indicate different levels of reliance on this crop from its early adoption ca. 4750 BCE to its incorporation as a staple food ca. 100 BCE (
Isotopic heterogeneity in U.S. Urban water supply systems reflects climatic, environmental, and sociodemographic factors: Implications for forensic identification. PLOS ONE.
The forensic application of stable oxygen isotope data from human tissues depends on naturally oc... more The forensic application of stable oxygen isotope data from human tissues depends on naturally occurring isotopic variation in drinking water across geographic areas. One factor which complicates interpretation of forensic data is local variability: if a wide range of drinking water values is in a small geographic region it may be difficult to identify or rule out that region as a location of origin. We examine data from community collection programs documenting tap water isotope variation within 30 cities\developed areas throughout the United States. Isotopic variation within individual developed areas ranged widely, from essentially nil to greater than 9‰ (δ 18 O interdecile range). Many (14/30) of the study areas exhibited multi-modal isotope distributions, even in cases where the isotopic range was very small (e.g., <2.0‰), suggesting that the use of multiple, isotopically different sources was common. Most variation was attributed to differences in the source-region altitude or degree of evaporation for different water sources, and we observe limited variation in areas where contrasts in these variables are small. Variation tended to be largest in cities across the western USA. We explored correlations between the magnitude of local isotopic variation and climatic, environmental, and socioeconomic variables. We found that higher levels of variation occurred at sites where local water resources were likely to be more isotopically heterogeneous and in lower supply, consistent with the development of supply systems in these areas that access diverse and isotopically heterogeneous water resources. We also found that variation was positively correlated with larger developed areas, suggesting that pressures related to city growth may affect the degree to which infrastructure tapping diverse water resources is developed. Collectively, our results suggest that the influence of local tap water isotope heterogeneity on the precision of forensic geolocation is systematic and somewhat predictable, information to be factored into future applications.
En el Noreste de Patagonia se han hallado múltiples sitios con entierros humanos. En el valle del... more En el Noreste de Patagonia se han hallado múltiples sitios con entierros humanos. En el valle del río Negro los entierros comparten ciertas características, tales como ubicarse en sectores elevados y reutilizarse para realizar entierros y otras actividades. Este patrón también se observa en el valle del río Colorado y en la costa atlántica de Patagonia. Hacia el Sur del río Negro, en los bajos o "travesía", no hay información sobre sitios mortuorios, pero sí inmediatamente al Sur de la travesía, en el piedemonte y meseta de Somuncurá. En esta región los sitios funerarios se distinguen de los del Norte por ubicarse en oquedades rocosas, ser únicamente de entierro y por lo general contener acompañamiento mortuorio. Este trabajo presenta los resultados del análisis de los restos humanos del sitio Aguada Cecilio (piedemonte de Somuncurá, Río Negro, Argentina) y los discute en relación con la variabilidad del registro bioarqueológico del Noreste de Patagonia durante el Holoceno tardío. El sitio contiene únicamente restos de subadultos con signos de manipulación postmortem y una punta de proyectil asociada. Su incorporación a la información bioarqueológica regional permitió discutir la variación en el patrón funerario entre el Norte y Sur del interior del Noreste de Patagonia.
Science & Justice, 2024
Isotopic analysis of human tooth enamel can provide life history information useful in forensic i... more Isotopic analysis of human tooth enamel can provide life history information useful in forensic identifiation.
