黑龙江铜山断裂的变形特征及铜山铜矿床蚀变带-矿体重建

发布时间：2018-01-24 16:50

  本文关键词： 铜山斑岩矿床 铜山断裂 变形特征 蚀变带-矿化体重建　出处：《岩石学报》2017年02期 　论文类型：期刊论文

【摘要】：黑龙江铜山铜矿床系多宝山铜矿田的重要组成部分,它和多宝山矿床同是中亚造山带东段最古老的斑岩铜矿床(奥陶纪)。铜山断裂为铜山斑岩铜矿床内最为重要的一条成矿后断裂,它截切矿体和蚀变带,因而导致矿化中心、深部找矿方向不明。现阶段的研究对其运动学特征还存有较大争议,缺乏对该带变形特征与性质的细致观察与鉴别。据此,本文开展详细地野外及室内研究工作,取得如下新认识:1)铜山断裂为近东西走向的压扭性断裂,最典型的构造几何学特征为发育北东-北东东走向劈理、构造透镜体、以及岩脉及热液脉扭曲现象。2)断裂带内石英、黄铜矿、黄铁矿、闪锌矿的镜下变形特征和石英C轴组构特征显示低温变形条件,依据矿物和岩石变形特点判断铜山断裂主体为脆性断裂。3)构造解析表明铜山断裂运动学特征为:上盘由南东向北西方向斜向逆冲。综合断裂上、下盘地质体界线、蚀变和脉系分布特征等,判断上盘相对下盘大致沿NW320°方向水平移动距离700~800m,垂向抬升550~700m,错开蚀变外带(青磐岩化带、石英-绢云母-伊利石-绿泥石化带)和矿化带。4)铜山断裂的次级断裂截切了中晚三叠世白云母花岗岩,推测铜山断裂活动时限晚于中晚三叠世。5)复原铜山断裂上盘和下盘的空间位置至铜山断层活动前,重建铜山铜矿床蚀变带-矿化体,初步判断铜山断裂活动前铜山矿床为纺锤形态。根据重建后矿化和蚀变的分布规律推断下盘Ⅲ号矿体的南侧位置应有尚未发现的成矿斑岩和矿体,为深部找矿提供了依据。
[Abstract]:The Tongshan copper deposit in Heilongjiang province is an important part of the Dobaoshan copper deposit. It is the oldest porphyry copper deposit in the eastern part of the Central Asian orogenic belt (Ordovician). The Tongshan fault is the most important post-metallogenic fault in the Tongshan porphyry copper deposit. As a result, the direction of deep prospecting in the mineralization center is not clear. The present research on the kinematic characteristics of the zone is still controversial and lacks careful observation and identification of the deformation characteristics and properties of the zone. In this paper, detailed field and laboratory studies have been carried out to obtain the following new understanding: 1) the Tongshan fault is a compression-torsional fault with a nearly east-west strike, and the most typical structural geometry is the cleavage of the east-north strike. The deformation characteristics of quartz, chalcopyrite, pyrite and sphalerite in the fault zone and the texture of quartz C-axis in the tectonic lens, as well as in the twisting of the veins and hydrothermal veins, show the low temperature deformation conditions. According to the characteristics of mineral and rock deformation, the main body of Tongshan fault is brittle fault. 3) structural analysis shows that the kinematics characteristics of Tongshan fault are as follows: the upper face is inclined thrust from south east to north west, and the Synthetical fault is on. The geological boundary, alteration and the distribution characteristics of vein system in the lower face are estimated to be 700 ~ 800m and 550 ~ 700m, respectively, and the distance of horizontal movement of the upper face relative to the footwall is about 700 ~ 800m along the direction of NW320 掳, and the vertical uplift is 550 ~ 700m. The secondary faults of the Tongshan fault in the staggered alteration outer zone (Qingwanglianlization zone, quartz-sericite Illite-green mud petrochemical belt) and mineralized zone. 4) cut off the Middle-Late Triassic Muscovite granite. It is inferred that the time limit of Tongshan fault activity is later than that of middle and late Triassic. 5) the spatial position of upper and lower face of Xiongtongshan fault is before the Tongshan fault, and the alteration zone-mineralization body of Tongshan copper deposit is reconstructed. According to the distribution law of mineralization and alteration after reconstruction, it is inferred that there should be ore-forming porphyry and ore-body that have not been discovered in the south side of orebody 鈪，

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