The analysis of gas compositions of fluid inclusions in quartz veins, which
were formed in metallogenesis of brittle-ductile shear metamorphism, and s
uffered from different grade shearing, shows that from mylonitized quartz v
ein --> primary mylonite quartz vein --> quartz vein mylonite, the total co
ntents of gas compositions, the contents of main component H2O and CO2 decr
ease, and the fluid inclusions in minerals of sheared rocks may be one of t
he main source of ore-forming fluid of gold deposit in ductile shear zone.
The quartz veins formed in two main metallogenetic stages have similar char
acteristics of hydrogen and oxygen isotope, delta O-18(H2O) = 5.25 parts pe
r thousand similar to 8.64 parts per thousand, deltaD(H2O) = - 70.9 parts p
er thousand similar to - 42.0 parts per thousand. Ore-forming fluids in she
ar zone were homogenized by shear metamorphism, and the range of hydrogen a
nd oxygen isotope change of ore-forming fluid is small.