新疆萨热阔布金矿床流体包裹体研究及矿床成因  

Fluid Inclusion Studies and the Genesis of the Sarekuobu Gold Deposit, Xinjiang

作　　者：秦雅静[1,2] 张莉[1] 郑义[1,2] 刘春发[1,2] 迟好刚 

机构地区：[1]中国科学院矿物学与成矿学重点实验室,广东广州510640 [2]中国科学院研究生院,北京100049 [3]招远黄金集团阿勒泰市招金昆合矿业有限公司,新疆阿勒泰836500

出　　处：《大地构造与成矿学》2012年第2期227-239,共13页Geotectonica et Metallogenia

基　　金：国家自然科学基金项目(41072062);国家973项目(2007CB411303);国家科技支撑计划项目(2007BAB25B03);中国科学院广州地球化学研究所知识创新工程领域前沿项目资助

摘　　要：新疆萨热阔布金矿床位于阿尔泰造山带南缘克兰火山-沉积盆地内,矿体呈脉状产于康布铁堡组上亚组地层中(D1k2)。不同成矿阶段石英脉中广泛发育流体包裹体,可划分为H2O-CO2包裹体(C型)、纯CO2包裹体(PC型)、水溶液包裹体(W型)及含子矿物多相包裹体(S型)四类。测温结果显示,成矿早阶段主要发育C型和PC型包裹体,均一温度范围为271～446℃,流体盐度介于5.9%～8.4%NaCleqv之间;中阶段主要发育C、PC、W和S型包裹体,均一温度低于早阶段,为236～374℃,流体盐度介于4.8%～15.0%NaCleqv之间;晚阶段主要发育W型包裹体,均一温度范围为139～264℃,流体盐度介于1.1%～6.9%NaCleqv之间。对成矿压力和深度的估算表明,成矿压力为90～330MPa,成矿深度为9～12km。综上所述,萨热阔布金矿成矿流体具有富CO2、中低盐度的变质流体特征,流体沸腾导致了成矿物质的沉淀。结合矿床地质特征,萨热阔布金矿床属于造山型金矿床。The Sarekuobu Au deposit is located in a Devonian volcanic-sedimentary basin of the Ahay orogenic belt. Volcanic rocks and sedimentary strata exposed in the area experienced greenschist-facies metamorphism. Ac- cording to the interrelation of quartz veins, the hydrothermal ore-forming processes of the deposit can be divided in- to early, middle and late stages, represented by pyrite-quartz, polymetallic sulfide-quartz and carbonate-quartz veinlets, respectively. The early-stage veins or minerals were structurally deformed and brecciated, indicating a compressional or trans-compressional setting. The middle-stage veinlets intruded and filled the fissures of the early- stage assemblages without deformation, suggesting a tensional shear setting. The late-stage veinlets mostly filled open-space of fissures that crosscut and altered the earlier stage veins. Four types of fluid inclusions（FIs） are dis- tinguished, including aqueous （W-type）, carbonic-aqueous （C-type） , purely carbonic （PC-type） and solid-bear- ing （S-type）. The early-stage quartz contain the C- and PC-type primary FIs, and the homogenization temperatures of the primary C-type fluid inclusions in the early stage quartz range from 271℃ to 446℃ with salinities ranging from 5.9% to 8.4% NaCleqv The middle-stage quartz trapped C-, PC-, W- and S-type fluids inclusions with the lower temperatures ranging from 236℃ to 374℃ and higher salinities ranging from 4.8% to 15.0% NaCleqv. Laser Raman analysis indicate that the gases in fluid inclusions are CO2, CH4and N2. The late-stage quartz veins contain only aqueous fluid inclusions with homogenization temperatures ranging from 139℃ to 264℃, and salinities ranging from 1.1% to 6.9% NaCleqv. The low salinity and high CO2 content indicate that the ore-forming fluid may be metamorphic fluid. In the middle stage, coexistence and similar homogenization temperature of C-, W- and S-types indicate that metal precipitation may result from fluid boiling and CO2-escaping. The estimated trapping

关 键 词：流体包裹体 萨热阔布金矿 造山型金矿 阿尔泰造山带 

分 类 号：P611[天文地球—矿床学] P618.51[天文地球—地质学]