Relation of Alkaline Volcanism and Active Tectonism Within the Evolution of the Isparta Angle, Sw Turkey

The Isparta Angle (IA) is formed along the boundary of the African and Eurasian plates by NE‐ and NW‐striking faults north of the Antalya Gulf in SW Turkey. The NE‐striking strike‐slip Burdur fault bounds the IA to the west and is probably the continuation of the Pliny system of the Hellenic arc; the NW‐striking Aksehir fault bounds it to the east. Platform‐type, parautochthonous Mesozoic carbonate sequences such as the Beydag and Anamas‐Akseki occur in the western and eastern parts of the IA, respectively, whereas allochthonous ophiolite nappes include the Antalya, Beysehir‐Hoyran, and Lycian nappes. The IA and adjacent areas are divided into three areas–the Teke, the Antalya, and the Akseki fragments–by NE‐, NW‐, and N‐striking active strike‐slip faults with normal components. IA region volcanics are alkaline and hyperkaline in character (potassic, ultrapotassic) and locally occur as subvolcanic stocks and dikes. They can be traced between the Afyon and Isparta regions. These volcanics consist mainly of latitic and trachytic lavas, leucitic and lamproitic dikes, and pyroclastic constituents. Alkaline volcanic centers are located on the west side of and parallel to the N‐S trend of the Egirdir‐Kovada (EK) graben. The volcanics range in age from 15 to 4 Ma and get younger from north to south; their arrangement along the N‐trending EK depression indicates the development of this volcanic activity contemporaneous with active tectonics during the late Miocene to early Pliocene. The volcanic centers are on the synthetic fault elements of the EK intracontinental rifting (or half‐graben) in connection to the northward movement of the African plate. The work on the relationship between alkaline volcanism and active tectonics of the Kuka‐Afyon‐Isparta (KAI) region is a novel approach based on the differences between the coeval calc‐alkaline/alkaline volcanics at the east and west of the KAI structural trend (KAIST).