Following an Eocene continent-are collision, the Western Anatolia region experienced a complete cycle of thickening and orogenic collapse. The early stage of collision-related volcanism, which was most evident during the Early Miocene (<21 Ma), produced a considerable volume of lavas and pyroclastic deposits of basaltic andesite to rhyolite composition. The volcanic activity continued into the Middle Miocene with a gradual change in eruptive style and magma composition. The Middle Miocene activity formed in relation to localised extensional basins and was dominated by lava flows and dykes of basalt to andesite composition. Both the Early and Middle Miocene rocks exhibit calc-alkaline and shoshonitic character. The Late Miocene volcanism (<11 Ma) was marked by alkali basalts and basanites erupted along the zones of localised extension.