Isotopic and geochemical characteristics of the late Miocene subalkali and alkali basalts of the southern part of the Russian Far East and the role of continental lithosphere in their genesis

Major oxides, trace elements (ICP-MS analysis), and Sr isotope ratios were analyzed in the late Miocene subalkaline and alkaline basaltoids of the southern part of the Russian Far East, which were formed during the final stage of the development of intraplate basaltic volcanism. Based on these data, variations in the main geochemical and mineralogical characteristics of various tectonomagmatic terranes were evaluated. The enriched and heterogeneous continental lithosphere modified to a varying extent by postaccretion subduction processes of different ages played a major role in the formation of the rocks. The first geochemical evidence was obtained for the subduction of the Solonker paleoceanic plate beneath the Amur microcontinent during the Permian.