【作者】 刘峰；

【导师】 王登红； 李厚民；

【作者基本信息】 中国地质科学院 ， 矿床学， 2005， 硕士

【摘要】 会泽铅锌矿的矿山厂、麒麟厂矿床是赋存在峨眉山玄武岩附近的下石炭统摆佐组（C₁b）碳酸盐岩地层中的含镓、铟、锗、镉的特富铅锌矿床。本文在学习总结前人工作成果的基础上，对矿山厂、麒麟厂矿床的地质学、矿石学、矿物学、地球化学、同位素年代学等方面特征进行了研究和总结，并探讨了矿床的成矿机制，初步建立了成矿模式。获得的主要认识有：1．矿山厂、麒麟厂断裂为导矿构造，矿床受层间断裂构造控制，矿体主要赋存在下石炭统摆佐组（C₁b）碳酸盐岩地层的层间断裂中，矿体顶底板岩性有三种组合类型：灰岩—灰岩型、白云岩—白云岩型、灰岩—白云岩型。2．成矿流体改造下石炭统摆佐组（C₁b）地层中的页岩，形成矿体中粘土矿物。3．成矿流体中成矿物质浓度较大，并以脉动的形式贯入成矿，形成铅锌富矿体；4．闪锌矿中的铁元素的含量随着成矿流体的脉动变化，形成闪锌矿的色带现象。5．稀土元素和微量元素的组成特征显示了热液成矿的特点；成矿物质和峨眉山玄武岩之间存在一定的物质来源关系。方铅矿、黄铁矿、闪锌矿中的硫同位素为壳源的；脉石方解石的碳、氧同位素特征和围岩碳酸盐岩的相近，显示脉石方解石的碳、氧可能源于围岩；铂族元素特征显示有源于幔源峨眉山玄武岩的物质加入。6．方解石的Sm-Nd同位素年代为220±14Ma，经分析显示成矿年代和峨眉山玄武岩活动年代相近。7．锗元素以类质同象置换锌元素的方式赋存在闪锌矿中。推测的成矿过程为：晚二叠世时期，峨眉地幔柱的活动使区域及矿区的构造格局发生了变化，形成了区域及矿区的张性成矿构造环境；在峨眉山玄武岩喷溢的临前期，峨眉山玄武岩浆是良好的热、气、液驱动源，促使区域上形成了大面积的成矿流体活动，同时提供部分成矿物质进入了成矿流体；成矿流体沿断裂运移，进入层间断裂成矿。富含铅锌成矿物质的成矿流体随着峨眉山玄武岩的脉动喷发活动，向碳酸盐岩地层的层间断裂中脉动贯入并成矿，形成了特富铅锌矿体；锗元素进入成矿流体中，以类质同象的方式赋存于闪锌矿中。二叠纪以后的晚燕山、喜马拉雅运动形成了区域上的逆冲推覆构造，使矿体的空间形态发生变化。更多还原

【Abstract】 Kuangshanchang and Qilinchang in Huize, Yunnan province, are the large Pb-Zn depositswith extremely enriched Ga, In, Ge and Cd in the carbonate rocks of the lower CarboniferousBaizuo Formation （C₁b） occurring near the Emeishan basalt. Based on the previews researchresults, the author has further done research on the characteristics of geology, petrology,mineralogy, geochemistry and geochronology in the Huize Pb-Zn ore deposit, concluded anddiscussed the metallogenetic mechanism, and also established a preliminary metallogenetic model.The main ideas that the author has are following:.1. Mineralization in Kuangshanchang and Qilinchang Pb-Zn deposits was supposed to bemainly controlled by the tectonic activities, and the fratures were the main structure aspassage-way for ore-forming fluid. Orebody mostly occurred in the fractures among carbonaterocks strata of the lower Carboniferous Baizuo Formation （C₁b）; hostrocks of the orebody includethree assemblages: limestone-limestone; dolostone-dolostone; limestone-dolostone.2. Shale in the strata of the lower Carboniferous Baizuo Formation （C₁b） formed the clayminerals in the orebody after the ore-forming fluid alteration.3. The ore-forming fluid with highly concentrated metals, pulsated into the interlayerfractures and formed the extremely rich Pb-Zn orebody.4. The conetent of Fe in sphalerite was banded following the pulsation of the ore-formingfluid, and this caused the phenomena of color bands in sphalerite.5. The characteristics of the trace elements and rare earth elements suggested that theore-forming elements had the same source and this source might relate to the Emeishan basalt. Thevalue of S isotopes in galena, pyrite and sphalerite showed that the source of S was crust; inaccordance with the similar value of C and O isotopes in calcite and the wall rocks, it suggestedthat the wall rocks might be the source of C and O. The characteristics of platinum group elementsshowed that partial ore-forming elements were from the mantle-related Emeishan basalt.6. The isotopic age by Sm-Nd dating of calcite was 220±14Ma, which was close to theepisode of the Emeishan basalt activity.7. Ge occurred in sphalerite as Zn’s isomorph.The metallogenetic process that the author proposed was: in the late Permian Period, theactivities of Emei mantle plume changed the tectonic pattern of this region and the mining district,and caused the tensional tectonic environment there; before the effusion of the Emeishan basalt,the Emeishan basaltic magma heated this region, drove the migration of the gas and liquid,impelled a large amount of ore-forming fluid to move and made some ore-elements dissolve in theore-forming fluid; ore-forming fluid followed the fratures and metals deposited in the layeredfractures among the carbonate rocks under the fit conditions. Following the pulsation of Emeishanbasalt, the ore-forming fluid pulsated into the interlayer fractures among the carbonate rocks and formed the pretty rich Pb-Zn ore; Ge entered the ore-forming fluid and then went into sphaleriteoccurring in sphalerite as Zn’s isomorph.. Tectonic activities after Permian Period, such asIndosinian and Himalayan orogeny, formed the regional thrust nappe structure and changed thespacial shape of the orebody.更多还原