Provenance of Chalcolithic and Early Bronze Age Obsidian Artifacts of Kul Tepe; Syunik Mine and the Lake Sevan as a Possible Seasonal Pasturelands of Kul Tepe

Obsidian artifacts were frequently used in prehistory and are widely found on archaeological sites around the world. Provenance studies of obsidian have been an issue of intense research and debate between archeaometry and geology. Different provenance studies were carried out in Anatolia and the Caucasus since the 1960s, but obsidian research in Iran is still at a very early stage and can be considered as terra incognita. Recent research on obsidian sources in Iran accompanied by prehistoric obsidian provenance studies gave the opportunity to establish a database, and to outline a horizon and perspective for future obsidian studies in Iran (Abedi et al., in prep.). Two seasons of excavation in Kul Tepe revealed the important material from Late Neolithic/Early Chalcolithic (Dalma) to Achaemenid periods. For the measurements a portable ED-XRF device (Thermo Scientific Niton XL3t) was used, equipped with an Ag anode at max. 50 kV, silicon drift detector. Some of the most reliable element concentrations in obsidian that can be obtained using portable ED-XRF are Rb, Sr, Y, Zr and Nb, if the concentrations are above the detection limit. Analysis by X-ray fluorescence of 53 obsidian artifacts from first season proved that the main source of obsidian for the workshops in Kul Tepe was Syunik (41 samples) but obsidian sources as far as west as the Lake Van region (Nemrut Dag (2) and Meydan Dag (4) and as far north as Gutansar (1), Bazenk (1), Choraphor (1) were also utilized and only one specimen had an unassigned source. In addition, according to second season obsidian artifacts analysis by pXRF it should be suggested that from 32 samples, 29 specimens belong to Syunik and only three samples come from Meydan Dag obsidian mine. A scatter plot of the Zr versus Y concentration allows recognition of three clusters which match the composition of the well-known sources: Syunik (24 artifacts), Geghasar (5 artifact) and Meydan Dağ (3 artifacts). Syunik is the closest source in the vicinity of Kul Tepe, not more than 75km far from the site (as the crow flies). Syunik material was used in all prehistoric periods at Kul Tepe but Geghasar obsidian obviously only in the Early Chalcolithic (Dalma) (2 samples), Kura-Araxes I (2 samples) and Kura-Araxes II (1 sample) periods. Meydan Dağ obsidian only in the Early Chalolithic (Dalma) (2 samples) and Late Chalcolithic 3 (Chaff-Face Ware) (1 sample) periods. Our results show that the site of Kul Tepe was involved in a broad network of trade and exchange of obsidian. The main and closest source of obsidian supplying the workshops at Kul Tepe was Syunik but obsidian sources as far as west as the Lake Van region (Nemrut Dag and Meydan Dag) and as far north as Gutansar were also utilized. The distances from Syunik and Nemrut Dag to Kul Tepe are about 75 km and 300 km, respectively. During the Early Chalcolithic Dalma period, two main obsidian supply zones are identified: Syunik-Gegham and Meydan Dag, whereas Syunik predominates. From LC1, a refocus on Syunik is attested. This could be explained, as indicated in the first season results, by a development of transhumans towards the Vorotan Valley. Such a development is suggested by the Kul Tepe excavations, where obsidian is imported in the form of pebbles, similar to those found in the Vorotan River at Godedzor.