东秦岭花岗伟晶岩的基本地质矿化特征

伟晶岩是一种特殊的火成岩类,东秦岭是我国重要的花岗伟晶岩分布区和稀有金属成矿区之一,这里广泛发育各种类型花岗伟晶岩,并形成4个大的花岗伟晶岩脉密集区。岩石化学、稀土配分和氧同位素研究结果显示,东秦岭的花岗岩与伟晶岩具有一致或相似的特点。其粗大的矿物组成,表明伟晶岩中富含挥发份并且是在封闭条件较好的地壳中深部形成的,是地壳深部过程的记录和区域侵蚀深度较大的标志。各种类型的花岗伟晶岩具特征的结构、成分和矿化分带现象,反映出深部透岩浆流体的成矿作用。东秦岭花岗伟晶岩受秦岭造山带主造山阶段的加里东期板块俯冲碰撞的影响,是同一板块俯冲碰撞构造体制下由花岗岩母岩浆分异、演化的结果。东秦岭花岗伟晶岩分布面积大、类型全、分异演化强烈、矿化普遍,是我国寻找花岗伟晶岩型稀有元素矿产、铀矿和部分宝石资源的有利地区。

The Main Geological and Metallogenic Characteristics of Granitic Pegmatite in Eastern Qinling Belt

Pegmatite is a special type of igneous rock. The eastern Qinling belt is one of the important granitic pegmatite distributions region and rare metal metallogenic provinces,where extensively crop out granitic pegmatite with different types and formed four pegmatite concentration zones. The studies on petrochemsitry,REE distribution patterns and oxygen isotopic compositions show that granite and pegmatite in the eastern Qinling belt possess the same or similar characteristics. And the coarse minerals indicate...