Petrographical, geochemical and petrological investigation of the Pelitli (Bayburt) granitoid

In this study, petrographical, geochemical and petrological characteristics of Pelitli Granitoid in the Pelitli (Bayburt) area were determined, and the evolution and origin of plutonic rocks were investigated.In the studied area located on the northern zone in the eastern Pontide; the basement is represented by Eocene aged andesite and pyroclastics. This unit are cut by the Pelitli Granitoid. All three units are overlie uncorformably by Quaternary alluvium.The Pelitli Granitoid is elipse shaped, and settled approximately in an area of 15.5 km2. It consists of diorite, granodiorite, tonalite, and granite, and includes abundant wall-rock xenoliths and mafic magmatic enclaves (MME). The Pelitli Granitoid shows disequilibrium textures showing magma mixing. The granitoid is generally I-type, low to high K calc-alkaline character, and peraluminous to metaluminous transitional. Major and trace element variations indicate significant role of plagioclase, pyroxene, hornblende and Fe-Ti oxide fractionation during the evolution of rocks.The petrological features indicate that fractional crystallisation has an important role, and magma mixing/mingling and assimilation less role during the evolution of Pelitli Granitoid. Geochemical data indicate that the plutonic rocks have occured via the partial melting of the meta-magmatic (amphibolitic) rocks.