内蒙古哈达门沟金矿区控矿构造特征研究

发布时间：2018-02-21 01:25

本文关键词： 哈达门沟构造变形控矿构造特征叠瓦状逆冲推覆构造　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：哈达门沟金矿区经历了漫长而复杂的地质演化,形成了多期次、多阶段的构造,这些构造严格控制着金矿脉的形成和演化。然而,长期以来对矿区构造的研究一直是相对薄弱的环节,对控矿构造的研究也有待深入推进。因此,研究哈达门沟金矿区的控矿构造特征,可以加强对该区构造变形特征的正确认识,有助于更清晰地认识该区内控矿构造对金成矿的影响,进而更好地服务于国家在该矿区的整装勘查工作。本论文以构造地质学相关基本论为指导,通过野外实测剖面、钻孔岩芯编录、样品系统采集并结合室内综合测试方法,主要取得以下认识:本区构造变形可识别出五期:第一期为韧性剪切变形,形成了韧性剪切带、柔流褶皱及矿物拉伸线理等;第二期为侧向挤压变形,形成了以乌拉山复背斜为代表的第二期褶皱、山前大断裂、山前钾化带所在断层及部分节理等;第三期为挤压变形,形成了第三期褶皱、逆冲推覆断层(很可能是叠瓦状逆冲推覆断层)、部分节理等;第四期为拉张变形,先期逆冲推覆断层遭受拉伸而张开,接受含金热液充填;第五期为伸展走滑变形,形成了破矿断层体系和部分节理等。以EW向1km的间距大量统计矿区内主要金矿脉中心线之间NS向的距离,获得相邻矿脉之间在NS向的距离集中在528m~564m之间,平均为543.5m,显示出金矿脉在平面上分部具有等间距性;钻孔勘探线剖面图和可控源大地电磁测量(CSMAT)剖面图显示出在剖面上,金矿脉在浅表倾角较大,往深部逐渐变缓有交汇趋势,因此容矿断层很可能为继承于先期(叠瓦状)逆冲推覆断层之上的正断层。破矿断层主要沿NW向、NE向及NNE向展布,大部分分布在大坝沟所在的F116断层的NE侧,很可能受到了F116断层的阻挡。控矿构造特征为:NEE向山前大断裂为矿区内控制性构造,各种岩脉和金矿脉充填在次级断层中。印支期早期,古亚洲洋向华北北缘俯冲消减,山前大断裂北侧形成了一系列近EW向的(叠瓦状)逆冲推覆断层,到印支-燕山期,华北北缘由同碰撞造山转为碰撞后张性环境,研究区发生构造反转,(叠瓦状)逆冲推覆断层遭受拉伸而张开,接受大规模含金钾质热液充填交代而形成金矿脉。
[Abstract]:The Hadamenggou gold deposit has undergone a long and complicated geological evolution, forming multi-stage and multi-stage structures, which strictly control the formation and evolution of gold veins. The study of ore-controlling structure has been a relatively weak link for a long time, and the study of ore-controlling structure needs to be further promoted. Therefore, the characteristics of ore-controlling structure in the Hadamenggou gold deposit are studied. It can strengthen the correct understanding of the structural deformation characteristics in this area and help to understand more clearly the influence of the internal ore-controlling structure on the gold mineralization. This paper is guided by the basic theory of tectonics geology, through field measurement section, drilling core cataloguing, sample system collection and combined with indoor comprehensive test method. The main results are as follows: the tectonic deformation in this area can be identified as five stages: the first stage is ductile shear deformation, forming ductile shear zone, soft flow fold and mineral stretching line, and the second stage is lateral compression deformation. The second stage of the fold represented by the Wulashan complex anticline, the large fault in front of the mountain, the fault and some joints of the kalitization belt in front of the mountain, etc., the third stage is the compression deformation, and the third stage is the fold of the third stage. Thrust nappe faults (most likely imbricate thrust nappe faults, partial joints, etc.); stage 4th, tensile deformation, pre-thrust nappe faults, which were stretched and opened, accepted gold-bearing hydrothermal filling; stage 5th, extensional strike-slip deformation, The breaking fault system and some joints were formed. The distance between the main gold veins in the mining area was counted by the distance of 1 km in EW direction, and the distance between the adjacent veins in NS direction was found to be between 528 m and 564 m. The average value is 543.5 m, which shows that the gold vein has equal spacing in the plane, and the borehole exploration line profile and the controlled source magnetotelluric survey (CSMATT) profile show that the gold vein has a large dip angle in the shallow surface and a tendency to converge gradually to the depth. Therefore, the ore-bearing fault is probably a normal fault inherited from the pre-stage (imbricate) thrust nappe fault, which is mainly distributed along the NW-trending NE and NNE directions, most of which are distributed in the NE side of the F116 fault located in the dam trench. The ore-controlling tectonics are characterized by the ore-controlling tectonics: the large fault in front of the mountains is the controlling structure in the mining area, and all kinds of veins and gold veins are filled in the secondary faults. In the early Indosinian period, the paleo-Asian ocean subducted to the northern margin of North China and subducted and subducted into the northern margin of North China. A series of near-EW (imbricate) thrust nappe faults were formed on the north side of the large fault front of the mountains. By the Indosinian to Yanshanian period, the northern part of North China was transformed into a post-collision extensional environment along with the collision orogeny. The tectonic inversion (imbricate) thrust nappe fault in the study area was stretched and opened, and the gold vein was formed by large scale hydrothermal filling of gold bearing potassium.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.51

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