青海省加吾金矿构造地球化学特征及深部成矿潜力分析

发布时间：2018-05-08 20:08

本文选题：青海加吾金矿 + 元素地球化学场　；参考：《长安大学》2015年硕士论文

【摘要】：位于青藏高原东北部同德—泽库印支期铜、铅、金成矿带中的加吾金矿,是武警黄金部队在前人工作基础上,经战略地质调查及预查工作中所发现,并认为经进一步勘探工作可取得更大找矿突破。但2008~2011年武警黄金部队在该矿区开展的勘探中,施工的探槽、探坑及钻孔见矿效果均不理想,因此对该区找矿前景产生很大质疑。本文在充分收集、整理和研究前人资料的基础上,结合野外实地调查结果,开展了加吾金矿所在区域及矿区的构造地球化学特征研究,分析了矿区深部成矿潜力,以期为矿区下一步工作部署提供依据。最终获得如下成果:(1)区域1:20万地球化学特征研究结果表明:该区中下三叠统隆务河组(T1-2l)地层中,Au、As、W、Sb、Hg、Bi等元素呈相对富集状态且离散程度较大,说明其是具有寻找金矿、钨矿、锑矿潜力的赋矿地层单元;区域内元素组合主要分为中低温成矿元素和中高温成矿元素两群,两群元素间相关性较弱,反映本区域至少经历中低温和中高温两期成矿热液活动。其中,中温成矿元素与铁族元素相关性较强,反映中温成矿热液活动与深部热液关系密切,也指示本区域具有深部物质的迁移与活动;区域元素地球化学场特征显示,区域断裂对元素地球化学场的分布具有明显控制作用,且加吾金矿所在的唐乃亥-加日亥地区发育中低温、中温成矿元素以及铁族等多种元素组合,表明该地区具有成矿热液叠加的现象,且深部热液在一定程度上参与了成矿。(2)矿区地质特征研究结果表明:矿区中下三叠统隆务河组的碳质板岩夹变质砂岩段(T1-2l3)中矿化蚀变强,是矿区的主要赋矿层;NW向和EW向断裂控制矿体的产出,为研究区主要控矿、容矿断裂;矿区岩浆岩主要为印支期花岗闪长岩体和花岗斑岩脉,均与成矿关系密切;矿区已圈出18条矿脉,走向与矿区断裂带发育方向一致,体现了构造对成矿的控制作用。(3)矿区化探异常特征研究结果表明:加吾金矿区Au、Ag、As、W、Sb等中低温成矿元素重合性较好,异常浓集中心明显;而Pb、Zn等中温成矿元素重合性好,其浓集中心与中低温成矿元素偏离,指示该异常区至少有中低温、中温两期成矿热液活动;此外,中低温成矿元素具有多级异常,而中温、高温元素只具有一级异常,说明该异常区深部可能有矿体存在,且矿体未遭到剥蚀。(4)矿区构造地球化学特征研究结果表明:矿区断裂破碎带及石英脉中Au、Ag、Cd、Hg、Zn、Pb、Sb等元素相对富集且分布不均匀,说明这些元素在矿区石英脉及断裂破碎带中局部富集成矿的可能性极大,矿区断裂破碎带以及充填石英脉的裂隙对成矿具有控制作用;矿区元素共生组合特征与区域相似,表明矿区至少经历低温和中温两期热液活动,且深部热液在一定程度上参与了成矿;矿区构造样与矿化样中元素的富集变化特征和共生组合特征相似,与非矿化样差异较大,显示矿床成矿受构造控制明显;分析矿区三条地球化学剖面可知,凡断裂发育处,岩石中Au的含量值均较大,且多处达到边界品位以上,反映断裂对成矿元素的迁移和富集具有良好控制作用;以线金属量衬度法分别计算各剖面水平分带可知,矿区含矿热液运移方向为由西南至东北,岩浆活动为成矿提供物质来源。(5)加吾金矿所在区域的元素共生组合及元素地球化学场分布等区域地球化学特征,以及矿区的化探异常、元素共生组合、构造地球化学以及稀土元素地球化学等矿区地球化学特征,均反映该区具有良好的深部成矿潜力;矿区已发现具有热液沸腾现象的热液角砾岩,以及脉状-网脉状矿石,应用深部成矿理论推测,矿区深部有形成大型成层状矿体的可能。
[Abstract]:Located in the northeastern part of the Qingzang Plateau, the gold deposits in the copper, lead and gold metallogenic belts in the Indo Zeku period of the eastern Qinghai Tibet Plateau are found on the basis of predecessors' work and found in the work of strategic geological investigation and pre investigation. The gold troops of the armed police force have been carried out in this mining area in 2008~2011. In the exploration, the exploration slots, pits and holes in the construction are not ideal, so there is a great challenge to the prospect of prospecting in this area. On the basis of fully collecting, sorting and studying the data of the predecessors, combining the field investigation results, we have carried out the study of the tectonic geochemistry characteristics of the region and mining area of the gold mine, and analyzed the mining area. The deep metallogenic potential can provide the basis for the next work deployment in the mining area. The results are as follows: (1) the result of the study on the geochemical characteristics of the 1:20 million in the region shows that the elements of Au, As, W, Sb, Hg and Bi are enriched and dispersed in the middle and lower middle three strata of the Long Wu River Formation (T1-2l). The mineral and antimony ore potential is the ore bearing stratum unit; the element combination in the region is mainly divided into two groups of middle and low temperature metallogenic elements and middle and high temperature metallogenic elements, and the correlation between the two groups is weak, reflecting the region at least experienced middle and middle temperature and middle and high temperature hydrothermal fluids. The activity of mineral hydrothermal activity is closely related to deep hydrothermal fluid, and it also indicates the migration and activity of deep material in this area, and the characteristics of regional element geochemical field show that the regional fracture has a clear control effect on the distribution of the element geochemistry field, and the middle temperature and middle temperature metallogenic elements are developed in the Tang Naihai - Jia - hi-hai region, which is located in the gold mine. The combination of the iron group and other elements indicates that the area has the superposition of metallogenic hydrothermal solution, and the deep hydrothermal fluid has been involved in the mineralization to some