新疆哈密市沙东钨矿成矿流体包裹体特征研究

摘要

Shadong W-sulfide deposit,hami,xinjiang,is a majior one which is found in mid-Tianshan terrane in recent years.This paper is concerned with fluid inclusions in quartz veins containing scheelite formed at the main stage of min eralization by petrography and microthermometry.The metallogenic temperature and metallogenic pressure are estimated to be 160-350 ℃ and (54.039～71.946)× 105 Pa respectively,it suggests that this deposit was formed in a depth of 1.8-2.4km.Ore-forming fluid is with medium to low salinity and rich in a variety of gaseous components.According to geological setting and features of the deposit and the result of microscopic measurement of fluid inclusions,the writer think that the ore forming fluid of shadong W-sulfide deposit is medium to high temperature,medium to low salinity system of NaC1-H2O-CO2 (-CH4) and derived from acidic magmatic hydrothermal fluid.The main ore bearing hydrothermal solution is rich in alkali,silicon,CO2,F and other volatile parts.In the process of mineralization,the fluid is not miscible and this plays an important role in the enrichment of tungsten.%新疆哈密市沙东钨矿是中天山地块首次发现的大型钨矿床,通过对沙东钨矿主成矿阶段形成的含白钨矿石英脉中流体包裹体进行岩相学和显微测温研究.初步确定矿床成矿温度为160℃～350℃,成矿压力为54.039～71.946 MPa,成矿深度1.80～2.40 km,成矿流体为富含多种气态组分的中低盐度流体.综合矿区成矿地质背景、矿床地质特征及流体包裹体显微测温成果认为,沙东钨矿矿床成矿流体为中高温、中低盐度的NaCl-H2O-CO2(-CH4)体系.成矿流体主要来自酸性岩浆热液,主要含矿热液富碱、富硅和富CO2、富F等挥发份流体.成矿过程中流体发生不混溶,对钨的富集起重要作用.