扬子地块西北缘震旦系灯影组铅锌矿的成矿地质背景

    Metallogenic geological background of lead-zinc polymetallic deposits of Sinian Dengying Formation in the northwestern margin of Yangtze landmass

    • 摘要: 按照“构造控盆、盆控相、相控矿”的思路,对铅锌矿形成的沉积盆地、含矿建造、控矿构造、岩相古地理等成矿条件进行研究,分析成矿特点,总结成矿规律。灯影期在扬子西北缘川西式基底上发育北东向、北北东向同生断裂,形成近北东向次级盆地和台地,构成台-盆相间的构造格局,次级盆地为局限盆地潮下相带沉积,台地边缘斜坡出现滑塌砾屑白云岩,沿同生断裂运移的含矿热液流体在角砾状白云岩中聚集成矿。研究结果表明,灯影组铅锌矿成矿明显受盆地半活动类型基底、镁质碳酸盐岩台地中次级盆地、控制次级盆地的同生断裂等因素的控制。

       

      Abstract: According to the train of thought “structure controls basin, basin controls facies and facies controls ore deposit”, the authors studied metallogenic conditions of lead-zinc deposits such as sedimentary basin, ore-bearing formation, ore-controlling structure, lithofacies and paleogeography, analyzed metallogenic characteristics and summed up the ore-forming regularity. In Dengying period, NE- and NNE-trending contemporaneous faults were developed on the Chuanxi-style basement in the northwest margin of Yangtze plate and, as a result, nearly NE-trending second-order basins and platforms were formed, which constituted the structural framework. of the platform alternate with the basin. The second-order basin was characterized by infratidal zone sediments of restricted basin, slump dolorudite appeared on the marginal slope of the platform, and ore-bearing hydrothermal fluids that migrated along contemporaneous faults were concentrated in brecciform marble to form ore deposits. Studies show that lead-zinc mineralization of Dengying Formation was obviously controlled by such factors as semi-active type basement of the basin, second-order basins in magnesian carbonate rock platform and contemporaneous faults that control the second-order basin.

       

    /

    返回文章
    返回