太白双王含金水压角砾岩体形成过程和金矿体预测  

Formation of Gold-bearing Hydrofracturing Breccia Body and Prognosis of Gold Ore Body in the Shuangwang Gold Deposit, Shaanxi Province

作　　者：汪劲草[1] 汤静如[2] 王国富[2] 史静海 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]中南大学,长沙410083 [3]陕西太白金矿,陕西太白721607

出　　处：《地质论评》2001年第5期508-513,共6页Geological Review

基　　金：国家自然科学基金(编号49772152);太白金矿找矿项目的成果

摘　　要：陕西双王含金角砾岩体为水压角砾岩体,是深源富碱含金流体使泥盆系一套热水沉积的富钠质岩系发生水力压裂作用形成的。早期共轴递进挤压使能干性富钠质岩系与非能干性富泥质岩系发生变形分解,分别形成近等距分布的透镜状弱变形域与线性强变形带。其中,弱变形域中央是一个相对低温、低压、高渗透率的透镜状天然泵吸中心;晚期的右旋高角度斜冲非共轴递进剪切使弱变形域中央最发育的一组节理和裂隙由压性转变为张性,并沟通深部的裂隙系统。泵吸中心巨大的压力降使深部的承压流体在富钠质岩系中产生周期性的构造泵吸—水力压裂—沉淀愈合作用。根据分解变形构造型式预测的隐伏含金水压角砾岩体已获钻探初步验证。The gold-bearing breccia bodies in the Shuangwang gold deposit, Shaanxi, which are identified to be hy-drofracturing breccia bodies, are formed by hydrofracturing of the deep-seated gold-bearing and alkali-rich fluids in the Devonian hydrothermal sodium-rich rock series. In the early period, the progressive coaxial compression caused the competent sodium-rich rock series and the uncompetent pelitic rock series to deform and partition , forming a lens-like weak-deformation domain distributed at approximate equidistance and a linear strong-deformation zone respectively. Among them, the core of the weak-deformation domain is a natural lens-like pumping centre with relatively low temperature,low pressure and high permeability. In the late period, the progressive uncoaxial shear of right-lateral and high-angle oblique thrusting caused the most developed joints and fractures in the core of weak-deformation domain to turn from compressional to extensional, and linked up with deep fracture systems. The large pressure decline in the pumping centre caused the deep-seated confined fluids to develop periodic tectonic pumping, hydrofracturing and precipitation healing in the sodium-rich rock series. The buried gold-bearing hydrofracturing breccia bodies predicted on the basis of the partitioning deformation tectonic type have been proved by drilling. h

关 键 词：水压角砾岩 变形分解 水力压裂 构造泵吸 金矿体预测 承压流体 

分 类 号：P618.51[天文地球—矿床学]