胶东三山岛金矿控矿构造特征和矿化强度分布

发布时间：2018-05-24 06:49

  本文选题：控矿构造 + 矿化强度　； 参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：胶东是我国主要的金矿集中区和黄金工业基地,三山岛金矿是胶东典型的超大型“焦家式”金矿床,其矿床地质研究程度较高,但在金品位分布规律及其与构造配套的研究上比较薄弱。论文在详细的野外地质调查基础上,运用数字-尺度分形和多重分形方法,查明了三山岛金矿床的控矿构造,解析了三山岛金矿矿化强度的影响因素,取得以下主要认识:成矿前,区域主压应力方位为NW向,三山岛-仓上断裂及其伴生的NE-NNE向断裂主体呈压性特征,NNE向的次级断裂间连通性较差,流体活动无运移通道,矿体难以形成。成矿期,区内的主应力方向转为近NE向,各断裂发生近EW向伸展,此时也形成了近SN向延伸的张性断裂,有利于流体活动,是主要的导矿和容矿构造。成矿后,NW向的三山岛-三元断裂破坏了大量构造和矿体。三山岛金矿可划分为四个成矿阶段:Ⅰ黄铁矿-绢英岩阶段;Ⅱ金-石英-黄铁矿-毒砂阶段;Ⅲ金-石英-多金属硫化物阶段;Ⅳ石英-碳酸盐阶段。Ⅱ、Ⅲ阶段为金主成矿阶段,其中Ⅱ成矿阶段中矿化没有定向性,黄铁矿以团块状为主,Ⅲ成矿阶段中多金属硫化物主要呈脉状,走向为北东向或南北向。通过三山岛金矿矿体参数的分布及矿化样式统计,将穿脉分为三个矿化等级,分别为强烈矿化穿脉(例如:-465中段46号穿脉)、中等矿化穿脉(例如:-510中段54号穿脉)和微弱矿化穿脉(例如:-510中段51号穿脉)。在数字-尺度分形方法中,随着矿化程度的加强,阈值逐渐增大,分维值逐渐减小;在多重分形方法中,强烈矿化穿脉的多重分形谱线较中等矿化和微弱矿化穿脉分布范围窄。应用多重分形方法,计算得出谱宽Δα的值在强烈矿化穿脉(Ⅰ)中最小,中等矿化穿脉(Ⅱ)中中等,微弱矿化穿脉(Ⅲ)中最大,显示强烈矿化穿脉的金品位分布最均匀,微弱矿化穿脉中金品位分布最不均匀。三山岛金矿金品位分布符合分形和多重分形,在Ⅱ成矿阶段,构造上无统一方向,微裂隙较少,矿化主要受水岩反应控制,金品位分布较为均匀;在Ⅲ成矿阶段,构造为强烈的伸展作用,导致微裂隙增加,使阈值增加,矿体受裂隙控制,金品位分布更为集中。
[Abstract]:Jiaodong is the main gold concentration area and gold industry base in China. Sanshandao gold deposit is a typical super large "Jiaojia" gold deposit in Jiaodong, which has a high degree of geological research. However, the study of gold grade distribution and its matching with the structure is relatively weak. On the basis of detailed field geological survey, using digital scale fractal and multifractal methods, the ore-controlling structure of Sanshandao gold deposit is found out, and the influencing factors of mineralization intensity of Sanshandao gold deposit are analyzed. The main results are as follows: before the mineralization, the principal compressive stress orientation of the area is NW direction, the main body of the Sanshando-Cangshang fault and its associated NE-NNE fault have poor connectivity between the secondary faults with the NNE direction, and there is no migration channel for the fluid activity. Ore bodies are difficult to form. During the metallogenic period, the principal stress direction in the area changed to near NE direction, and the faults extended in the near EW direction. At this time, the tensile faults extending in the near SN direction were formed, which is favorable to fluid activity and is the main ore-conducting and ore-containing structure. After mineralization, a large number of structures and orebodies were destroyed by the Sanshandao-ternary fault in NW direction. Sanshandao gold deposit can be divided into four metallogenic stages: 鈪，

本文编号：1928100