The obsidian sources and distribution systems emanating from Gaua and Vanua Lava in the Banks Islands of Vanuatu Volume 1 Christian Reepmeyer A thesis submitted for the degree of Doctor of Philosophy of The Australian National University September 2009 To the best of my knowledge, the research presented in this thesis is my own except in cases where I acknowledge the work of other researchers. This thesis has not been submitted in any form for any other degree at this or any other university. Christian Reepmeyer Reepmeyer 2009 Abstract This thesis examines the history of social interaction within communities in the Vanuatu Archipelago and between Vanuatu and other regions in the Western Pacific as reflected by variations in lithic raw material sources and the technology of stone artefacts. Two major bodies of data are incorporated: (1) geochemical analysis of obsidian from sources and archaeological assemblages using laser ablation – inductively coupled plasma mass spectrometry data (LA-ICPMS) and (2) technological analyses of flaked artefacts using quantitative attribute data. Fieldwork to locate intact sources combined with comprehensive geochemical analysis of obsidian outcrops in Northern Vanuatu was required as there was previously no clear understanding of the number of obsidian outcrops exploited in the past and their associated elemental compositions. Preliminary geochemical research suggested that more than the two identified obsidian outcrops may have been utilised. To assess the presence of additional obsidian sources, surface collections of artefacts throughout the Banks Islands as well as excavated assemblages from sites in Vanuatu and adjacent areas were also geochemically fingerprinted. The research showed that the two known source regions on the islands of Vanua Lava and Gaua are indeed the only existing sources and that no additional outcrops were exploited. Furthermore, the internal variation of the two sources is very limited. Consequently, artefacts previously associated with putative additional obsidian sources in the Banks Islands, such as artefacts found in Fiji, were shown not to be derived from Vanuatu. To analyse changes in the production, distribution and consumption of lithic artefacts throughout the research area, assemblages were selected covering the entire 3000-year timeframe of human occupation in Vanuatu and the Southeast Solomons. In total 21 assemblages were analysed to understand the processes shaping social interaction between communities. To provide a theoretical framework for explaining changes in the intensity of interaction, economic approaches to resource maximisation in the production and consumption patterns of transported material were assessed. It is concluded that because they depend too much on the notion of the scarcity of resources in their evaluation of the concept of value, these theoretical orientations were insufficient to explain the pattern of spatial and temporal distribution of the lithic artefacts. Alternative models are proposed that focuses on the importance of environmental factors. Variations in the frequency of ENSO over time create risks that can be mitigated by increased communication and social interaction resulting from exchange of stone raw material. In context of this interpretation, obsidian is seen as an item reflecting and strengthening interaction networks, but it is assumed that it was not the main force initiating or shaping these networks. Abstract i Reepmeyer 2009 Acknowledgements I am indebted to the many people I encountered on the way to complete this PhD. First of all I would like to thank my supervisor panel, for giving me the intellectual, emotional and financial support, without which this work could not have been accomplished. My main supervisor, Matthew Spriggs, took me on board his project. I am sincerely grateful that he took this gamble and hope that this thesis will not disappoint the trust he advanced. Stuart Bedford’s expertise in fieldwork and Pacific archaeology was invaluable for the success of this project. Both Matthew and Stuart provided support, encouragement and extensive comments on papers and thesis drafts during the years of this PhD for which I am deeply grateful. For the post-fieldwork data analysis and writing-up period my special thanks goes to my advisor Robin Torrence. Robin’s extensive comments on drafts of papers and thesis were invaluable. Discussions with Robin on my occasional visits to Sydney were always challenging, rewarding and helped shaping the argument in this thesis substantially. Robin and Peter White kindly offered a room at their house on these occasions for which I am very thankful. I would especially like to thank Wal Ambrose, who introduced me to the mysteries of obsidian provenancing