摘要:
吉林夹皮沟金矿带中所发育的含金脉系,无一例外地赋存于规模不等、方向不同的剪切带之中。研究表明,由于区内NW向主剪切带的长时期右行走滑,诱发两侧岩块(尤其是东侧上盘的夹皮沟花岗-绿岩地体)中形成大量的次一级剪切褶皱群和剪切脉系,并产生强烈的渐进应变。区域右行走滑控制脉系的基本形态和构造方位,渐进应变则制约脉系内部的构造细节;据此可以对夹皮沟金矿带内次一级剪切脉系的几何方位和发育规律进行鉴别。属于R和D的含矿剪切裂隙在两维的延展上较为稳定;而T属于水平单剪体制下形成的张性裂隙,如果它生成后没有进一步叠加剪切应变的话,理论上其三维延展要比R和D差一些。研究不同力学性质的含矿裂隙的发育规律,在找矿勘探和成矿预测中具有重要的实际应用价值。
Abstract:
The auriferous veins occurring in the Jiapigou Gold Belt are almost within shear zones of varied orientations and scales.Our study indicates that the regional NS-trending major shear zone had experienced a long-term right-lateral shearing,which resulted in the formation and progressive straining of the secondary shear folding and vein systems along the major shear zone.It is suggested that regional right-lateral shearing controls the general shapes and orientations of the veins,and progressive straining controls their internal structural details of vein systems.Based on these criterions,different vein types,such as R,R',D,T defined by Riedel shear shstem,could be identified within in the Jiapigou shear zone,which may have practical usefulness in mineral prediction and exploration.
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