摘要
对瑶岗仙石英脉型钨矿床的石英、萤石和夕卡岩型钨矿床中石榴石流体包裹体的岩相学特征研究表明,与成矿有关的包裹体主要有三类:富液相、富气相和含子晶的多相包裹体。脉型钨矿床中石英包裹体均一温度范围为180℃～300℃,盐度0.88～6.45 wt%NaCl eqv;矽卡岩型钨矿床中石榴石包裹体的均一温度范围为190℃～300℃,盐度0.1～8.95wt%NaCl eqv;成矿溶液的密度为0.81～0.89g/cm^3,表明形成这两种类型矿床的成矿流体均属于中温、低盐度、低密度的流体;成矿压力为120～160MPa,成矿深度约为7～9km,因此该矿床是在中高压力、中深成条件下形成的。激光拉曼探针分析表明,石英中包裹体的气相成分比石榴石中的更富含 CH_4、CO_4和 H_2O 等挥发份,说明流体是一种介于岩浆与热液之间的过渡性流体,具有上部偏液、下部偏浆的特点。由于该区自燕山期以来软流圈上隆,岩石圈经历了强烈的伸展、减薄作用和壳幔相互作用,而 C-H 还原性组分的增加,指示流体很可能来自于深部的地幔过渡带或者软流圈。
There are three dominant types of fluid inclusion related to metallogensis in Yaogangxian quartz-vein wolframite deposit and skarn scheelite deposit ： liquid-rich inclusion, gas-rich two-phase inclusion and daughter-minerals bearing polyphase inclusion. The homogenized temperatures and salinity of fluid inclusions in quartz range from 180℃ to 300℃ and from 0.88 to 6.45 wt% NaCl eqv, of the inclusions in garnet vary from 190℃ to 300℃ and from 0.1 to 8.95 wt% NaCl eqv respectively. Density of the fluids is 0.81 ~ 0.89g/cm^3. These features represent that the fluids are medium temperature, low density and low salinity in the two types of fluids in this tungsten deposits. Pressure of the fluid was 120 ~ 160MPa, indicating that the two types of tungsten deposits were formed at depth of 7 ~ 9km. The analytic results get by Laser Laman Spectroscopy, indicate that the fluid is rich in volatile components, such as CH4, CO2 and H2O. Therefore, from the formation of the skarn scheelite to the quartz-vein, the fluid is the transitional fluid between magma and hydrothermal. Since Yanshanian Period, this area suffered asthenosphere upwelling, lithospheric extension, thinning and crustmantle interaction, so the fluid riched in C-H of W-bearing quartz vein of Yaogangxian tungsten deposit most likely came from mantle transition belt or asthenosphere.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第9期2263-2273,共11页
Acta Petrologica Sinica
基金
中国科学院知识创新工程重要方向项目(KZCX3-SW-125)
国家基金重点项目(40634020)
国家973项目(2007CB411408)
关键词
瑶岗仙
石英脉型黑钨矿矿床
流体包裹体
激光拉曼探针分析
成矿物质来源
Yaogangxian, Quartz-vein wolframite tungsten deposit, Fluid inclusion, Laser Raman spectroscopy, Origin of themineral substance
