Abstract: In order to find out the ore-forming fluid characteristics and metallogenic mechanism of Xiongcun No.III deposit,the geological characteristics of No.III deposit is analyzed in detail and tests on the inclusions at quartz-sulfide veins and hydrogen and oxygen isotopes are conducted.The research results show that,the homogenization temperatures and salinities of fluid inclusions range from 170 ℃ to 310 ℃ (peak temperature at 220 ℃) and 1.20% to 30.1% respectively.Its hydrogen and oxygen isotopes range from -134.3‰ to -118.5‰ and -0.8‰ to -0.2‰ respectively,which indicates that,the ore-forming fluid is a mixture of magmatic water and atmospheric precipitation,and has the characteristics of middle temperature and middle-low salinities.The minerals precipitated of Xiongcun No.III deposit mainly relates to mixture of magmatic water and atmospheric precipitation and the crystallization of magnetite within potassic alteration zone.

Key words: Porphyry, Ore-forming fluid, Hydrogen and oxygen isotopes