Anomalous Source of the Dovyren Magmas: from Neoarchean Protolith to the Upper Riphean Crystallization History

Results of isotope-geochemical studies of the Upper Riphean rocks from the Dovyren Intrusive Complex and comagmatic metavolcanics of the Synnyr Ridge in northern Transbaikalia, Russia, are summarized. The trace-element geochemistry and data on radiogenic isotopes (Rb–Sr, Sm–Nd, and Re–Os), combined with data on the sulfur and oxygen isotope compositions, indicate that the Dovyren magmas were derived from an anomalous and long-lived source, produced in relation to Neoarchean processes of mantle melting that had formed a heterogeneous protolith with signatures of lower crustal contamination during the early evolution of the Siberian Craton.