ASSESSING THE POTENTIAL FOR CENTRAL ARCTIC NATIVE COPPER PROVENANCE IN ARCHEOLOGICAL CONTEXTS USING LA-ICP-MS

For the past 2 millenia, indigenous societies across Arctic and Subarctic North America have exploited native copper resources in the Central Arctic and Western Subarctic. Multiple waves of migration in the past have brought different societies into contact with Central Arctic copper sources, including Paleo-Inuit as early as 2500 BC, Athapaskan speaking ancestral Dene by AD 750, and Thule Inuit by AD 1250. As a geographically restricted resource on the northern landscape, native copper fostered and reinforced trade relationships, but also created the potential for conflict when multiple ethnic groups exploited them concurrently. There are two major sources of native copper in the Central Arctic - the ca. 720 Ma Naktusiak lava flows of northern Victoria Island and the ca. 1270 Ma Coppermine River Group basalts of the Nunavut mainland. In both the Natkusiak and Coppermine source regions native copper occurs in a relatively pure state, ranging in size from small placer deposits of ‘float copper’ washed downstream from primary deposits, to large slabs that can potentially weigh hundreds of kg and be repeatedly mined. The relative extents to which copper from these two sources was used in the early manufacture and trade of copper tools is uncertain. Ethnohistoric Dene and Inuit oral traditions document a vast geographic knowledge of resources, including both Natkusiak and Coppermine sources. Some Dene oral tradition also suggests knowledge of both Central Arctic and Western Subarctic copper sources. The ability to distinguish these sources geochemically and assess the feasibility of determining provenance of archaeological copper artefacts is the goal of this research. Geological samples from Coppermine and Natkusiak sources were analyzed using LA-ICP-MS to determine if they could be differentiated using trace elements. Copper artefacts from 14 archaeological sites were also analyzed. These mostly represent objects from the Thule Inuit tradition, but also include Paleo-Inuit and Athapaskan contexts. Preliminary results from this analysis will be presented, with implications on understanding the Thule copper technological system and for the future research potential for this methodology.