投稿时间:2015-08-03
修订日期:2016-10-20
网络发布日期:2017-03-11
中文摘要:闽北政和-建瓯矿集区内大药坑金矿床是一个赋存于韧性剪切带中的小型矿床。在野外地质调查基础上,通过分析载金矿物黄铁矿电子探针成分和硫化物硫、铅同位素组成,探讨了大药坑金矿床的成矿作用问题。研究表明,大药坑金矿床黄铁矿的Co/Ni比值大多在1~5之间,为岩浆热液成因黄铁矿,成矿热液的温度和盐度均较高,也表现出岩浆热液的性质;金属硫化物的δ34SCDT均为靠近0的较低正值(0.1‰~3.4‰),说明成矿物质为岩浆来源,硫化物的铅同位素比值以及高μ(238U/204Pb)和ω(232Th/204Pb)等特征,说明成矿物质具有壳幔混源特征。结合区域研究资料,认为大药坑金矿床形成于东南沿海区域强烈壳幔作用时期,与燕山期火山-侵入杂岩有关,矿床成因类型为岩浆期后热液型。
Abstract:The Dayaokeng deposit located in the Zhenghe-Jianou ore concentration area is a small-sized gold deposit hosted by ductile shear zone. To investigate metallogenesis of the Daoyaokeng gold deposit, the authors carried out some experiments including EPMA and S-Pb isotopes. Most Co/Ni ratios of pyrites are 1~5 and, furthermore, the temperature and salinity of fluids are both high, suggesting magmatic hydrothermal origin.δ34SCDT values of pyrite, sphalerite, galenite are 2.7‰~3.4‰, 2.2‰ and 0.1‰~0.5‰, respectively, which are positive values close to 0‰ (δ34SCDT value of troilite), so it is reasonable that metal materials originated from magma. Pb isotope ratios of sulfide are 18.237~18.557 (206Pb/204Pb), 15.628~15.799 (207Pb/204Pb) and 38.446~38.988 (208Pb/204Pb) respectively; in addition, μ(238U/204Pb)and ω(232Th/204Pb) are high, suggesting that the ore-forming materials might have resulted from mixing of ore-forming materials derived from the crust and the mantle. Combined with previous regional researches, the authors hold that the Yanshanian volcanic-intrusive complexes had a close relationship with the Dayaokeng gold deposit, the deposit was developed at the stage of strong crust-mantle interaction of southeast coast block, and the metallogenic type of the gold deposit is postmagmatic hydrothermal type.
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中图分类号:P618.31
文献标志码:
基金项目:本研究得到中国地质调查局地质调查项目"武夷山成矿带龙泉-上杭地区地质矿产调查"(编号:DD20160037)和"中国矿产地质与成矿规律综合集成和服务(矿产地质志)"(编号:DD20160346)资助
引用文本:
肖凡,班宜忠.2017.闽北大药坑金矿床黄铁矿成分标型及硫、铅同位素组成研究[J].矿床地质,36(1):171~184XIAO Fan,BAN YiZhong.2017.Study of S, Pb isotopes and composition typomorphic characteristics of pyrites in Dayaokeng gold deposit, northern Fujian Province[J].Mineral Deposits36(1):171~184
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