The use of strontium isotopes as an indicator of migration in human and pig Lapita populations in the Bismarck Archipelago,Papua New Guinea

This paper examines the potential use of strontium isotopes (⁸⁷Sr/⁸⁶Sr) for identifying migration within Lapita populations and their commensal animals, specifically the pig (Sus scrofa). Lapita people (ca. 3300–2200 BP) were the initial colonists of the island groups to the east of the Solomon Islands, spreading from Papua New Guinea to Tonga and Samoa within a few centuries. Mobility is assumed to have been an important mechanism for maintaining cultural solidarity between Lapita communities. It has been previously argued that Lapita populations became progressively more sedentary over time after the initial colonising events. Two Lapita sites, Kamgot and Balbalankin, from the Anir Islands in the Bismarck Archipelago are included in the analysis and fall within the Early (ca. 3300–3000/2900 BP) and Middle (ca. 3000/2900–2700 BP) Lapita periods respectively.