投稿时间：2012-07-27
修订日期：2013-08-29
网络发布日期：2013-10-29
中文摘要:弓长岭铁矿床二矿区富铁矿体在空间上与由石榴子石、角闪石、绿泥石等矿物组成的交代岩关系密切,显示与热液活动相关。根据交代岩中矿物共生组合、交代岩与矿体的穿插交代关系等特征,将弓长岭铁矿床二矿区富矿成矿过程分为早期热液交代阶段、晚期热液交代阶段和石英脉阶段。对这3个阶段石英中的流体包裹体进行了岩相学、显微测温和激光拉曼光谱分析。结果表明,不同测定对象中的流体包裹体类型相似,主要有富液相、富气相及含子矿物多相包裹体等类型。但它们的均一温度和盐度有明显差别,早期热液交代阶段石英中的包裹体均一温度主要集中于340~398℃,盐度主要集中于0.88%~6.3%和33.5%~40.6%两个区间,成矿流体以富CO2的CO2-CH4-H2O的中低盐度、中高温热液流体为主,并混有含石盐子矿物的高盐度、中高温热液流体,有大量磁铁矿富矿形成;晚期热液交代阶段石英中的包裹体均一温度主要集中于230~280℃,盐度主要集中于0.88%~4.96%,该阶段成矿流体为含CO2的CO2-H2O±CH4的中低温、低盐度热液流体,是富矿的较重要成矿阶段;石英脉阶段石英中的包裹体均一温度主要集中于150~180℃,盐度主要集中于1.06%~2.07%,该阶段流体为含CO2-H2O的低盐度、低温的热液流体,与富矿的形成关系不大。
Abstract:The high-grade ores in No. 2 mining area of the Gongchangling iron deposit have close genetic relationship with skarnoid consisting of garnet, amphibole, chlorite, suggesting significant correlation with the hydrothermal activity. According to mineral association of skarnoid as well as mineral intersection and metasomatism of skarnoid and high-grade ores, the ore-forming process of high-grade ores of No.2 mining area of the Gongchangling iron deposit is divided into the early hydrothermal metasomatism stage, the late hydrothermal metasomatism stage and the quartz vein stage. Through petrographic and microthermometric studies and Laser Raman spectroscopy of fluid inclusions from quartz of skarniod of the early hydrothermal metasomatism stage, quartz of the late hydrothermal metasomatism stage and quartz of the quartz veins stage, the authors have found that the fluid inclusions compositionally include liquid-rich, gas-rich and daughter mineral-bearing multiphase inclusions. Although the types of the fluid inclusions of the three stages are similar, there are significant differences in homogenization temperatures and salinities. The fluid inclusions of the early hydrothermal metasomatism stage quartz yielded homogenization temperatures of 340~398℃, salinities of 0.88%~6.3% and 33.5%~40.6%. The fluid of this stage is characterized by high temperature, low salinity and high content of CO2-CH4-H2O, mixed with the fluid of high salinity, high temperature and halite daughter minerals,with the formation of a lot of high-grade ores. The fluid inclusions of the late hydrothermal metasomatism stage quartz yielded homogenization temperatures of 230~280℃ and salinities of 0.88%~4.96%. The fluid of this stage is characterized by low salinity, low temperature and low content of CO2-H2O±CH4, implying that this stage might have been a relatively important stage for the formation of high-grade ores. The fluid inclusions of the quartz vein stage quartz yielded homogenization temperatures of 150~180℃ and salinities of 1.06%~2.07%. The fluid of this stage is characterized by low salinity, low temperature and the existence of CO2-H2O.
keywords:geochemistry banded iron formations metasomatic rock hydrothermal metasomatism fluid inclusion Gongchangling
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中图分类号：P618.31
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基金项目:本文为国家"973"项目之课题"沉积变质型铁矿成矿环境与富矿形成机制"(编号: 2012CB416801);国土资源部公益性行业科研专项经费项目之课题"辽宁弓长岭沉积变质型铁矿科学基地研究"(编号: 200911007-15)和"我国北方沉积变质型岩浆型铁矿富矿成矿地质作用研究"(编号: 201111002);地质矿产调查评价项目"辽冀地区沉积变质型铁矿控矿因素和勘查技术方法组合优选"(编号: 1212011120988)联合资助的成果
引用文本：
刘明军,李厚民,李立兴,杨秀清,姚良德,洪学宽,陈靖,姚通,白云.2013.辽宁弓长岭铁矿床二矿区流体包裹体研究[J].矿床地质,32(5):989~1002LIU MingJun,LI HouMin,LI LiXing,YANG XiuQing,YAO LiangDe,HONG XueKuan,CHEN Jing,YAO Tong,BAI Yun.2013.A study of fluid inclusions from No.2 mining area of Gongchangling iron deposit in Liaoning Province[J].Mineral Deposits32(5):989~1002
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