Obsidian, an ‘ideal’
material for sourcing studies

The success of obsidian sourcing studies in Archaeology relies on several of its characteristics evocated in the previous chapter, mainly (a) its glassy texture - which records the scars of the fabrication process and (b) its presence on a large number of sites and contexts. Moreover, the fragility of this glassy material renders the manufactured objects delicate enough to necessitate a regular replacement, therefore placing them in the category of ‘consumption goods’. The production of such a significant amount of objects thus allows to reveal the typological trends and evolutions present within an assemblage, and ultimately to replace it within a broader chrono-cultural context.

We also have to mentioned its main archaeometric interest, i.e. the uniqueness of each source’s geochemical composition. Obsidians of a singular flow will indeed be characterised by a very specific ‘fingerprint’, and the differences in composition within it will be relatively insignificant, or at least much smaller than between separate sources (Glascock et al., 1998). This differences in composition normally observed between different flows is what makes provenance studies possible: by allowing us to geochemically characterise every one of them with precision, we are normally able to match an artefact’s fingerprint to a particular source, and thus propose an origin for the raw material used for its fabrication.

In the last two years, more than 2200 obsidian artefacts were characterized non-destructively, thanks to our analytical strategy specifically adapted to these assemblages: our approach relies on several analytical methods, mainly a portable XRF ([pXRF]; used both in the field and in the lab), and the use of the Laser Ablation Inductively Coupled Plasma Mass Spectrometry ([LA-ICP-MS]; in the laboratory). These artefacts originate from no less than 22 archaeological sites: the excavated settlements of Kültepe I, Nakhchivan Tepe, Ovçular Tepesi, Uçan Agil, Sorşu, and Zirinçlik, as well as the surveyed sites of Batabat, Bûlôv Qayasi, Çay Ağzi, Çadirdaşi, Çalxanqala, Demirle, Dere Sahbuz, Kolani, Mesmeliagil, Partağ, Qazançi Kale, Şanışölen, Selesüz, Testamas, Tumbul Tepe, Uçan Agil, and Zoğala. Altogether, these assemblages cover a long period - from the Neolithic to the Bronze Age (Kura-Araxes), which allows synchronic and diachronic comparisons for an overview of the obsidian economies of these regions and of their evolution through time.

This project complements the larger research program led in the area since 2013, looking at the emergence of the first mining industries in the Caucasus (Program ANR/DFG ‘Mines’, Dir. Dr Catherine Marro, Dr Thomas Stöllner).