The Qiangsheng gold deposit belongs to quartz vein type. The fluid inclusions consist of four types： aqueous single-phase inclusions, aqueous two-phase inclusions, carbonated two-phase inclusions and carbona- ted thr...The Qiangsheng gold deposit belongs to quartz vein type. The fluid inclusions consist of four types： aqueous single-phase inclusions, aqueous two-phase inclusions, carbonated two-phase inclusions and carbona- ted three-phase inclusions. The fluid inclusions are characterized by low salinity （5%-9% NaCl eqv） , low density （0.66-0.72 g/cm^3 ） and medium temperature （210℃-250℃）. The pressure of ore-forming is 60-95 MPa and the metallogenic depth is about 5.49-7.56 km. During the mineralizing process, ore-forming fluid under- went fluid unmixing in CO2-H2O-NaCl system. The stable isotope resuhs indicate that the ore-forming fluids mainly generated from mantle, with the participation of a small amount of atmospheric water. Comprehensive studies have suggested that Qiangsheng gold deposit belongs to the type of mesothermal hydrotherm with mantlederived fluid participating in mineralization.展开更多
Based on the geology and geochemistry of gold-bearing quartz veins in the Jiudian gold deposit of Pingdu,Shandong Province,the geological and geochemical indicators of occurrence of deep-seated ore bodies in the Jiudi...Based on the geology and geochemistry of gold-bearing quartz veins in the Jiudian gold deposit of Pingdu,Shandong Province,the geological and geochemical indicators of occurrence of deep-seated ore bodies in the Jiudian gold deposit have been summarized.Extent occurrence of wide,intensive,varied alteration zones around the gold-bearing quartz veins and continual presence of diorite porphyrite and lamprophyry indicate the probable occurrence of deep-seated ore bodies at depth of gold lodes.As,Sb and Hg belong to the head halo elements, and their anomalies could reveal the probable occurrence of the deep-seated ore bodies below.展开更多
The oxygen isotope composition of minerals from quartz veins and host eclogites in the Dabie terrane was measured in order to place geochemical constraints on the origin and transport of metamorphic fluid. The results...The oxygen isotope composition of minerals from quartz veins and host eclogites in the Dabie terrane was measured in order to place geochemical constraints on the origin and transport of metamorphic fluid. The results are discussed together with structural and petrological relationships between quartz vein and wallrock. The quartz veins can be temporally classified into three groups: (1) synmetamorphic vein which would be formed prior to eclogite-facies recrystallization when they were exhumated from mantle depths to deep crustal levels; (2) early retrogressive vein which was formed in the early stage of eclogite exhumation subsequent to the recrystallization, the vein-forming fluid is still relevant to the eclogites; (3) late retrogressive vein which was formed in the late stage of eclogite exhumation from deep crustal to upper crustal levels, oxygen isotope fractionation between vein quartz and host eclogite significantly deviates from equilibrium values and the vein-forming fluid was principally derived from granitic gneiss hosting the eclogites. For the synmetamorphic vein, it appears that local advective transport of fluid is the predominant mechanism in the processes of vein precipitation; the scale of oxygen isotope homogenization within the veins is much larger than that within the associated eclogites. The vein-forming fluid would be derived from the exsolution of dissolved hydroxyls within eclogite minerals due to significant pressure decrease. Fluid flow prior to the eclogite-facies recrystallization and the early retrogression may occur mainly along pressure gradients.展开更多
基金Supported by projects of Geological Exploration of Jilin Province(No.22201300111)Shanhou Gold Deposit of Laixi of Shandong Province(SDLX2012-3-28)
文摘The Qiangsheng gold deposit belongs to quartz vein type. The fluid inclusions consist of four types： aqueous single-phase inclusions, aqueous two-phase inclusions, carbonated two-phase inclusions and carbona- ted three-phase inclusions. The fluid inclusions are characterized by low salinity （5%-9% NaCl eqv） , low density （0.66-0.72 g/cm^3 ） and medium temperature （210℃-250℃）. The pressure of ore-forming is 60-95 MPa and the metallogenic depth is about 5.49-7.56 km. During the mineralizing process, ore-forming fluid under- went fluid unmixing in CO2-H2O-NaCl system. The stable isotope resuhs indicate that the ore-forming fluids mainly generated from mantle, with the participation of a small amount of atmospheric water. Comprehensive studies have suggested that Qiangsheng gold deposit belongs to the type of mesothermal hydrotherm with mantlederived fluid participating in mineralization.
基金Supported by Project of China Geological Survey(No.1212011085480 )Key Scientific and Technological Development Project of Jilin Province (No.20090479)
文摘Based on the geology and geochemistry of gold-bearing quartz veins in the Jiudian gold deposit of Pingdu,Shandong Province,the geological and geochemical indicators of occurrence of deep-seated ore bodies in the Jiudian gold deposit have been summarized.Extent occurrence of wide,intensive,varied alteration zones around the gold-bearing quartz veins and continual presence of diorite porphyrite and lamprophyry indicate the probable occurrence of deep-seated ore bodies at depth of gold lodes.As,Sb and Hg belong to the head halo elements, and their anomalies could reveal the probable occurrence of the deep-seated ore bodies below.
基金the Ministry of Science and Technology of China (Grant No. G1999075503) and the Chinese Academy of Sciences (Grant No. KZCX2-107).
文摘The oxygen isotope composition of minerals from quartz veins and host eclogites in the Dabie terrane was measured in order to place geochemical constraints on the origin and transport of metamorphic fluid. The results are discussed together with structural and petrological relationships between quartz vein and wallrock. The quartz veins can be temporally classified into three groups: (1) synmetamorphic vein which would be formed prior to eclogite-facies recrystallization when they were exhumated from mantle depths to deep crustal levels; (2) early retrogressive vein which was formed in the early stage of eclogite exhumation subsequent to the recrystallization, the vein-forming fluid is still relevant to the eclogites; (3) late retrogressive vein which was formed in the late stage of eclogite exhumation from deep crustal to upper crustal levels, oxygen isotope fractionation between vein quartz and host eclogite significantly deviates from equilibrium values and the vein-forming fluid was principally derived from granitic gneiss hosting the eclogites. For the synmetamorphic vein, it appears that local advective transport of fluid is the predominant mechanism in the processes of vein precipitation; the scale of oxygen isotope homogenization within the veins is much larger than that within the associated eclogites. The vein-forming fluid would be derived from the exsolution of dissolved hydroxyls within eclogite minerals due to significant pressure decrease. Fluid flow prior to the eclogite-facies recrystallization and the early retrogression may occur mainly along pressure gradients.
