Alternative models of volcanic glass quarrying and exchange in Hawai'i

138 volcanic glass artifacts recovered from Site 50–10–19–30173 at Ka'ūpūlehu, Hawai'i Island were sourced to Pu'uwa'awa'a using EDXRF. Site 50–10–19–30173 is a beach sand deposit with volcanic glass and other traditional Hawaiian artifacts that was sealed by an AD 1800–1801 lava flow. The proportion of Pu'uwa'awa'a volcanic glass in the assemblage is consistent with a cost surface model proposed recently. It is shown that the fall off in Pu'uwa'awa'a volcanic glass is exponential for the cost surface for Hawai'i Island, as it is for two alternative distance decay models, which also yield good fits to the volcanic glass data. A straight line distance overland model provides an easy way to generate predictions. A depot model, where Pu'uwa'awa'a volcanic glass is brought to Kahuwai Bay at Ka'ūpūlehu and distributed by canoe, fits the existing data somewhat better than the two overland transport models. It has been argued on the basis of distributional data and technological analyses that Pu'uwa'awa'a volcanic glass was a common pooled resource. The analysis presented here supports this idea by noting the lack of evidence for directional trade in the residuals of the fit to the exponential curve. Recommendations for future research are offered.