内蒙古东不拉格钼铅锌矿床的成矿年代及成矿流体特征
发布时间：2018-07-26 14:31
【摘要】：通过野外调研、辉钼矿Re-Os定年和流体包裹体研究,对内蒙古西乌旗东不拉格钼铅锌矿床的成矿时代、成矿背景和成矿流体特征及流体演化进行了探讨。研究结果表明,矿区发育斑岩型钼矿化和热液脉状铅锌矿化,二者为同一构造岩浆事件的产物。钼、铅锌成矿均与区内石英二长斑岩有关,辉钼矿Re-Os定年结果表明,成矿时代为中侏罗世(165.2±2.8 Ma),是中国东部燕山期大规模成矿事件的产物。流体包裹体测试结果表明,成矿流体主要来自岩浆水,早期成矿流体具有高温、高氧逸度、富Fe和含CO_2的特征。从成矿早阶段至晚阶段成矿流体从高温(312~534℃)、高盐度(高达63.9%NaCleq)向低温(158~166℃)低盐度(低至0.35%NaCleq)演化。隐爆造成的岩浆减压沸腾是岩浆流体出溶的主要机制,早期岩浆流体由于减压和降温过程造成热液发生CO_2与水的不混溶及流体沸腾,这是早期钼沉淀的主要机制,而岩浆流体与还原性地层的水岩反应引起的氧逸度降低及大气水的加入则是铅锌沉淀的主要机制。
[Abstract]:Through field investigation, Re-Os dating and fluid inclusion studies of molybdenum deposits, the metallogenic age, metallogenic setting, ore-forming fluid characteristics and fluid evolution of the Dongboulag Molybdenum Pb-Zn deposit in Xiwuqi, Inner Mongolia are discussed. The results show that porphyry molybdenum mineralization and hydrothermal vein lead-zinc mineralization are developed in the ore area, which are the products of the same tectonic magma event. Molybdenum and lead-zinc mineralization are all related to quartz monzonitic porphyry in this area. The Re-Os dating results of molybdenum indicate that the metallogenic age was the product of large-scale metallogenic event of Yanshanian period in eastern China (165.2 卤2. 8 Ma),). The results of fluid inclusion test show that the ore-forming fluids mainly come from magmatic water and the early ore-forming fluids are characterized by high temperature, high oxygen fugacity, rich Fe and CO_2. The ore-forming fluid evolved from high temperature (312 ~ 534 鈩，
本文编号：2146317
[Abstract]:Through field investigation, Re-Os dating and fluid inclusion studies of molybdenum deposits, the metallogenic age, metallogenic setting, ore-forming fluid characteristics and fluid evolution of the Dongboulag Molybdenum Pb-Zn deposit in Xiwuqi, Inner Mongolia are discussed. The results show that porphyry molybdenum mineralization and hydrothermal vein lead-zinc mineralization are developed in the ore area, which are the products of the same tectonic magma event. Molybdenum and lead-zinc mineralization are all related to quartz monzonitic porphyry in this area. The Re-Os dating results of molybdenum indicate that the metallogenic age was the product of large-scale metallogenic event of Yanshanian period in eastern China (165.2 卤2. 8 Ma),). The results of fluid inclusion test show that the ore-forming fluids mainly come from magmatic water and the early ore-forming fluids are characterized by high temperature, high oxygen fugacity, rich Fe and CO_2. The ore-forming fluid evolved from high temperature (312 ~ 534 鈩，
本文编号：2146317
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