云南易门铜厂铜矿床地球化学特征及成因研究

发布时间：2018-06-04 01:06

本文选题：易门铜厂 + 地球化学　；参考：《昆明理工大学》2015年硕士论文

【摘要】：易门铜厂矿床位于扬子地台西南缘的昆阳裂谷内,属易门铜矿带的东矿带,是该矿带的典型矿床之一。本文依托校企合作项目《易门铜厂及外围铜矿成矿规律与找矿预测研究》(编号：KKK0201321099)进行选题。论文以铜厂矿床的典型矿体为重点研究对象,针对矿体特征、矿床地球化学等研究薄弱环节,在前人研究以及系统的野外工作的基础上,运用光学显微镜、等离子体质谱仪ICP-MS分析,开展同位素测试分析、元素地球化学及流体包裹体分析等,研究了矿化类型、’矿石组构特征、成矿物质来源、成矿物理化学条件等,对矿床地质特征、矿床地球化学以及矿床成因等进行研究,取得以下成果和认识：1、铜厂矿床的矿化类型主要有两种,即沉积成岩型和热液脉状型铜矿,本文称之为铜厂式矿体和尖山式矿体。2、铜厂式矿体主要赋存于落雪组中,主要呈层状和似层状,矿石矿物为斑铜矿,粒径在0.05mm-0.50 mm之间,多在0.10mm以下。矿石具有泥-微晶结构、粉-细晶结构,层理构造、缝合线构造。尖山式矿体产于构造较为复杂的部位,不受层位控制,主要呈网脉状随石英-方解石脉分布,矿石矿物主要是黄铜矿,粒径多在0.05-0.25mm之间,个别大于lmm,矿石具有交代结构、固溶体分离结构,网脉状、浸染状等构造。3、铜厂式矿体中黄铁矿的Co/Ni介于0.51-1.74之间,平均1.062,显示沉积-成岩作用成因的特征,而尖山式矿体中黄铁矿的Co/Ni达2.65,显示热液作用成因。4、硫同位素的研究表明,铜厂式矿体的δ34S呈离散型分布,具沉积成因特征。尖山式矿体的σ34S的分布相对局限,具典型的岩浆硫的特征。尖山式硫源来自深部,在一定程度上受到浅层硫的混染。5、铅同位素研究表明,铜厂矿床中硫化物Pb同位素数据较分散,变化范围较大,放射性成因Pb很高,铅的来源具复杂性。6、铜厂式矿体的成矿物质来源于地层,并受后期热液的影响。矿体受到地层、岩性和岩相古地理的控制,成矿时代与含矿层的时沉积间一致；尖山式矿体的成矿物质源于深部,矿体受到构造和岩性的影响,成矿时代为晋宁期。7、本矿区铜矿的成矿总体为一种沉积成岩+深源热液叠加成矿模式。
[Abstract]:The Yimen copper deposit is located in the Kunyang rift in the southwestern margin of the Yangtze platform. It belongs to the east ore belt of the Yimen copper ore belt and is one of the typical deposits in the ore belt. This paper is based on the cooperation project of school and enterprise < study on metallogenic regularity and Prospecting of Yimen Copper Plant and its periphery copper deposit "(No.: KKK0201321099)." This paper focuses on the typical orebodies of Tongchang ore deposit. Aiming at the weak links of ore body characteristics and deposit geochemistry, based on the previous studies and systematic field work, the optical microscope is used. ICP-MS analysis by plasma mass spectrometer, isotopic analysis, element geochemistry and fluid inclusion analysis have been carried out to study the texture characteristics, ore-forming source, ore-forming physicochemical conditions, etc. The geological characteristics, geochemistry and genesis of the deposit are studied, and the following results and understanding are obtained. There are two main types of mineralization in Tongchang deposit: sedimentary diagenetic type and hydrothermal vein type copper deposit. The orebodies in this paper are called Tongchang orebodies and Jianshan orebodies. The orebodies of Tongchang type mainly occur in the Luoxue formation, which are mainly layered and bedded. The ore minerals are porphyry ore with particle size between 0.05mm-0.50 mm and below 0.10mm. Ore has mud-microcrystalline structure, powder-fine crystal structure, bedding structure, suture structure. The quartz-calcite vein distributes mainly in the quartz-calcite vein of the quartz-calcite vein. The ore mineral is mainly chalcopyrite with the particle size between 0.05-0.25mm and Lmm, and the ore has metasomatic structure. The separation structure of solid solution, reticulate vein and disseminated structure. The Co/Ni of pyrite in Tongchang-type orebody ranges from 0.51-1.74 with an average of 1.062, indicating the characteristics of sedimental-diagenetic genesis. The Co/Ni of pyrite in the Jianshan orebody is 2.65, which indicates that the hydrothermal process is. 4. The study of sulfur isotope shows that the 未 34S of the orebody of Tongchang type is distributed discretely and has the characteristics of sedimentary genesis. The distribution of 蟽 34S in the Jianshan orebody is relatively limited and has the characteristic of typical magmatic sulfur. The quarter-type sulfur source comes from deep and is mixed by shallow sulfur to some extent. The lead isotope study shows that the Pb isotopic data of sulphide in Tongchang deposit are scattered, the range of variation is large, and the radiogenic Pb is very high. The source of lead is complex. 6. The ore-forming material of Tongchang-type orebody comes from strata and is influenced by hydrothermal solution in later stage. The orebody is controlled by strata, lithology and lithofacies paleogeography, and the ore-forming age is consistent with that of ore-bearing strata, and the ore-forming material of Jianshan orebody originates from the deep, and the orebody is influenced by structure and lithology. The metallogenic epoch is Jinning period. The ore-forming model of copper deposit in this mine is a sedimentary diagenetic deep-source hydrothermal superposition metallogenic model.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.41

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