The Geochemical Provenance of Pre-Contact Copper Artifacts from the Gaspereau Lake Area, Nova Scotia: Analytical Approaches, Challenges and Interpretation

Jacob J Hanley1, Jessica Whattam1, Catherine Cottreau-Robins2, Christopher RM McFarlane3, W. Bruce Stewart4 and Mike Sanders4, (1)Saint Mary's University, Halifax, NS, Canada, (2)Nova Scotia Museum, Halifax, NS, Canada, (3)University of New Brunswick, Fredericton, NB, Canada, (4)Cultural Resource Management Group Ltd., Halifax, NS, Canada

Contact First Author: Jacob J Hanley; jacob.hanley@smu.ca

Abstract ID#: 36235

 

English Abstract:
In-situ microanalysis of archaeological materials by laser ablation ICP-MS is rapid and virtually non-destructive compared to bulk techniques (XRF, NAA), allowing compositional variability to be assessed at high spatial resolution. We used LA-ICPMS to compare trace element concentrations in 28 copper artifacts (worked natural “nuggets”) from the Gaspereau Lake area of Kings County, Nova Scotia to natural samples from Michigan (7 deposits) and Nova Scotia (3 deposits) providing constraints on geological provenance.

Intra- and inter-sample variations in trace element concentrations at hand sample and deposit scales are <20% (relative) whereas previous NAA and XRF data is compromised by contaminating mineral inclusions in the copper that cannot be excluded in the large sample volumes required for these methods. Comparison of patina and fresh metal show systematic enrichments in Zn, Sn, Fe, As and Au in patina and S, Sb, Co, Ni and Ge in fresh copper matrix; however, this fractionation resulting from oxidation does not impact composition sufficiently to limit the use of fresh copper or even patina in provenance studies.

Eight of the artifacts were derived from 2 principle copper sources on the Bay of Fundy coast that can be easily differentiated from one another by their contrasting Ag/Pb ratios. (Cap D’Or and Margaretsville-Victoria Beach). The remaining 20 artifacts are not from the Bay of Fundy, or any Michigan sources (enriched in As relative to Fundy) and comprise 5 distinct yet geographically unidentified provenance groupings.

Preliminary results reassert the importance of local (Fundy) copper to pre-contact period indigenous peoples of Nova Scotia and the Maritimes, and negate the Lake Superior model. The diversity of copper sources indicated has significance in the broader context of territorial procurement of copper, and trade relationships between groups of aboriginal peoples in the Atlantic Northeast.

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