西南三江兰坪盆地金满铜矿床成因研究:来自铜和硫同位素的联合约束

发布时间：2018-01-01 20:13

本文关键词：西南三江兰坪盆地金满铜矿床成因研究:来自铜和硫同位素的联合约束　出处：《岩石学报》2016年08期 　论文类型：期刊论文

【摘要】：三江地区兰坪盆地中-新生代砂岩和板岩中赋存有脉状铜矿床,其成因一直存在争议。本文选取金满矿床作为实例进行了详细的铜和硫同位素研究。解析了该矿床成矿物质来源及其富集机理。研究表明金满矿床具有多期性、成矿物质多来源性。硫同位素数据显示,大部分分布在-5.0‰~+3.4‰之间,个别富集硫的轻同位素,δ~(34)S值达-10.1‰、-11.4‰、-11.6‰,认为硫主要来源于盆地蒸发岩硫酸盐,通过有机质热分解作用还原成H_2S,同时有少量生物成因硫及深部来源硫。铜同位素研究表明,成矿早阶段铜同位素δ~(65)Cu值在零附近,铜主要来源于深部地壳或上地幔,晚阶段硫化物富集铜的轻同位素,δ~(65)Cu值达-1.10‰、-1.02‰,铜主要来自盆地内成矿流体流经的地层。结合研究区成矿物质来源、流体性质及地质背景,认为不同性质流体混合发生氧化还原作用促使金属硫化物沉淀是金满矿床主要形成机制。另外,成矿流体沿断裂上涌,外界条件突变,压力下降,气体逸出等过程对硫化物沉淀也起到一定作用。
[Abstract]:The Lanping basin in the Sanjiang area - the new generation of the occurrence of sandstone and slate in vein copper deposit, the cause has been controversial. This paper selects full gold deposit as an example to study copper and sulfur isotope. Detailed analysis of the source of ore-forming materials and enrichment mechanism. Research shows that the gold deposit is full of multi period mineralization. Material sources. Sulfur isotope data show that most of the distribution between -5.0% ~+3.4%, the individual light sulfur isotope enrichment, 8 ~ (34) S value reached -10.1%, -11.4%, -11.6%, that of sulfur mainly comes from basin evaporite sulfate, reduced to H_2S by organic thermal decomposition at the same time, there is a small amount of biogenic sulfur and deep source sulfur. Copper isotope research shows that the early mineralization stage of copper isotope ~ (65) Cu value near zero, copper mainly comes from deep crust or upper mantle, late stage light isotope enrichment of copper sulfide, 8 ~ (65) Cu value reached -1.10%, -1.02%, mainly from the copper basin metallogenic fluid through the strata. With the study of minerals, fluid properties and geological background, that the mixture of different redox properties of fluid promotes metal sulfide precipitation is full of gold deposits formed mechanism. In addition, the ore-forming fluids along fracture upwelling conditions mutation, pressure drop, gas and other precipitation process also plays a role of sulfide.

【作者单位】：中国地质大学地质过程与矿产资源国家重点实验室;
【基金】：国家重点基础研究发展规划项目(2015CB452603、2009CB421008) 高等学校学科创新引智计划(B07011) 教育部长江学者和创新团队发展计划(IRT0755) 中央高校基本科研业务费(2652015430、2652015315、2652015314)联合资助
【分类号】：P618.41;P597
【正文快照】： 中国地质大学地质过程与矿产资源国家重点实验室,北京100083State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing 100083,ChinaYang LF,Shi KX,Wang CM,Wu B,Du B,Chen JY,Xia JS and Chen J.2016.Ore genesis of t

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