五河地区朱顶—石门山断裂带构造地球化学研究

Structural Geochemistry Study of Zhuding-Shimenshan Fault Zone in Wuhe Area

运用构造地球化学方法对五河地区朱顶—石门山韧性剪切带及两盘岩石进行主微量元素研究,结果表明:自断裂带两侧围岩向内带SiO2、TiO2含量渐次递增,Al2O3、Fe2O3、MgO、K2O含量渐次递减,CaO、Na2O、灼失量呈现双峰折线状,表明主量元素受控于该剪切带的构造作用;微量元素中Au与Cu、Pb、Mo、Ag、Zn则呈良好的变化关系,相关系数分别为0.99、0.97、0.96、0.96、0.81,可作为该区良好的找金标志。根据断裂带微量元素的聚类分析,表明Au、Ag、Pb、Zn、Cu、Bi为同一元素组合,暗示了金矿与铜矿、方铅矿、闪锌矿、银矿为伴生矿物。而Au与Pb、Mo元素的相关性研究表明,该区金矿属于中—高温热液成矿,充分证实断裂构造不仅对断裂带各类岩石元素有明显的控制作用,而且制约金矿的形成。

This paper emphasizes on the study of the major and minor elements by the tectono-geochemical methods on Zhuding-Shimenshan fault zone s ductile shear zone of Wuhe region. As the results illustrate,the contents of SiO 2 ,TiO 2 gradually increase along both sides of the wall rock to the inside of the fault zone,the contents of Al 2 O 3 ,Fe 2 O 3 ,MgO and K 2 O decrease and the ignition loss of CaO and Na 2 O curved as bimodal pattern. These above-mentioned phenomena indicate that the major elements are influenced by the tectonism within the fault zone. Moreover,the correlation index between minor elements Au and Cu,Pb,Mo,Ag,Zn in the ductile shear fault and both hanging wall and footwall are 0.99,0.97,0.96,0.96 and 0.81 respectively,which shows that the peaks of the above-mentioned elements are good prospecting criteria for gold ore. The cluster analysis on minor elements in the fault zone indicates that the Au,Ag,Pb,Zn,Cu and Bi belong to the same elements composition and that proves gold ore is associated with copper,galena,sphalerite and silver ore. The correlation index between Au and Pb,Mo suggests that the gold ore in the resea area is medium-hypothermal mineralization.As a result,fault structure affects the chemistry elements of various rock and controls the gold ore significantly in the study area.