• 责任者：Liu Jiangtao (State Key Laboratory of Geological Processes and Mineral Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Yang Liqiang
• 刊名：Acta Petrologica Sinica
• 出版年：2013
• 卷期：29(11)
• 关键词：斑岩铜矿床 ; porphyry copper deposit ; 云南 ; Yunnan Province
• 页码：p.3914-3924
• 图表：7 illus., 5 tables, 57 refs.
• 分类号：1001
• issnNo：ISSN1000-0569
• isbnNo：CN11-1922/P

     Porphyry Cu deposits are usually closely related to ore-forming fluid with high oxygen fugacity. The Pulang complex, parent rock of the Pulang copper deposit which has the largest single ore reserves in Asia, has oxidized magma characteristics, but the mineral assemblages and fluid compositions are consistent with those of reduced porphyry copper-gold deposits. The minerals in ores are characterized by large amount of pyrrhotite, the assemblages of chalcopyrite-pyrrhotite-pyrite, and there are lots of reducing compositions, such as CO2, CO and CH4 in the ore-forming fluid, and with fo2 values below the fayalite-magnetite-quartz oxygen buffer. These reduced compositions probably originates from the carbonaceous phyllite that surrounds the Pulang complex or the deep mafic magma. The copper solubility in reduced fluid is lower than that in the oxidized fluid, but the gold solubility is not affected by the redox conditions. The CH4 reduced the SO2 into S2- which is the basic material of molybdenite. The reduced ore fluids are probably the main reason of low Cu grade mineralization hut with massive Au, Mo mineralization. The discussion of reduced characteristic of the Pulang copper deposit benefits the further studies of the deposit genesis, and the metallogenic mechanism of regional porphyry deposits.