and ICPMS. He always offered a helping hand in reading drafts, sample preparation and was very open to me to use his equipment. I am even more so indebted to him, as he kindly allowed me to use unpublished material from his earlier ICPMS sessions. The success of the fieldwork would not have been possible without the kind generosity of many people in Vanuatu. In particular the staff of the Vanuatu Culture Centre and the fieldworker on Vanua Lava, jif Eli Field Malau; on Gaua, jif Victor Lini; on Ureparapara, jif Harrison and on Mota Lava, Franklyn Woleg. All of them provided invaluable expertise in finding archaeological sites and obsidian outcrops. Special thanks goes to Tom from Lemon, his strong arm helped to speed up the western Vanua Lava survey substantially. I would like to extent my thanks to the people of the Ambek and Lesa village on Vanua Lava, and Aver and Tarasag on Gaua. Your hospitality will not be forgotten. Peter Hiscock let me participate in his projects here in Australia and provided help in the lithic analysis for which I am very grateful. Jean-Christophe Galipaud kindly granted me access to his collection of obsidian artefacts from the Torres Islands and the Makue site on Aore. His hospitality on a visit in Noumea was much appreciated. Jean- Christophe and Mary-Clare Swete-Kelly kindly shared their research on the unpublished dataset from Makue. I would also like to thank Graeme Ward for letting me access his field notes from his research in the Banks Islands. Simon Best kindly granted the permission to re-analysis the Lakeba artefacts with LA-ICPMS and Tianlong Jiao, permitted me to re-analyse the Tikopia obsidian collection from the Bishop Museum, Hawaii, and to sample several artefacts. Geoffrey Clark shared his wide knowledge of Fiji and Tongan archaeology with me for the re-interpretation of the Fiji-Vanuatu connention. Acknowledgements iii Reepmeyer 2009 The geochemical analysis could not have been done without the help from Charlotte Allen from the ICPMS laboratory at RSES and Frank Brink in the Microscopy Unit at RBSB both at the ANU. Peter Sheppard provided analysis for several pieces of obsidian with pXRF, shared his opinion about the results and kindly supplied a sample from the Kermadec Islands for re-analysis. For the PIXE-PIGME analysis I would like to thank the ANSTO Team, Mihail Ionescu, Michael Prior and Ed Stelcer. Grahame Bailey provided invaluable support for the interpretation of the results. Nina Kononenko, ANU and Australian Museum Sydney, supplied the analysis of the use-wear on two sets of artefacts and Jon Woodhead, Melbourne University, conducted the MC-ICPMS analysis on two samples from Lakeba, Fiji. Ulrike Troitzsch, Department of Earth and Marine Sciences, ANU, carried out the XRD analysis. Over the years I was in correspondence with many researchers in- and outside of the ANU who shared their opinions and wisdom with me. I would like to thank Glenn Summerhayes, Jim Specht, Sue O’Connor, Jean Kennedy, Peter Bellwood, John Terrell, Matiu Prebble, Simon Haberle, Wally Johnson and Steve Eggins for their knowledge in interpreting the data and their interest in this research project. Special thanks also to the administration of the School of Archaeology and Anthropology at the ANU: Sue Fraser, Liz Walters and Dave MacGregor. Their efficiency in finding new ways of funding, keeping paper work at a minimum and always positive demeanour made working in this department so easy. At the ANU I met so many friends who made the time in Canberra so memorable. I would especially like to thank Alex Mackay and Iona Flett. They not only had to endure reading drafts of this thesis, but they also continuously challenged my arguments over the occasional beer or two, which provided the necessary perspective for the line of thought I hoped to pursue. Oliver McGregor, Ben Marwick, Mirani Litster and Anna Wills also gave very useful comments during the data analysis phase. I would especially like to thank Feli Hopf for sharing the last year of the PhD with me, enduring long working days and non-existent weekends without critique, and reading thesis drafts besides her own many commitments. Thank you. The research and fieldwork was funded by an Endeavour International Postgraduate Research Scholarship and an Australian National University PhD Scholarship. Fieldwork and geochemical data analysis was supported by an Australian Research Council grant to Matthew Spriggs and Stuart Bedford. Additional field work was supported by a Rhys Jones Scholarship. MC-ICPMS analysis was funded by an ARC grant to Geoffrey Clark. The PIXE-PIGME analysis was supported by an AINSE grant to Stuart Bedford and radiocarbon dates were funded by the CAR radiocarbon scheme. Zu guter letzt möchte ich meiner Familie