Geoff completed his Masters work at the University of Auckland before moving to the Australian National University to complete his doctoral thesis.
Geoff's research focuses on two main areas:
- Excavation of a Waterlogged Mãori Village. Kohika was a late Mãori lake village in the Bay of Plenty occupied for a period in the latter half of the 17th century and unusually preserved because of its wetland location. Abandoned because of flooding, it remained untouched until 1974 and its excavation and analysis has been a thirty-year task by a number of scholars from different disciplines, making this the major New Zealand excavation of recent times. The diversity of the evidence uncovered and the specialist analysis done on the material reveals extensive information about the social and domestic activities of a village community well before the advent of the pakeha. The research covers diet, wooden artefacts, fibrework, obsidian, houses (including the oldest-known carved house), and animal remains. There is important information on the trade, economy, leisure, and social hierarchy of these early New Zealanders, and the site is an important contribution to our understanding of late prehistoric Mãori culture in the North Island.
- The Colonisation of the Pacific. The exploration and colonisation of the Pacific was one of the most remarkable episodes of human prehistory. Early seagoing explorers had no prior knowledge of Pacific geography, no documents to record their route, no metal, no instruments for measuring time and none for navigation. Geoff has done archaeological fieldwork in eastern Indonesia, New Guinea, the Solomon Islands and Fiji. He has sailed on traditional New Guinea canoes and on one occasion took his own 11-metre yacht across the western Pacific retracing the route of the first Pacific explorers. This experience, plus computer simulation of voyaging, has influenced his view of how the Pacific was first settled.
In 1999 he was elected as a Fellow of the Royal Society of New Zealand, and as a Fellow of the Society of Antiquarians of London in 2005.