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Laguna Santa Elena (8.9290° N, 82.9257° W, 1055 m a.s.l.) is a small lake in the Diquís archaeological sub-region of southern Pacific Costa Rica. Previous analyses of pollen and charcoal in a sediment core from Santa Elena revealed a nearly 2,000 year history of vegetation change, maize cultivation and site occupation that is consistent with the archaeological record from the lake basin and surrounding area. Here we present the results of new loss-on-ignition, geochemical and bulk stable carbon (δ13C) and nitrogen (δ15N) isotope analyses of the Santa Elena sediments that supplement and refine the previous reconstruction. Like many lakes in Central America and the Caribbean, Laguna Santa Elena was a magnet for humans throughout its history. As a result, the lake experienced vegetation modification by humans and maize cultivation at varying intensities over a long duration. The Santa Elena sediments provide a record of palaeoenvironmental change during times of major culture change and increasing cultural complexity in the Diquís region, which occurred during intervals of broader changes driven by external forcing mechanisms, including the Terminal Classic Drought (TCD), the Little Ice Age (LIA) and the Spanish Conquest. Our high resolution lake sediment study from Santa Elena reveals details of these events at the local scale that are unobtainable by other means, including the timing of the initial intensification of maize cultivation at ca. 1,570 cal BP (AD 380) and two intervals of population decline coinciding with the TCD at ca. 1,085 cal BP (AD 865) and near the start of the LIA at ca. 683 cal BP (AD 1267).
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Refining Potential Source Regions via Combined Maize Niche Modeling and Isotopes: a Case Study from Chaco Canyon, NM, USA
The application of geochemical sourcing methods to archaeological questions continues to grow, as does the need for innovation in applying these methods. The process of sourcing materials is to rule out potential areas in favor of the most likely origin. It will foreseeably remain true that additional data could reveal other potential sources for an artifact. However, the use of multiple methods to further refine potential sources should not be neglected. In this paper, we use maize niche modeling in tandem with isotopic data to refine possible source regions of archaeological deer from Chaco Canyon, NM, USA (ca. AD 800–1250). Previous research on this prehistoric community demonstrated an extensive non-local procurement system where small mammals were garden-hunted in plots lying > 40 km from the canyon and the procurement of deer from upper elevations at > 90 km. The upper elevation procurement of deer will be tested by adding carbon isotopes and maize niche modeling to previously published strontium and oxygen isotopic data. As browsers with an affinity for maize, deer harvested in low to mid elevations within the maize farming niche should have carbon isotope ratios reflecting C4 plant consumption. Growing degree days in this region place the most salient limits on the elevation of maize production and define the region corresponding to a maize-free diet. Analyses of archaeofaunal deer from Pueblo Bonito indicate that hunting occurred at a higher elevation than the maize farming niche. These results demonstrate the utility of combining geochemical sourcing methods with paleoenvironmental modeling.
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- Award ID(s):
- 1637171
- PAR ID:
- 10074698
- Date Published:
- Journal Name:
- Journal of archaeological method and theory
- ISSN:
- 1573-7764
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/s10816-017-9359-
