【作者】 张瑞忠；

【导师】 杨立强；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2008， 硕士

【摘要】 大尹格庄金矿床是胶东招平断裂带中部典型的大型破碎带蚀变岩型金矿床。论文以系统的野外地质观测和矿床探采资料为基础,综合分析了大尹格庄金矿床的成矿背景、地质特征、控矿构造和矿化网络空间结构特征,探讨了其矿体定位规律,并进行了成矿预测。矿区内断裂构造发育,主要有招平断裂、大尹格庄断裂、南周家断裂、南沟断裂,金矿床的形成与分布严格受到断裂构造控制。招平断裂既是控矿构造,又是导矿和容矿构造,沿玲珑花岗岩体与胶东群的接触面展布,矿床产于断裂下盘的玲珑花岗岩体中。大尹格庄断裂是晚于招平断裂的成矿前或成矿期构造,它把招平断裂错为南北两段,北段形成Ⅱ号矿体群,南段形成Ⅰ号矿体群,两者地质特征有较大的差异。南周家断裂为成矿后的浅部脆性断裂,南沟断裂为成矿前的基底构造,二者对矿体没有明显的影响。矿床的构造-蚀变-矿化分带明显,构造分带控制了蚀变和矿化分带,形成了有序分布的矿化类型。距断裂面由近到远依次发育了黄铁绢英岩带、黄铁绢英岩化花岗质碎裂岩带、黄铁绢英岩化花岗岩带。大尹格庄金矿床的矿体分布总体上受各级构造联合控制,各级构造的影响作用随深度变化。在浅部,主干控矿构造控制矿化总体展布(蚀变带的分布),次级构造则控制了矿体在蚀变带内赋存的具体位置、形态及局部富集,矿体一般形态复杂,多呈枝脉状,矿化类型多样,品位变化较大;随深度的增加,浅脆性次级构造控矿作用逐渐减弱,主干断裂不但控制了矿化蚀变带的展布,而且直接控制了矿体在蚀变带内的产出样式,矿体形态简单,随招平断裂主裂面变化,多呈大脉状,矿化类型单一,品位分布均匀。Ⅰ、Ⅱ号矿体的厚大部位自上而下明显向NE方向侧伏。主矿体定位于招平断裂带内;一定规模的NEE向次级断裂、与招平断裂主裂面平行的次级断裂、招平断裂带与其分支组成的的“y”字型构造、多条NE与NW向断裂交汇而成的菱形区、构造岩和断层泥厚大部位、已知矿体NE侧伏方向是成矿有利位置。预测成矿重点区在已知矿体的NE侧伏方向,预获金金属量158,421kg。更多还原

【Abstract】 Dayin’gezhuang gold deposit, hosted in altered granitoid, is a typical large-scale altered deposit located in the fracture zone of the center part of Zhaoping fault belt, northwest Shandong province. Basing on systemic geological field observations and exploring-mining documentation, the paper analysed comprehensively geological characteristics, ore-controlling structures, mineralization networks characteristics of the deposit and studied orebody distribution regularities, and prospected the most advantageous targets for new ore bodies.There are many faults in the mining field that control the orebodies distribution. The Zhaoping fault, being not only the ore-controling but also the ore fluids transmitting and ore hosting structure, occurres along the interface of Linglong granite and Jiaodong Group. Most of the mined ore bodiesis are hosted in the altered Linglong granite which located on the footwall of the Zhaoping fault. The Dayin’gezhuang fault formed later than the Zhaoping fault, and might be earlier than mineralization event or syn-mineralization. The Dayin’gezhuang fault divided the ore bodies into two groups, north ore bodies group and south ore bosy group. The north group is named No.2 orebodies group, and the south part is named No.1 orebodies group. The No.1 and the No.2 groups are different in alteration and mineralization characteristics. The Nanzhoujia fault is a shallow and brittle fault after mineralization. The Nangou fault is a basement structure .The Nanzhoujia fault and the Nangou fault have no obvious control on gold mineralization.The deposit show obvious structure-alteration-mineralization zonings. Structure zones controlled the alteration zones and mineralization zones, forming regularly distributed mineralization and alteration patterns. From proximal to distal of the Zhaoping fault, alteration zones are pyrite-beresite, beresitizated cataclastic granite, and beresitizated granite.Orebody distribution in the Dayin’gezhuang gold deposit is generally controlled by faults and fractures of different scale. The structure control on ore bodies varies with depth. In shallow, the main ore-controlling structures confined the altered belt distribution. Secondary structures control the specific ore bodies’positions, shapes and partial enrichment of gold mineralization. Orebodies reveal complex branch-vein shape with various mineralization types and grades. With the increase of depth, the effect of shallow-brittle secondary ore-controlling structures gradually reduced. Main structure controls not only altered belt distribution but also the patterns of the orebodies. Orebodies show simple large vein shapes which varies with main structures, single mineralization type and stable in grades.Thick parts of No.1 and No.2 orebodies group pitch NE.The main orebodies are located within Zhaoping fault belt. Some NEE trending secondary structures, structures parallel to Zhaoping fault,“y”style structures constituted by main structure and secondary structures, rhombic zones confined by NEE structures and NW structures, sections of great thickness of tectonite and fault gouge, NE pitching direction of the known orebodies are all favorable targets for gold mineralization.The NE trending direction of known orebodies is the key forecast zone where we may probably get 158421 kg AU.更多还原