Tuesday, January 13, 2015

Provenance of Copper? Not so Fast

I promised I wouldn't link to these "Paper-$", however de-validating the provenance of copper could definitely upset the EBA apple cart so I posted.  The abstract at least begins an interesting discussion, even though the content is buried in a Early Paleolithic form of media.

If you took a Late Bronze Age widget and knew the no-kidding elemental history of the item, there is no reason that all or any of the material was recently mined.  For example, a bronze sword probably consisted various items that were hoarded, sold and then melted down by a smith.  Early in the life of those donor items, those materials were created from items that were hoarded and melted, and so on, and so on, ad infinitum.

If you apply this to the Beaker problem of Britain, for example, could we know that any of the material was mined directly from Ross Island within the Beaker period?  Obviously Beakers had mining camps on Ross Island, but does that necessarily mean anything for a copper dagger in Britain?  How much of the Bell Beaker copper in Britain came from Grooved Ware culture copper?  Would we even know?  The Isles definitely had a short pre-Beaker Copper Age period, but it apparently didn't make it to the grave.

Twentieth Century archaeology probably never really considered the fact that 90% of any metal item ever made in the history of mankind was made of recycled material.  If you were to consider 1% yearly growth in the total amount of refined metal over five thousand years, or really, ten thousand years if you want to go back to the source, then how much additional material would actually have to be mined per year?

Abstract

The analysis and interpretation of the chemical composition of copper-alloys is one of the longest ongoing research projects within archaeological science. Beginning in the late 18th century these data have been consistently used to try and link objects with distinct metal sources. This paper argues the traditional provenance model for copper alloys is fatally flawed. Through pursuing a ‘pure’ source signal, chemical and isotopic datasets have been removed from their context and history. Social engagement with metal through processes such as reuse, recycling, and curation were rarely considered important by analysts. We offer an alternative model that unites the available legacy scientific datasets with process-metallurgy, archaeological and geographical context, and new conceptual approaches. Rather than provenance, we offer an empirical model of metal flow. Here objects are seen as snapshots of a wider metal stream; their final scientific characterisation including echoes of their previous forms and contexts. Through a series of case studies we highlight how the reinterpretation of existing datasets can disentangle the complex life histories of units of copper.


Form and Flow: The ‘Karmic Cycle’ of Copper Bray, Cuenod, Gosden, Hommel, Liu, Pollard, January 2015 [Link]

1 comment:

  1. One thing with that though is if people were forever sacrificing high value objects or burying them with the owner that would limit recycling.

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