Study on the fluid inclusion from Dongxiang copper deposit, Jiangxi Province, China

According to the study on the metallogenic fluid characteristic from Dongxiang copper deposit, we examine the metallogenic mechanism, the nature and origin of ore-forming fluid. Based on petrographic observations of ore-bearing quartz collected from the deposit, we have found that there are three different generations of quartz. Fluid inclusion studies show that the homogenization temperature and primary salinities are 144 similar to 195 degrees C and 0.35% similar to 4.95% NaClegv in the first generation, respectively. The second generation formed in relatively higher temperature range 193 similar to 298 degrees C, and salinities are 1.40% similar to 6.59% NaCleqv. The thrid generation of quartz mainly consists of pyrite, chalcopyrite and quartz, the primary inclusions are generally three types: vapor (type II), brine (type I), and daughter-mineral bearing multiphase inclusions (type V) in the third generation. The statistics on the measured filling temperatures of type II and type V reveal peaks at 300 similar to 340 degrees C and 280 similar to 320 degrees C respectively, while those on the salinities of fluid inclusions peak at 0.35% similar to 5.86% NaCleqv and 29.4% similar to 41.9% NaCleqv respectively. Raman analysis of the fluid inclusions indicates that, in the gaseous phase, water vapor is dominant with small amount of CO2 and CH2. Hydrogen and Oxygen isotopic compositions are within the range of magmatic water. Fluid boiling resulted in the discharge of a large amount of copper from Cu-bearing fluid.