Petrogenesis, Geodynamics and Radiometric Age Dating of Safakhaneh Mass, Northwest of Iran

Safakhaneh batholith, situated at 47 km southwest of Shahin Dezh, northwest of Iran, is located in the central Iran structural zone intersecting the Cretaceous rocks. The absolute age of the batholith, determined for the first time by K - Ar method, has been calculated 69.535 Ma. showing upper Cretaceous - Paleocene epoch and Laramide tectonic orogeny. Geochemical investigations of the batholith show that the major part of the batholith is of mantle magma, in which magmatic changes of the crystalline differentiation and contaminations have occurred. The crystalline differentiation has caused the formation of different rock types of quartz monzonite, quartz monzodiorite, tonalite, granodiorite and monzogranite respectively. Primary magma of the rocks is of calc - alkaline and generally metaluminous. The specifications of batholith rocks can be compared with the I - Type Caledonian granites. From the tectonic point of view, the specifications of the batholith can be comparable with the volcanic arc granitoids (VAG).