江南造山带东段北缘鄣公山地区成矿地质特征及成矿条件研究

Ore-forming geological characteristics and metallogenic conditions in Zhanggong mountain area of east north rim of the Jiangnanorogenic belt

鄣公山地区属江南钨锑金锡多金属成矿带九岭-鄣公山钨锑金成矿亚带,对矿床(点)成矿地质特征、金属元素分布特征、地球化学特征、控矿条件研究显示:金和铜铅锌多金属矿化受溪口岩群和瑶里-江潭构造基性岩带控制,产于韧性变形带叠加的后期脆性构造破碎带中,并赋存于次级断裂和裂隙中;锑、钨、钼矿化与燕山期酸性岩浆热液活动关系密切,赋存于岩体中及内外接触带;金、钨、锡、铋为研究区优势成矿金属;鄣源基性岩和新元古界地层(包括溪口岩群和双桥山群),具壳幔混源特征,暗示壳幔相互作用参与利于成矿,中酸性脉岩类形成时代基本为晚侏罗-早白垩世,属燕山期中酸性侵入岩体同一岩浆演化晚期产物,基性脉岩具与晚白垩世玄武岩源岩浆特征和成因亲缘性,与陆壳引张构造背景密切相关;韧性变形带叠加的次级断裂系统形成的蚀变破碎带或挤压片理化带中的后期破碎带,及挤压破碎带两侧的张性破碎带是聚矿有利部位,区内以燕山期为主的成矿特点,有早期动热变质成矿与后期岩浆热液改造叠加成矿特征。

Zhanggong mountain area belongs to the Jiangnan W-Sb-Au-Sn polymetallicmetallogenic belt of Jiu ridge - Zhanggong mountain W-Sb-Au mineralization belt. Ore-forming geological characteristics, metal elements distribution characteristics, geological and geochemical characteristics, and ore-controlling geological conditions of ore deposit/point are researched and research results show： Au and Cu-Pb-Zn polymetallic mineralization controlled by Xikou rocks and Yaoli-Jiangtan tectonic rock zone mainly originated from the late brittle tectonic fracture zone of ductile deformation zone overlay, and occurrence in the secondary faults and fissures; Sb, W, Mo closely related to Yanshanianmagmatic hydrothermal activities, occurrence in rock mass and the inner and outer contact zone;Au,W,Sn,Bi as the study area advantage ore- forming metal;Zhangyuansource rock and Neoproterozoic strata （including Xikou rocks and Shuangqiaoshan group） have the feature of crust-mantle mixed source, and indicate that crust-mantle interactions involved in mineralization;acidic vein rocks formed in the basic of late Jurassic and early cretaceous age, which are in the mid-term acidic intrusive rock mass, are the same of the late magmatic evolution; marie vein rocks and late cretaceous basalt magma source characteristics and genesis of affinity,are closely related to the continental crustal extension and tectonic setting; the secondary fracture of ductile deformation zone overlay system formed by altered fracture zone and fracture zone in the late of extrusion stretch of the physical and chemical,and extrusion fracture zone on both sides of the tensile fracture zone are ore positions; the area is metallogenic characteristics of Yanshan period mainly, whose characteristics are early dynamic thermal metamorphic mineralization and late magmatic hydrothermal superimposed mineralization.