Genesis and age of zircon from alkali and mafic rocks of the Elet’ozero Complex, North Karelia

The paper presents a study of zircon from the Middle Paleoproterozoic Elet’ozero high-Ti layered ultramafic-mafic-alkaline intrusive complex with carbonatites and Sm-Nd isotope system of rock-forming minerals in ferrogabbro sample from this complex. Zircons extracted from syenite and ferrogabbro samples have similar pattern and experienced two main independent episodes of secondary transformation. The first episode was accompanied by the partial...