云南普朗斑岩型铜多金属矿床气液隐爆角砾岩的发现及其找矿意义

云南普朗铜多金属矿是格咱岛弧内一个典型的斑岩型矿床,尽管前人对该矿床开展了若干研究,但对于该矿床是否存在叠加成矿作用仍存在争议。研究团队在普朗典型矿床调研过程中,在普朗I号探矿平硐中首次发现了气液隐爆角砾岩。详细的岩相学及矿相学研究表明,隐爆角砾岩角砾为含矿石英二长斑岩,胶结物为细粒石英,且细粒石英中含有黄铜矿连晶。根据气液隐爆角砾岩产出位置及特征推断,隐爆作用系石英二长斑岩就位之后的岩浆活动引起,并伴随成矿作用发生。普朗斑岩型铜多金属矿成矿作用由卡尼阶与诺利阶两个成矿阶段构成,其中铜成矿作用跨越了卡尼阶和诺利阶,而钼成矿始于诺利阶。综合分析指出,普朗矿区深部具有斑岩型钼(铜)多金属矿的找矿潜力。

Discovery of Liquid Cryptoexplosive Breccia and Its Prospecting Significance in Pulang Porphyry Copper Polymetallic Deposit

The Pulang super-large copper-polymetallic deposit is one of typical porphyry deposits within Geza island arc in Yunnan Province.Though previous researchers have carried out lots of studies on this deposit, there is still controversy about superimposed mineralization.By the field investigation, authors of this paper discovered the hydrothermal cryptoexplosive breccia for the first time in the No I prospecting pit in the Pulang deposit.Detailed studies on its petrography and mineragraphy show that, the breccia is ore-bearing quartz monzonite porphyry cemented by fine-grained quartz which containing chalcopyrite.Combining with its location and characteristics, it can be concluded that the hydrothermal explosion was caused by magmatic activity after the quartz monzonite porphyry intruding, and accompanied with mineralization.The copper polymetallic mineralization in the Pulang porphyry deposit experienced Carnian and Norian, and copper mineralization spanned both periods, while molybdenum mineralization began at Norian.Comprehensive analysis leads to the view that there is the huge prospecting potential of porphyry molybdenum (copper) at deep in the Pulang deposit.