| 滇东北乐红大型铅锌矿床流体包裹体地球化学 |
| Received:December 12, 2016 Revised:February 05, 2017 点此下载全文 |
| 引用本文：ZHAO Dong,HAN RunShen,REN Tao,WANG JiaSheng,WU HaiZhi,ZHANG XiaoPei,CUI JunHao.2018.Characteristics of fluid inclusions geochemistry of Lehong large-sized Pb-Zn ore deposit, northeastern Yunnan Province[J].Mineral Deposits,37(5):1018~1036 |
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| Author Name | Affiliation | E-mail | | ZHAO Dong | Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
Southwest Institute of Geological Survey, Geological Survey Center for Nonferrous Metals Resources, Kunming 650093, Yunnan, China | | | HAN RunShen | Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
Southwest Institute of Geological Survey, Geological Survey Center for Nonferrous Metals Resources, Kunming 650093, Yunnan, China | 554670042@qq.com | | REN Tao | Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
Southwest Institute of Geological Survey, Geological Survey Center for Nonferrous Metals Resources, Kunming 650093, Yunnan, China | | | WANG JiaSheng | Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
Southwest Institute of Geological Survey, Geological Survey Center for Nonferrous Metals Resources, Kunming 650093, Yunnan, China | | | WU HaiZhi | Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
Southwest Institute of Geological Survey, Geological Survey Center for Nonferrous Metals Resources, Kunming 650093, Yunnan, China | | | ZHANG XiaoPei | Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
Southwest Institute of Geological Survey, Geological Survey Center for Nonferrous Metals Resources, Kunming 650093, Yunnan, China | | | CUI JunHao | Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
Southwest Institute of Geological Survey, Geological Survey Center for Nonferrous Metals Resources, Kunming 650093, Yunnan, China | |
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| 基金项目:本文得到国家自然科学基金项目（编号：41572060、U1133602）、中国地调局整装勘查综合研究项目（编号：12120114013901）、云南省矿产资源预测与评价工程实验室（编号：2011）和云南省昆明理工大学创新团队项目（编号：2012、2010）联合资助 |
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| 中文摘要:乐红铅锌矿床是扬子地块西南缘滇东北铅锌（银）多金属矿集区中的典型代表之一。通过对该矿床不同成矿阶段闪锌矿、石英、重晶石和方解石中流体包裹体岩相学、显微测温学和显微激光拉曼探针等测试，阐述了该矿床成矿流体性质和演化特征，并探讨了其成矿过程。研究发现，该矿床流体包裹体主要包括4类：Ⅰ类气相、Ⅱ类水溶液相（由Ⅱa型-富液相气液两相、Ⅱb型-富气相气液两相、Ⅱc型纯液相组成）、Ⅲ类含CO2三相（VCO2+LCO2+LH2O）及Ⅳ类含子矿物（L+V+S）包裹体。结果显示，重晶石阶段的均一温度为240.3~319.3℃，w（NaCleq）为2.24%~10.73%，表现出中高温-中低盐度流体性质；白云石-黄铁矿-石英阶段具有中-高温（219.8~310.1℃），中盐度（w（NaCleq）为7.02%~17.61%）特征；闪锌矿-方铅矿-黄铁矿阶段，包括S1闪锌矿具有中温（217.8~292.2℃）-中盐度（w（NaCleq）为8.81%~16.71%）性质；S2闪锌矿具有中低温（180.2~241.3℃）-中盐度（w（NaCleq）为7.73%~18.47%）性质；S3闪锌矿具有中低温（140.4~227.4℃）-中低等盐度（w（NaCleq）为0.35%~19.21%）的流体性质，通过该阶段中含CO2三相包裹体测试，估算成矿压力和成矿深度分别为45~74.9 MPa（平均58.2 MPa）、1.7~2.8 km。方解石阶段均一温度为165.3℃，中等盐度，w（NaCleq）为11.28%，表现出低温-中等盐度的特征。不同成矿阶段的包裹体温度大致反映了该矿床成矿流体从早阶段至晚阶段，呈现中高温、中低盐度→中温、中等盐度→中低温、中低盐度的演化过程；早期高温-低盐度深部流体在热动力和构造应力驱动下大规模运移，受断裂构造影响发生减压沸腾作用，同时与大气降水发生混合，成矿流体物化性质陡变引起铅锌硫化物等的沉淀，并最终形成矿床。该研究为揭示矿床流体性质、演化及矿床成因提供了证据，深化了“构造-流体‘贯入’成矿”模型，亦对深化矿床成矿机制与指导找矿预测具有重要意义。 |
| 中文关键词:地球化学 成矿过程 热液成矿阶段 乐红铅锌矿床 滇东北矿集区 |
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| Characteristics of fluid inclusions geochemistry of Lehong large-sized Pb-Zn ore deposit, northeastern Yunnan Province |
