江西香炉山矽卡岩型白钨矿矿床成因与流体特征

Fluid characteristics and genesis of Xianglushan skarn scheelite deposit in Xiushui,Jiangxi Province

香炉山白钨矿矿床位于江西修水县城西北35km处，是一座超大型白钨矿矿床。文章通过对该矿床蚀变矿化特征的研究，表明香炉山白钨矿矿床的矿化类型主要为矽卡岩型，其次为蚀变岩型（云英岩化型）。根据产状和岩相学特征进一步可将矿床的矿化过程划分为3个阶段：①矽卡岩化阶段；②白钨矿-白云母-石英阶段；③石英-硫化物阶段。流体包裹体测温结果显示，矽卡岩化阶段均一温度为354～518℃，峰值为465℃，w（NaCleq）为,6．88％～13．4％；白钨矿一白云母～石英阶段均一温度为225～408℃，峰值为340℃，w（NaCleq）为2．41％～12．28％；石英-硫化物阶段均一温度为185344℃，峰值为280℃，训（NaCl田）为2．41％～11．58％。该矿床的成矿流体为典型的中一高温、中低盐度流体体系。流体中富含F、P、H20等挥发分对成矿的运移和富集起到一定的作用，而CO2对钨的迁移作用不大。流体包裹体岩相学及测温结果揭示了流体在矽卡岩阶段经历沸腾或不混溶过程，含F、低盐度、成矿流体呈酸性，有利于钨矿的沉淀，这些是含矿流体内钨迁移与成矿的重要因素。

Located 35 km northwest of Xiushui County in Jiangxi Province, the Xianglushan scheelite deposit is a su- perlarge scheelite skarn deposit. This study focused on the fine granite body and orebody by using such means as systematic petrographical study, electron microprobe analysis, microthermometry and Raman probe analysis. Combined with deposit geology, mineralization could be divided into three parallel stages： the skarn stage, the scheelite-quartz- muscovite stage and the quartz-sulphide stage. Two types of fluid inclusions, i.e., liquid-rich （ I ） and gas-rich （ Ⅱ ）inclusions, were observed. The fluid inclusions of stage I are characterized by high tem- peratures （354--518℃） and low to medium salinity （ w （NaCleq） 6.88% -- 13.4% ）. The fluid inclusions of stage Ⅱ exhibit medium to high temperatures （225--408℃） and low to medium salinity （w（NaCeq） 2.41 % 12.28% 1. The fluid inclusions of stage Ⅱ have medium temperatures （185- 344℃） and low salinity [ w（NaCleq） 2.41%- 11.58 %）. The ore fluid system of the Xianglushan scheelite deposit is characterized by typical high temperature and low salinity. The fluids of the ore-forming stage are rich in F, P, H2O, CH4 with- out CO2, which must have played an important role in migrating and depositing. The petrography and tempera- ture measurement results of fluid inclusions reveal that the fluid of the skarn stage underwent the boiling pro- cess, which provided the suitable physical and chemical environment for migration of ore fluid. In addition, fluid physical and chemical environment was changed by greisenization, which might have been the main factor for the precipitation of tungsten.