Abstract:The genesis of the Qibaosban ore deposit, a well-known large-sized polymetallic deposit in Hunan Province, has long been a subject of much controversy, and the authors have tentatively advanced in this paper their own opinions on this problem on the basis of a summarization of various characteristics of this deposit. Located at the east end of the Yonghe-Hengshan second-order syncline of the Yongbe-Qibaoshan-Guizhuwan fault-fold zone, the mining area is stratigraphically simple and structr1Ially complex; the repeated activities of Indo-Sinian granite porphyry provided favorable conditions for mineralization. The orebodies are unexceptionally confined to various structures and fractures, and the main orebody is controlled by fault F2 which coincides basically with the pseudoconformity surface between Hutian Group and Dataag Stage.In addition to the major metallogenic elements such as sulfur, copper, lead, zinc and iron, the deposit has considerable amounts of associated rare earth elements and precious metals, thus greatly raising its commercial value. From large quantities of laboratory data cited in this paper, the following conclusions have been drawn: the deposit was formed at moderate to small depths-from several hundred meters to some 2 kilometers below the surface; major sulfides crystallized from 200℃ to 300℃;sulfur isotopic composition of sulfides is basically in agreement with that of medium water, both close to the sulfur isotopic composition of meteorite; isotopic composition of lead indicates fundamentally a normal lead with only thorium lead having slightly higher values, μ<10, ω<41; ore-forming fluids were acid-slightly alkaline-weakly alkaline mixed magmatic hydrothermal solutions, and metallogenic elements were transported in the form of chloride complexes} metallogenic materials were derived mainly from lower crust or upper mantle; the medium carrying metallic materials was mixed magmatic water related to Qibaoshan intrusive mass. All these data have led the authors to formulate a metallogenic model, suggesting that this deposit should be genetically assigned to post-magmatic high-medium temperature hydrothermal filling-replacement type.
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陆玉梅, 殷浩然, 沈瑞锦.1984.七宝山多金属矿床成因模式[J].矿床地质,3(4):53~60.1984.Genetic Model Of The Qibaoshan Polymetallic Ore Deposit[J].Mineral Deposits3(4):53~60
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