Rare Earth–Uranium–Thorium Mineralization in the Molybdenum Ores of the Buluktaevskoe Mo–W Deposit (Western Transbaikalia, Russia)

Abstract

—The Buluktaevskoe molybdenum–tungsten deposit is considered a close analog of W–Mo deposits within the large Dzhida orefield, in which the Pervomaiskoe molybdenum and Inkurskoe and Kholtosonskoe tungsten deposits are known. Fifteen ore minerals were identified in the molybdenum ores of the Buluktaevskoe deposit; in addition to molybdenite, they include sulfides (pyrite, galena, and chalcopyrite), tungstates (wolframite and scheelite), molybdates (powellite and wulfenite), and a relatively large number of minerals containing rare earth elements (REE), U, and Th (Th-bearing monazite, brannerite, thorite, and uraninite); among them are previously unknown minerals: fluorine-bearing thorium molybdate and minerals with compositions corresponding to rare mineral species, orthobrannerite and kobeite-(Y). Interrelations and specific chemical compositions of the uranium–thorium–rare earth element minerals are discussed. It was established that these minerals formed in the course of hydrothermal alteration processes, at the early (molybdenite) development stage of the Buluktaevskoe molybdenum–tungsten deposit.