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河南省金城金矿床位于桐柏—商城韧性剪切带南部、大别山西北侧。矿床赋存于中元古界苏家河群浒湾岩组变质岩中。在详细分析金城金矿床地质特征的基础上,研究共生花岗斑岩脉的微量元素、稀土元素地球化学特征,共生石英的氧同位素、共生石英流体包裹体中CO2的碳同位素及共生黄铁矿的硫、铅同位素组成特征,并与老湾金矿和燕山晚期灵山花岗岩体对比。研究发现,本区花岗斑岩脉的稀土配分曲线和微量元素蛛网图与灵山花岗岩体几乎完全重叠,稀土元素和微量元素特征参数较为一致,结合区域资料推断本区与矿体共生的花岗斑岩脉来源于燕山晚期岩浆活动。黄铁矿δ34S值变化范围为-6.9‰～5.5‰,均值为2.3‰,与区域上地层和岩浆岩硫同位素对比,认为金城矿床载金黄铁矿的硫主要来源于浒湾岩组围岩。载金黄铁矿铅同位素和浒湾岩组地层铅同位素范围相当,均有下地壳铅源的特征,结合硫同位素分析,认为金城金矿床载金黄铁矿的铅主要来源于浒湾岩组围岩。δ18OSMOW变化范围为5.5‰～11.4‰,极差为5.9‰,均值为8.4‰,具有岩浆热液石英的特征;δ18CPDB变化范围为-6.3‰～-2.8‰,极差为3.5‰,均值为-4.4‰,具有岩浆源或深部源碳(-7‰)和沉积碳酸盐岩来源碳(0)混合的特征;综合研究表明,本矿床成矿物质主要来源于浒湾岩组含金岩石建造,部分来源于燕山晚期岩浆热液活动。
Jincheng gold deposit in Henan Province is located in Tongbai - Mall ductile shear zone south of the northwestern side of the Dabie Mountains. Deposits occur in the Middle Proterozoic Su Jiahe Group Huwan rock metamorphic rocks. Based on the detailed analysis of the geologic features of Jincheng gold deposit, the characteristics of trace elements, geochemical characteristics of rare earth elements, oxygen isotopes of coexisting quartz, carbon isotopes of CO2 in coexisting quartz fluid inclusions and symbiotic pyrite Sulfur and lead isotopic compositions, and compared with the Laowan gold deposit and the late Yanshan granite. It is found that the distribution pattern of rare earth elements and trace element cobweb of the granite porphyry vein in this area almost completely overlap with the Lingshan granite body, and the characteristic parameters of rare earth elements and trace elements are consistent. Based on the regional data, it is inferred that the granite Porphyry veins from the late Yanshan magmatism. The δ34S values of pyrite range from -6.9 ‰ to 5.5 ‰, with an average of 2.3 ‰. Compared with the sulfur isotopes of the upper strata and magmatic rocks, it is concluded that the sulfur of the gold-bearing pyrite in the Jincheng deposit mainly comes from the surrounding rocks of the Huwanan Formation. According to the analysis of sulfur isotopes, it is concluded that the lead content of gold-bearing pyrite in Jincheng gold deposit mainly comes from the surrounding rock of Huwanan Formation . The δ18OSMOW ranged from 5.5 ‰ to 11.4 ‰, with a maximum of 5.9 ‰ and an average of 8.4 ‰, with the characteristics of magmatic hydrothermal quartz. The δ18CPDB ranged from -6.3 ‰ to -2.8 ‰ with an average of 3.5 ‰ with a mean of - 4.4 ‰, which is characterized by the mixing of magmatic source or deep source carbon (-7 ‰) and sedimentary carbonate source rock (0). The comprehensive study shows that the ore-forming materials of this deposit mainly come from the formation of gold-bearing rocks in Huwanan Formation , In part from late Yanshanian magmatic hydrothermal activity.