While biogeochemical analyses of residential history have revolutionized the study of paleomobility, the monolithic categories of "local" and "non- local" obscure a great deal of important variation in individual migrant experiences. Furthermore, these binarized designations may not always provide a culturally salient indicator of social difference. Here, the authors take a novel approach to integrating previously published biogeochemical 87 Sr/ 86 Sr data with intra- site biodistance analysis of cervicometric dimensions in order to access a diversity of migration experiences within both "local" and "non- local" individuals (n n = 73) at Non- Grid 4, a ritual shrine site in Epiclassic (600- 900 C.E.) central Mexico, where a minimum of 180 individuals were sacrificed and interred. We generate an estimated phenotypic distance matrix using Mahalanobis distances (d2) d 2 ) to identify possible n th generation migrants among individuals who appeared biogeochemically "local." The integration of biogeochemical and cervicometric data thus adds a time depth to their analyses of paleomobility in ancient Mexico beyond first- generation migrants identified by biogeochemical methods alone. The article also examines "non- local" sacrificial victims' phenotypic affinities and available 87 Sr/ 86 Sr data to reconstruct possible migration networks and motivations for migrant individuals relocating to central Mexico during the Epiclassic. This broader contextualization of migrant experiences allows the authors to consider how and why these migrants' lives ended in violence in their new homeland more holistically.

While biogeochemical analyses of residential history have revolutionized the study of paleomobility, the monolithic categories of “local” and “non-local” obscure a great deal of important variation in individual migrant experiences. Furthermore, these binarized designations may not always provide a culturally salient indicator of social difference. Here, the authors take a novel approach to integrating previously published biogeochemical 87Sr/86Sr data with intra-site biodistance analysis of cervicometric dimensions in order to access a diversity of migration experiences within both “local” and “non-l ocal” individuals (n = 73) at Non-Grid 4, a ritual shrine site in Epiclassic (600– 900 C.E.) central Mexico, where a minimum of 180 individuals were sacrificed and interred. We generate an estimated phenotypic distance matrix using Mahalanobis distances (d2) to identify possible nth generation migrants among individuals who appeared biogeochemically “local.” The integration of biogeochemical and cervicometric data thus adds a time depth to their analyses of paleomobility in ancient Mexico beyond first-generation migrants identified by biogeochemical methods alone. The article also examines “non-local” sacrificial victims’ phenotypic affinities and available 87Sr/86Sr data to reconstruct possible migration networks and motivations for migrant individuals relocating to central Mexico during the Epiclassic. This broader contextualization of migrant experiences allows the authors to consider how and why these migrants’ lives ended in violence in their new homeland more holistically. Si bien los análisis biogeoquímicos de la historia residencial han revolucionado el estudio de la paleomovilidad, las categorías monolíticas de “local” y “no local” oscurecen una gran cantidad de variaciones importantes en las experiencias individuales de los migrantes. Además, es posible que estas designaciones binarizadas no siempre proporcionen un indicador culturalmente destacado de la diferencia social. Aquí, tomamos un enfoque nove-doso para integrar datos biogeoquímicos 87Sr/86Sr publicados previamente con análisis de biodistancia dentro del sitio de dimensiones cervicométricas para acceder a una diversidad de experiencias de migración dentro de individuos “locales” y “no locales” (n = 73) en Non-Grid 4, un santuario ritual fechado al Epiclásico (600–900 a.C.) en el centro de México donde se sacrificaron y enterraron un mínimo de 180 individuos. Generamos una matriz de distancia fenotípica estimada utilizando las distancias de Mahalanobis (d2) para identificar posibles migrantes de enésima generación entre individuos que parecían biogeoquímicamente “locales.” La integración de datos biogeoquímicos y cervicométricos agrega una profundidad temporal a nuestros análisis de paleomovilidad en el México antiguo más allá de los migrantes de primera generación identificados solo con métodos biogeoquímicos. También examinamos las afinidades fenotípicas de las víctimas sacrificiales “no locales” y los datos 87Sr/86Sr disponibles para reconstruir las posibles redes migratorias y las motivaciones de las personas migrantes que se trasladaron al centro de México durante el Epiclásico. Esta contextualización más amplia de las experiencias de los migrantes nos permite considerar de manera más holística cómo y por qué las vidas de estos migrantes terminaron en violencia en su nuevo hogar.

