Does Carneiro's circumscription theory help us understand Maori historyα An analysis of the obsidian assemblage from Pouerua Pa, New Zealand (Aotearoa)

Circumscription theory, originally proposed to explain the rise of state society, is appealing in that it gives us an elegant, straightforward way to account for warfare among farming communities in the transition to complex societies. It predicts that as populations increase, groups will come in to conflict over limited prime land, and thus explain why we see a spatial correlation between good farmland and fortifications; as has been noted in New Zealand (Aotearoa). But, to date we do not have strong data to support the notion that conflict between Maori was primarily about access to farmland, and counter to circumscription theory, ethnography suggests exclusive ownership was discouraged. Here we test the efficacy of circumscription for understanding Maori history using obsidian artefact data from Pouerua Pa, a fortification in the heart of Ngā Puhi's tribal territory. New geochemical sourcing clears up ambiguities in source assignments and shows shifts in access to local sources and long distance exchange. We interpret these changes as being consistent with circumscription having been a factor in the earliest stage of fortification construction, and easing over time as the area was largely confederated under a single tribal identity in the early post-contact period. © 2013 Elsevier Ltd.