Basalt geochemistry reveals high frequency of prehistoric tool exchange in low hierarchy Marquesas Islands (Polynesia)

Exchange activities, formal or otherwise, serve a variety of purposes and were prominent in many Pacific Island societies, both during island settlement and in late prehistory. Recent Polynesian studies highlight the role of exchange in the region’s most hierarchical polities where it contributed to wealth economies, emergent leadership, and status rivalry in late prehistory. Building on this research, we hypothesized that exchange in low hierarchy chiefdoms (kin-based polities where there are distinctions between commoners and elites but ranking within the latter is lacking, weak, or ephemeral) would differ in frequency and function from that associated with strongly hierarchical polities. We address this hypothesis through geochemical, morphological, and distributional analyses of stone tools on Nuku Hiva, Marquesas Islands. Non-destructive Energy-Dispersive X-ray Fluorescence (EDXRF) and destructive Wavelength-Dispersive X-ray Fluorescence (WDXRF) analyses of 278 complete and broken tools (adzes, chisels, preforms) from four valleys identify use of stone from at least seven sources on three islands: five on Nuku Hiva and one each on Eiao and Ua Pou. A functional analysis demonstrates that no tool form is limited to a particular source, while inter-valley distributions reveal that the proportions of non-local or extra-valley tools (43 to 94%, mean = 77%) approximate or exceed results from other archipelagoes, including those from elite and ritual sites of Polynesian archaic states. Intra-valley patterns also are unexpected, with non-local stone tools being recovered from both elite and commoner residential areas in near-equal proportions. Our findings unambiguously demonstrate the importance of exchange in late prehistoric Marquesan society, at varied social and geographic scales. We propose the observed patterns are the result of elites using non-local tools as political currency, aimed at reinforcing status, cementing client-patron relations, and building extra-valley alliances, consistent with prestige societies elsewhere and early historic accounts from the Marquesan Islands.