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鸡冢岩体为经历两次岩浆脉动上侵而成的复式深成岩体,化学成分表现为贫SiO2,低MgO,富CaO、Na2O,岩石类型为偏铝质高钾钙碱性岩系,属岩浆混合花岗岩。研究表明,花岗岩及其中暗色微粒包体在地球化学特征上具有相似的稀土、微量元素含量和配分模式。成分变异图解显示,SiO2与Al2O3、K2O、CaO、MgO、FeO 、TiO2及稀土、微量元素La-Ce、Nd-Sm、La-Ba、Th/Yb-Ta/Yb之间具有较好的线性关系。氧同位素地球化学特征表明花岗岩形成过程中有大量幔源组分加入,说明鸡冢岩体为岩浆混合作用产物,其形成与华北陆块南缘陆内俯冲造山作用有关。
The Zhizuka massif is a complex deep pluton invaded by two magmatic pulsations. Its chemical composition is characterized by poor SiO2, low MgO, rich CaO and Na2O, and the rock type is a partial high-K calc-alkaline rock series, belonging to the magma Mixed granite. The results show that the granite and dark-colored granulite inclusions have similar geochemical characteristics of REE, trace elements and patterns of partitioning. Composition variation diagrams show that there is a good linear relationship between SiO2 and Al2O3, K2O, CaO, MgO, FeO, TiO2 and REEs, trace elements La-Ce, Nd-Sm, La-Ba and Th / Yb-Ta / Yb . Oxygen isotope geochemical characteristics indicate that a large amount of mantle source components are added during granite formation, indicating that the Zhizuka massif is a product of magmatic mixing and its formation is related to intracontinental subduction orogeny in the southern margin of the North China block.