驼路沟喷气沉积型钴（金）矿床成矿地质背景及矿床成因的地球化学限制

驼路沟矿床是东昆仑南部造山带中新发现的钴(金)矿床,它的含矿岩系是一套浅变质的(绿片岩相)震旦-寒武纪火山-沉积岩系.火山岩是一套中-酸性凝灰岩及熔岩,其元素地球化学特征类似于活动大陆边缘或弧火山岩;沉积岩包括碎屑岩和黑色页岩,它们具有活动大陆边缘沉积岩的元素地球化学极性,部分沉积岩具有现代大陆弧地区沉积岩的元素地球化学特征.岩相学、矿物学及元素地球化学研究证明,作为主岩之一的石英钠长岩是典型的喷气沉积岩,而并非"脉岩",它不但是钴(金)矿体的重要找矿标志,而且也是喷气沉积矿床的重要鉴别标志.钴(金)矿石组构及矿石矿物的世代显示其主要与海底喷气沉积成矿作用有关,在后期的碰撞造山过程中,受到了改造和活化.矿石和喷气沉积岩的痕量元素地球化学特征表明,它们同属喷气-成矿流体较远离喷气中心的海底沉积物.总之,岩(矿)相学及元素地球化学资料证明,驼路沟钴(金)矿床主要属喷气沉积矿床,形成于震旦-寒武纪东昆仑南缘的活动大陆边缘环境.

Geochemical Constraint on the Metallogenetical Geological Background and Genesis of Tuolugou Sedimentary-Exhalative Cobalt-Gold Deposit

Tuolugou cobalt-gold deposit is a newly discovered deposit in the southern margin of Eastern Kunlun orogen, hosted in an epimetamorphosed (green schist facies) Sinian-Cambrian volcanic-sedimentary rocks. The volcanic rocks consist of a suite of intermediate to siliceous tuff and lava, its geochemistry indicates that it is similar to active continental marginal or arc volcanic rocks. The sedimentary rocks composed of clastic rocks and black shales, show the geochemical characteristics of active continental marginal sedimentary rocks, some of them show the feature of modern continental arc sedimentary rocks. The study on the petrology, mineralogy and elementary geochemistry indicate that the quartz albitite, as one of host rocks, is not dikes but typical exhalative-sedimentary rock, which is not only an important indicators for ore prospecting, but also an important discriminating criteria for sedimentary-ex-halative genesis of the deposits. The ore structure and generation of cobalt-gold ore minerals suggest that their formation mainly related to submarine sedimentary exhalation, reformed and mobilized in late collision orogenesis. The trace elementary geochemistry of cobalt-gold ore and exhalative-sedimentary rocks suggest that both of them belong to vent-distal sedimentary-exhalative genesis that exhalative-metallogenetic fluids were far from exhalation center. In conclusion, the data on petrology and elementary geochemistry indicate that Tuolugou cobalt-gold deposit mainly belong to sedimentary-exhalative genesis, and formed in the Sinian-Cambrian active continental marginal environment at the southern margin of Eastern Kunlun orogen.