A Study on Fluid Inclusions of the Jianquanzi Gold Deposit at Alashan County,Inner Mongolia,China

In this study,petro facies,micro-thermometry,hydrogen and oxygen isotopics,and fluid inclusions in quartz from the Jianquanzi gold deposit,Alashan,Inner Mongolia,China were studied.The results showed that fluid inclusions in quartz were small in size,mostly ranging from 2 to 8 μm.These inclusions consisted of gas and liquid phases (type Ⅰ) as well as gas,liquid and CO2 phases (typeⅡ) .Homogenization temperatures,salinities and densities of the fluid inclusions ranged from 182.5 to 308.6℃ (averaging 295℃ ) ,2.07% to 9.21% (averaging 6.03% ) and 0.74 to 0.93 g /cm3,respectively.Based on the average ore-forming pressure which is 218.6 × 105Pa,the estimated average ore-forming depth pressure is 2.186 km,belonging to the shallow to medium depth type.The ore-forming fluid seems to be a mixture of magmatic and metamorphic waters mixing with meteoric water.Fluid-wallrock interaction,along with the decreasing of temperature and pressure,possibly induced gold to concentrate and deposite within the shear zone.