These applications depend on the availability of reference data documenting isotopic values for individuals with
known life history and on the comparability of data from reference and case work samples. Here we build on
previous methodological research, which has largely focused on paleontological and archaeological samples, and
conduct experiments using enamel from modern human teeth targeting three sample preparation variables
(sample particle size, storage conditions, and chemical pretreatments). Our results suggest that differences in
particle size affect the effiiency of sample reactions during pretreatment and analysis, with coarse particles
giving reduced loss of enamel carbonate during acid pretreatments but producing slightly higher oxygen isotope
values than fie particles during analysis. Data for samples stored in dry and ambient environments following
pretreatment were indistinguishable, suggesting no exchange of oxygen between samples and ambient water
vapor. Finally, chemical pretreatments with a range of commonly used reactants and conditions showed a
pervasive, moderate oxygen isotope shift associated with acetic acid treatment, which may be caused by exchange of enamel hydroxyl groups with reagents or rinse waters. Collectively, the results emphasize the
importance of methodological standardization to improve comparability and reduce potential for bias in the
forensic application of tooth enamel isotope data.
2023. González Venanzi et al. Special pet, special care. Diet, provenance, and health analyses of a dog reveal strong ties with humans in Patagonia, 2023
The introduction of the dog in Patagonia is recorded from the Late Holocene. Documents from the n... more The introduction of the dog in Patagonia is recorded from the Late Holocene. Documents from the nineteenth century indicate that dogs had various utilitarian roles among hunter-gatherers, including hunting aids, protection and war, carrying loads, and as exchange goods. Most of them had no special status, typically subsisting on food scraps and hunting leftovers, were in bad or poor physical and nutritional condition, and suffered physical abuse. Nevertheless, a select few dogs, including those of the hairless variety, received special care and attention from humans. They were in good physical and nutritional condition and appeared to have been used as companion animals of people with prestigious positions. These dogs were regularly provided with cooked food, owned horses, and even were offered sacrificed horses as a form of treatment during their illnesses. Through an interdisciplinary osteobiographical study (phenotype, age, stable isotopes –δ13C, δ15N, δ18O–, microremains of the dental calculus, paleopathology, and entheseal changes), we evaluate whether a dog recovered from a funerary context of Patagonian hunter-gatherers represents the archaeological correlate of a special position animal. The canid exhibited mobility impairments that surely prevented it from hunting large herbivores. Despite this, it was regularly fed meat from human prey and human-made meals containing fruits of Neltuma sp. and underground storage organs. Following its death, the dog was given an individual burial within a mortuary niche located in a dedicated area for human bodies. The results provide evidence that this canid held a special or distinct position, possibly indicating emotional bonds with the hunter-gatherers.
Journal of Archaeological Science, 2023
Ceramic technology makes an abrupt appearance in the New World Arctic at circa 2800 cal BP. While... more Ceramic technology makes an abrupt appearance in the New World Arctic at circa 2800 cal BP. While there is general consensus that the ultimate source of these Alaskan pottery traditions lay in continental NE Asia, the motivations for the adoption of pottery in Alaska have remained unclear. Through organic residue analysis we investigated the function of Norton pottery in Southwest Alaska, and the extent to which its function changed in later periods under the increasing northern inflence of Thule culture in the region (from ca. 1000 cal BP). Our results show clear evidence of aquatic resource processing in all pottery vessels. Regional variability due to environmental and ecological differences are apparent in the pottery. The majority of Norton pottery was from inland riverine locations and the function of this early pottery was to process anadromous fish, with only limited evidence of other resources. After 1000 cal BP more sites appear on the coast, and while pottery technology changes dramatically at this time, this is not as clear in pottery function which remains aimed at local abundant aquatic resources. We hypothesize that pottery was adopted into Alaska as part of a riverine adaptation and suggest that targeted human exploitation of large riverine systems may have facilitated its expansion into Southwest Alaska. Furthermore, we suggest that this pattern might extend back into Siberia where Alaskan pottery originates.
