【摘要】 长坑金银矿床方解石的δ13C值为-3．23‰，方解石和石英的δ18O分别为8．64‰～18．61‰和9．60‰～13．0‰，其范围与其它卡林型金矿相似。结合大本（Ohmoto）模式的理论分析，认为成矿热液的总联同位素组成可大致取为-2‰～－17‰，即碳主要来自地层中的沉积碳酸盐，部分来自有机碳。推导出水岩交换过程中流体氢、氧同位素演化的一般性协变方程并进行了理论模拟，认为成矿流体以燕山晚期一第三纪的加热大气降水或建造水为主。更多还原

【Abstract】 In the Changkeng gold-silver deposit, central Guangdong, the δ13C values of calcite are - 3. 23‰to - 0. 25‰ and the δ18O values of calcite and quartz are 8. 64‰ to 18. 61‰ and 9. 6‰ to 13. 0‰ respectively, similar to those of other Carlin-type gold deposits. Combined with the theoretical model presented by Ohmoto (1974), the carbon isotopic composition of the hydrothermal system is taken to be - 17‰ to - 2‰ suggesting that the carbon in the deposit is derived mainly from sedimentary carbonates in the country rocks, and partly is contributed by organic carbon. A general evolution equation of oxygen and hydrogen isotopes of water is derived for water/rock exchange. Based on the theoretical modeling, it is concluded that the mineralizing fluids are derived mainly from heated meteoric or for mation waters during the Late Yenshanian stage to the Tertiary period.更多还原