Cole-Cole模型参数在时间域激电找矿中的应用

The application of Cole-Cole model parameters to the time domain induced polarization prospecting

常规的时间域激电法获得参数较少,仅有电阻率和极化率两个参数,这使得激电异常往往难以准确解译,具体体现在矿体解译信息量较少和探测分辨率差上,特别是在极化率或电阻率数值接近的一些共生及伴生的矿产勘探中,如炭质灰岩、黄铁矿和褐铁矿共生的一些矿山。为了丰富矿体地质信息,提高对矿体的认识,减少误判和漏判,文中利用激电效应的时间响应可用Cole-Cole模型来描述的特征,通过阻尼最小二乘法实现时间响应与时间域Cole-Cole模型的最佳拟合,从而获得多种Cole-Cole模型参数。实际应用证明,该方法经济、有效,可通过多种物理参数综合解释,实现对激电异常更全面的认识和正确的推断解释,同时提高了时间域激电在深部找矿中的分辨率。

the routine time domain induced polarization can only obtain two parameters,i.e.,resistivity and polarizability,which often makes it difficult to accurately interpret induced polarization anomaly and thus causes less information for orebody interpretation and poor detection resolution. Such a phenomenon is especially prominent in the exploration of some ore resources characterized by associated or accompanying minerals like carbonaceous limestone,pyrite and limonite whose resistivities or polarizabilities are close to each other. In order to enrich orebody geological information,improve the understanding of orebody and reduce mistaken or incomplete judgement,the authors utilized the feature that Cole-Cole model could describe time response of induced polarization effect and employed damping least squares method to realize the best fitting of the time response with time domain Cole-Cole model so as to obtain varied kinds of Cole-Cole model parameters. Practice shows that this method is economical and effective and,through integrated interpretation of varied kinds of physical parameters,it can realize more overall understanding and correct induction and interpretation of induced polarization and also improve the resolution of the time domain induced polarization in deep prospecting.