Journal of Anthropological Archaeology
This paper discusses the maize consumption record among hunter-gatherers outside assumed producti... more This paper discusses the maize consumption record among hunter-gatherers outside assumed production areas in northeastern Patagonia. We evaluated if this anomalous record is the result of occasional events of local production/consumption; the transport of the microremains in the teeth of individuals after consuming maize in non-local production areas; or the local consumption of maize after its transport/exchange from production areas. Archaeobotanical results showed that analyzed individuals, including maize-consumers, mainly consumed local wild plants. Maize was not cultivated locally, and its consumption was unusual but not extraordinary in northeastern Patagonia. Oxygen isotope values of analyzed individuals are strongly compatible with local water sources, which imply that the mobility range of them must have not exceeded extra-Andean North Patagonia. For this reason, the most plausible explanation for the presence of maize in the local archaeological record is that this plant to have entered northeastern Patagonia through exchange, probably from southern Andes (central Chile or central-west Argentina).
Quaternary International, 2022
This work seeks to explore human mobility in the lower course of the Colorado River (Argentina) d... more This work seeks to explore human mobility in the lower course of the Colorado River (Argentina) during the Middle and Late Holocene (ca. 5900-250 years BP) through the analysis of stable oxygen isotopes (δ 18 O) of bone bioapatite. The δ 18 O values are interpreted and compared with those from North Patagonia and Western Pampas to evaluate mobility at a regional scale. Forty-one adult individuals of both sexes from 12 archaeological sites were analyzed. δ 18 O c values were transformed into drinking water (δ 18 O dw). The results were compared with the hydrological baseline generated for central-eastern North Patagonia and real rainfall data and predictive rainfall models. ẟ 18 O c values indicate higher values in individuals corresponding to Middle Holocene (− 0.7‰) compared with the Initial Late Holocene (− 3.1‰) and Final Late Holocene (− 2.3‰) and statistically significant differences between Middle Holocene and Late Holocene. Based on the δ 18 O dw values, 17.1% (7/41) correspond to hydrologic zones defined for central-eastern North Patagonia, and 48.8% to the real and predictive rainfall models. Although differences in δ 18 O dw values are observed between the Middle and Late Holocene, it is not yet possible to propose precise human mobility geographical directions in the study area. Nevertheless, during the Late Holocene, the δ 18 O c values showed that individuals buried in the study area could have shared some water sources with those from Western Pampas and nearby sectors from Northeastern Patagonia, such as the lower course of the Negro River.
Archaeological and Anthropological Sciences , 2022
This study discusses the biological and social implications of a disabling injury sufered by a La... more This study discusses the biological and social implications of a disabling injury sufered by a Late Holocene hunter-gatherer
from Northeastern Patagonia. Osseous modifcations were analysed through macroscopy, radiography, computed tomography,
and three-dimensional models. The diferential diagnoses followed bioarchaeological and modern clinical literature, and the
overall case was interpreted within the Bioarchaeology of Care theoretical framework. The individual presented a healed
fracture of the lateral tibial plateau, a highly disabling injury of the inferior limb, which constrained its locomotion and could
have caused new demands on other parts of the body. The restricted mobility produced by this type of fracture and the state
of remodelling imply that the individual received diferent levels of interpersonal attention throughout the progression of
the healing process. The model of care for this individual recognizes at least a stage of “direct support” for basic tasks in
the short-/medium-term and then “accommodation assistance” in the long-term while he became more autonomous. Apart
from thoroughly describing an infrequent injury, this study case provides clear evidence of interpersonal care strategies
among Patagonian hunter-gatherer
MAGALLANIA, 2022
Se presenta un estudio multi enfoque basado en entierros humanos provenientes de Laguna del Junca... more Se presenta un estudio multi enfoque basado en entierros humanos provenientes de Laguna del Juncal, depositados en forma de bochones en las colecciones de dos museos regionales del Alto Valle del Río Negro desde la década de 1970. Los restos presentan la característica coloración oscura que ha dado lugar a numerosas menciones a lo largo de la historia de la arqueología del río Negro. El objetivo de este trabajo es estudiar la coloración de los restos (natural vs. antrópica) y evaluar su cronología. Para ello se presenta una caracterización bioarqueológica, cronológica y tafonómica de los individuos y sus matrices sedimentarias, utilizando análisis químicos y microscópicos. Se excavaron dos individuos, un adulto y otro subadulto, ambos con escaso material cultural asociado y fueron datados en 720 ± 24 y 754 ± 24 años AP respectivamente. La preservación del adulto es entre regular y buena, mientras que el subadulto presentó peor preservación. Mediante microanálisis químicos (MEB) se registró alto contenido de manganeso y hierro en los sedimentos, así como en el material óseo, lo cual explicaría su coloración oscura. Se discuten los resultados en el marco de los conocimientos actuales de los entierros del noreste de Patagonia.
