柞水县杨木沟斑岩型钼矿围岩蚀变特征研究

发布时间：2018-10-23 20:54

【摘要】：蚀变围岩作为斑岩钼矿矿床的重要特征之一,备受学者们重视。蚀变围岩的物理化学条件和热液性质为推断矿床的演化、成矿元素的迁移、富集、矿石沉淀及丰富成矿理论提供了有力的证据。同时,蚀变岩也可以作为重要的找矿标志。论文以陕西省柞水县杨木沟钼矿床为研究对象,在矿区地质资料收集、野外地质调查与矿石系统采样的基础上,室内借助反光显微镜鉴定、电子探针分析和岩石地球化学测试等现代地质学分析手段,获得了围岩蚀变矿物化学成分、主量元素地球化学、微量元素地球化学等数据,确定了矿床蚀变类型及蚀变分带,查明各期蚀变事件的产出环境及所引起的矿化现象,总结了找矿标志,并分析了矿床的成因。研究结果认为：杨木沟斑岩钼矿床围岩蚀变类型主要为硅化、钾长石化、黑云母化、绢英岩化、绿泥石化、泥化及青磐岩化。其中辉钼矿化与硅化、钾长石化关系最为密切。矿化现象明显受到地质构造的控制,矿体主要集中于fl与f2构造蚀变带之间和其临近的上下盘附近,并与构造带产状一致。蚀变矿物中Si、K含量很高,说明Mo的富集异常跟石英脉密切相关。在热液入侵过程中有Cu、Zn、Ni、Co、V、 Nb、Sc、Ba等元素的带出,有Pb、Ag、Hf、Zr等元素的带入,说明围岩蚀变在不同温度环境都有发生。在δEu—Sr图中发现,矿区引起围岩蚀变的热流体主要来自于壳源,但也受到幔源的微弱影响。地表的负地形、石英脉、褐铁矿矿化带可作为直接的找矿标志。
[Abstract]:As one of the important characteristics of porphyry molybdenum deposit, altered surrounding rock is paid more attention by scholars. The physicochemical conditions and hydrothermal properties of the altered surrounding rock provide strong evidence for the inference of the evolution of the deposit, the migration and enrichment of ore-forming elements, the deposit of ore and the enrichment of ore-forming theory. At the same time, altered rock can also be used as an important prospecting marker. This paper takes Yangmugou molybdenum deposit in Zhashui County, Shaanxi Province as the object of study. On the basis of geological data collection, field geological investigation and ore system sampling, indoor identification is carried out by means of reflective microscope. By means of modern geological analysis, such as electron probe analysis and rock geochemistry test, the data of chemical composition of alteration minerals, geochemistry of major elements and geochemistry of trace elements are obtained, and the alteration types and alteration zones of the deposits are determined. The occurrence environment of alteration events and the mineralized phenomena caused by them are found out, the prospecting criteria are summarized, and the genesis of the deposits is analyzed. The results show that the alteration types of surrounding rock of Yangmugou porphyry molybdenum deposit are mainly silicification, potassium feldspar, biotite, sericite, greenstone, mudstone, mudstone and qinwanglitization. Molybdenum mineralization is most closely related to silicification and potassium feldspar. The mineralization phenomenon is obviously controlled by geological structure. The orebody is mainly concentrated between fl and f2 structural alteration zone and its adjacent upper and lower plates, and is consistent with the occurrence of tectonic zone. The high content of Si,K in altered minerals indicates that the enrichment anomaly of Mo is closely related to quartz veins. In the process of hydrothermal intrusion, Cu,Zn,Ni,Co,V, Nb,Sc,Ba and other elements are taken out, and elements such as Pb,Ag,Hf,Zr are brought in, which indicates that the alteration of surrounding rock occurs in different temperature environments. In the 未 Eu-Sr diagram, it is found that the heat flux caused by wall rock alteration in the mining area mainly comes from the crust source, but is also slightly affected by the mantle source. The surface negative topography, quartz vein and limonite mineralization zone can be used as direct prospecting markers.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.65

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