滇西放羊山Cu-Zn-Pb矿床成矿流体来源和成因  

A Study on the Source of Ore-forming Fluid and Genesis of the Fangyangshan Cu-Zn-Pb Deposit in the Western Yunnan

作　　者：贾祯 邓明国[1] 张权 谢恩彩 耿齐卫 陈伟 苏岩 陈俞宏 牛春晖 JIA Zhen;DENG Ming-guo;ZHANG Quan;XIE En-Cai;GENG Qi-wei;CHEN Wei;SU Yan;CHEN Yu-hong;NIU Chun-hui(Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming 650093,China;Yongchang Lead-Zinc Mining Co.,Ltd.,Baoshan 678300,China;Yunnan Institute of Geology&Mineral Resources Exploration,Kunming 650051,China;West Yunnan University of Applied Sciences,Dali 671000,China;Yunnan Diqing Nonferrous Metals Co.,Ltd,Shangri-La 674400,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]云南永昌铅锌股份有限公司,云南保山678300 [3]云南省地质矿产勘查院,云南昆明650051 [4]滇西应用技术大学,云南大理671000 [5]云南迪庆有色金属有限责任公司,云南香格里拉674400

出　　处：《矿物学报》2022年第4期413-424,共12页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(批准号:41762009,41363001)。

摘　　要：放羊山Cu-Zn-Pb矿床位于我国滇西保山地块镇康芦子园矿集区内,是区内近期发现的首个富铜的铅锌矿床。据野外地质调查和镜下鉴定,认为该矿床至少存在2期热液(热液期、叠加期)成矿。C、H、O稳定同位素组成特征研究表明,2期成矿流体均以岩浆热液来源为主,伴有大气降水的混入和水-岩反应等地质作用的参与。热液期、叠加期硫化物微量元素特征均反映矿床成因为岩浆热液型。其中,闪锌矿的w(Cd)为555.66×10^(-6)~900.04×10^(-6),w(Ga)为0.81×10^(-6)~1.88×10^(-6),反映高温闪锌矿的特征;黄铁矿Co/Ni值介于1.18~13.90之间,显示中温岩浆热液型黄铁矿的特征。叠加期方铅矿的ln[w(Bi)/10^(-6)]和黄铜矿的Zn/Cu值均分别高于热液期方铅矿和黄铜矿,暗示叠加期热液温度略高于热液期。对比研究区域内矿床认为,放羊山矿床为与隐伏中酸性岩体相关的、受2期同源岩浆热液流体叠加富集成矿的产物。The Fangyangshan Cu-Zn-Pb deposit, located in the Zhenkang ore-concentrated area of the Baoshan block in the western Yunnan(SW China), is the first Cu-rich lead-zinc deposit recently discovered in this area. According to field observation and microscopic identification, it is believed that there are at least two stages(hydrotherm, superimposed) of mineralization occurred in the deposit. The characteristics of C, H and O stable isotopic compositions indicate that the ore-forming fluids of two mineralization stages are both mainly sourced from the magmatic hydrothermal fluid, with influence of involved meteoric water and the water-rock interaction. The compositional characteristics of trace elements of sulfides of two ore-stages reflect that the metallogenesis of the deposit belongs to the magmatic hydrothermal type.Especially, The Cd contents of sphalerites vary from 555.66×10^(-6)to 900.04×10^(-6)and Ga contents of sphalerites vary from 0.81×10^(-6)to 1.88×10^(-6), reflecting the feature of high-temperature sphalerite. The Co/Ni values of pyrites, varying from 1.18 to 13.90, show characteristics of the magmatic hydrothermal pyrite. The ln[w(Bi)/10^(-6)] values of galenas and Zn/Cu values of chalcopyrites of the superimposition stage are respectively higher than those of galenas and chalcopyrites of the hydrotherm stage, suggesting that the temperature of hydrothermal fluid of the superimposition stage should be slightly higher than that of the fluid in the hydrotherm stage. Based on comparative study on geological and geochemical characteristics of deposits in the area, it is believed that the Fangyangshan deposit was formed by the superimposed enrichment mineralizations of magmatic hydrothermal fluids of two stages in association with the concealed intermediate-acid magmatic intrusions.

关 键 词：C-H-O同位素 矿物微量元素 成矿流体来源 矿床成因 放羊山 滇西 

分 类 号：P597[天文地球—地球化学] P618.4[天文地球—地质学]