Anales de Arqueología y Etnología, 2021
RESUMEN En este trabajo se presentan los resultados de la caracterización de la ancestría materna... more RESUMEN En este trabajo se presentan los resultados de la caracterización de la ancestría materna de dos individuos inhumados en el sitio arqueológico Chimpay, en el valle del río Negro, a finales del siglo XIX. Se trata del entierro doble de una mujer adulta con un variado y abundante acompañamiento funerario y de un hombre que vestía un uniforme militar del Estado argentino. En trabajos previos basados en el análisis de la evidencia arqueológica, bioarqueológica y etnohistórica se planteó como hipótesis principal que el contexto correspondía al entierro de un líder militar mapuche, aunque no se había confirmado fehacientemente la ancestría del individuo. A fin de contrastar esta hipótesis, se presentan aquí los resultados del análisis de la ascendencia materna de ambos individuos a partir del estudio de la secuencia de la HVR I del ADN mitocondrial (ADNmt). Como resultado se obtuvo la
Latin American Antiquity, 2020
This article discusses a Mapuche Indigenous mortuary context of the nineteenth century from the m... more This article discusses a Mapuche Indigenous mortuary context of the nineteenth century from the middle valley of the Negro River in northern Patagonia, Argentina, which is characterized by a double burial of a man and a woman. The use of both archaeological and ethnohistorical data allows us to hypothesize that the burial is of a man with a high status in the political and military hierarchy (cacique or capitanejo) and that the corpse of the woman was one of his wives who was sacrificed so she could accompany the man in his trip to Allhue Mapu, the land of souls. We contextualize this site with existing knowledge about the suttee practice in the Pampas and Norpatagonia during the eighteenth and nineteenth centuries. This case is an example of the burial ritual known as suttee that occurred between the last decades of Indigenous autonomy (1850-1880) and the first decades after the state conquest of their territory (1880-1900). En este artículo se discute un contexto mortuorio indígena Mapuche del siglo diecinueve hallado en el valle medio del río Negro (norte de la Patagonia, Argentina) y caracterizado por el entierro doble de un hombre y una mujer. La articulación entre los datos arqueológicos y etnohistóricos nos permite hipotetizar que este entierro es el resultado del ritual funerario de un hombre con cierta jerarquía política y militar (cacique o capitanejo) y que el cadáver de la mujer habría sido incluido como resultado del sacrificio de una de sus esposas para acompañar al hombre en su viaje al Allhue Mapu o tierra de las almas. La interpretación de este sitio implicó su contextualización dentro del conocimiento existente en torno a la práctica del suttee en las Pampas y Norpatagonia durante los siglos dieciocho y diecinueve. Concluimos que este sitio podría ser el resultado de un ritual de entierro conocido como suttee y que este evento se produjo entre las últimas décadas de la autonomía indígena (1850-1880) y las primeras décadas luego de la conquista estatal de sus territorios (1880-1900).
