湘东北小坑桥金矿成矿元素地球化学特征研究

Study on Geochemistry Characteristics of Ore-Forming Elements in the Xiaokengqiao Gold Mine,Northeast Hunan Province

本文探讨小坑桥矿区成矿元素地球化学特征,分析了地层、构造、岩浆岩等与金的成矿关系。结果表明,冷家溪群黄浒洞组地层对金的成矿作用贡献大,金矿化体主要产在近东西向断裂破碎带的拉张裂隙中。土壤地球化学异常特征显示,成矿元素Au异常规模较大,强度值高,具有2~3级浓度带,浓集中心明显,异常形态呈近EW向展布,与后来发现的含金蚀变体基本吻合。从元素组合特征看,Au、As、Sb为矿区的特征元素组合,与金成矿关系密切。元素垂向分带显示,Au、Sb特征元素出现在中部和下部,暗示矿区深部很可能存在隐伏金矿体。

This work analyzed the correlations of metallogenesis of the gold deposits among strata, structure, and magmatic rock based on the geo- chemistry characteristics of ore - forming elements in the Xiaokengqiao mining area. The results suggest that the Pt21nh stratum took an important role in mineralization of the gold deposits. The gold mineralized bodies mainly occur within the extensional fissures in a nearly east - west trending fault zone. The geochemical anomalies of soil reveal that the anomalies of Au secondary halos are large in size, and have an obvious concentration zone of 2 - 3 level, where anomalies spread in nearly east - west direction, consistent with the gold body that was later found. The combinations of elements show that the Au, As and Sb are characteristic combination of elements, which are closely related to the gold mineralization. The vertical zoning of elements shows that the characteristic elements of Au and Sb are present in both the middle and the lower, implying the existence of possible concealed zold bodies at denth.