滇西热林钼铜矿床成矿流体特征与钼铜分离机制

发布时间：2018-04-15 10:20

  本文选题：热林钼铜矿床 + 流体包裹体　； 参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：热林钼铜矿床是近年来在义敦地体南部新发现的较大的一个斑岩型矿床。矿床具有明显的上铜下钼特征,作者根据岩相学特征划分成矿期次,利用流体包裹体显微测温、激光拉曼以及氢氧同位素测试来分析成矿流体的来源、演化以及钼与铜的分离机制,得到基本结论如下:1、矿体全部位于二长花岗斑岩中,其成矿作用可划分为四个阶段:硅酸盐-氧化物(Si-O)阶段,石英-辉钼矿(Qtz-Mo)阶段,石英-黄铜矿(Qtz-Cu)阶段,碳酸盐岩(C)阶段。2、矿床发育四种包裹体:气液两相(VL)型,富气相(LV)型,含NaCl子晶三相(SL)型和含CO2三相(LC)型。Si-O阶段发育VL、LV与LC型,多为LV型;Qtz-Mo阶段和Qtz-Cu阶段皆发育全部四种包裹体,但前者LC型含量少于后者;C阶段发育VL与LV型,多为VL型。3、各阶段成矿流体均一温度依次为374.8~501.7℃,290.7~482.3℃(主要为380~440℃),268.2~462.8℃(主要为320~380℃),182.3~279.5℃。均一温度呈现依次变低的趋势,且在阶段之间存在重合,指示流体演化是连续的。4、Si-O阶段,成矿流体源于初始岩浆流体;Qtz-Mo阶段,流体主要是岩浆水,并有沸腾作用发生;Qtz-Cu阶段混入了大气降水并也有沸腾作用发生;C阶段的流体是岩浆水与大气降水的混合物。5、Si-O阶段流体高温富碱,为相对氧化环境;Qtz-Mo阶段为中高温、高酸度的相对还原环境;Qtz-Cu阶段为中低温、低酸度的相对氧化环境。成矿流体的氧化还原环境、酸碱度以及温度随时间的变化使得热林钼铜矿床的钼与铜在不同的时间沉淀,而矿床上铜下钼的空间差异是由流体的温度、钼与铜对硫的争夺以及流体不混溶(沸腾作用)引致的。
[Abstract]:The hot forest molybdenum copper deposit is a large porphyry deposit discovered recently in the southern part of the Yidun terrane.The ore deposit has obvious characteristics of upper copper and lower molybdenum. According to the petrographic characteristics, the authors divide the ore forming stages into stages, and analyze the source of ore-forming fluids by using fluid inclusion microthermometry, laser Raman and hydrogen and oxygen isotopic measurements.The basic conclusions are as follows: 1. The orebodies are all located in the Erchang granitic porphyry. The ore-forming process can be divided into four stages: silicate-oxide Si-O stage, quartz-molybdenum stage, and quartz-molybdenum stage.Quartz-chalcopyrite (Qtz-Cu) stage, carbonate rock (C) stage. 2. There are four types of inclusions developed in the deposit: gas-liquid two-phase (VLV) type, gas-rich gas phase (LVL) type, NaCl sub-crystalline three-phase (SLL) type and CO2 three-phase (LCL) type. Si-O stage develops VLLV-LC type.Most of the inclusions developed in the LV type Qtz-Mo stage and the Qtz-Cu stage, but the content of the LC type in the former type was lower than that in the latter stage, which developed VL and LV type.The homogenization temperature of the ore-forming fluid in each stage is 374.8501.7 鈩，

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