Petrology of Post-Collisional Calc-Alkaline Yozgat Volcanics

Yozgat Volcanics is located in Central Anatolian Crystalline Complex within central Anatolia, and in the northwest of the province of Yozgat. Middle-Upper Eocene Yozgat Volcanics are composed of basaltic andesite, andesite and dacite. Yozgat Volcanics show calc-alkaline character which presence of plagioclase phenocryst with sieve texture and epitacsitic quartz xenocrystals prove magma mixing. Besides, geochemical analyses show that there are olivine-clinopyroxene fractionation from basaltic andesite to andesite, and plagioclase-hornblende fractionation from andesite to dacite. In addition to that it has been observed that there is a signature of partial melting and continental contamination during magma evolution based on geochemical analysis. The northern branch of Neo-Tethys subducted beneath of Eurasia plate in central Anatolia in stage of Santonian-Campanian. Following this subduction event Izmir-Ankara Suture Zone occurred due to continent-continent collision. Lower-Middle Eocene basaltic rocks originated from mantle dasitic rocks originated partial melting of lower continental crust respectively. It has been thought that andesite was formed by homogeneous mixing of basic and acidic volcanic rocks.