青海祁漫塔格地区中生代构造-岩浆作用与成矿

MESOZOIC TECTONO-MAGMATISM AND MINERALIZATION IN THE QIMANTAG AREA,QINGHAI

中生代是祁漫塔格地区一个重要的构造-岩浆作用活跃期和成矿高峰期,不仅控制了铁多金属大型矿集区的分布,而且使先期形成的矿床活化、迁移、富集和再就位。构造-岩浆作用的多旋回决定了相应成矿也具有多期性、多样性和复成因的特点。岩浆弧相俯冲-碰撞杂岩形成主要的成矿母岩,而岩浆活动期间的区域裂谷相和板内岩浆相一般零星成矿或不成矿。三叠纪中-晚期的大规模幔源岩浆底侵及其与壳源岩浆混合形成的花岗质岩浆,为成矿储备了丰富的元素基础,形成了区域上特色的斑岩-矽卡岩型铁、铜多金属矿床成矿组合。

As an important active period of tectono-magmatism and golden age of mineralization in the Qimantag area,Mesozoic not only controlled the distribution of large iron-polymetallic ore deposits,but also activated,migrated,enriched and repositioned the deposits formed earlier.The polycycles of tectono-magmatism led to mineralization of multiphase,diversity and complex genesis.The main metallogenic parent rocks are formed by the magmatic arc subduction-collision complex,while the regional rift and intraplate magmatic facies during magmatic activity are generally sporadic in mineralization or non-metallogenic.The large-scale mantle-derived magma underplated and mixed with the crust-derived felsic magma to form the granitic magma in the middle and late Triassic period,which provided abundant elements as a base for mineralization,and formed the regionally distinctive porphyry-skarn combination type of iron and copper polymetallic deposits.