%0 Journal Article %T Characteristics of Fluid Inclusions and Metallogenesis of Annage Gold Deposit in Qinghai Province, China %A Jianqing Lai %A Peijiao Ju %A Jinjin Tao %A Baorong Yang %A Xiaoyun Wang %J Open Journal of Geology %P 780-794 %@ 2161-7589 %D 2015 %I Scientific Research Publishing %R 10.4236/ojg.2015.511067 %X The Annage gold deposit is located at the east part of the eastern Kunlun orogenic belt. The characteristics of ore-forming fluids and metallogenesis were discussed by using fluid petrography, micro-thermometry and hydrogen-oxygen isotope analysis. Three stages, namely quartz-pyrite stage (A), quartz-polymetallic-sulfide stage (B) and quartz-ankerite stage (C) were included in the hydrothermal process as indicated by the results of this study. Inclusions developed in ore-bearing quartz veins from stages A and B are of three types: aqueous inclusions (type I), CO2-bearing inclusions (type II) and pure COinclusions (type III). All three types of inclusions, mainly type I, are presented in stage A, having homogenization temperatures at 180กใC - 360กใC, and salinities ranging from 0.53% to 21.44%. In addition to development of type I inclusions, type II and III inclusions increase significantly in stage B, with homogenization temperatures ranging from 160กใC to 330กใC, and salinities are from 1.32% to 22.01%. Based on micro-thermometry, fluids in Annage deposit are of H2O-NaCl-CO2 type with medium-high temperature (140กใC - 395กใC) and medium-low salinity (0.53% - 22.01%). Results of hydrogen-oxygen isotope analysis show that ore-forming fluid is mainly CO2-rich magmatic fluid, mixed with shallow groundwater or metamorphic hydrothermal in the late mineralization stages. Calculated metallogenic pressures are in the range of %K Fluid Inclusions %K Hydrogen-Oxygen Isotope %K Ore-Forming Fluid %K Metallogenesis %K Annage %K China %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=61398