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 Gul f 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 t he Hellenic arc; the NW-striking Altsehir fault bounds it to the east. Platform-type, parautochthonous Mesozoic carbonate sequences such as the Beydaglan and Anamas-Akseki occur in the western and eastern parts of the IA, respectively, whereas allochthonous ophiolite nappes inclu de the Antalya, Beysehir-Hoyran, and Lycian nappes. The IA and adjacen t areas are divided into three areas-the Teke, the Antalya, and the Ak seki fragments-by NE-, NW-, and N-striking active strike-slip faults w ith normal components. IA region Volcanics are alkaline and hyperkalin e in character (potassic, ultrapotassic) and locally occur as subvolca nic stocks and dikes. They can be traced between the Afyon and Isparta regions. These volcanics consist mainly of latitic and trachytic lava s, leucitic and lamproitic dikes, and pyroclastic constituents. Alkali ne volcanic centers are located on the west side of and parallel to th e 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 arrange ment along the N-trending EK depression indicates the development of t his volcanic activity contemporaneous with active tectonics during the late Miocene to early Pliocene. The volcanic centers are on the synth etic fault elements of the EK intracontinental rifting (or half-graben ) in connection to the northward movement of the African plate. The wo rk on the relationship between alkaline volcanism and active tectonics of the Kirka-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).