上東鑛床 의 同位元素硏究

Stable Isotope Study on the Sangdong Deposit

Representative sulphide samples from the Sangdong skarn orebody and quartz veins show relatively narrow ranges of sulphur isotope values ranging from ⁺5.5 to ⁺6.9 permil and average ⁺5.0 permil with a standard deviation of 0.77 permil. Much higher temperature isotopic temperatures than homogenization temperatures may indicate even minerals in contact did not form together in isotopic equilibrium. Under conditions of formation of the skarn and quartz veins, δ³⁴ H₂S ranges from ⁺4.5 to ⁺5.3 permil, suggesting a magmatic origin for the sulphur. Carbon and oxygen isotope values seem to show some of the spread of increasing δ¹³C values of the interbedded limestone with distance from the central zone of the Sangdong mineralization. Negative values of δ¹³C fluids appear to be typical of many ore deposits including those of magmatic origin. Calculated δ¹⁸O values of the fluids are typical of those derived from magmatic sources.