Source and Evolution of the Ore-Forming Fluids of Carlin-Type Gold Deposit in the Youjiang Basin, South China: Evidences from Solute Data of Fluid Inclusion Extracts
Source and Evolution of the Ore-Forming Fluids of Carlin-Type Gold Deposit in the Youjiang Basin, South China: Evidences from Solute Data of Fluid Inclusion Extracts
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华南右江盆地卡林型金矿床成矿流体的来源与演化——来自流体包裹体提取物溶质数据的证据
DOI：
10.1007/s12583-020-1055-x
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发表时间：
2021-02-01
影响因子：
3.3
通讯作者：
Yang, Wu
中科院分区：
文献类型：
--
作者：
Jin, Xiaoye;Yang, Chengfu;Yang, Wu
成矿流体的来源和演化对于认识卡林型金矿床的成因具有重要意义。由于这些矿床中热液矿物的粒度非常细且结构复杂，传统地球化学方法对矿石流体成分的来源和演化的限制长期以来一直是一个挑战。在本研究中，我们提出了右江盆地水银洞、泥堡和亚塔金矿床中石英、方解石、雄黄和萤石中流体包裹体提取物的压浸分析溶质数据，为成矿流体的来源和演化提供了新的见解。结果表明，流体包裹体提取物中高达 2 508 的 Cl/Br 摩尔比表明岩浆热液的贡献。在 Cl/Br 与 Na/K 比值图上，盆地与岩浆-热液流体之间的混合现象很明显，表明岩浆-热液流体附近的成矿期乳白色石英反映了成矿流体的岩浆来源，而限定盆地流体附近的晚期成矿晶簇石英和雄黄表明了晚期成矿期盆地流体的输入。尽管水银洞、泥堡和八田金矿床的主要围岩分别为生屑灰岩、沉积凝灰岩和钙质粉砂岩，但流体包裹体提取物的溶质数据记录了它们在富钠岩浆热液与富钙、富镁围岩之间经历了类似的流体-岩石反应。这项研究强调，通过压榨浸出分析获得的流体包裹体提取物的溶质数据有可能对卡林型金矿床的成矿流体的来源和演化进行指纹识别。
The source and evolution of ore-forming fluids is important to understand the genesis of Carlin-type gold deposit. Constraints on the source and evolution of ore fluid components by the conventional geochemical methods have long been a challenge due to the very fine-grained nature and complex textures of hydrothermal minerals in these deposits. In this study, we present the crush-leach analyzed solute data of fluid inclusion extracts within quartz, calcite, realgar, and fluorite from the Shuiyindong, Nibao, and Yata gold deposits in the Youjiang Basin, providing new insights into the source and evolution of ore-forming fluids. The results show that the high molar Cl/Br ratios up to 2 508 in fluid inclusion extracts are indicative of a contribution of magmatic hydrothermal fluids. Fluids mixing between basinal and magmatic-hydrothermal fluids are evident on the plots of Cl/Br versus Na/K ratios, showing that ore-stage milky quartz near the magmatic-hydrothermal fluids reflects magma origin of the ore-forming fluids, whereas late ore-stage drusy quartz and realgar near the defined basinal fluids suggest the later input of basinal fluids in late-ore stage. Although the predominately host rocks in Shuiyindong, Nibao and Yata gold deposit are bioclastic limestone, sedimentary tuff, and calcareous siltstone, respectively, the solute data of fluid inclusion extracts records they underwent the similar fluid-rocks reactions between the Na-rich magmatic hydrothermal fluids and the Ca- and Mg-rich host rocks. This study highlights the solute data of fluid inclusion extracts obtained by crush-leach analyses have the potential to fingerprint the source and evolution of ore-forming fluids of the Carlin-type gold deposit.