滇西中甸红山矽卡岩型Cu矿床成矿流体演化

发布时间：2018-04-27 03:16

  本文选题：红山Cu矿床 + 流体包裹体　； 参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：红山Cu矿床是义敦岛弧南段已探明规模最大的斑岩-矽卡岩型矿床,然迄今对其矿床成因的认识模糊不清,这在一定程度上制约了对红山Cu矿床形成原因和矿化富集规律的认识。为此,论文在矿床地质研究的基础上,通过岩相学观察,厘定了成矿阶段,开展了流体包裹体类型、显微测温和C-H-O同位素测试分析,据此探讨了成矿流体的来源、演化与矿床成因机制。1、探明主矿体属矽卡岩型,其成矿作用过程可划分为矽卡岩期和石英-硫化物期;前者包括早期矽卡岩、晚期矽卡岩两个阶段,后者包括早期硫化物、晚期硫化物两个阶段。2、流体包裹体主要分为四类:气液两相(VL)、富气相(LV)、含Na Cl子矿物三相(SL)和含CO2三相(LC)。早期矽卡岩阶段,包裹体主要为VL、LV、SL、LC型,大多数为为LV型;晚期矽卡岩阶段,包裹体主要为VL型;早期硫化物阶段,包裹体类型有VL、LV、SL、LC型;晚期硫化物阶段,包裹体主要类型为VL型。3、成矿流体在各阶段的均一温度为:早期矽卡岩阶段402.1~529.9℃,晚期矽卡岩阶段187.1~450.1℃,早期硫化物阶段201.4~451.2℃,晚期硫化物阶段163.5~293.5℃。在石英-硫化物期,不同包裹体类型共存、气液比变化大、均一温度近似,说明在有沸腾作用发生。4、氢氧同位素组成显示成矿流体的来源为:斑晶石英中同位素数据研究显示成矿热液以岩浆水为主;在早期矽卡岩阶段和晚期矽卡岩阶段,岩浆热液与大理岩之间发生水岩反应;而在石英-硫化物期,岩浆水与大气降水混合。5、成矿流体的均一温度、盐度在各成矿阶段逐渐降低,且在相邻的成矿阶段发生重合,表明流体演化的连续性。其形成和演化经历过程可能为:减压沸腾、岩浆热液、挥发分与碳酸盐岩接触交代、流体混合作用。红山Cu矿床主要的金属富集沉淀机制为流体的沸腾作用。
[Abstract]:The Hongshan Cu deposit is the largest proven porphyry skarn type deposit in the southern segment of Yidun Island Arc. To some extent, it restricts the understanding of the formation reason and mineralization enrichment law of Hongshan Cu deposit. Therefore, on the basis of the geological study of the deposit, the metallogenic stage is determined by petrographic observation, the types of fluid inclusions, microthermometry and C-H-O isotopic analysis are carried out, and the source of the ore-forming fluids is discussed. The mechanism of evolution and genesis of the deposit shows that the main orebody belongs to skarn type and its metallogenic process can be divided into skarn period and quartz-sulfide stage, the former includes two stages: early skarn, late skarn, and early sulfide. The fluid inclusions are mainly classified into four types: gas-liquid two-phase VLA, gas-rich gas phase CO2, NACl-containing mineral three-phase (SLL) and CO2 three-phase (LCV), which are mainly classified into four types of late sulfides in two stages, that is, gas-liquid two-phase (VLV). In the early skarn stage, the inclusions mainly belong to the type of VLT LVS SLN LC, mostly LV type, in the late skarn stage, the inclusions are mainly of the VL type, in the early stage of sulphide, the types of the inclusions are the type of VLL LVS SLC, the late stage of sulphide, and the type of the late stage of sulphide. The main types of inclusions are VL type. 3. The homogenization temperature of ore-forming fluid in each stage is 402.1U 529.9 鈩，

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