Rethinking Chronology in Barrow, Alaska: Assessing ∆R Variation and Applying Bayesian Chronological Models

Summary

Over 200 radiocarbon dates from archaeological contexts are available from the Point Barrow vicinity, along northern Alaska’s Arctic coast, which has been occupied by hunter-foragers from the Birnirk period (AD 500–900) to the present day. Stable isotope analysis (δ13C and δ15N) of ancient humans from the Point Barrow vicinity indicates their diets were very rich in marine protein, and therefore interpretation of these radiocarbon dates has been hindered by radiocarbon offsets.

Radiocarbon ages from marine-derived carbon will be anomalously old if not corrected for the Marine Reservoir Effect (MRE), the radiocarbon age offset between contemporaneous marine and terrestrial carbon. Modern MRE values from the Alaskan Arctic are highly varied, from several hundred to over a thousand years, due to the extended residence time of 14C in oceanic environments. It is questionable how reflective modern values are of those from the past because changes in upwelling, climate, and ocean currents will inevitably result in changes in local MRE values through time. Here we present new temporally specific ∆R estimates, which is the local deviation from the global surface water MRE, and apply these in a Bayesian chronological model to better estimate the timing of ancient activity.

This Resource is Part of the Following Collections

• Society for American Archaeology 82nd Annual Meeting, Vancouver, BC (2017)   •
• Arctic and Subarctic Coasts: Current Research and Modern Challenges

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Record Identifiers

Abstract Id(s): 16715