地球化学数据含量—面积多重分形方法中台阶效应的处理方法

A processing technique of step effect in concentration-area multifractal method

在水系沉积物地球化学测量的数据处理中,地质体不同所导致的地球化学背景差异往往影响异常圈定的准确度,使其更容易产生非矿异常,从而削弱了致矿的弱小异常。笔者以分形分布的叠加规律为基础,从数学角度探讨了台阶效应数据对元素地球化学分形分布形式的影响,随后提出了一种在含量—面积分形理论中消除台阶效应的改进处理方法。通过该方法对研究区图幅按地球化学背景分类圈定子区,分别研究其分形分布圈定的异常,结果表明,该方法能准确过滤岩性信息,识别低背景区弱小矿致异常。该方法适用于受岩性影响较显著地区的地球化学矿致异常提取。

In the geochemical stream sediment survey,obvious differences in geochemical backgrounds of different geological bodies will affect the anomaly delineation and even lead to enhancement of anomalies irrelevant to mineralization,which weakens the mineralization-related weak anomalies.In this paper,the influence of step effect data on the fractal distribution form is discussed from the mathematical view based on the superposition law of fractal distribution,and an improved method for eliminating step effects in concentration-area fractal theory is proposed.In this method,the authors divide the study area based on geochemical background and then discuss fractal distribution forms respectively.The result shows that this method can accurately filter irrelevant lithology information and identify weak anomalies caused by mineralization in low-background sub-zone.It is applicable to the extraction of geochemical mineralization-related anomaly in the areas seriously affected by lithology.