A Qualitative and Quantitative Analysis of the Obsidian Sources on Aotea (Great Barrier Island), and their Archaeological Significance.

Abstract

This thesis investigates the natural occurrence of obsidian on Aotea, an island situated in the outer Hauraki Gulf, off the North Island of New Zealand. There are multiple obsidian sources located on the island, of which it has been reported that some of it was exploited for use prehistorically. Although there have been basic reports made on these sources in the past, the island has never been subject to in-depth analysis. This thesis presents information pertaining to the differing quality of the obsidian that is present on the island; its abundance, availability and geochemical variation. It then takes the information gained from these analyses and compares it to archaeological obsidians recovered from six prehistoric sites located within the Tamaki Region which showed that the only source that was exploited on Aotea was one which is associated with Te Ahumata, a mountain consisting of mainly rhyolitic sinter. This source was not prevalent in the Tamaki Region during the Archaic phase of occupation but became the dominant source in the later Classic phase, when it became more common than obsidian from Mayor Island, New Zealand‘s most exploited obsidian source.