粤东莲花山断裂带高山寨钨多金属矿床流体包裹体研究

高山寨钨多金属矿床处于粤东梅州地区,位于莲花山断裂带的北西侧,属新华夏系第二个隆起褶皱带南段与南岭东西复杂构造带南缘交接复合部位。研究基于详细的岩相学观察,对该矿床含矿石英脉中的10个石英包裹体片中流体包裹体进行显微测温和激光拉曼光谱分析,从而为探讨其流体性质及成矿机制提供依据。通过研究分析,该矿床主要有五种类型流体包裹体,分别为:富液相、富气相、纯液相、纯气相以及含CO_2三相流体包裹体。选取富液相流体包裹体和少量的含CO_2三相流体包裹体进行测温。据温度测试结果推测,石英中的流体包裹体经历至少两次流体活动。富液相流体包裹体均一温度分布较广(156℃～380℃),可分为低温区间(181℃～240℃)、高温区间(261℃～338℃);含CO_2三相流体包裹体的均一温度(290℃～347℃)与富液相的流体包裹体均一温度高温区间的较为一致,但三相流体包裹体盐度(0.4%～4.9%)低于富液相包裹体(1.2%～12.5%)。从本次实验结果推测高山寨钨矿床成矿机制为:在成矿流体演化过程中,高温阶段发生流体沸腾作用,导致部分金属矿物发生沉淀;低温阶段成矿流体经历了自然冷却作用及与低温低盐度的流体混合作用,导致金属矿物沉淀富集成矿。

STUDY OF FLUID INCLUSIONS OF THE GAOSHANZHAI TUNGSTEN POLYMETALLIC DEPOSIT IN LIANHUASHAN FAULT ZONE,EASTERN GUANGDONG PROVINCE

The Gaoshanzhai tungsten polymetallic deposit on northwestern side of the Lianhuashan fault zone in Meizhou area of eastern Guangdong Province occurs at the conjunction position of the second uplift fold belt of the Neocathaysian and the southern margin of Nanling E-W complex tectonic belt.On the basis of petrographic observation,the fluid inclusions in quartz of the ore-bearing vein are analyzed by microthermometry and Laser Raman Spectroscopy so as to provide the basis for discussing the fluid property and metallogenic mechanism.Five types of fluid inclusions are determined by the analysis,including rich liquid phase,rich gas phase,pure liquid phase,pure gas phase and CO2-bearing three phase fluid inclusions.The temperature measurement objects are mainly liquid-rich inclusions,with a small amount of CO2-bearing three phase inclusions.It shows that there are at least two stage fluid activities in the mining area.The liquid-rich fluid inclusions have relatively wide range of homogeneous temperature distribution(156 ℃~380 ℃),which can be divided into low temperature range(181 ℃~240 ℃) and high temperature range(261 ℃~338 ℃).Homogenization temperature of the CO2-bearing three-phase fluid inclusions(290 ℃~347 ℃) is the same as that of the liquid-rich fluid inclusions,but the salinity of CO2-bearing three phase inclusions(0.4%~4.9%)is lower than that of the liquid-rich inclusions(1.2%~12.5%).It is considered that during the evolution of ore-forming fluids in the Gaoshanzhai tungsten deposit,the fluid boiling occurred in the high temperature stage and then resulted in the precipitation of partial metal minerals.At the low temperature stage,the ore-forming fluid experienced the effect of natural cooling and the mix with the low-temperature and low-salinity fluid and resulted in the enrichment of metal mineral precipitation.