We describe the petrogenesis of three phases of Late Oligocene to Middle Miocene felsic volcanism that occurred in the western part of the southeastern Anatolian orogen. All units are calcalkaline. The S-type character of these volcanic rocks is supported by their peraluminous natures (A/CNK 1.11-3.14) and high (up to 9.89%) normative corundum contents. Elevated Rb/Sr ratios and low MgO and Fe2O3 total of the first phase suggest that it might represent melts lacking entrained Fe-Mg-rich crystals, and that the magma developed by muscovite-dehydration melting. Relatively lower Rb/Sr ratios and higher Ba, Sr and Eu concentrations, and high zircon-saturation temperatures of the last two phases, indicate that these melts formed by water-saturated melting.