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太华绿岩带位于华北地台西南缘,长约700公里,由晚太古代太华群火山—沉积岩系组成,其同位素年龄约26亿年,已变质到铁铝榴石角闪岩相。在舞阳发育有与大洋拉斑玄武岩共生的科马提岩。这套岩系金、银丰度高,形成紧密的线状褶皱,断裂构造极为发育。岩浆岩以基性火山岩和花岗岩为主。金矿分布于该绿岩带的西北段,主要产于近东西向的复背斜轴部断裂中。金矿化类型有含金石英脉型和含金蚀变岩型。金矿化主要赋存于太华群下部变质岩中,具明显的层控特征。矿石成分复杂,组构多种多样,金品位不均匀。金的成矿作用具有多期性和多阶段性。矿石铅同位素为古老弱异常铅,模式年龄为7～9亿年。金矿床,花岗岩和太华群的硫同位素组成相似,但它们的年龄相差甚远。这显示了硫同位素的继承性和层控性。氢、氧同位素组成显示变质水特征。成矿流体来自太华群。成矿模式:火山—沉积—区域变质—混合岩化—扩容成矿—改造—叠加作用。作者提出四个成矿远景地段。
Taihua greenstone belt is located in the southwestern margin of the North China Platform, about 700 km long, composed of the late Archean Taihuatao volcano-sedimentary rock series. Its isotopic age is about 2.6 billion years and it has metamorphosed amphibole amphibolite facies. In Wuyang, there are komati rocks that are symbiotic with oceanic basalt basalts. The rock series of gold, silver abundance, the formation of tight linear fold, fracture structure is extremely developed. Magmatic rocks are mainly basic volcanic rocks and granites. The gold deposits are located in the northwestern segment of the greenstone belt and are mainly produced in the nearly east-west syncline fault faulting. Gold mineralization types include auriferous quartz vein type and gold-bearing alteration rock type. Gold mineralization mainly occurs in the lower metamorphic rocks of Taihua Group, with obvious stratiform control characteristics. Ore complex composition, a variety of structures, gold grade uneven. The mineralization of gold is multi-stage and multistage. Lead isotope of ore is an ancient weak anomaly lead, with a model age of 7-900 million years. Gold deposits, granites and Taihuas are similar in sulfur isotopic composition, but their ages vary widely. This shows the inheritance and layer control of sulfur isotopes. Hydrogen and oxygen isotopic compositions show metamorphic water characteristics. The ore-forming fluids come from Taihua Group. Metallogenic model: volcano - sedimentary - regional metamorphism - mixed rock - expansion of mineralization - transformation - superimposed effect. The authors propose four prospecting prospects.