ZHAO Dong1,2, HAN Run-sheng1,2*, WANG Jia-sheng1,2, REN Tao1,2
（1. Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China; 2. South-West Institute of Geological Survey, Geological Survey Center for Nonferrous Metals Resources, Kunming 650093, China）
Abstract: 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.
Keywords：REE; ore-forming fluid origin; Lehong Pb-Zn ore deposit; deposit concentration district, northeastern Yunnan
E-mail: 554670042@qq.com
ACTA MINERALOGICA SINICA Vol. 37, No. 5, 2017, Page 588-595
