Geology of the Göllüdağ
The geology of the Göllüdağ volcanic complex has been studied intensively (Mouralis 2002, Mouralis 2003, Türkecan et al. 2004, Binder et al. 2011). The focus of the Obsidian Use Project is to propose for the first time a detailed cartography of the obsidian sources (K. Erturaç, ANR post-doctoral fellow in CNRS/IFEA, Sakarya University, Balkan et al. 2011; Erturaç et al. 2010). This work was done following an agreement between the CNRS in IFEA, the Department of Prehistory of the Istanbul University and the Istanbul Technical Üniversity/EIES.
Furthermore, a normalization of the different geological scales and toponimy has been proposed for the region notably to avoid all misunderstanding when the distribution of obsidian oucrops are analysed in the litterature. The original model of the dome extrusion and the formation of obsidian outcrops proposed by D.Mouralis is now developed with a larger set of data. A systematic sampling of the outcrops has been organized to better understand the distribution of obsidians in the region. The chemical analysis was made in LA-ICP-MS in IRAMAT (Orléans). New sources were found. They are in some cases associated to workshops or shelters showing anthropic remains. A better definition of the Göllüdağ-East obsidian sub-groups has been reached and the advantages and limits of the LA‐ICP‐MS method better underlined. Investigations in magnetic properties were conducted on the same samples to test the accurency of the method in the most complex volcanic context of Anatolia (LSCE, Gif-sur-Yvette). İn complement, we have been able to test the mechanical properties of several obsidians from the Göllüdağ and Nenezidağ to understand their behaviour to controlled mechanical constrains (LTDS, Ecole Centrale de Lyon). This integrated approach allows us to better understand the occupation and use made of the Central Anatolian volcanic complex by ancient groups, their sourcing strategies and to evaluate the variability of the raw material itself. This multidisciplinary approach allows us to build up a GIS for the Göllüdağ Project, a tool to integrate and better analyse the geological and archaeological data available.