不同岩浆体系过程,钨分配特征不同,迁移沉淀和成矿机制表现也截然不同.热液型钨矿在时空和成因上,与花岗岩岩浆体系有着密切联系.在花岗岩岩浆体系中W主要以钨酸(根)和碱性钨酸盐离子存在并迁移,后因流经理化条件(温度、盐度、pH值)骤变而沉淀成矿.分析4种典型钨矿床实例显示:①均与A型花岗岩体系有关,夕卡岩型和斑岩型钨矿与I型也有关;②成矿流体来源并无明显壳幔之分,均有大气饱和水参与,夕卡岩型钨矿可能有幔源流体加入,斑岩型和云英岩型钨矿成矿流体较复杂,受变质水影响较大;③石英脉型钨矿中以气液两相水溶液包裹体为主,属中—中高温、中低盐度NaCl-H2O±CO2体系;夕卡岩型、斑岩型及云英岩型钨矿中除富气液相水溶液包裹体外,还含有钠盐、钾盐子晶包裹体,均属中高—高温、高盐度NaCl-H2O-KCl±CO2体系.%In different processes of magma system,the distribution of tungsten differs,as well as migration and precipitation ore -forming mechanism.There is close relationship between hydrothermal tungsten ore and granite magma system in spatial and temporal aspects and genesis.Tungsten tends to be transported as simple tungstate or alkali-tungstate ion,and precipitate to form hydrothermal tungsten deposit when physical and chemical conditions (temperature,pressure and pH) change suddenly.By analyzing four types of tungsten deposits,the results show that ①related to A type granite magmatic system.The skarn type and porphyry type tungsten deposits are mainly related to Ⅰ type granite magmatic system;② no obvious identification of source of ore-forming fluid from crust or mantle,there is atmospheric water mixed;The fluid of skarn type tungsten deposit maybe partly from Mantle source;The source of ore-forming fluid of porphyry and greisen type tungsten deposits are more complicated and influenced by metamorphic water greatly;③ The inclusion type in quartz vein type tungsten deposit is mainly gas and liquid two-phase aqueous inclusion,with characteristics of high temperature and low salinity in NaCl-H2O+CO2.The inclusion in skarn type,porphyry type and greisen type tungsten deposits includes not only rich vapor liquid aqueous inclusion type,but also sodium salt,potassium salt crystal inclusion,which belong to a medium-high and or the high temperature,high salinity of NaCl-H2O-KCl±CO2 system.
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