四川会理小青山地区钠长(石)岩成因初探

The preliminary study of the (albite) albitite from the Xiaoqingshan region , Huili, Sichuan

笔者从岩石学、岩石化学、稀土元素地球化学特征等方面对小青山地区的钠长岩进行了初步探讨。该区的钠长岩主要受构造控制 ,分布于破碎带及其两侧 ,具有从中心到围岩的对称分带性特征。钠长岩中存在大量的交代残余结构。通过岩石化学成分和稀土元素地球化学特征 ,尤其是通过Q型群分析表明 :该区的钠长岩化学成分复杂 ,且与千枚岩 /板岩有一定的相关性。笔者认为该区的钠长岩为热液交代的产物 ,其被交代的原岩主要为古元古界的一套富含Si和Al的浅变质岩系。区内的铜 (金 )

The preliminary study of the (albite) albitite from the Xiaoqingshan region, Huili, Sichuan has been made on the basis of petrology, petrochemistry and REE geochemistry. The occurrence of the albitite studied here is chiefly constrained by the geological structures and distributed along the fractures, and displays a symmetric zonation from centers to wall rocks. The replacement remnant textures are apparently visible in the rocks. The Q mode cluster analyses suggest the complicated chemical compositions of the albitite, that may be correlated with phyllite and slate. The albitite from the study area is interpreted to have a hydrothermal replacement origin, and its primitive rocks consist of the Early Proterozoic Si and Al rich low grade metamorphic rock series, in which the copper (gold) deposits are hosted.