非线性地球化学矿化元素组合求异方法在西藏洞噶普矿区的应用

摘要

复杂的地质作用和控制因素常常使得地球化学元素的分布特征呈非线性,传统的线性模型在处理元素非线性分布具有一定的局限性和不适应性。文中以研究地球化学矿化元素组合为主线,应用aiNet网络模型（带权的不完全连接网络）对地球化学数据做预处理,应用FastICA算法（快速定点独立分量分析）求取矿化元素组合,应用分形含量面积法圈定元素异常下限,应用分形含量梯度法确定元素异常浓集分带,形成了一套地球化学矿化元素组合求异的非线性方法体系,并在西藏洞噶普矿区1∶1万土壤地球化学测量资料的应用中取得了良好的效果。%Complicated geological processes and controlling factors always make the distribution of geochemical elements having nonlinear characteristics.Traditional linear model methods are limited due to the character of nonlinear element association.In this paper,we adopted aiNet to preprocess geochemical data in order to study the geochemical metallogenic element association.Fractal content-area method was used to determine the anomaly threshold of elements.Fractal content-gradient method was used to determine the zone of element concentration.Thus a series of nonlinear metallogenic element association method system to seek out geochemical anomaly has been formed.We applied this nonlinear method for anomaly seeking of geochemical metallogenic element association to process 1∶10000 soil geochemical survey data from Donggapu mining area of Tibet and had achieved good results.