【摘要】 长坑矿床金、银矿石硫化物的δ￣（３４）Ｓ分别以高离散的负值和相对较集中的正值为特征。在主要成矿阶段硫同位素基本达到平衡或近平衡分馏条件下，采用大本模式分析表明，硫同位素分布特征可能与成矿流体物理化学条件不同有关，即形成金矿石的热液偏酸性、ｆ＿ｏ＿２效高．而银矿化期的流体近中性、ｆ＿ｏ＿２较低：此外，伴随硫化物沉淀的储库效应对此也有一定的影响。热液的总硫同位素组成可取为４‰─７‰，应主要来自围岩中的沉积硫。成矿机制包括流体混合、氧化作用、水一岩反应。更多还原

【Abstract】 The values of sulfides from the gold and silver Ores in the Changkeng gold- silver deposi. Guangdong Province, are characterized by highly scattered negative values and relatively gathered positive values, respectively. The conditions of near-equi- librium fractionation of sulfur isotopes are indicated by reasonable sulfur temperatures for sulfide pairs. On the basis of theoretical model presented by Ohmoto (1972), it is suggested that the difference in S values between the gold and silver ores could result from different physic-chemical condiditions of oreforming fluids , i. e, the gold ores were formed under acid and relative higher conditions, while silver ores under near-neutral to weak-basic and lower conditions . Moreover , the reservoir effect of sulfur isotope caused by sulfide precipitation may also have influence upon it. The calculated sulfur isotopic composition of the fluid system is to, suggest- ing that the sulfur in the gold-silver deposit is mainly of sedimentary origin. The mineralization mechanisms include mixing of fluids, oxidation and water rock interac- tion.更多还原