招平金矿带构造控矿机理及深部成矿预测

发布时间：2018-05-13 14:44

本文选题：构造控矿 + 构造样式　；参考：《中国地质大学(北京)》2017年博士论文

【摘要】：胶东是我国最重要的黄金基地,准确厘定该矿集区内控矿断裂带的浅表构造控矿型式与深部结构特征是金成矿理论研究与深部找矿实践亟待解决的重要课题。论文选取招平金矿带为研究对象,以金成矿系统形成的构造动力学过程与机理为主线,聚焦成矿构造样式与渗透性结构,研究招平金矿带构造控矿机理,构建构造控矿模式,进行深部成矿预测,获得以下主要成果:1、招平金矿带内金矿化样式可划分为韧性剪切带中浸染型、片理化带内蚀变岩型、脆性断裂带内碎裂岩型和次级断裂、节理内石英脉型金矿化四种。前两种矿化宽度较小,指示断裂构造发生了韧性和脆韧性变形,破碎带及赋矿围岩渗透率低,成矿流体集中在断层核,以渗透流为主;后两种矿化宽度较大,指示破碎带及赋矿围岩渗透率高,成矿流体集中在次级断裂和裂隙内,以隧道流为主。2、招平断裂带为由一条或几条近平行主干断裂及其下盘次级断裂和裂隙组成的南窄而低北宽而高的帚状断裂,其形成可能与大型构造地震活动有关。主震发生时,形成一系列近平行主裂面,主震产生的高渗透性构造维持时间较短,不易成矿;在断层交汇和走向转弯处破裂传播受到阻滞,致使发生一系列余震,余震发生时在主裂面上下盘形成一系列次级断层和节理,产生的高渗透率构造维持更长时间,含金成矿流体易在这些构造内运移沉淀成矿。3、招平断裂带走向上从北到南,横向上从下盘到上盘,垂向上从浅部到深部,构造变形由脆性变形→韧-脆性变形→韧性变形发生变化。韧性变形阶段岩石渗透性差,水岩作用弱;脆性变形阶段断裂带渗透性强,水岩作用强。4、招平金矿带形成于华北克拉通岩石圈NW-SE向伸展构造背景下,其内金矿床严格受招平主断裂及其次级断裂和节理构造控制,金矿化的分布和产出与成矿构造性质及断裂带渗透性结构时空变化具有密切的关系。5、金矿体主要赋存在断裂带走向转向NE、断裂倾角突变及多组断裂交汇、次级羽状裂隙密集和主断裂下盘断层泥厚大处;低密度、低磁化率、高电阻、高极化率是关键找矿信息。结合夏甸、大尹格庄金矿床控矿构造特征和构造组合型式及广域电磁测深勘探,在夏甸金矿区-1000米以下提出了4个有利成矿靶区,在大尹格庄金矿区-1200米以下提出了5个有利成矿靶区。
[Abstract]:Jiaodong is the most important gold base in China. It is an important task to determine the superficial structural ore-controlling pattern and deep structural characteristics of the internal ore-controlling fault zone in this ore concentration area. The theoretical study of gold mineralization and the practice of deep ore-prospecting need to be solved urgently. This paper takes Zhaoping gold belt as the research object, taking the tectonic dynamic process and mechanism of gold mineralization system as the main line, focusing on the ore-forming structure style and permeability structure, studying the structural ore-controlling mechanism of Zhaoping gold belt, and constructing the structural ore-controlling model. The main results of deep metallogenic prediction are as follows: 1. The gold mineralization patterns in Zhaoping gold belt can be divided into ductile shear zone disseminated type, sheet physicochemical zone inner altered rock type, brittle fault zone fragmentation rock type and secondary fault. Four types of quartz vein type gold mineralization in joints. The first two types of mineralization have smaller width, indicating ductile and brittle ductile deformation of fracture structure, low permeability of fracture zone and ore-bearing surrounding rock, and concentrated ore-forming fluid in fault nucleus, mainly permeable flow, the latter two kinds of mineralization have larger mineralization width. It indicates that the fracture zone and the ore-bearing surrounding rock have high permeability, and the ore-forming fluid is concentrated in the secondary faults and fractures. The tunnel flow is the main one and the Zhaoping fault zone is composed of one or more near-parallel main faults and the South narrow, low north width and high broomlike faults composed of secondary faults and fractures in the lower wall, which may be related to the large-scale tectonic seismicity. When the main shock occurred, a series of near parallel main fracture planes were formed, and the high permeability structures produced by the main shock lasted for a short time and were not easy to be mineralized, and the propagation of rupture and propagation at the intersection of faults and the bend of the strike were blocked, resulting in a series of aftershocks. A series of secondary faults and joints were formed in the lower face of the main fracture surface at the time of the aftershock, and the resulting high permeability structure lasted longer, the gold-bearing ore-forming fluid was easy to migrate and precipitate in these structures, and the Zhaoping fault zone moved upward from north to south. The structural deformation changes from brittle deformation to brittleness deformation and ductile deformation. In the ductile deformation stage, the permeability of rock is poor, the action of water rock is weak, the permeability of fault zone in brittle deformation stage is strong, the action of water rock is strong .4.The Zhaoping gold belt is formed in the NW-SE extensional tectonic setting of North China Craton lithosphere. The gold deposit is strictly controlled by Zhaoping main fault and its secondary faults and joint structures. The distribution and production of gold mineralization are closely related to the temporal and spatial changes of metallogenic structure and permeability structure of fault zone. The fault gouges with dense secondary plume fissures and main fault footwall are very thick, and low density, low magnetic susceptibility, high resistance and high polarizability are the key prospecting information. Combined with the ore-controlling structural characteristics and structural assemblage patterns of Xiadian and Dayingezhuang gold deposits and wide area electromagnetic sounding exploration, four favorable ore-forming targets are proposed in Xiadian gold deposit area below -1000 meters. Five favorable ore-forming targets have been proposed in Dayingezhuang gold deposit area below-1200 meters.
【学位授予单位】：中国地质大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P618.51

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