陕西省小秦岭金矿区典型北东向剪切带构造与矿化特征研究

发布时间：2018-03-19 10:10

本文选题：剪切变形带　切入点：北东向矿脉　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：小秦岭金矿区位于华北板块南缘,是我国第二大金矿区。金矿区内广泛发育剪切变形带,有近东西向、北东向、近南北向以及北西向等多组走向,并且脉体的发育受剪切变形带所控制。其中,近东西向剪切变形带中的含金石英脉发育数量最多、规模较大、矿化特征最明显;北东向矿脉规模次于近东西向矿脉,其数量和规模较近南北向以及北西向矿脉多。早期对近东西向剪切带的特征研究较多,对其构造以及矿化特征研究程度较深,而对于北东向剪切带的构造与成矿特征以及与东西向剪切带的构造关系等方面的认识并不清晰。北东向剪切带的走向在30-60°之间,倾向有北西向以及南东向,按照其倾角又可以大致分为以70°左右为主的北北东走向与以30°左右为主的北东东走向剪切带,两组方向的剪切带在构造特征方面具有各自的特征;在矿化特征方面,两组矿脉的矿物组合类型以及矿化的主要阶段也有差异。本文选取北东向的剪切带开展研究,运用构造地质学、矿物学等学科的研究方法,主要研究了北东向剪切带的几何学、运动学特征及动力学背景;研究了北东向脉体的矿化类型以及矿物组合,并通过对样品进实验处理来探讨其成矿阶段以及矿化特征。通过对Q505、Q401、Q154、Q110、Q185、Q881、Q240等多条北东向矿脉所在的剪切带在地表和在不同中段的构造特征与矿化特征的研究认为:(1)北东向剪切带根据构造特征可以分为北东东与北北东走向的剪切带,并且剪切带控制石英脉透镜体呈雁列式排列。北东东向剪切带,倾向以北西为主。运动特征以中低角度的逆冲作用为主,兼有左行走滑运动,其形成受到区域上北西向挤压力的作用。北北东向剪切带倾向有南东向和北西向。运动特征以左行走滑为主,兼有高角度的逆冲运动,其形成受到区域上北北西向挤压力的作用。(2)北东东走向的矿脉的矿化特征以黄铁矿化为主,矿化呈带状或者沿构造面理分布,成矿热液阶段属于第二阶段的石英-黄铁矿化阶段,矿床为中高温矿床。北北东向矿脉的矿化类型为硫多金属矿化,矿化以带状或沿构造面理发育,成矿阶段属于第三期的石英-硫多金属矿化阶段,矿床为中高温矿床。
[Abstract]:The Xiaoqinling gold deposit area is located in the southern margin of the North China plate and is the second largest gold deposit in China. The development of vein body is controlled by shear deformation zone, in which the gold-bearing quartz vein in the near east-west shear deformation zone has the largest number, larger scale and the most obvious mineralization characteristics, and the north-east vein is inferior to the near east-west vein. The number and scale of the ore veins are more than those of the near north-south direction and the north-west direction. In the early stage, the characteristics of the near-east-west shear zone were studied more, and the structural and mineralized characteristics of the shear zone were studied more deeply. However, the structural and metallogenic characteristics of the NSE shear zone and the tectonic relationship with the EW shear zone are not clear. The NSE shear zone tends to strike between 30 掳and 60 掳, and tends to be NW and SE. According to its inclination angle, it can be roughly divided into NNE strike with about 70 掳and east-west shear zone with about 30 掳. The two groups of shear zones have their own structural characteristics and mineralization characteristics. The types of mineral assemblages and the main stages of mineralization are also different between the two groups. In this paper, we select the NE-trending shear zone to carry out research, and use the methods of tectonic geology, mineralogy and other disciplines to study the geometry of the NE-trending shear zone. The mineralization types and mineral assemblages of the NE vein are studied. The metallogenic stage and mineralization characteristics of Q505N Q401C Q401C Q154N Q110Q185Q185Q881N Q240 are discussed by means of sample processing. The tectonic and mineralized characteristics of the shear belts located on the surface and in different middle sections of the ore veins are considered to be north of Q505Q401C / Q154Q10Q185Q881 / Q240 and the study of the structural and mineralized characteristics of the ore-forming zone on the surface and in different middle segments. According to the structural characteristics, the east-trending shear zone can be divided into the shear zone of east-west and the NNE strike. The shear zone controls the arrangement of quartz vein lens in the form of geese. The north east-west shear zone tends to be north-west. The movement is characterized by low-and low-angle thrust and left-lateral strike-slip motion. The formation of the shear zone is influenced by the extrusion force in the upper NW direction of the region. The NNE shear zone tends to be south to east and north to west. The movement is mainly left strike-slip with a high angle thrust movement. The mineralization characteristics of the vein in the east-west strike are mainly pyrite, and the mineralization is zonal or distributed along the tectonic plane. The ore-forming hydrothermal stage belongs to the second stage of quartz-pyrite mineralization, and the ore deposit is of medium and high temperature. The mineralization type of NNE vein is sulfur polymetallic mineralization, and the mineralization is zonal or along the tectonic plane. The ore-forming stage belongs to the third stage of quartz-sulfur polymetallic mineralization.
【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】：2017
【分类号】：P618.51

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