滇东南老君山洒西钨矿床地质特征及成矿流体研究

发布时间：2018-04-26 12:50

  本文选题：流体包裹体 + 氢-氧-硫同位素　； 参考：《中国地质大学(北京)》2016年硕士论文

【摘要】：洒西钨矿床是老君山矿集区内典型的钨矿床。矿体赋存于下元古界洒西岩组(Pt1s)中,区内的构造主要是SE-NW的推覆构造,与成矿相关的岩浆岩为燕山期老君山花岗岩。矿体包括石英脉型和浸染型两种类型。浸染型矿体受地层和构造控制主要呈似层状,形态简单。石英脉型呈脉状,一方面叠加于层状矿体之上,促使矿化更加富集；另一方面也能单独形成较富的脉状矿体。该矿床的形成经历了三个矿化阶段,分别为硅酸盐阶段(矽卡岩阶段)、氧化物一硫化物阶段(钨酸盐)和碳酸盐阶段,白钨矿主要在前二阶段形成。通过进行流体包裹体的研究测试,洒西钨矿床从硅酸盐一氧化物硫化物一碳酸盐阶段,流体均一温度呈现不断降低趋势(360-230℃),同时盐度也逐渐降低。洒西钨矿的成矿流体为一套贫CO2,较低盐度(多数10%),中等温度的NaCl-H2O不混溶流体体系。通过H-O-S同位素测试,洒西钨矿床成矿流体主要来源是岩浆水,混有建造水或大气降水。同位素及元素化学分析显示,成矿物质具有多源性主要来源于岩体和高钨背景值的地层。矿床成矿时代为早白垩世,推覆构造是控矿的主要因素之一,洒西钨矿床总体的成因类型为中温热液脉型白钨矿床。
[Abstract]:Saoxi tungsten deposit is a typical tungsten deposit in Laojunshan ore concentration area. The orebody occurred in the Lower Proterozoic Sexi formation (Pt1s). The structure in the area is mainly SE-NW nappe, and the magmatic rocks associated with mineralization are Yanshanian Laojunshan granite. The orebody consists of quartz vein type and impregnated type. The ore bodies are stratiform and simple by strata and tectonics. The quartz vein type is veinlike on the one hand superimposed on the layered orebody which promotes the mineralization to be more enriched on the other hand it can form a rich vein ore body alone. The formation of the deposit has gone through three mineralization stages: silicate stage (skarn stage), oxide-sulfide stage (tungstate) stage and carbonate stage, while scheelite mainly formed in the first two stages. Through the study and test of fluid inclusions, from the stage of silicate-oxide sulfide-carbonate stage, the homogenization temperature of fluid presents a decreasing trend of 360-230 鈩，

本文编号：1806095