青海同仁岗察岩体多金属矿床流体包裹体特征

Characteristics of fluid inclusions in the Gangcha polymetallic deposit in Tongren, Qinghai

作者选择岗察岩体中江里沟、双朋西、谢坑三个矿床作为研究对象,在矿床主成矿期部位采集样品,磨制成测温片。对流体包裹体划分期次和类型,进行包裹体测温及数据处理,并计算出矿区流体的相关盐度。选出代表性的包裹体进行拉曼光谱分析,测得包裹体的活性成分。研究区均一温度主要分布在两个区域:250~400℃和400~550℃,是岩浆岩在不同演化阶段的不同体现。成矿流体体系具有中高温、中等盐度与高盐度共存的特征。本次研究丰富了岗察岩体的成矿流体组成与演化的研究成果,为研究区的矿产勘查工作提供了重要信息。

This paper focuses on the Jiangligou, Shuangpengxi and Xiekeng deposits in the Gangcha pluton. Samples were collected from the part of the deposit formed in the main metallogenic period, and then ground into thin sections for temperature measurement. The fluid inclusions are classified by type and stage for followup temperature measurement and data processing, and calculation of relevant salinity of the fluid in the deposit area. The representative inclusions were selected for analysis by Raman spectroscopy, and measurement of active components. The homogenization temperatures fall in two ranges for the study area: 250~400 ℃ and 400~550 ℃, which are different manifestations of magmatic rocks in different evolution stages. The salinity distribution ranges from 5% to 20% and 30% to 60% in the study area. The ore-forming fluid system is characterized by the coexistence of medium-high temperature, moderate and high salinity. The Raman spectrometry shows that the fluid is mainly composed of H2O for the liquid phase, and is similar to the NaCl-H2O system. The gas phase is relatively complex and contains a small amount of CO2and CH4. This study adds to the research results of ore-forming fluid composition and evolution of the Gangcha pluton, and provides important information for mineral exploration in the study area.