新疆达布达地区祖母绿的矿物学及光谱学特征研究

发布时间：2018-04-30 14:56

  本文选题：祖母绿矿床 + 矿物学特征　； 参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：新疆南部达布达祖母绿矿床是于2004年首次发现产出于碳酸盐岩脉的较优质的祖母绿矿床。本论文通过对前人地质资料的充分挖掘和归纳类比、野外地质调研,运用多种分析测试手段着重进行对新疆祖母绿宝石的矿物学特征、光谱特征的分析研究,并将其与哥伦比亚祖母绿在物理性质及谱学特征方面进行了对比研究;初步分析了矿床成因,同时对该区祖母绿矿床的开发现状提出思考的意见,为评价该区祖母绿质量和经济价值有较为重要的意义。矿物学研究表明,新疆达布达祖母绿矿的矿石矿物主要为绿柱石和石英,脉石矿物主要为方解石、石英和少量黄铁矿、电气石、磷灰石等,矿物组合为绿柱石-方解石-石英组合。电子探针结果表明较高的Cr和Fe含量分别为0.3~0.7%,0.2~0.8%。并从宝石学鉴定特征来看,新疆祖母绿应属较高品质的祖母绿。流体包裹体研究表明,新疆祖母绿流体包裹体均一温度变化范围为280~340℃,属中高温度流体;盐度变化范围为14%~40%,属高盐度流体,并估算出成矿流体密度平均值为0.99g/cm3。得出结论,新疆达布达祖母绿成矿流体均一温度较高,为中高温、高盐度流体。谱学特征研究表明:(1)拉曼光谱证实了新疆达布达祖母绿具有稳定位移特征的拉曼散射峰,谱峰的总体趋势一致,样品不同方向的光谱显示了绿柱石矿物晶体结构的差异,显示其流体包裹体中的气相均以CO2为主。(2)红外光谱分析表明新疆祖母绿晶体结构中不同方向振动基团存在光谱的差异;CO2含量比哥伦比亚的较高;祖母绿中以II型水占优,I型水与II型水的振动强度表现出此消彼长的关系。(3)紫外-可见光光谱分析显示新疆祖母绿样品与哥伦比亚祖母绿的紫外图谱基本一致,主要由Cr3+致色;祖母绿颜色产生差异主要与致色离子Cr3+、V3+、Fe3+的含量有关,V3+、Fe3+对其色调产生微调作用。在系统对新疆祖母绿流体包裹体特征及光谱学辅助研究的基础上,结合矿床地质特征,认为该矿床属于碳酸盐型中高温热液型矿床。
[Abstract]:The Dabda emerald deposit in southern Xinjiang is the first high quality emerald deposit found in carbonate veins in 2004. In this paper, the mineralogical and spectral characteristics of emeralds in Xinjiang are analyzed and studied by fully excavating and summing up the geological data and comparing with other geological data, and by means of field geological investigation and many kinds of analytical and testing methods. A comparative study was made on the physical properties and spectral characteristics of the deposit with that of the Colombian emerald, and the origin of the deposit was preliminarily analyzed, and the views on the present situation of the development of the emerald deposit in this area were put forward. It is of great significance to evaluate the quality and economic value of emerald in this area. Mineralogical studies show that the ore minerals of the Dabda emerald deposit in Xinjiang are mainly Beryl and quartz, while the gangue minerals are mainly calcite, quartz and a small amount of pyrite, tourmaline, apatite, etc. The mineral assemblage is a Beryl-calcite-quartz combination. The results of electron probe showed that the higher Cr and Fe contents were 0.30.70 and 0.20.80, respectively. According to the identification characteristics of gemology, Xinjiang emerald should be a high quality emerald. The study of fluid inclusions shows that the homogeneous temperature range of emerald fluid inclusions in Xinjiang is 280 ~ 340 鈩，

本文编号：1825007