山东招远河东金矿床地质特征与矿床成因研究

发布时间：2018-06-03 16:29

  本文选题：山东招远 + 河东金矿　； 参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：河东金矿位于焦家断裂带的分枝断裂一望儿山断裂南段,矿体围岩蚀变发育,构造复杂。本文通过对河东金矿成矿地质特征、H-O-S稳定同位素地球化学特征和流体包裹体的研究,矿床控矿条件的分析,探讨成矿流体的性质与成矿的关系以及该矿床的成矿机制,得出以下认识:(1)河东金矿分布在NE向焦家断裂带的分支断裂望儿山断裂带内的破碎蚀变岩中,并受其控制。望儿山断裂控制着成矿流体热液活动,从而为河东金矿床形成所需的成矿流体和成矿物质提供了运移通道和沉淀场所。(2)河东金矿床的成矿作用与区内郭家岭花岗岩和玲珑花岗岩没有直接关系,它们仅是矿床的直接围岩,根据区内脉岩与矿床的空间和时间上的关系,河东金矿的成矿作用应该与区内中基性脉岩有关。(3)H-O-S稳定同位素地球化学研究表明,河东金矿床成矿流体来源于幔源,到成矿中晚期,有大气降水参与,表现为混合来源特征;河东金矿硫源与郭家岭花岗岩中硫的来源一致,成矿物质来源于前寒武纪变质基底岩石和白垩纪壳幔相互作用上涌的岩浆组分中所携带的成矿物质,具有混合来源特征。(4)根据流体包裹体显微测温结果,成矿流体温度为222℃~302℃,属于中低温度热液流体,热液沿着断裂裂隙充填并与围岩发生水-岩反应发生交代作用(如硫化作用),流体具有不混溶性,矿体分布在破碎蚀变岩带中,矿石具有明显的交代充填结构,据此推测,河东金矿应该为中低温热液裂隙充填交代蚀变岩型金矿床,流体的不混溶以及Au(HS)2-的溶解度降低可能是河东金矿床金沉淀富集成矿的最主要因素。
[Abstract]:Hedong gold deposit is located in the south section of the branch fault-Wangershan fault of Jiaojia fault zone. Based on the study of the ore-forming geological characteristics of Hedong gold deposit, the stable isotopic geochemical characteristics of H-O-S and fluid inclusions, and the analysis of ore-controlling conditions of the deposit, the relationship between the ore-forming fluid properties and mineralization and the metallogenic mechanism of the deposit are discussed in this paper. The following conclusions are obtained: (1) the Hedong gold deposit is distributed in and controlled by the broken altered rocks in the Wangershan fault zone of the branch fault zone of the NE-trending Jiaojia fault zone. The Wangershan fault controls the hydrothermal activity of ore-forming fluids. The ore-forming process of the Hedong gold deposit is not directly related to the Guojialing granite and Linglong granite in the Hedong area, which provides a migration passage and a sedimentation place for the ore-forming fluids and ore-forming materials needed for the formation of the Hedong gold deposit. They are only the direct surrounding rock of the deposit. According to the relationship between dike rocks and the space and time of the deposit, the mineralization of Hedong gold deposit should be related to the stable isotopic geochemistry of the middle and basic dike rocks in the area. The ore-forming fluid of the Hedong gold deposit comes from mantle source, and from the middle to the late metallogenic period, there is the participation of atmospheric precipitation, which is characterized by mixed source, and the sulfur source of Hedong gold deposit is the same as that of Guojialing granite. The ore-forming materials derived from the Precambrian metamorphic basement rocks and the minerals carried in the Cretaceous crust-mantle interaction upwelling magma have mixed source characteristics. The ore-forming fluid temperature is 222 鈩，

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