Journal of Archaeological Science: Reports , 2020
Central-eastern North Patagonia is characterized by a severe environmental fragmentation due to t... more Central-eastern North Patagonia is characterized by a severe environmental fragmentation due to the scarce and heterogeneous distribution of fresh water. The main local wet zones, the Negro and Colorado river valleys in the North and the Somuncurá Foothills in the South are separated by a large and harsh dry land, the travesía. In this paper, we assess the effects of this environmental fragmentation in the mobility of the Late Holocene hunter-gatherers through the analysis of the stable isotopes of oxygen in both enamel and water sources. We analyzed the δ 18 O of the enamel carbonate of 64 human teeth from 42 individuals from the Negro River valley (n = 30) and the Somuncurá Foothills (n = 12) and transformed them into drinking water values (δ 18 O dw) to be compared with an oxygen water baseline built from the most important surface water sources of the area. Our results show variable mobility, but they also highlight two trends regarding the direction of the movement. First, people buried at the Negro River valley seem to have consumed more regularly water from the Colorado River in the North than from other water sources located farther south (e.g. Somuncurá Foothills). Second, the δ 18 O dw values from the Somuncurá sample show east-to-west prevalent mobility along the foothills, far from the northern water sources (e.g. Colorado River). This weak connectivity between the northern and the southern parts of the study area (Negro and Colorado river valleys and Somuncurá Foothills) is probably related to the harsh environmental constraints imposed by the travesía. Our isotopic results in conjunction with the available archaeological and ethnohistorical data indicate that this large dry land acted as a marginal space in terms of human exploitation and that it certainly influenced human mobility.
Journal of Archaeological Science, 2020
Strontium isotopes (87 Sr/ 86 Sr) are used as geochemical tracers for paleomobility studies becau... more Strontium isotopes (87 Sr/ 86 Sr) are used as geochemical tracers for paleomobility studies because they display predictable and stable patterns in ecosystems primarily controlled by the underlying geological regimes. While bedrock geology is stable over thousands of years, geomorphological processes can influence the 87 Sr/ 86 Sr in ecosystems over archeologically relevant timescales. Among these geomorphological processes, the deposition and reworking of volcanic sediments over Quaternary timescales are little studied but could be an important control of 87 Sr/ 86 Sr variations in many archeological regions. North Patagonia is a key archeological region to address animal and human movements, and an ideal location to test the influence of Quaternary volcanism on 87 Sr/ 86 Sr variation as it is located downwind of major volcanic centers. In this study, we aim to assess the main environmental and geological controls of bioavailable 87 Sr/ 86 Sr and to build a high-resolution isoscape using a machine learning regression framework for forthcoming paleomobility studies. We sampled several locations and analyzed different types of samples (N ¼ 94). The ratios show a limited range of variation, which is not related to the bedrock geology. Rather, bioavailable 87 Sr/ 86 Sr variations display a progressive increase going eastward (away from the Andes), following dust aerosol deposition and elevation variations (R 2 ¼ 0.71, RMSE ¼ 0.00041). We argue that this trend relates to the deposition and reworking of unradiogenic volcanic sediments by aeolian, fluvial and glacial erosion during the Quaternary. As most of this sediment reworking occurred during glacial periods, the current bioavailable 87 Sr/ 86 Sr variations across the study area likely represent a long-term average that varied little during the Holocene. Consequently, our isoscape provides a solid base for Holocene paleo-mobility studies in North Patagonia and underlines the importance of Quaternary volcanism processes for interpreting 87 Sr/ 86 Sr data in paleomobility studies in volcanic regions.
