Wetherbee Dorshow

Strontium Isotopes and the Reconstruction of the Chaco Regional System: Evaluating Uncertainty with Bayesian Mixing Models

Strontium isotope sourcing has become a common and useful method for assigning sources to archaeological artifacts. In Chaco Canyon, an Ancestral Pueblo regional center in New Mexico, previous studies using these methods have suggested that significant portion of maize and wood originate in the Chuska Mountains region, 75 km to the East. In the present manuscript, these results were tested using both frequentist methods (to determine if geochemical sources can truly be differentiated) and Bayesian methods (to address uncertainty in geochemical source attribution). It was found that Chaco Canyon and the Chuska Mountain region are not easily distinguishable based on radiogenic strontium isotope values. The strontium profiles of many geochemical sources in the region overlap, making it difficult to definitively identify any one particular geochemical source for the canyons pre-historic maize. Bayesian mixing models support the argument that some spruce and fir wood originated in the San Mateo Mountains, but that this cannot explain all 87Sr/86Sr values in Chaco timber. Overall radiogenic strontium isotope data do not clearly identify a single major geochemical source for maize, ponderosa, and most spruce/fir timber. As such, the degree to which Chaco Canyon relied upon outside support for both food and construction material is still ambiguous.

Shabik’Eschee Village in Chaco Canyon: Beyond the Archetype

Abstract This study revisits an earlier publication in this journal (Wills and Windes 1989) in which a settlement model involving seasonal mobility and limited household autonomy was outlined for Shabik’eschee Village, a Basketmaker III period (ca. A.D. 400–750) site in Chaco Canyon, New Mexico. We return to that work for three reasons. First, the original interpretation has been challenged and an alternative view offered in the form of a large sedentary village. Second, the issue of Basketmaker III sedentism is central to recent efforts to identify and understand a Neolithic Demographic Transition in the northern Southwest. And third, we have obtained new field data from Shabik’eschee and Chaco that contributes to this debate. We conclude that our understanding of Shabik’ eschee’s history is improved by both new data and the ongoing consideration of alternative models, but the site does not contain evidence for a sedentary village.

Prehistoric deforestation at Chaco Canyon

Ancient societies are often used to illustrate the potential problems stemming from unsustainable land-use practices because the past seems rife with examples of sociopolitical “collapse” associated with the exhaustion of finite resources. Just as frequently, and typically in response to such presentations, archaeologists and other specialists caution against seeking simple cause-and effect-relationships in the complex data that comprise the archaeological record. In this study we examine the famous case of Chaco Canyon, New Mexico, during the Bonito Phase (ca. AD 860–1140), which has become a prominent popular illustration of ecological and social catastrophe attributed to deforestation. We conclude that there is no substantive evidence for deforestation at Chaco and no obvious indications that the depopulation of the canyon in the 13th century was caused by any specific cultural practices or natural events. Clearly there was a reason why these farming people eventually moved elsewhere, but the archaeological record has not yet produced compelling empirical evidence for what that reason might have been. Until such evidence appears, the legacy of Ancestral Pueblo society in Chaco should not be used as a cautionary story about socioeconomic failures in the modern world.

‘Marineness’, the Underwater Seascape and Variability in Maritime Adaptations in the Late Ceramic Age Northern Lesser Antilles

ABSTRACT To investigate potential variation between the fishing practices of contemporaneous Late Ceramic Age villages in the northern Lesser Antilles, we model expectations for each site based on local marine habitat and bathymetry and compare them to observed differences in zooarchaeological assemblages. The predictive model approximates which taxa were the most likely to have been targeted by fishers from each site, assuming that the majority of fishing likely occurred within short distances from each settlement. A comparison of expectations and archaeological observations is used to expose potential differences between sites in preferred fishing areas and techniques, preferred foods, or social distinctions. This variability is argued to reflect a fishing community’s ‘marineness’, or the interrelationship members have with the unique composition of marine resources and underwater seascape adjacent to their villages.