Duff's adze typology versus Polynesian adze exchanges

The inter-archipelago exchange of adzes after colonisation was not considered in the widely referred to culture historical Polynesian adzetypology developed by New Zealand archaeologist, Roger Duff. This portable x-ray fluorescence (pXRF) geochemical study re-examinedthe assemblage of the adzes in museum collections that were classified into Duff Types by archaeologists Gonzalo Figueroa and EduardoSanchez. This paper investigates the geochemical patterning of the Polynesian basalt adze types found on the Pitcairn and Gambier Islandsby (1) identifying volcanic rock type of the artefact (2) matching the geological sources used to make the artefacts using a DiscriminantFunction Analysis (DFA) and, (3) comparing an artefact’s identified source to its recorded find spot. The results of the analyses conductedin this paper identified that 16 (8%) adzes had originated from different island groups than where they were collected from in the twentiethcentury. These adze exchanges provide more evidence of long-distance Polynesian connections that occurred after people initiallycolonised central east Polynesia and thus further refutes the idea that these islands were occupied in isolation–acritical re-evaluation ofDuff’s typology is therefore required.