某地钽铌钨铍矿化花岗岩

The tantalum-, niobium-, tungsten-, beryllium-mineralized granite described in this paper is identified as albitizied fine-grained muscovite granite and occurs as a small discordant taeolity with a bulging central part, dipping and finning out outwards.A crust of quartz-pegmatoid, several tens of centimeters thick, dsvelopes in its apices. Major rock-forming minerals are plagioclase, mierocline, albite, muscovite and quartz. Partsehinite, fluorite and topaz are characteristically abundant among accessory minerals. Rare element and base metal minerals include wolframite,scbeellte, microlite, raanganese-rich columbite, berly, phenacite, xenotirae, monazite,cassitcrite, raolybdenite, bisrauthinite, etc. Niobium and beryllium mineralizations are uniformly present throughout the rock body, but tantalum is feund richer in upper parts than in lower parts. It is tentatively suggested that this is a differentiationmctasomatic deposit of fracture-filling type originated during late magmatic stage.