The petrographic and geochemical properties of the neogene volkanites outcroping on the Erzurum-Cat region

In this study, petrographic and geochemical features of the volcanic rocks extending to Erzurum, Çat and Tekman districts in the south of Erzurum province were investigated. Palandöken volcanics constituting the study are Upper Miocene aged and are composed of primary volcanic product lavas and pyroclastic products. As a result of the petrographic studies, it was determined that the lavas are composed of basalt, basaltic andesite, andesite, trachite and dacit composition and the tuffs are composed of lithic and crystal tuff composed of pyroclasts of these rocks. In the lavas showing different textural features, usually porphyritic texture, there are also textures showing the magma mixture. The content of SiO2 in the study volcanics generally varies between 52,98-67,68%. In geochemical nomenclature, rocks varying from basal to dacitic are compatible with petrographic data. Generally, it is thought that fractional crystallization processes are effective in the formation of these rocks with high and medium K and calc-alkaline properties. Generally, these volcanic rocks with the same origin characteristics are thought to be composed of a source of lithospheric mantle origin and spinel lherzolitic composition. However, it is thought that the variations observed in these volcanics occur due to assimilation-fractional crystallization and magma mixture, especially due to subcontinental crust contamination. It is seen that Palandöken volcanites, which are determined to be within plate basalt feature in geotectonic classification diagrams, are in conform with the volcanism in the Eastern Anatolia compression zone / accretion complex