云南马厂箐矿田浅成低温热液-斑岩型Cu-Mo-Au多金属成矿系统  

Epithermal-porphyry Cu-Mo-Au ploymetal metallogenic system in Machangqing ore field,Yunnan

作　　者：王治华[1] 葛良胜[1] 郭晓东[1] 王梁[1] 袁士松[1] 杨立强[2] 

机构地区：[1]武警黄金地质研究所,廊坊065000 [2]中国地质大学地质过程与矿产资源国家重点实验室,北京100083

出　　处：《岩石学报》2012年第5期1425-1437,共13页Acta Petrologica Sinica

基　　金：973国家重点基础研究发展计划项目(2009CB421008);武警黄金指挥部专项基金项目(HJ09-03)联合资助

摘　　要：马厂箐Cu-Mo-Au多金属矿田位于西南三江复合造山带中段,是带内金多金属矿床的典型代表。矿田内矿化类型复杂,元素组合多样。围绕马厂箐富碱杂岩体矿化类型、元素组合、围岩蚀变呈明显的分带。在岩体中形成斑岩型铜-钼矿床;在岩体与地层内外接触带形成接触交代型(角岩型、夕卡岩型)铜-钼(铁)矿床;在岩体外围地层中形成浅成低温热液金-铅-锌矿床。对应的围岩蚀变表现为自岩体中心向外依次为强硅化带→石英钾长石化带→石英钾长石绢云母化带→夕卡岩化带→中低温热液蚀变。同位素测年结果表明3种类型的矿床成矿均发生于33.7～35.8Ma,金矿床略晚于铜-钼矿床,并与矿田内马厂箐杂岩体侵入时代(33～37Ma)一致。岩矿石的H、O、Pb、S同位素和流体包裹体系统研究表明,从斑岩型铜-钼矿床→接触交代型铜-钼(铁)矿床→浅成低温热液金-铅-锌矿床,矿石中流体包裹体均一温度、盐度和均一压力逐渐降低,成矿物质(矿质和流体)也逐渐从以深部岩浆源为主,演变为以围岩地层和大气降水为主。矿田内不同类型矿床间的时空及成因联系,反映它们是同源岩浆不同演化阶段成矿作用的产物,含矿热液的物化性质及时空迁移决定了它们在不同部位产出不同的矿床类型,构成与富碱斑岩有关的浅成低温热液-斑岩Cu-Mo-Au多金属成矿系统。Three types of deposit found in Machangqing ore field：porphyry-type copper-molybdenum deposit is in the Machangqing complex intrusion,contact-metasomatic-type copper-molybdenum（iron） deposit in inner and outside the contact between strata and the intrusion and epithermal gold-lead-zinc deposit in outside strata.Wallrock alteration zonation is clear,from the center of intrusion to outside,showing strong silicification → quartz,K-feldspar → quartz,K-feldspar,sericitization → skarn → low-middle-temperature hydrothermal alteration.Isotope-dating shows the metallogenesis age of three types of deposit is 33.7 ～ 35.8Ma,and gold deposit is slightly later the copper-molybdenum deposit,according with the intrusion age（33 ～ 37Ma）.H,O,Pb,S isotopes and fluid inclusions suggest that from porphyry copper-molybdenum deposit → contact-metasomatic copper-molybdenum（iron） deposit → epithermal gold-lead-zinc deposit,homogeneous temperatures,salinities of fluid inclusion and homogeneous pressures are decreasing trendingly.The metals and fluid for ore-forming are mainly from the magma system in the early in porphyry-type copper-molybdenum deposit,and change into wallrock and precipitate water in later in epithermal gold-lead-zinc deposit.The relationships of time,space and material of different types of deposit insinuate they are products of different envolution stages of same source magma.Physics and chemical characteristics and migration conditions of hydrothermal determine different deposit types occurring different positions.A metallogenic system consist of porphyry-type and epithermal copper-molybdenum-gold ploymetal related to alkalic-rich porphyry is built up in this paper.

关 键 词：浅成低温热液型 斑岩型 富碱杂岩 多金属成矿系统 马厂箐矿田 云南 

分 类 号：P611.1[天文地球—矿床学]