Geochemistry of the Ultrapotassic Rhyolitic magmas and a problem of their relation to rare-metal granites: melt inclusion study (the Khangilay ore node, East Transbaikalia, Russia)

摘要

The complex of volcano-plutonic rocks and connected with them rare-metal ore nodes from the Transbaikalia in a whole has been studied aiming to clarify a problem of rare metal granite (RG) origin. In a result of this research specific volcanics and subvolcanics, which form dikes, small rods, and/or covers, have been found out. On the structural-textural features, mineral, and chemical composition of the rocks of this complex from the Transbaikalia the ongorhyolites, ongonites, elvans, trachyrhyolites and trachydacites (TRD) have been recognized and studied. Rocks mentioned above are closely associated in space with massifs of Li-F granites, which show a distinct geochemical relation with them. Study of this rock association varying in composition and crystallization degree allows obtaining perspective data on the condition and mechanism of volatile-saturated granite melt generation, evolution of a regime/condition of volatiles, estimation of a grade of mantle-crust interactions.