陕西省柞水县庙沟—韭菜沟金矿控矿地质特征及找矿前景

Geological characteristics of ore control and prospect of prospecting for Miaogou-Jiucaigou gold deposit in Zhashui County,Shaanxi Province

庙沟—韭菜沟金矿位于中秦岭晚古生代柞水—山阳热水沉积盆地的中部,大西沟-穆家庄-黑沟菱铁、贵多金属成矿带西段。区内出露的大西沟组第二岩性段(D2d2)上部层位及第三岩性段(D2d3)下部层位,分别是大西沟—银洞子菱铁铅银多金属矿、桐木沟锌矿、穆家庄铜矿、庙沟—韭菜沟金矿的主要赋矿层或矿源层,同属晚古生界泥盆系与热水喷流沉积作用有关的Fe-Cu-Ag-Au成矿系列。尤其是泥盆系大西沟组上段(D2d3(1-2))的中部层位形成一长度大于8km的庙沟—韭菜沟—笊篱沟金成矿富集带,成矿条件优越,金矿体受层间构造控制,均与黄铁矿化铁白云石石英脉相关,蚀变类型为黄铁矿化、硅化、铁白云石化、毒砂化等。通过分析其控矿地质特征、控矿因素,总结找矿标志,探讨了矿床成因类型,结合物化探成果及与热液成因矿床类比,认为本矿区深部具有良好的找矿前景。

The Miaogou-Jiucaigou deposit is located in middle part of late Paleozoic Zhashui-Shanyang sedimentary basin of Qinling Mountains,western of Daxigou-Mujiazhuang-Heigou siderite-expensive polymetallic metallogenic belt.The upper layer of second rock section(D2d2)and lower strata of third rock section(D2d3)of Daxigou group exposed in the area are main ore bearing layer or source layer of the Daxigou Yindongzi siderite,lead,silver polymetallic deposit,the Tongmugou zinc deposit and the Mujiazhuang copper deposit,which all belong to the Fe-Cu-Ag-Au metallogenic series related to the late Paleozoic Devonian system and hot water exhalative sedimentation.Especially,an over 8km long gold rich belt in Miaogou-Jiucaigou-Zhualigou which occurrence in middle part of upper layer of Daxigou group(D2d3(1-2))of Devonian system has advantage mineralization conditions.The gold ore body controlled by interlayer structure,were related to pyritization ankerite quartz veins,and alteration types are pyritization,silicification,dolomitization,arsenopyrite and so on.Based on the analysis of its ore controlling geological characteristics and ore controlling factors,the ore prospecting indicators are summarized,and the genetic types of ore deposits are discussed.Combined with the results of geophysical and geochemical exploration and the analogy with hydrothermal deposits,it is considered that the deep part of the mining area has good prospecting potential.