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| Abstract:The Lehong lead-zinc deposit is one of the typical deposits in the northeastern Yunnan lead-zinc ore concentration area. According to the petrography as well as the laser Raman microspectroscopic and micro-thermometry of fluid inclusions, the authors discovered sphalerite, quartz, barite and calcite of different mineralization stages, and expounded the origin, property and evolution of ore-forming fluid and the metallogenic processes. There are four types of fluid inclusions, i.e., pure gaseous-type (Ⅰ), gas-aqueous-type (Ⅱ) which is composed of aqueousrich gas-aqueous-type inclusions (Ⅱ a), gas-rich gas-aqueous-type inclusions (Ⅱ b) and pure liquid-type inclusions (Ⅱc), VCO2+LCO2+LH2O three-phase inclusions (Ⅲ), and three-phase inclusions containing daughter minerals (Ⅳ), respectively. The test results show that the homogenization temperature in the barite stage varies from 240.3℃ to 319.3℃, the salinity varies from 2.24% to 10.73%, and it is shown that the fluid occurred in mediumhigh temperature and low-middle salinity. The dolomite-pyrite-quartz stage occurred in middle-high temperature (219.8~310.1℃)and medium-low salinity(w(NaCleq) 7.02%~17.61%). The ore-forming fluid in the sphaleritegalena-pyrite stage shows that the sphalerite of first generation (S1) formed in medium temperature (217.8~292.2℃) and medium salinity (w(NaCleq) 8.81%~16.71%). The sphalerite of second generation (S2) formed in medium-low temperature (180.2~241.3℃) and medium salinity (w(NaCleq) 7.73%~18.47%). The sphalerite of third generation (S3) formed in medium-low temperature (140.4~227.4℃) and medium-low salinity (w(NaCleq) 0.35%~19.21%). Based on three-phase inclusions with CO2 in S3, it is estimated that the pressure and depth of mineralization varies from 45 MPa to 74.9 MPa with an average of 58.2 MPa and 1.7 km to 2.8 km, respectively. In the calcite stage, the homogenization temperature is 165.3℃, and the salinity w(NaCleq) is 11.28%. In this stage the ore-forming fluid had low temperature and medium salinity. The homogenization temperatures of diffe-rent stages can roughly indicate the evolutionary process of the ore-forming fluid from early stage to late stage. The temperature appears in the evolutionary trend of medium-high temperature and medium-low salinity→medium temperature and medium salinity→ medium-low temperature and medium and low salinity. The fluid in the early stage decompressed and boiled by structural stress, and was mixed with meteoric water at the same time. Hydrothermal fluid migrated upward along the Lehong fault, and injected into the faults in the host rocks. When the physical-chemical conditions of ore-forming fluid changed, the ore-forming materials in the fluid precipitated in secondary order faults or cracks near the Lehong fault, and formed the Lehong lead-zinc deposit. Meanwhile, strong dolomitization, pyritization and silicification and some other alterations occur near the edges of fault zones. This discussion about metallogenic process not only provides important evidence for further improvement of metallogenic model of "the fluid penetrating and mineralization", but also has important significance in predicting the location of the orebodies. |
| keywords:Thegeochemistry ore-forming process metallogenic stage Lehong Pb-Zn deposit northeastern Yunnan ore concentration area |
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