Physicochemical parameters of mineralization such as temperature, pressure, salinity, density, composition and boiling of ore fluids as well as pH, Eh, fo2 and reducing parameter in theprocess of mineralization of maj...Physicochemical parameters of mineralization such as temperature, pressure, salinity, density, composition and boiling of ore fluids as well as pH, Eh, fo2 and reducing parameter in theprocess of mineralization of major ore deposits in the study district have been obtained by the authors through systematic observation and determination of characteristics and phase changes of fluid inclusions at different temperatures and analysis of gaseous and liquid phase compositions of the inclusions, thus providing a scientific basis for the division of mineralization-alteration stages, types of mineral deposits and minerogenetic series and the deepening of the knowledge about the ore-forming processes and mechanisms of mineral deposits. It is indicated that the deposits of the same type have similar fluid inclusion geochemical features and physicochemical parameters though they belong to different minerogenetic series, while the compositions of inclusions are not conditioned by deposit types but closely related to the minerogenetic series of deposits.展开更多
In recent years big strides have been made in the exploration of ores in the central-south segment of the Da Hinggan Ling Range,though some debates still exist on the metallogenesis and sources of ore-forming material...In recent years big strides have been made in the exploration of ores in the central-south segment of the Da Hinggan Ling Range,though some debates still exist on the metallogenesis and sources of ore-forming materials.Pyrite and other sulfides in direct relation to the Pb-Zn-Ag ore deposits were chosen for the He and Ar isotopic analysis of ore-forming fluids,and the first He and Ar isotope data have been obtained from the study region.3He/4He ratios in 14 samples collected from 7 mining districts are 2.17×10-6-12.52×10-6,averaging 6.86×10-6 and their R/Ra ratios are 1.56-9.01 Ra,averaging 4.37 Ra.By projecting the data points onto the 3He-4He concentrations diagram,all the points fall near the mantle helium area.The calculated mantle-source helium ratios are within the range of 19.58%-76.96%,with an average of 49.52%.Argon isotopic characteristics are close to those of mantle source,indicating that the ore-forming material was transport upwards via the multi-stage evolution of mantle plume and concentrated as ores in the favorable loci of mantle branch structures.展开更多
The ages for porphyry Mo deposits in south segment of Da Hinggan Mountains, Northeast China, are not well known. Five molyhdenite samples from the Aolunhua （奥伦花） porphyry Mo deposit, five molybdenite samples from...The ages for porphyry Mo deposits in south segment of Da Hinggan Mountains, Northeast China, are not well known. Five molyhdenite samples from the Aolunhua （奥伦花） porphyry Mo deposit, five molybdenite samples from the Yangchang （羊场） porphyry-quartz vein Mo deposit and two molybdenite samples from the Banlashan （半拉山） porphyry Mo deposit were selected for Re-Os dating. Three deposits are spatial-temporally associated with the granite porphyry stock. Re-Os isochron age of 131.2±1.9 Ma was obtained for the Aolunhua porphyry Mo deposit. The Yangchang Mo deposit provides isochron age of 138.5±4.5 Ma for two groups of molybdenite （within porphyry ore and within quartz vein）. The Banlashan porphyry Mo deposit provides model ages of 140.5±2.4 and 143±2.2 Ma. All of these Re-Os ages are consistent presumed Yanshanian ages for granite intrusions, formed in crust thinning setting in Cretaceous in North China.展开更多
文摘Physicochemical parameters of mineralization such as temperature, pressure, salinity, density, composition and boiling of ore fluids as well as pH, Eh, fo2 and reducing parameter in theprocess of mineralization of major ore deposits in the study district have been obtained by the authors through systematic observation and determination of characteristics and phase changes of fluid inclusions at different temperatures and analysis of gaseous and liquid phase compositions of the inclusions, thus providing a scientific basis for the division of mineralization-alteration stages, types of mineral deposits and minerogenetic series and the deepening of the knowledge about the ore-forming processes and mechanisms of mineral deposits. It is indicated that the deposits of the same type have similar fluid inclusion geochemical features and physicochemical parameters though they belong to different minerogenetic series, while the compositions of inclusions are not conditioned by deposit types but closely related to the minerogenetic series of deposits.
文摘In recent years big strides have been made in the exploration of ores in the central-south segment of the Da Hinggan Ling Range,though some debates still exist on the metallogenesis and sources of ore-forming materials.Pyrite and other sulfides in direct relation to the Pb-Zn-Ag ore deposits were chosen for the He and Ar isotopic analysis of ore-forming fluids,and the first He and Ar isotope data have been obtained from the study region.3He/4He ratios in 14 samples collected from 7 mining districts are 2.17×10-6-12.52×10-6,averaging 6.86×10-6 and their R/Ra ratios are 1.56-9.01 Ra,averaging 4.37 Ra.By projecting the data points onto the 3He-4He concentrations diagram,all the points fall near the mantle helium area.The calculated mantle-source helium ratios are within the range of 19.58%-76.96%,with an average of 49.52%.Argon isotopic characteristics are close to those of mantle source,indicating that the ore-forming material was transport upwards via the multi-stage evolution of mantle plume and concentrated as ores in the favorable loci of mantle branch structures.
基金supported by the National Natural Science Foundation of China (No. 40972065)
文摘The ages for porphyry Mo deposits in south segment of Da Hinggan Mountains, Northeast China, are not well known. Five molyhdenite samples from the Aolunhua （奥伦花） porphyry Mo deposit, five molybdenite samples from the Yangchang （羊场） porphyry-quartz vein Mo deposit and two molybdenite samples from the Banlashan （半拉山） porphyry Mo deposit were selected for Re-Os dating. Three deposits are spatial-temporally associated with the granite porphyry stock. Re-Os isochron age of 131.2±1.9 Ma was obtained for the Aolunhua porphyry Mo deposit. The Yangchang Mo deposit provides isochron age of 138.5±4.5 Ma for two groups of molybdenite （within porphyry ore and within quartz vein）. The Banlashan porphyry Mo deposit provides model ages of 140.5±2.4 and 143±2.2 Ma. All of these Re-Os ages are consistent presumed Yanshanian ages for granite intrusions, formed in crust thinning setting in Cretaceous in North China.
