新构造运动对加吾金矿床赋存状态的影响研究

发布时间：2018-03-13 18:33

本文选题：加吾　切入点：青藏高原隆升　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：加吾金矿位于青海省同德—泽库印支期Au、Ag、As、Sb、Hg成矿带上,经历多期造山运动,成矿条件优越并经多年和多个单位的勘查与勘探,认为经进一步勘探可以取得大的找矿突破。但2008-2011年武警黄金部队在矿区进行金矿勘探工作中,施工的探槽、探坑及钻孔见矿效果均不理想,初步分析认为可能与青藏高原新生代以来强烈隆升背景下,矿区新构造运动对矿体的破坏效应有关。为摸清加吾矿区找矿前景,研究矿区新构造运动特征及其对金矿体的破坏效应,对于下一步的勘探工作科学、合理的部署具有重要的理论与工程意义。论文在对矿区地质、地球化学及构造特征分析的基础上,通过研究青藏高原隆升以来矿区断裂的新构造活动特征,以期揭示断裂活动对矿体的破坏效应。取得主要认识结果如下:1、矿区一带地形地貌及构造变形受区域I、II两级断裂控制,崩塌、滑坡、泥石流及围岩变形等不良地质现象十分普遍,深切沟谷及谷中谷、多层套叠洪积扇、多级阶地等构造地貌十分发育,新生代以来在青藏高原剧烈隆升环境下新构造运动十分强烈。2、矿区一带元素地球化学场、地球化学综合异常、矿体赋存条件及成矿过程分析均显示对于金成矿十分有利,加吾矿区具有优越成矿背景及良好的找矿前景,且深部找矿潜力巨大。3、矿区内NW-NNW向和近EW向两组断裂是主要的控矿构造,并可分为III、IV、V三个级别,多级断裂联合控制矿体的产出。新生代以来,这些断裂在NE方向的最大主压应力作用下,以发生逆冲和右行走滑活动为主,并且在第四纪30万年以来有过活动。4、断裂的新构造活动对矿体的破坏效应表现为通过逆冲、正断或是走滑的运动方式使矿体不同程度变形甚至直接错断,最大断错位移超过3m。破矿效应具体分为三类:一为由于断裂的切割及活动使基岩坡体、矿体发生变形、弯曲甚至反倾;二为断裂逆冲、正断或是走滑活动直接将矿体错断,使得矿体在深部的分布不具备连续性和规律性;三为强烈的剪切作用使矿体的产出形态并不规整而多为香肠状或透镜体状,局部地段减薄尖灭。因此依据矿体地表产状设计的平硐、钻孔等工程,在对矿体进行揭露时,往往不见矿。5、针对上述情况,提出下一步金矿勘探工作部署中,增加钻孔、平硐、槽探布置密度,并开展深部钻探;同时开展大比例尺的综合地球物理、地球化学勘探工作,并配合以同比例尺的地表岩石地球化学测量,以期指导深部钻探验证。
[Abstract]:The Jiawu gold deposit is located in the Augnian-Zecu Indosinian Au-Ag-As-Sb-Hg metallogenic belt in Qinghai Province. It has undergone many orogenic periods and favorable metallogenic conditions, and has undergone many years of exploration and exploration by several units. It is considered that a great breakthrough in prospecting can be achieved through further exploration. However, in the gold exploration work carried out by the Armed Police Gold Army in the mining area from 2008 to 2011, the effect of prospecting trough, hole and borehole in construction is not satisfactory. The preliminary analysis suggests that it may be related to the destructive effect of neotectonic movement on orebodies in the context of the strong uplift of the Qinghai-Tibet Plateau since the Cenozoic. It is of great theoretical and engineering significance to study the characteristics of neotectonic movement and its destructive effect on gold ore bodies for the next step of exploration. Based on the analysis of geochemical and tectonic characteristics, the characteristics of neotectonic activity of mining area faults since the uplift of the Qinghai-Xizang Plateau have been studied. The main results are as follows: 1. The topographic landforms and structural deformation in the mining area are controlled by the two grade faults of the area I ~ (II), collapse, landslide, and so on, the main results of which are as follows: (1) the main results are as follows: 1. The bad geological phenomena such as debris flow and surrounding rock deformation are very common, the deep gully and the middle valley, the multi-layer superimposed flood fan, the multilevel terrace and other structural landforms are well developed. Since the Cenozoic, the neotectonic movement is very strong in the environment of violent uplift of Qinghai-Xizang Plateau. The geochemical field of elements in the ore area, geochemical comprehensive anomalies, the occurrence conditions of orebodies and the analysis of ore-forming process all show that it is very favorable for gold mineralization. Jiawu ore area has superior metallogenic background and good prospecting prospect, and deep prospecting potential is huge. The NW-NNW and near EW faults are the main ore-controlling structures, and can be divided into three grades. Since the Cenozoic, these faults, under the action of the largest principal compressive stress in the NE direction, have been dominated by thrusting and right-strike-slip activities. Moreover, since the Quaternary period, there have been some activities. 4. The failure effect of the neotectonic activity of the fault on the orebody is that the orebody is deformed or even directly broken by thrust, positive fault or strike-slip motion. The maximum fault displacement is more than 3 m. The ore breaking effect can be divided into three categories: one is that the bedrock slope body is deformed, bent or even reversed due to the cutting and activity of the fault, the other is the fault thrust, the direct fault or the strike-slip activity directly disconnecting the orebody. The distribution of the orebody in the deep is not continuous and regular, the third is that the strong shear action causes the ore body to produce irregular shape, but mostly sausage or lens. Therefore, according to the orebody surface occurrence design of adit, drilling and other projects, when the orebody is exposed, there is often no ore .5. in view of the above situation, it is put forward that in the next step of gold exploration deployment, additional boreholes and adit should be added. At the same time, the integrated geophysical and geochemical exploration on a large scale is carried out, and the geochemistry survey of surface rocks on the same scale is carried out in order to guide the verification of deep drilling.
【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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