Petrological investigation of Late Cretaceous magmatism in Kaboodan area, NE Iran: Evidence for an active continental arc at Sabzevar zone

New zircon U-Pb dating indicates widespread Cretaceous magmatism in the Kaboodan area which includes two distinct geological zones of Sabzevar and Taknar at the NE of Iran. The Cretaceous igneous rocks were formed during 99–75 Ma and are consist of various extrusive and intrusive groups. All igneous rocks of Kaboodan have geochemical characteristics indicative of an active continental arc setting and there is no genetic linkage between the extrusive and intrusive rocks. The extrusive rocks appear at the Sabzevar zone and consist of basaltic andesite, andesite, dacite, and different pyroclastic units. The basaltic andesite samples are the most primitive extrusive rocks with low 87Sr/86Sri (∼0.704) and high ɛNdt values (> +6) while other samples show variable isotopic ratios (87Sr/86Sri = 0.704–0.708 and ɛNdt = +1.41 to +4.25).