阿尔泰阿拉尔岩体周缘花岗岩序列与伟晶岩成因关系探讨

阿拉尔岩体由华力西期黑云母花岗岩和印支期钾长花岗岩组成。其黑云母花岗岩主岩体周围环带状分布的伟晶岩脉群带, 由内带到外带表现出伟晶岩类型由低级向高级演化、稀有金属矿化也有简单向复杂演化的规律性, 且花岗岩时代和岩浆成矿系列基本与伟晶岩类型、时代、矿化特征相互对应。通过总结, 初步认为它们是以阿拉尔似斑状黑云母花岗岩岩基为其母岩体, 经重熔形成的再生岩浆沿阿拉尔岩体外缘侵入的卫星岩体, 或由阿拉尔岩体的岩浆分异演化过程中形成的不同成分系列岩浆分期脉动注入的产物。正是由于这种岩浆演化时间跨度大、多单元岩石成分交互过渡产出以及有利的空间断裂构造环境是稀有金属伟晶岩产出的重要条件。

Relationship between the Sequences of Granite around Alar Biotite Granite and Pegmatite Causes,Altay, Xinjiang

The Alar rock is composed of Hercynian biotite granite and Indosinian K-feldspar granite, which have a number of pegmatite veins around it. The pegmatite type evolution gets stronger gradually from inner to exterior, and rare metal metals mineralization also evolves from simple to the complex. The formation era and magmatic metallogenic series of granite basically correspond with those of the pegmatite. It is concluded that based on Alar porphyraceous biotite granite, these pegmatite veins are satellite rock produced by regenerated magma intruding along the edge of the Alar biotite or they may be formed by pulsing injection of series of magma with many different components during Alar rock magmatic differentiation evolution. The big time span of magmatic evolution, together with multi-unit rock composition interactive transitional output and favorable faults tectonic environment are the important conditions for rare metal pegmatite output.