The Caribbean & Mesoamerica Biogeochemical Isotope Overview (CAMBIO) is an archaeological data community designed to integrate published biogeochemical data from the Caribbean, Mesoamerica, and southern Central America to address questions about dynamic interactions among humans, animals, and the environment in the region over the past 10,000 years. Here we present the CAMBIO human dataset, which consists of more than 16,000 isotopic measurements from human skeletal tissue samples (δ13C, δ15N, δ34S, δ18O, 87Sr/86Sr, 206/204Pb, 207/204Pb, 208/204Pb, 207/206Pb) from 290 archaeological sites dating between 7000 BC to modern times. The open-access dataset also includes detailed chronological, contextual, and laboratory/sample preparation information for each measurement. The collated data are deposited on the open-access CAMBIO data community via the Pandora Initiative data platform ( https://pandoradata.earth/organization/cambio ).

OBJECTIVES:The role of migration in the cultural development of central Mexico has long been debated. Archaeological models suggest that central Mexico likely experienced increased migration during the Epiclassic period (600-900 CE) and that migrants may have originated in northwestern Mexico. While previous biodistance analyses of Classic and Postclassic populations have come to similar conclusions, none have incorporated Epiclassic skeletal populations. This study uses multi-scalar biodistance analyses to directly evaluate archaeological Epiclassic migration models within central Mexico.MATERIALS AND METHODS:This study uses finite mixture and relationship (R) matrix analyses of cervicometric tooth dimensions to reconstruct patterns of biological affinity among Classic and Epiclassic Mesoamerican populations (n = 333), including at the central Mexican Epiclassic shrine site of Non-Grid 4 where the remains of at least 180 individuals were interred.RESULTS:Estimated inter-site phenotypic distances demonstrate support for some degree of both biological continuity and extra-local gene flow within central Mexican populations during the Classic-Epiclassic transition. Furthermore, estimated phenotypic distances and finite mixture posterior probabilities indicate central Mexican Epiclassic populations were biologically diverse, originating from various source populations throughout Mesoamerica, including the Bajío region, the Malpaso Valley, and the Oaxaca Valley.DISCUSSION:Results suggest that emphasizing both local and extra-local gene flow rather than population replacement may be more appropriate to understand central Mexican population structure during the Classic-Epiclassic transition. Moreover, analyses support previous archaeological migration models positing that Epiclassic migrants into central Mexico originated in northwestern Mexico, but also find evidence of Epiclassic migrants originating from previously unanticipated locales like southern Mexico.

Bioarchaeological studies are highly successful in accessing multivalent past social identities. This study applies social identity theory to contexts of violence, developing a theoretical framework to investigate identity-based violence at the Epiclassic (600-900 CE) central Mexican shrine site of Non-Grid 4, where at least 180 individuals were ritually sacrificed and interred. Ethnohistoric and archaeological data indicate that geographic origin was a culturally significant indicator of social difference in pre-Hispanic Mesoamerica. This study therefore reconstructs the residential histories of sacrificed individuals (n = 73), analyzing radiogenic strontium (Sr-87/Sr-86) and stable oxygen (delta O-18) isotopes to consider how the perception of social difference, inferred from geographic origins, contributed to the selection of victims of ritual violence. Biogeochemical results demonstrate that 70% of sampled sacrificed individuals were born and lived their early lives outside of the Basin of Mexico, migrating into the region later in life. In contrast, only 22% of individuals were born and lived in the Basin their entire lives. Observed paleomobility patterns among sacrificial victims thus suggest that they were targeted for identity-based violence based on their divergent geographic origins in the volatile socio-political landscape of the Epiclassic Basin of Mexico.

