滇东北乐红大型铅锌矿床稀土元素地球化学特征  

REE Geochemical Characteristics in Lehong Large Lead-Zinc Deposit, Northeastern Yunnan Province, China

作　　者：赵冻 韩润生[1,2] 王加昇[1,2] 任涛[1,2] ZHAO Dong;HAN Run-sheng;WANG Jia-sheng;REN Tao(Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China;South-West Institute of Geological Survey, Geological Survey Center for Nonferrous Metals Resources, Kunming 650093, China)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093 [2]有色金属矿产地质调查中心西南地质调查所,云南昆明650093

出　　处：《矿物学报》2017年第5期588-595,共8页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(批准号:41572060;U1133602);中国地调局整装勘查综合研究项目(12120114013901);云南省矿产资源预测与评价重点工程实验室(2012)项目;云南省;昆明理工大学创新团队项目

摘　　要：乐红铅锌矿床位于扬子地块西南缘,是滇东北铅锌(银)多金属矿集区中的典型代表。通过不同中段典型矿化-蚀变样品中白云石、方解石、重晶石及闪锌矿稀土元素地球化学研究,探讨了该矿床的成矿流体来源。灰黑色白云岩、脉状-团块状白云石、斑团状-脉状重晶石、脉状方解石和各世代闪锌矿的∑REE均较低,均值分别为6.44×10-6、5.62×10-6、4.66×10-6和8.88×10-6,S1:1.12×10-6,S2:0.35×10-6,S3:2.75×10-6;δEu分别为0.72、0.80、68.27和0.65,S1:2.08,S2:3.78,S3:0.75;稀土配分模式为LREE富集-HREE亏损的右倾型。白云石、方解石和闪锌矿在REE配分模式、Eu和Ce异常及La/Ho-Y/Ho图解上的分布等均与未蚀变白云岩接近,表明成矿流体主要来源于碳酸盐地层中的循环水;而早阶段重晶石稀土元素特征差别明显,可能与早期深部流体有关。综合研究表明成矿流体具多源性,可能为源自于深部流体沿构造带运移至有利部位与碳酸盐岩地层中循环水发生混合。Eu、Ce异常特征表明,从成矿早阶段到成矿晚阶段,成矿过程经历了早期高温、氧化→成矿期中高温、弱还原→晚期中低温、还原的演化过程。The Lehong lead-zinc deposit is a typical lead-zinc deposit concentrated district in northeastern Yunnan Province, China. The study on rare earth element geochemistry of dolomite, unaltered dolomite, calcite, barite and sphalerite in the typical mineralized alteration zone of Lehong Pb-Zn ore deposit in different level adits was conducted. The origin of ore forming fluids in the deposit were also discussed. Rare earth elements show that ∑REE gray-black dolomite, vein-agglomerate dolomite, spotted-veined barite, vein calcite and disseminated - veins - agglomerated sphalerite are low, with the mean ∑REE being 6.44× 10-6, 5.62× 10-6, 4.66× 10-6 and 8.88× 10-6, S1：1.12× 10-6, S2：0.35× 10-6, S3, 2.75×10-6, respectively. The mean of Eu/Eu＊ ratios are 0.72, 0.80, 68.27, and 0.65, with S1, 2.08; S2, 3.78;and S3, 0.75, respectively. The pattern of REE with enriched LREE is right-dip curve. The distributions of dolomite, calcite and sphalerite in REE patterns, Eu/Eu＊ ratios, Ce/Ce＊ ratios and La/Ho-Y/Ho diagrams are all close to those of unaltered dolomite, indicating that the ore - forming fluids are mainly derived from the construction water in the carbonate strata. The characteristics of rare earth elements in the early stage are significantly different; it may represent the early deep fluid REE characteristics. The comprehensive study shows that the ore-forming fluids of this deposit have many characteristics. It is possible that the hydrothermal fluid originates from the deep part migrates along the structural belt to the favorable site and conveys mixed with the water in the carbonate formation. Eu and Ce anomaly show that from the early stage of mineralization to the late stage, ore-forming process is according the order of early stage →mid-stage → late stage; the formation of Lehong deposit had undergone the process of weak reduction at medium-high temperature, oxidation→ medium temperature, weak reduction →medium-low temperature, reduction.

关 键 词：稀土元素 成矿流体物源 乐红铅锌矿床 滇东北矿集区 

分 类 号：P595[天文地球—地球化学] P618.401[天文地球—地质学]