【作者】 杨忠芳；

【导师】 刘兴德；

【作者基本信息】 成都理工大学 ， 矿物学、岩石学、矿床学， 2010， 硕士

【摘要】 会理大铜矿铜矿床是四川省重要的中型铜矿床之一,它位于川滇南北向构造带中段与南岭东西向构造带西延交接部位,处于康滇地轴中生代断陷盆地—会理盆地的南西侧。本文通过对大铜矿铜矿床区域地质背景、矿床地质特征等的地质资料收集、整理和野外实地地质调查等工作,并结合该铜矿床地球化学特征的研究,对大铜矿铜矿床的矿床成因有了进一步认识。会理大铜矿铜矿床产于中生代晚白垩世小坝组地层中,小坝组地层岩性为一套河湖相紫红色碎屑沉积岩。矿区主要褶皱构造为青蛙甲背斜和向斜,断层不发育,对矿体影响较小。矿体呈层状、似层状产出,产状与围岩基本一致。矿石主要原生金属矿物为辉铜矿和斑铜矿,次生金属矿物主要为孔雀石等。矿石结构构造比较简单,主要为结晶粒状及溶蚀结构和侵染状胶结构造。矿体围岩无明显蚀变现象。通过对该矿床地球化学特征研究表明,含矿围岩与矿体在常量元素、微量元素、稀土元素的组合上,具有相似的配分特征,显示它们具同源性,成矿物质主要来源于地层建造。矿石铅同位素组成反映其物质来源主要为壳源,而矿石硫同位素δ34S值为-13.3‰～﹢2.8‰,反映硫主要来自沉积物中的硫酸盐细菌还原作用和部分生物有机硫。流体包裹体研究表明低温低压条件下的成矿特征。除此之外,本文通过对该铜矿床成因的研究,还对大铜矿铜矿床的沉积相和成矿模式做了简要分析。本文认为该铜矿床是属于河流沉积相沉积,古河道凸岸的滨河床浅滩与成矿作用密切相关。铜元素的富集成矿作用主要发生在成岩中期—晚期。成矿环境为氧化向还原的过度环境。成矿期大体经历了沉积阶段、构造运动阶段和构造运动相对稳定阶段三个时期。成矿物质在后期的成岩作用过程中再度活化、转移、富集而成。综合研究显示,大铜矿铜矿床为一沉积砂砾岩型层控铜矿床。最后,本文根据对大铜矿矿床成因的认识,对大铜矿铜矿床的远景找矿指出方向。更多还原

【Abstract】 The Huili Datongkuang copper deposit is one of the most important medium-sized copper deposits in Sichuan province. It is located between the middle of Sichuan and Yunnan tectonic zone and the West extension of Nanling east-west tectonic belt. In the Kangdian axis of the Mesozoic rift basin-southwestern side of the Huili Basin. Based on the geology information collection, collation and field geological investigation about the regional geological background, geological features of ore deposit in Datongkuang copper deposit, binding the researches of the geochemical characteristics of the copper deposits, this paper has a new light about the Datongkuang copper deposit.The Huili Datongkuang copper deposit produced in the Xiaobazu strata of late cretaceous in the Mesozoic, the Xiaobazu strata’s lithology is a set of stratigraphic about the fluvial and lacustrine facies mauve clastic sedimentary rocks. Datongkuang mining area’fold structures are mainly Qingwajia anticline and Qingwajia syncline. The faults are not developed, which have less impact on the orebody. The ore bodies occur as stratified oe stratoid basically concordant with the wall rock. The major primary metal minerals of ore are chalcocite and bornite, and the secondary metal minerals are malachite and azurite, etc. Ore texture and structure are simply, the ores are mainly in granular crystalline and dissolution textures and infection cementation structures. The ore rock has not significant altered phenomenon.Based on the research of the character of ore geochemistry characteristics, it indicates that ore-bearing wall rock and orebody’s macro elements, micro element and Rare-Earth Element have similar composition, which shows homology. Metallogenic materials are mainly from the stratigraphic formatiom. The components of lead isotopes reflect that the metallogenetic materials mainly come from the crust while theδ34S values range from -13.3‰to 2.8‰of ores indicate that sulfur was derived mainly from bacterial reduction of sulphates and bioaccumulation organic sulfur. Based on the study on the fluid-inclusion geochemistry of the ore deposit, it is suggested that the ore formed under the conditions of low temperature and low pressure.In addition, through the causes of the copper deposit, this paper made some brief analysis of the sedimentary pacies and metallogenic modle about the Datongkuang copper deposit. This text thinks that this copper deposit belongs to fluvial deposit. Old channel’s convex bank river bed accumulation had concentration with mineralization. The copper enrichment and mineralization in the mine field mainly occurs between the middle diagenesis and the late diagenesis, metallogenic environment was redox environment. Mineralization period experienced three major evolutionary stages: sedimentary stage, tectogenesis period and the relatively stable tectonic movement stage. The metallogenic material occursed mobilization, migration and enrichment in the later process of diagenesis again.Comprehensive studies on the analytical results indicate that the ore genesis of Datongkuang copper deposit is a sedimentary sandy gravel type stratabound deposit. In the end, according to the understanding of ore genesis about the Datongkuang copper deposit, this paper makes a suitability assessment of evaluation of mineral about the Datongkuang copper deposit.更多还原