extent. (2) the study of geological characteristics of the mining area shows that the mineralization and alteration of the carbonaceous slate sandstone section (T1-2l3) of the middle and lower three superposition of the Long Wu formation of the mining area is strong and altered, which is the main ore bearing layer of the mining area; NW direction and EW The output of the fault control ore body is the main ore control and ore bearing fracture in the study area. The magmatic rocks in the mining area are mainly the Indosinian granodiorite and granite porphyry veins, which are closely related to the mineralization; the mining area has been circling 18 veins, and the direction is consistent with the development direction of the mining area. (3) geochemical anomalies in mining area The results of the study show that the middle and low temperature metallogenic elements of Au, Ag, As, W and Sb in gucin mining area are good, and the center of abnormal enrichment is obvious, while Pb, Zn and other middle temperature mineralization elements have good recoincidence and the concentration center deviates from the middle and low temperature metallogenic elements, indicating that the anomalous area has at least middle and low temperature, and the middle temperature two phases of metallogenic hydrothermal activity; in addition, medium and low temperature metallogenic elements. There is a multilevel anomaly, and the medium temperature and high temperature elements only have first order anomaly, which indicates that there may be ore bodies in the deep part of the anomaly area and the ore body is not denuded. (4) the results of structural geochemical characteristics of the mining area show that the elements of Au, Ag, Cd, Hg, Zn, Pb and Sb in the fractured zone and quartz vein of the mining area are enriched and distributed unevenly, indicating that these elements are not evenly distributed. The possibility of eutrophication in the quartz vein and fracture zone of the mining area is great. The fracture fracture zone and the fissures filled with quartz veins have control effect on the mineralization, and the symbiotic combination characteristics of the mining area are similar to those of the region, indicating that the mining area at least experienced the two phases of hydrothermal activity at low temperature and middle temperature, and the deep hydrothermal solution is certain to some extent. Metallogenesis and mineralization are similar to those of the elements in the mining area and the mineralized samples, which are similar to the characteristics of the accumulation and variation of the elements and the characteristics of the non mineralized samples, which show that the ore deposit is controlled obviously by the structure. The analysis of three geochemical profiles in the mining area shows that the content of Au in the rock is higher than that in the rock, and many places are above the boundary grade. The reflection fracture has a good control effect on the migration and enrichment of the metallogenic elements. It is known that the migration direction of ore bearing hydrothermal fluid is from southwest to northeast, and the magmatism provides material source for mineralization. (5) the element symbiotic assemblage and elemental geochemical field in the region of the gold mine where the gold mine is located. The geochemical characteristics of the area, geochemical anomalies in the mining area, the symbiotic combination of elements, the tectonic geochemistry and the geochemistry of rare earth elements all reflect the good deep metallogenic potential in this area, and the hydrothermal breccia with hydrothermal boiling, and the pulse network vein ore have been found in the mining area. According to the metallogenic theory, it is possible to form large stratified orebodies in the deep part of the mining area.

【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.51

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