摘要
对黑龙江省三矿沟矽卡岩型铁铜矿床内花岗闪长岩中石英斑晶、硫化物阶段及石英-碳酸盐阶段的石英、方解石中流体包裹体的岩相学、显微测温学和显微激光拉曼光谱分析等的研究结果表明,流体包裹体有富液相、富气相和含子矿物多相包裹体3种类型;花岗闪长岩石英斑晶中的含子矿物多相包裹体均一温度均值为432℃,盐度在30.92 wt%～63.91wt%NaCl eqv.之间,平均为52.96 wt%NaCl eqv,代表了高温、高盐度岩浆流体;硫化物阶段形成的黄铜矿磁铁矿矿石中流体温度主要介于323～424℃之间,盐度介于8.95 wt%～62.51 wt%NaCl eqv.之间;硫化物阶段形成的黄铜矿矿石中流体温度主要介于333～441℃之间,盐度介于8.28 wt%～65.32 wt%NaCl eqv.之间;石英-碳酸盐阶段流体温度主要介于124～140℃之间,盐度介于1.65 wt%～4.34 wt%NaCl eqv.之间。铁铜矿石均形成于高温、高盐度阶段,以岩浆热液为主,在成矿晚期,由于大气降水的混合,形成了少量低温、低盐度流体,成矿流体以富Na、K、Ca、Cl^-和CO_3^(2-)的高盐度流体为特征,主体属于 NaCl-H_2O-CO_2-H_2S-CH_4体系。成矿流体在300～400℃区间内发生了强烈的沸腾作用,导致大量金属硫化物和少量金属氧化物沉淀,沸腾作用对三矿沟铁铜矿床的形成起到至关重要的作用。
The fluid inclusions of Sankuanggou skarn Fe-Cu deposit can be classified into liquid-rich two-phase, gas-rich two-phase and daughter mineral-bearing polyphase types. Based on the studies on petrography, microthermometry and Laser Raman Spectrographic analyses of fluid inclusions in the quartz phenocrysts from granodiorite and fluid inclusions in the quartz and calcite from the ores formed in sulfide and quartz-carbonate stages, respectively. The homogenization temperatures of fluid inclusions for the quartz phenocrysts average 432 degrees C, and salinities range from 30.92 wt% to 63.91 wt% NaCl eqv. with average of 52.96 wt% NaCl eqv. indicating that the fluid is dominated by magmatic water with high temperature and high salinity. Homogenization temperatures of fluid inclusions for the chalcopyrite magnetite ores, chalcopyrite ores and quartz-carbonate veins range mainly from 323 to 424 degrees C, 333 to 441 degrees C, and 124 to 140 degrees C respectively, corresponding to salinities of 8.95 wt% similar to 62.51 wt% NaCl eqv., 8.28 wt% similar to 65.32 wt% NaCl eqv and 1.65 wt% similar to 4.34 wt% NaCl eqv., respectively. Both iron and copper ores are formed by high-temperature and high-salinity fluid, and the ore-forming fluid belongs to NaCl-H(2)O-CO(2)-H(2)S-CH(4) system, which is characterized by high Na, K, Ca, Cl(-) and CO(3)(2-) components. In late stage, the ore-forming fluid evolved to the low-temperature and low-salinity aqueous solution because of the mixture of meteoric water. The boiling event of ore-forming fluid occurred in sulfide stage with temperature of 300 similar to 400 degrees C triggered by tectonic decompression processes, resulting in formation of massive metal sulfides and magnetite. The fluid boiling was favorable for formation of the Sankuanggou skarn Fe-Cu deposit.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2009年第10期2631-2641,共11页
Acta Petrologica Sinica
基金
国家973计划项目2006CB403508课题
国家自然科学基金项目40772055
国家科技支撑计划项目2007 BAB25 B03课题资助
