北衙金矿外带似层状Pb-Zn-Ag多金属矿床地质特征及成因

发布时间：2018-03-05 11:16

  本文选题：地质特征　切入点：地球化学特征　出处：《金属矿山》2016年01期 　论文类型：期刊论文

【摘要】：北衙金多金属矿床地处金沙江—红河富碱斑岩带南段,是该带上成矿作用与富碱斑岩有关矿床的代表。通过对北衙金矿外围似层状Pb-Zn-Ag矿床地质特征及地球化学特征进行研究,得出了以下结论:1赋矿围岩为三叠系中统北衙组灰岩,相对富集Pb、Zn、Au、Ag等成矿元素,是铅锌银矿的有利矿源层;2成矿流体为NaCl-H_2_O-CO_2体系,具有中—低温、中—低盐度的特征,来源于富碱斑岩体结晶分异的岩浆热液;3矿石S同位素含量-2.4‰~+2.8‰,指示矿床硫与斑岩体有相同的来源,均来自深部地幔,后期有部分地层硫的加入,矿石Pb同位素分析结果指示成矿物质来源于壳幔混合;4特定的北衙组碳酸盐岩地层条件、北衙—芹河NNW向向斜构造及斑岩的岩浆活动,构成了北衙金矿外带似层状Pb-Zn-Ag多金属矿床的主要控矿因素。综合该矿床地质特征、地球化学特征、控矿因素,对矿床成因进行了探讨,认为北衙金矿外带似层状Pb-Zn-Ag多金属矿床是富碱斑岩分异热液成矿作用的结果,是北衙富碱斑岩金多金属成矿系统外带的产物。
[Abstract]:The Beiya gold polymetallic deposit is located in the southern section of Jinshajiang-Honghe alkali rich porphyry belt, and is the representative of mineralization and alkali-rich porphyry related deposits in this belt. The geological and geochemical characteristics of layered Pb-Zn-Ag deposits in the periphery of Beiya gold deposit are studied. The following conclusions are drawn that the surrounding rock of the No. 1 ore-bearing system is the limestone of the Beiya formation of the Middle Triassic system, which is relatively rich in the ore-forming elements such as Pb, Zn, Zn, au, Ag and so on. It is a favorable ore-forming fluid of the lead-zinc-silver deposit, which is a NaCl-H_2_O-CO_2 system with the characteristics of medium-low temperature and medium-low salinity. The S isotopic content of magmatic hydrothermal Qiu 3 ore derived from the crystallization differentiation of alkali-rich porphyry is -2.4 鈥，

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