摘要
对夹皮沟地区夹皮沟群变质岩—斜长角闪岩及夹皮沟和二道沟金矿金矿石中的流体包裹体进行了岩相学、显微测温及单个包裹体成分激光拉曼光谱研究。结果表明:金矿石中发育水溶液相、含 CO_2相及 CO_2相等三类包裹体,成矿过程中,流体经历了 NaCl-H_2O-CO_2体系的不混溶作用,各类包裹体均一温度157.2℃～440℃,盐度1.8%～11.6%NaCl eqv,流体密度0.54～0.96g/cm^3;变质岩中以发育含子矿物多相包裹体为主,其均一温度为260℃～480℃,盐度为36.5%～54.8%NaCl eqv,流体密度为1.06～1.17g/cm^3,反映了变质流体为一中温、高盐度、高密度均匀 NaCl-H_2O 热液体系。成矿流体与变质流体存在明显差异,表明该区金矿床成矿流体并非来自太古代变质热液。结合新近的流体包裹体氢、氧同位素分析结果和测年数据,认为本区金矿成矿流体以来自岩浆热液为主,矿床成因属中生代岩浆热液矿床。
Petrographic, microthermometric and laser Raman spectroscopic studies were carried out on fluid inclusions in quartz from metamorphic rocks-amphibolite-and gold ores in the Jiapigou Group in the Jiapigou area. The results show that three types of primary fluid inclusion occur in quartz from ores ： aqueous phase, CO2-bearing phase and CO2 phase. The ore-forming fluids were once the immiscible NaCI-H2 O-CO2 system and the various types of inclusion are characterized by homogenization temperatures ranging from 157.2 to 440℃, salinities between 1.8 and 11.6% NaCI equiv and fluid densities from 0.54 to 0.96g/cm^3. The fluid inclusions in quartz from metamorphic rocks are mainly daughter crystal-bearing polyphase ones with homogenization temperatures from 260 to 480℃, salinities from 36.5 to 54.8% NaCI equiv and fluid densities from 1.06 to 1.17g/cm^3 , reflecting that the metamorphic fluids were a homogenous NaCl-H2O system with medium temperatures, high salinities and high densities. The appreciable difference between the ore-forming fluids and metamorphic fluids suggests that the ore-forming fluids of the gold deposits in the area are not of Archean metamorphic origin. According to the above mentioned, combined with the latest hydrogen and oxygen isotopic analyses and mineralization age data of the fluid fluids, the authors believe that the ore-forming fluids were mainly derived from magmatic hydrothermal fluids and that the gold deposits are Mesozoic magmatic hydrothermal ones.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第9期2198-2206,共9页
Acta Petrologica Sinica
基金
国家自然科学基金(40572117)
地质大调查项目(1212010634001)
吉林大学科研启动金
关键词
吉林夹皮沟
脉型金矿床
流体包裹体
成矿流体
流体不混溶作用
Jiapigou, quartz vein type gold deposit, fluid inclusion, ore-forming fluid, fluid immiscibility
