Tephrostratigraphic Correlation and Ceramic Seriation in Bayesian Calibration: A Case Study from Coastal Ecuador

Summary

This is an abstract from the "Constructing Chronologies II: The Big Picture with Bayes and Beyond" session, at the 86th annual meeting of the Society for American Archaeology.

The radiocarbon record from sustained archaeological field research in the Jama Valley of coastal Ecuador has provided a robust dataset for Bayesian chronological modeling using multiple archaeological sites from a valley-wide landscape. This paper delves into greater detail on the development of the model’s prior probabilities that utilized iterative multi-site stratigraphic sampling coupled with ceramic seriation in order to correlate key events (volcanic ashfalls) and longer phases of cultural occupation across the valley landscape over 3,600 calendar years. While correlation of three principal volcanic ashfalls (tephras) was straightforward in most cases and aided greatly in the initial Bayesian modeling, recent tephrochronological studies on a macroregional scale have identified additional tephras in the Holocene stratigraphic sequence of the Jama Valley that are not readily identifiable in sampled archaeological contexts. Two possible reasons for this are identified, the first being closely spaced volcanic eruptions depositing different tephras in rapid succession, and the second being cryptotephras in archaeological contexts that may have resulted from human disturbance processes. Potential solutions are proposed that involve new techniques for in-field analysis of volcanic sediments using handheld laser-induced breakdown spectroscopy (LIBS) and/or portable X-ray fluorescence (pXRF) instrumentation.

This Resource is Part of the Following Collections

• Constructing Chronologies II: The Big Picture with Bayes and Beyond   •
• Society for American Archaeology 86th Annual Meeting, Online (2021)

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Record Identifiers

Abstract Id(s): 32450