Uploads
Papers by Alejandro Serna
concentra una gran diversidad y abundancia de restos arqueológicos. En la década de 1970, en
sus inmediaciones se excavó el sitio San Javier, pero su información permaneció inédita. Este
trabajo tiene por objetivo generar una primera caracterización del conjunto bioarqueológico del
sitio, con énfasis en la estructura sexo-etaria, cantidad de individuos inhumados, rasgos
tafonómicos y cronología, evaluando su relación con otros contextos mortuorios del noreste de
Patagonia. En San Javier se inhumaron al menos 22 individuos de ambos sexos y diferentes
edades, la muestra presenta excelente estado de conservación, huellas antrópicas y pigmentación
rojiza, producto del tratamiento postmortem de los cuerpos. La frecuencia en que se observan
huellas antrópicas y pigmento entre elementos óseos de adultos y subadultos presenta diferencias
significativas, sugiriendo prácticas rituales diferenciales según la edad o limitaciones en la
muestra. Los fechados radiocarbónicos (1710 ± 60 a 340 ± 40 años AP) aportan evidencia para
cerrar el vacío de información sobre la ocupación humana de la laguna entre ca. 2500 y 750 años
AP y confirman la persistencia de su uso mortuorio durante el Holoceno tardío. Además, San
Javier proporciona evidencia clara de entierros secundarios con pigmento rojizo en el valle
inferior del río Negro, ampliando la distribución espacial conocida de estas prácticas. El sitio
refuerza el rol de la laguna del Juncal como punto neurálgico de actividades mortuorias y rituales
integrando prácticas compartidas a escala regional.
insights into past interactions between these groups and their environments, as well as between
groups with diffrent economies and social structures. The Patagonia region, South American Southern
Cone, has been traditionally perceived as dominated by game hunting. This perception has changed
by recognizing a broader spectrum of diet, where local wild and exotic domesticated plants, would
have been intertwined in these hunter-gatherer lives. However, the nature of the archaeological record
preservation obscures an accurate assessment of their role. Here, we quantifid the contribution
of plants and other resources to hunter-gatherer paleodiets through biomolecular methods and
statistical analysis (multivariate and Bayesian). We analyzed the carbon and nitrogen stable isotope composition (δ13Ccol, δ15N) of human remains (n = 30) and fauna/flra (n = 52) from Northern Patagonia,
and radiocarbon dated specifi individuals related to exotic domesticated plants (maize). Our results show that one-third of the overall intake was based on the systematic exploitation of local wild plants, while maize appears to have functioned as an imported edible commodity obtained from distant food
producers.
These applications depend on the availability of reference data documenting isotopic values for individuals with
known life history and on the comparability of data from reference and case work samples. Here we build on
previous methodological research, which has largely focused on paleontological and archaeological samples, and
conduct experiments using enamel from modern human teeth targeting three sample preparation variables
(sample particle size, storage conditions, and chemical pretreatments). Our results suggest that differences in
particle size affect the effiiency of sample reactions during pretreatment and analysis, with coarse particles
giving reduced loss of enamel carbonate during acid pretreatments but producing slightly higher oxygen isotope
values than fie particles during analysis. Data for samples stored in dry and ambient environments following
pretreatment were indistinguishable, suggesting no exchange of oxygen between samples and ambient water
vapor. Finally, chemical pretreatments with a range of commonly used reactants and conditions showed a
pervasive, moderate oxygen isotope shift associated with acetic acid treatment, which may be caused by exchange of enamel hydroxyl groups with reagents or rinse waters. Collectively, the results emphasize the
importance of methodological standardization to improve comparability and reduce potential for bias in the
forensic application of tooth enamel isotope data.
from Northeastern Patagonia. Osseous modifcations were analysed through macroscopy, radiography, computed tomography,
and three-dimensional models. The diferential diagnoses followed bioarchaeological and modern clinical literature, and the
overall case was interpreted within the Bioarchaeology of Care theoretical framework. The individual presented a healed
fracture of the lateral tibial plateau, a highly disabling injury of the inferior limb, which constrained its locomotion and could
have caused new demands on other parts of the body. The restricted mobility produced by this type of fracture and the state
of remodelling imply that the individual received diferent levels of interpersonal attention throughout the progression of
the healing process. The model of care for this individual recognizes at least a stage of “direct support” for basic tasks in
the short-/medium-term and then “accommodation assistance” in the long-term while he became more autonomous. Apart
from thoroughly describing an infrequent injury, this study case provides clear evidence of interpersonal care strategies
among Patagonian hunter-gatherer