摘要
乔尕山和河台金矿床属典型韧性剪切带金矿床 ,分别产于志留—泥盆系及震旦系云开群地层中。在 2个矿床含金石英脉及糜棱岩中首次发现了熔融包裹体及流体_熔融包裹体 ,对解决此类型矿床成因具重大意义。乔尕山金矿床包裹体均一温度 :熔融包裹体为 90 0～ 110 0℃ ,液相包裹体为 2 85～ 390℃ ;河台金矿包裹体均一温度 :熔融包裹体为 870℃ ,不混熔液相包裹体为 5 30℃ ,液相包裹体为 180～ 35 0℃。前者流体性质属Na+ _K+ _Ca2 + _SO2 -4 _HCO-3 _Cl-体系 ;后者流体性质属K+ _Ca2 + _Mg2 + _Na+ _SO2 -4 _HCO3 -_Cl-体系。运用电子显微镜能谱对熔融包裹体子矿物进行分析 ,鉴定出石英、钾长石、硅灰石及铝硅酸盐等 9种子矿物 ,它们分别组成不同矿物组合 ,为熔融包裹体在矿脉中存在提供了重要的实验依据。在变质深熔作用及强烈动力变质作用下 ,沉积变质岩可以形成铝硅酸盐熔融体 ,具熔体_流体性质 。
The Qiaogashan gold deposit and the Hetai gold deposit are two typical ductile shear gold deposits, which are hosted in Silurian_Devonian strata and Sinian Yunkai Group respectively. In this research, the authors have discovered for the first time melt inclusions and fluid_melt inclusions in ore_bearing quartz and mylonites of these two deposits, which is of great significance in solving the genetic problem of this type of gold deposits. The homogenization temperatures of melt inclusions and liquid inclusions in the Qiaogashan gold deposit are 900～ 1?100℃ and 285～390℃ respectively. The ore_forming fluids are of Na +_K +_Ca 2+ _SO 2- 4_HCO - 3_Cl - system. The homogenization temperatures of melt inclusions, unmixed liquid inclusions and liquid inclusions in the Hetai gold deposit are 870℃, 530℃and 180～350℃ respectively. The ore_forming fluids belong to K +_Ca 2+ _Mg 2+ _Na +_SO 2- 4_HCO - 3_Cl - system. The daughter minerals of melt inclusions were analyzed by means of SEM. Quartz, orthoclase, wollastonite, sialicate and other five minerals were identified, which respectively formed unique mineral assemblages. This analysis has further proved the existence of melt inclusions in ore veins. Sedimentary metamorphic rocks could form sialicate melt characterized by melt to fluid features under the condition of metamorphic anatexis and severe dynamic metamorphism. The ore_forming process was related to multi_stage sialicate melt and fluid actions.
出处
《矿床地质》
CAS
CSCD
北大核心
2001年第3期208-215,共8页
Mineral Deposits
基金
国家自然科学基金 (编号 :49873 0 18
4970 3 0 43 )
高等学校博士学科点专项研究基金 (编号 :980 5 5 80 7)
广东省自然科学基金 (编号 :0 12 5 5 )资助项目
