No abstract

Bronze is the defining metal of the European Bronze Age and has been at the center of archaeological and science-based research for well over a century. Archaeometallurgical studies have largely focused on determining the geological origin of the constituent metals, copper and tin, and their movement from producer to consumer sites. More recently, the effects of recycling, both temporal and spatial, on the composition of the circulating metal stock have received much attention. Also, discussions of the value and perception of bronze, both as individual objects and as hoarded material, continue to be the focus of scholarly debate. Here, we bring together the sometimes-diverging views of several research groups on these topics in an attempt to find common ground and set out the major directions of the debate, for the benefit of future research. The paper discusses how to determine and interpret the geological provenance of new metal entering the system; the circulation of extant metal across time and space, and how this is seen in changing compositional signatures; and some economic aspects of metal production. These include the role of metal-producing communities within larger economic settings, quantifying the amount of metal present at any one time within a society, and aspects of hoarding, a distinctive European phenomenon that is less prevalent in the Middle Eastern and Asian Bronze Age societies.

a b s t r a c tThe quest for suitable data, data treatments and statistical methods for identifying the provenance of iron artifacts has led to a variety of analytical strategies. Researchers working on the problem have been slow to develop or adopt the use of multivariate statistical techniques, despite their successful implementation in other archaeomaterials sourcing frameworks. This paper explores the analytical potential of a comprehensive multivariate statistical strategy for identifying the primary production origins of bloomery iron artifacts using bulk chemical analyses of bloomery smelting slag and slag inclusions in iron artifacts. This strategy includes a multivariate model for identifying distinct slag inclusion types introduced during smelting and refining. Principal component analysis and linear discriminant analysis are then applied to smelting slag training sets to create multivariate provenance fields, the chemical distributions of which are defined by kernel density estimation. Single and multi-group evaluation methods are examined. Appropriate data transformations are discussed to facilitate the projection of the chemistry of "unknown" slag inclusions into the multidimensional space generated by the smelting slag groups of known provenance. The efficacy of this strategy is demonstrated through its application to a previously examined data set derived from three iron production experiments and a published archaeological example. Results indicate that an appropriately designed multivariate strategy can be an effective tool for evaluating provenance hypotheses for bloomery iron artifacts.

Haeng were analysed in hand specimen, microstructurally by refl ected-light microscopy and scanning electron microscopy (SEM), and chemically by polarising energy dispersive x-ray fl uorescence spectrometry ([P]ED-XRF) and scanning electron microscopy with energy dispersive x-ray fl uorescence spectrometry (SEM-EDS). Resulting analytical data were used to generate detailed technological reconstructions of copper smelting behaviour at the two sites, which were refi ned by a programme of fi eld experimentation.Results indicate a long-term improvement in the technical profi ciency of Valley metalworkers, accompanied by an increase in the human effort of copper production. This shift in local 'metallurgical ethos' is interpreted as a response to rising regional demand for copper in late prehistory.4