摘要
根据龙陵东部花岗岩岩体穿插关系及同位素年龄,花岗岩作用可分为3期8个阶段,3个中心。主要岩石类型是黑云母二长花岗岩和白云母花岗岩。花岗岩的成因类型为壳源重熔型和变质交代型。 岩浆演化从早阶段到晚阶段,随酸碱度增加锡逐渐富集成矿。主要矿化类型有:含锡及稀有金属花岗岩,含锡及稀有金属伟晶岩,含锡矽卡岩和角岩型,锡石—黑钨矿—电气石石英脉和含锡多金属硫化物型。
The Rb-Sr and K- Ar determinations of granitic diagennetic age give a range of 25-526 m. y. of East Longling Granite. On the basis of isotopic data and the intersection of the rock body, granitic action are classified into three cycles, eight phases and three centers. Principal petrofabric types are biotite monzonitic granite and muscovite-granite, rich in SiO2,tin and poor in CaO, MgO, K2O, Na2O.
Initial strontium isotopic ratios (87sr/86sr) are determined as 0.7132-0.7242 by whole rock Rb-Sr isochron method. The genetic types of granite are remelting type and metamorphic-metasomatic type in continental crust (cf. ' S' type of Chappel and White).
The acidity and alkalinity obviously increase with the evolution of granites from early phase to later phase ,the tin concentrated gradually and formed mineralization. The major types of tin mineralization are as follows: tin-rare metals- bearing granitic type, tin-rare metals-bearing pegmatitic type, tin-bearing skarn-hornstone type, cassiterite-wolframite-tourmaline- quartz type and tin bearing polymetallic sulfate type.
出处
《矿产与地质》
1990年第2期25-34,45,共11页
Mineral Resources and Geology
