陕西省宁强县火峰垭金矿床地质特征及控矿因素分析

发布时间：2018-04-18 02:09

本文选题：金矿床 + 地质特征　；参考：《成都理工大学》2017年硕士论文

【摘要】：火峰垭金矿床位于勉略宁地区,是陕西有名的“金三角”,区内矿产资源丰富,其东部地区已发现多个中—大型金多金属矿床,特别是金矿的发现,体现了该区良好的金矿找矿前景。本文以矿床学为基础,在对矿区进行详细的野外地质调研和大量的前人资料综合整理的前提下,采用搜集研读前人工作资料、野外地质调查、室内分析等工作手段,在区域地质背景、矿区地质特征、矿体特征研究的基础上,对火峰垭地区金矿的控制因素进行了分析,得到如下结论:通过大量矿区地质调查结合区域金矿研究成果认为,火峰垭金矿床的成因类型属海相火山沉积—后期构造热液型金矿床。大量勘探成果表明,矿体主要是受地层、岩性及韧性剪切构造控制,个数多,规模小,呈脉状,分段集中,平行斜列产出。矿体受后期构造裂隙的控制,金矿体产状与地层产状呈20°~50°斜交,矿体倾角较陡。通过大量矿体地质特征研究,矿体主要有石英脉型金矿石和细碧岩型金矿石,以石英脉型为主。地层控制了矿体的产出。Pt2-3Bk22-2b层为中基性火山岩建造。该层中金元素异常明显,金元素含量高,是区内重要的矿源层和含金母岩。金矿体受岩性控制的特征也较明显,均为糜棱岩化细碧岩。在结合区域成矿背景、区域构造演化史及矿区构造特征的基础上认为,构造剪切带是良好的导矿、容矿通道。晋宁期皱变形,形成成为良好的矿液通道,为后期成矿奠定了基础;澄江期发生强烈的挤压事件,形成良好的矿液通道;侵入大量的基性—中酸性岩体、岩脉,为成矿物质的活化迁移提供了良好的动热条件。深部的糜棱岩化作用使得Au等组分及其它成矿元素一起被活化分异形成含矿热液;近地表的不同部位形成相应蚀变糜棱岩型、构造蚀变岩型和石英脉型金矿化,从而造成不同类型金矿化的叠加。岩浆活动提供了部分成矿物质来源,并促使了后期元素的富集成矿。古大陆裂解时期,中—基性岩体的侵入,为本区内生金属矿床的形成奠定了成矿物质基础。岩浆上侵活动带来的热能可使岩体的围岩中的溶液升温,成矿物质发生活化,直接形成或参与形成成矿溶液,然后运移、富集成矿。通过矿区内找矿标志研究认为,金矿体与石英脉密切相关,特别是北北东向一组石英脉与矿化关系最为密切。围岩蚀变与金矿化密不可分,而黄铁矿化与金矿化关系则更为密切,黄铁矿含量多少直接决定金矿体品位的高低变化,是寻找金矿体重要标志。糜棱岩化细碧岩是寻找含金蚀变细碧岩的间接标志。片理化带及其次一级构造发育地段及见有石英脉斜切地层,产状急剧变化地段是金富集的有利部位。
[Abstract]:The Huofengya gold deposit is located in the Mianliuoning area and is a famous "golden triangle" in Shaanxi Province. The area is rich in mineral resources. In the eastern part of the area, many medium-large gold polymetallic deposits, especially gold deposits, have been discovered.It reflects the good prospect of gold prospecting in this area.On the basis of ore deposit science, on the premise of detailed field geological investigation and comprehensive collation of a large number of previous data, this paper adopts the working methods of collecting and studying previous work data, field geological survey, indoor analysis and so on.Based on the study of regional geological background, geological characteristics of mining area and orebody characteristics, the controlling factors of gold deposit in Huofengya area are analyzed. The conclusions are as follows: through a large number of geological surveys of mining areas combined with regional gold ore research results, it is considered that,The genetic type of Huofengya gold deposit is marine volcanic sedimentary-late tectonic hydrothermal gold deposit.A great deal of exploration results show that the orebodies are mainly controlled by strata lithology and ductile shear structures with large number small scale vein shape segmental concentration and parallel oblique production.The orebody is controlled by the late structural fissures. The occurrence of gold orebody is 20 掳/ 50 掳oblique, and the dip angle of the orebody is steep.Through the study of the geological characteristics of a large number of orebodies, the orebodies mainly consist of quartz vein type gold ore and fine blue rock type gold ore, mainly quartz vein type.The formation controls the formation of the orebody. Pt2-3Bk22-2b is a medium-basic volcanic rock formation.It is an important source bed and mother rock of gold bearing in this area, because of the obvious anomaly of gold elements and the high content of gold elements.The characteristics of gold orebodies controlled by lithology are also obvious, they are mylonitic fine-blue rocks.On the basis of the regional metallogenic background, the history of regional tectonic evolution and the structural characteristics of the mining area, it is considered that the tectonic shear zone is a good ore-conducting and ore-accommodating channel.In Jinning period, it was wrinkled and deformed and formed into a good ore-liquid channel, which laid a foundation for late mineralization. In Chengjiang period, a strong extruding event formed a good ore-liquid channel, and intruded into a large number of basic-intermediate-acid rock masses and veins.It provides a good dynamic thermal condition for the activation and migration of ore-forming materials.The deep mylonitization causes au and other metallogenic elements to be activated and differentiated together to form ore-bearing hydrothermal solution, and the corresponding altered mylonite type, tectonic altered rock type and quartz vein type gold mineralization are formed in different parts near the surface.This results in the superposition of different types of gold mineralization.Magmatic activity provides a partial source of ore-forming materials and promotes the enrichment of elements in the late stage.During the pyrolysis of the Paleocontinent, the intrusions of the meso-basic rock bodies established the ore-forming basis for the formation of the endogenic metal deposits in this area.The thermal energy brought by the magmatic intrusion can heat up the solution in the surrounding rock mass, activate the ore-forming material, directly form or participate in the formation of the ore-forming solution, and then migrate and enrich the ore-forming solution.It is considered that gold ore body is closely related to quartz vein, especially a group of quartz veins in NNE direction, which is most closely related to mineralization.The alteration of surrounding rock is closely related to gold mineralization, while pyrite mineralization is more closely related to gold mineralization. The content of pyrite directly determines the change of gold ore body grade, which is the mark of seeking gold ore body weight.Mylonitization is an indirect sign of seeking gold-bearing altered rock.The sheet physicochemical belt and its secondary tectonic development area and quartz-vein oblique cut strata are favorable for gold enrichment.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.51

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