Obsidian Analysis and Modelling Exchange in the Western Mediterranean

It was 25 years ago that Cann and Renfrew first introduced the use of elemental analysis to characterize artifacts of obsidian and match them with their geological sources in the Mediterranean region. Since then several analytical techniques (OES, XRF, NAA, AAS, Microprobe, Mossbauer, Magnetic Sourcing) have been proven useful in discriminating between obsidian sources, and general distribution patterns of obsidian artifacts have been determined for many source systems, including the Western Mediterranean.

In addition, there have been several attempts at using models to better understand obsidian exchange systems and the social organization behind them (Renfrew, in Sabloff and Lamberg-Karlovsky eds., Ancient Civilization and Trade, 1975:3-60; in Earle and Ericson eds., Exchange Systems in Prehistory, 1977:71-90; Ammerman et al., in Hodder ed., The Spatial Organisation of Culture, 1978:179-96; Torrence, Production and Exchange of Stone Tools, 1986). Despite this interest in reconstructing prehistoric exchange systems, not enough data has been accumulated from the western Mediterranean to test these models. There are barely 300 published artifacts that have been analyzed, and this includes samples from 90 different sites covering a time span of more than 5000 years!

A program of analyses is now underway to augment the western Mediterranean database, so that statistically significant inferences may be made about obsidian distribution patterns for discrete time intervals. Diachronic changes may then be correlated with advances in technology, changes in socio-political organization, or cultural preference.