摘要
罗卜岭斑岩型铜钼矿位于紫金山矿田北东侧,产于四坊花岗闪长岩和罗卜岭花岗闪长斑岩体内。矿体平面上呈半环形展布,空间上呈马鞍状,矿石主要为浸染状和网脉状构造。根据矿物组合与脉体穿插关系,将矿区各类热液脉体分为早、中、晚三阶段,分别为:早阶段钾长石-石英±磁铁矿±辉钼矿脉,产于钾化蚀变带;中阶段石英±辉钼矿脉±黄铜矿±黄铁矿脉和硬石膏-黄铜矿脉,产于被绢英岩化叠加的钾化蚀变带和绢英岩化蚀变带;晚阶段石英±石膏±黄铁矿脉,产于绢英岩化带和明矾石-迪开石-绢英岩化蚀变带。早、中阶段脉石矿物中以富气相水溶液和含子晶包裹体为主,其次为CO2包裹体和富液相水溶液包裹体,偶见纯CO2类包裹体;晚阶段仅发育富液相的水溶液包裹体。早阶段包裹体均一温度集中在420～540℃之间,盐度介于0.4%～62.9%NaCleqv,流体属NaCl-CO2-H2O体系。中阶段包裹体均一温度集中在340～480℃,盐度为0.5%～56.0%NaCleqv,CO2含量降低,压力、氧逸度低于早阶段。晚阶段水溶液包裹体均一温度为140～280℃,盐度为0.4%～8.4%NaCleqv。中阶段流体沸腾作用强烈,导致大量硫化物沉淀,晚阶段流体演变为NaCl-H2O体系,可能有大气降水混入。
The Luoboling porphyry Cu-Mo deposit locates in the northeastern Zijinshan ore field,and is hosted by Sifang granodiorite and Luoboling granodiorite porphyry.Orebodies are saddle-like in shape and contain various hydrothermal veinlets.Ore structures are mainly dissemination,stockwork and veins.According to mineral assemblages and crosscutting relationships,the ore-forming process and veins are divided into early,middle and late stages,i.e.the early stage feldspar-quartz±magnetite±molybdenite veins in the potassic silicate alteration zone,the middle stage quartz±molybdenite±chalcopyrite±pyrite veins and anhydrite-chalcopyrite veins in the phyllic alteration zone and the potassic alteration zone overprinted by the phyllic alteration zone,and the late stage quartz±gypsum±pyrite veins in the phyllic alteration zone and the alunite-dickite-phyllic alteration zone.Fluid inclusions in minerals of the early and middle stages are mainly vapor-rich aqueous and daughter mineral-bearing inclusions,together with minor CO2-rich and liquid-rich aqueous inclusions;whereas the late stage minerals only contain liquid-rich aqueous inclusions.Homogenization temperatures and salinities of fluid inclusions in the early stage range from 420℃ to 540℃ and 0.4% to 62.9% NaCleqv,respectively;while those of the middle stage range from 340℃ to 480℃ and 0.5% to 56.0% NaCleqv,respectively.Volume percentage of CO2 phase and oxygen fugacity of fluid inclusions in middle stage minerals are lower than those in the early stage.The late-stage liquid-rich aqueous inclusions yield homogenization temperatures of 140℃~280℃ and salinities of 0.4%~8.4% NaCleqv.It is concluded that boiling occurred in middle stage and caused precipitation of voluminous sulfides as stockworks;and that the fluids evolved into NaCl-H2O system,with an input of meteoric water.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第5期1410-1424,共15页
Acta Petrologica Sinica
基金
国家科技支撑计划(2009BAB43B04)资助
关键词
流体包裹体
罗卜岭斑岩铜钼矿床
紫金山矿田
福建省
Fluid inclusion
Luoboling porphyry Cu-Mo deposit
Zijinshan ore field
Fujian Province
