武当西缘六斗金矿及银洞沟银多金属矿床成因研究
发布时间：2018-10-19 07:54
【摘要】：武当地区地处南秦岭造山带关键地带,受俯冲碰撞造山作用的影响,区内印支期韧性剪切带控制的金银多金属矿床发育。本文选择武当西缘地区的六斗金矿和银洞沟银多金属矿床为研究对象,在矿床地质特征、稳定同位素、及流体包裹体等方面分别进行解剖分析,探讨成矿机制,确定矿床成因。论文对比总结了武当地区成矿规律,为该区金、银金矿床成矿理论提供了新的线索。六斗金矿位于武当西缘十堰断裂以北。耀岭河群与上部陡山坨组之间的韧性滑脱剪切构造带为主控矿构造。金矿体呈似层状、透镜状分布于南北向及北西向和北东向次级断裂中。矿化类型有破碎带蚀变岩型和石英脉型两种。充填矿物稳定同位素研究表明,初始成矿流体为变质流体,后不同程度混入大气降水,成矿物质来源于赋矿围岩。原生流体包裹体形态规则,气液比均一。矿床形成于中温(210~220℃)、中压(140~150Mpa)环境。银洞沟银多金属矿床位于武当西缘、十堰断裂以南。矿床受银洞沟背斜和韧性剪切带联合控制。矿体具向西倾斜、平面侧列及垂直分带特征,由浅及深,从银矿体逐渐过渡为铅锌矿体。银洞沟主体矿化经历石英-铅锌矿化阶段、银金矿化阶段(包括糖粒状石英-银金矿化亚段、糖粒状石英-含铅、锌的银金矿化亚段)、块状石英-铁白云石脉弱矿化阶段等三个阶段。矿脉以高角度近东西走向陡脉为主,少量低角度缓脉发育,为同期成矿作用结果。矿体成矿后受到明显的构造改造,如矿体的石香肠化、揉皱及X共轭剪节理,推测主要是南北向挤压的结果。充填矿物稳定同位素研究表明,初始成矿流体为变质流体,但大气降水对银洞沟成矿作用也有贡献。流体包裹体类型多样,揭示矿床形成于中温(280~290℃)、中压(200~220Mpa)环境,成矿深度为11.5~12.5km。结合现有的年代学数据,认为六斗金矿为典型的造山型金矿,形成于印支晚期;银洞沟银多金属矿床为韧性剪切带控制的中温热液脉型矿床(类似于造山型银矿),形成于印支早期。
[Abstract]:The Wudang area is located in the key zone of the South Qinling orogenic belt. The gold and silver polymetallic deposits controlled by the Indosinian ductile shear zone are developed under the influence of subduction and collision orogeny. In this paper, the Ludou gold deposit and Yindonggou silver polymetallic deposit in the western margin of Wudang are selected as the research objects. The geological characteristics, stable isotopes and fluid inclusions of the deposit are anatomically analyzed, the metallogenic mechanism is discussed and the genesis of the deposit is determined. This paper contrasts and summarizes the metallogenic law in Wudang area, which provides a new clue for the metallogenic theory of gold and silver deposits in this area. Ludou gold deposit is located north of Shiyan fault in the west margin of Wudang. The ductile detachment shear zone between the Yaolinghe group and the upper Doushantuo formation is the main ore-controlling structure. The gold orebody is layered and lenticular distributed in the NNE and NW and NE secondary faults. There are two types of mineralization: altered rock type and quartz vein type. The stable isotopic study of filling minerals shows that the initial ore-forming fluid is metamorphic fluid, and then mixed into the atmospheric precipitation to varying degrees, and the ore-forming material originates from the host rock. The primary fluid inclusions are regular in shape and homogeneous in gas-liquid ratio. The deposit was formed in a medium temperature (210 ~ 220 鈩，
本文编号：2280574
[Abstract]:The Wudang area is located in the key zone of the South Qinling orogenic belt. The gold and silver polymetallic deposits controlled by the Indosinian ductile shear zone are developed under the influence of subduction and collision orogeny. In this paper, the Ludou gold deposit and Yindonggou silver polymetallic deposit in the western margin of Wudang are selected as the research objects. The geological characteristics, stable isotopes and fluid inclusions of the deposit are anatomically analyzed, the metallogenic mechanism is discussed and the genesis of the deposit is determined. This paper contrasts and summarizes the metallogenic law in Wudang area, which provides a new clue for the metallogenic theory of gold and silver deposits in this area. Ludou gold deposit is located north of Shiyan fault in the west margin of Wudang. The ductile detachment shear zone between the Yaolinghe group and the upper Doushantuo formation is the main ore-controlling structure. The gold orebody is layered and lenticular distributed in the NNE and NW and NE secondary faults. There are two types of mineralization: altered rock type and quartz vein type. The stable isotopic study of filling minerals shows that the initial ore-forming fluid is metamorphic fluid, and then mixed into the atmospheric precipitation to varying degrees, and the ore-forming material originates from the host rock. The primary fluid inclusions are regular in shape and homogeneous in gas-liquid ratio. The deposit was formed in a medium temperature (210 ~ 220 鈩，
本文编号：2280574
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