A growing number of studies strive to examine wooden archaeological remains recovered from Norse sites in the North Atlantic, contributing to a better understanding of patterns in both wood exploitation and woodland management. Despite the limited diversity and abundance of trees in the North Atlantic islands, the Medieval Norse kept using wood in most everyday activities including the construction and repair of buildings and boats, the production of artifacts and tools, and as a source of fuel. The proximity of the Greenland settlements with the northeastern American coast, puts them at the forefront in the exploration and exploitation of remote resource regions. While some species may have arrived both as driftwood or imported material, there is currently no method to conclusively identify archaeological wood remains as driftwood. Here, we use biogeochemical analysis of stable hydrogen (δ2H), stable oxygen (δ18O), and radiogenic strontium (87Sr/86Sr) isotopes in soil, water, and modern plant samples from various sites in Greenland and Canada to characterize expected local isotopic baselines. While 87Sr/86Sr isotope ratios do not provide a clear distinction between the regions of interest, δ2H and δ18O ratios appear to help discriminate not only between regions but also specific sites. In addition, we completed a pilot study of archaeological wood samples obtained in Greenland to test the effectiveness of the 87Sr/86Sr biogeochemical baseline. Results demonstrate that at least in some cases, diagenetic processes were not sufficient to mask a non-local 87Sr/86Sr signature.

Radiogenic strontium isotopes (87Sr/86Sr) have long been used in analyses of paleomobility within Mesoamerica. While considerable effort has been expended developing 87Sr/86Sr baseline values across the Maya region, work in central Mexico is primarily focused on the Classic period urban center of Teotihuacan. This study adds to this important dataset by presenting bioavailable 87Sr/86Sr values across central Mexico focusing on the Basin of Mexico. This study therefore serves to expand the utility of strontium isotopes across a wider geographic region. A total of 63 plant and water samples were collected from 13 central Mexican sites and analyzed for 87Sr/86Sr on a Thermo-Finnigan Neptune multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). These data were analyzed alongside 16 published 87Sr/86Sr values from two additional sites within the region of interest. A five-cluster k-means model was then generated to determine which regions of the Basin of Mexico and greater central Mexico can and cannot be distinguished isotopically using 87Sr/86Sr values. Although the two clusters falling within the Basin of Mexico overlap in their local 87Sr/86Sr ranges, many locations within the Basin are distinguishable using 87Sr/86Sr values at the site-level. This study contributes to paleomobility studies within central Mexico by expanding knowledge of strontium isotope variability within the region, ultimately allowing researchers to detect intra-regional residential mobility and gain a greater understanding of the sociopolitical interactions between the Basin of Mexico and supporting outlying regions of central Mexico.

Archaeological chemists compare the radiogenic strontium isotope ratios of humans to those of the environment in order to assess paleomobility in contexts across the world, spanning from periods before modern humans to current forensic applications. These methods rely on the variability of bioavailable strontium isotope ratios that is typically attributed to the age and composition of the geology, among other environmental factors. One such factor, the Sea Spray Effect, refers to the homogenizing impact of marine strontium on the radiogenic strontium isotope ratios found in terrestrial settings that are incorporated into the human diet by eating coastal foods. This paper explores the impact of sea spray and ocean-derived strontium on bioavailable strontium isotope ratios through the analysis of plant samples that were systematically collected along three 200 m-long transects and a hilltop control location. The uninhabited island of Inishark, Co. Galway, Ireland provides a close to pristine setting that allows these findings to be generalized to coastal contexts worldwide. Mixing models are used to interpret the impact of sea spray in comparison to that of the underlying geology and soils. The results highlight the patterned and variable manner in which ocean-derived strontium is taken up by terrestrial plants at varying distances from the coast. We suggest that the morphology of the droplet cloud formed by sea spray as it travels to shore may result in a dead zone, causing less sea spray to land directly next to the sea cliffs. The spatial and isotope data indicate that ocean-derived strontium does not have as great of an impact directly adjacent to the shoreline as it does on the isotope ratios found between 50 and 200 m from the coast. The archaeological implications of this finding include the need for more intensive baseline sampling and increased uncertainty when discussing conclusions about paleomobility in coastal settings.