Prehistoric Obsidian Exchange on Rapa Nui

The four sources of rhyolitic obsidian on Rapa Nui (Maunga Orito, Moti Iti, Rano Kau I [Te Manavai], Rano Kau II) were differentially utilized throughout prehistory (ca. AD 1200–1860). In order to document the nature of quarry exploitation and obsidian distribution, energy dispersive X-ray fluorescence was used to characterize the elemental composition of each source. The classification of 331 archaeological samples from inland habitation sites, ritual centers, and crematoria by discriminant analysis revealed selective patterns of obsidian usage. Obsidian from Rano Kau II was rarely used while Maunga Orito and Rano Kau I glasses were present in nearly equal proportions at inland domestic habitation sites. Motu Iti obsidian was a rare occurrence at interior locations but more frequent at coastally located ritual centers, crematoria, and caves. Surface architecture in the form of an elite house at Maunga Orito, restricted source usage, and the sacred nature of the offshore islets, suggested an elit...