Raw Material Studies (continued)

Raw material exchange

Exchange is here defined as in Renfrew (1977, 72), that is '... in the case of some distributions it is not established that the goods changed hands at all; [exchange] in this case implies procurement of materials from a distance, by whatever mechanism'.

Once a territorial structure has been defined, it is possible via raw material studies to examine communication forms within and between these territories. This is usually carried out in the form of distribution analyses and with the production of fall-off curves as an important aid. The shape of fall-off curves may, for example, indicate whether exchange took place in the form of down-the-line exchange (gradually declining curve) or as directional exchange (multi-peaked curve) (Renfrew 1977).

Analysis of artefact size and degree of repair and recycling with growing distance to the raw material sources may also shed light on this issue, as down-the-line exchange has a tendency to see artefacts shrink in size with growing distance. Indicators of raw material value within an exchange network are: numerical presence (a raw material's numerical presence in relation to distance to source); artefact size; artefact types (ie, was a raw material mainly used for mundane tasks or as prestige objects); tool ratios; use-wear; and depositional patterns (ie, whether artefacts in specific raw materials are mainly recovered from domestic or from ritual/burial contexts).

Raw materials like Arran pitchstone, Antrim flint, and Yorkshire flint were distributed across vast areas via complex exchange networks, with pitchstone having been recovered from sites more than 400km from the sources on Arran (Ballin 2009). The research necessary to deal with these spatial structures and social networks must involve a high degree of ethno-archaeological input.

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The prehstoric Cnoc Dubh quartz quarry, Lewis, Western Isles. (Ballin 2004).

The prehstoric Cnoc Dubh quartz quarry, Lewis, Western Isles. (Ballin 2004).