Provenance studies of obsidian artefacts in the Near East using an interdisciplinary approach

Obsidian provenance studies is a popular archaeometric research subject, as (1) this natural glass was widely used specially by Neolithic men for tool making and (2) it is one of the rare materials that may be used for reconstructing ancient exchange networks and cultural relations during prehistoric times. Obsidian was recognised in distinct volcanic districts, and its chemical-physical properties are peculiar to the specific occurrence and can be used for its characterisation. Since early 90's of last century international research projects were established aimed to contribute to (1) a better knowledge of location, chemical properties and chronology of the obsidians of Anatolia and of the Transcaucasian region and to (2) a better understanding of their circulation during prehistoric times. This work reports the results of these studies performed with an interdisciplinary approach - extensive surveying and sampling, chemical characterization using Instrumental Neutron Activation Analysis (INAA) with data reduction and chronological reconstruction using the fission-track (FT) dating method. Ages of the ~ 80 analysed obsidians from the study region distribute over a relatively large interval, from few tens thousands years (Acigol complex, Cappadocia, and Lake Van Quaternary volcanoes) up to more than 20 Ma (Galatean volcanic massif, northern Anatolia). More than 200 artefacts from several prehistoric sites representing a large time span, since Mesolithic up to early Iron Age, were also analysed. Both INAA as well as FT dating turned to be efficient tools for characterization of the sources and for correlation of artefacts with them. Moreover, results of this study prove the potentiality of a multidisciplinary approach based on different techniques, that may turn very useful in case of dubious source identification. Artefacts originated from the main Anatolian obsidian source areas - such as the Galatean massif (Oligocene-early Miocene), the Cappadocian volcanic district (Pleistocene), the Karliova-Bingol-Mu^ triangle (Pliocene) and the volcanic complexes located along the north coast of lake Van (Pleistocene) were regognised also at great distances. On the contrary, due to the great abundance of obsidian occurrences present in the Transcaucasus, in this region circulation of obsidian appear to be related to geographic criteria.