川中下寒武统龙王庙组白云岩阴极发光特征与成岩流体

Cathodoluminescence characteristics and diagenetic fluids of dolomites in lower Cambrian Longwangmiao formation of central Sichuan basin

四川盆地中部地区寒武系龙王庙组是我国近年发现的重要天然气储层,对川中地区龙王庙组的46个白云岩岩心样品进行阴极发光分析,结合Mn、Fe元素分析发现:龙王庙组白云岩普遍具有较弱的阴极发光性,与其较低的Mn含量有关;不同结构类型的白云岩具有不同的阴极发光性,Fe/Mn值对其起主要控制作用;早成岩阶段的大气水作用,中成岩阶段的地下流体作用和表生作用阶段的大气水作用等对龙王庙组白云岩的阴极发光特征起主要的控制作用。

Lower Cambrian Longwangmiao formation of central Sichuan basin is one of China's important natural gas reservoirs,which was discovered in recent years.Through cathodoluminescence analysis of 46 dolomite core samples of Longwangmiao formation,in combination with Mn and Fe element analysis,it is found that dolomites in Longwangmiao formation are generally of weaker cathodoluminescence characteristic,which is related with the lower Mn content.Different dolomites with different structure types have different cathode luminance and the Fe/Mn value has the major control function on it.The atmospheric water in early diagenetic stage,the subsurface fluid in middle diagenetic stage and the atmospheric water in supergene stage have the major control function on dolomite cathodoluminescence characteristics in Longwangmiao formation.