冀北东坪金矿“反倾”构造与控矿研究

Research on the "anti-inclined"structure and orecontrolling of Dongping gold deposit in northern Hebei

文章运用Riedel剪切裂隙理论,系统解析“反倾”构造的成因与成矿机制,为矿床二次开发利用提供理论依据。在基于东坪金矿区域构造格局的Riedel剪切裂隙系统中,早期R’型裂隙(NNW355°±)与后期T型裂隙叠加,形成继承性构造裂隙,即矿区NNW走向NE倾向的“反倾”构造经由不同期次裂隙复合叠加演化而成。NWW向“反倾”构造与本区二级系统内的R型裂隙均基本吻合,表明NWW向“反倾”系列构造是伴随区域应力场的变化,即早期主压应力转换为晚期应力偶之后,由后期二级剪切裂隙系统中R型裂隙演化而成。

The article applies Riedel's shear fracture theory to systematically analyze the genesis and mineralization mechanism of "anti-inclined"structures,providing a theoretical basis for the secondary development and utilization of ore deposits.In the Riedel shear fracture system based on the regional tectonic framework of Dongping gold mine,the early R'type fracture(NNW355°±)and the late T type fracture are superimposed to form inheritance structural fractures,that is,the "anti-inclined" structure with NNW strike NE dip in the mining area is evolved through the composite superposition of fractures in different stages.The NWW trending "anti-inclined"structure is basically consistent with the R-type fractures in the secondary system of this area,indicating that the NwW trending "anti-inclined"series of structures is accompanied by changes in the regional stress field,that is,after the early principal compressive stress is converted to the late stress couple,it is evolved from the R-type fractures in the later secondary shear fracture system.