Continental arc volcanism and tectonic setting in Central Anatolia, Turkey

The Neogene and Quaternary volcanism of Central Anatolia represents the central sector of the Anatolian Volcanic Arc. related to continental collision between the Afro-Arabian and Eurasian plates. It is closely associated with a complex system of tectonic depressions related to brittle deformations of transtentional type and which commenced in the Late Miocene. The volcanism here considered can be divided into three main periods of activity, separated by important deformative and erosive events. The first period is represented by a mostly andesitic effusive activity. The second period is characterized by the emplacement of a thick ignimbritic sequence and shows an areal distribution up to 11,000 km2. Seven ignimbrite units have been recognized. The three main units were found at a distance of more than 100 km from the presumed source area. Geological and sedimentological data lead us to recognize the Melendiz Dag volcanic complex and the Ciftlik caldera as the probable ignimbrites source vent. During the third period great andesitic-basaltic stratovolcanoes and a number of prevalently acid monogenic centres developed. The relationship between the volcanic activity is clearly conditioned by the main transcurrent fault systems present in Central Anatolia. The Neogene-Quaternary volcanic activity prevalently developed along the ENE-WSW Karaman-Sivas lineament. Most of the great central volcanoes developed at the intersection between the ENE-WSW trends and the Ecemis and Tuz Gölü transcurrent faults. The structural interpretation of the Quaternary monogenic centres is more difficult. Probably they are related to the very recent N-S fault swarms which cross the Anatolides and the Taurus Range. © 1988