Radiocarbon dating legacy collections: A Bayesian analysis of high-precision AMS 14C dates from the Par-Tee site, Oregon

Abstract

Archaeological materials in museum collections provide an excellent opportunity for researchers to investigate social, cultural, and environmental change. However, the precision of the archaeological analysis and interpretation is dependent on a firm understanding of the site chronology. The Par-Tee site (35CLT20), located on the northern Oregon Coast, produced a large archaeological collection including artifacts and faunal remains excavated in the 1960s and 1970s. Radiocarbon dates have been obtained on materials from the Par-Tee collections by several different researchers since the 1970s, but these data have not been adequately assessed for chronometric hygiene. To establish a reliable chronology for the Par-Tee site, we obtained new high-resolution accelerator mass spectrometry (AMS) radiocarbon dates and collagen peptide mass fingerprinting of cervid bones from throughout the site. We evaluate these new radiocarbon dates along with previous radiocarbon dates from the site, using chronometric hygiene assessments and Bayesian statistics to build a refined chronology for the Par-Tee site and museum collection. Previous research suggests site habitation occurred between 350 cal BC to cal AD 1150. Our reassessment of the site chronology suggests the primary site habitation occurred from cal AD ~100–800. We also identified evidence of subsequent site occupation around cal AD ~1490–1635 supporting previous interpretations of site habitation after the primary shell midden forming occupation. The latter occupation may be associated with a change in site use from a semi-sedentary village to a cemetery.