天堂山花岗质岩石条带状构造的成因与演化

THE GENESIS AND EVOLUTION OF GRANITIC ROCK'S STREAKY STRUCTURES IN TIANTANGSHAN AREA

天堂山地区花岗质岩石中条带状构造异常发育，据成因可分为分异条带状构造和构造置换———复合条带状构造两种类型。它们的形成与岩石变形变质作用有密切关系，形成和演化过程可分为３个阶段：递进变形变质阶段；重熔活化阶段；构造置换改造阶段。分异条带状构造是岩石在递进变形变质作用过程中具不同熔点的矿物发生分离和分异形成的；构造置换———复合条带状构造是重熔活化阶段形成的长英质脉体和先期分异条带一起又受到强烈的构造置换改造，发生平行化而成。

The streaky structures of granitic rock extraordinarily develop in Tiantangshan area, they can be regarded as two types as differentiated streaky structure and transpositional-compound streaky structure according to their geneses. Their formations have close relations with rock's deformation and metamorphism. The processes of their formations and evolutions can be devided into three phases: progressive deformation and metamorphism phase; anatectic remobilization phase; structural transposition phase. The differentiated streaky structure formed in the progressive deformation and metamorphism process of granitic rock in which the minerals with different melting-points came to separate and differentiate; the transpositional-compound streaky structure originated in the process in which the felsic veins forming during anatectic remobilization phase and previous differentiated streaks were reformed together by intense structural transporsitions becoming parallel.