基于主成分分析的化探异常圈定新方法——以新疆西准噶尔地区1:50000岩屑数据为例

以新疆西准噶尔地区阿克巴斯陶1∶50 000万岩屑数据为对象,利用相关、偏相关分析和R型聚类分析确定研究区成矿元素组合为Cu-Mo-Zn-W-Sb-Bi-As(铜钼成矿组合)与Au-As-Bi(金成矿组合);基于主成分分析,以线性方法将2组成矿元素重组为新的变量N1(Cu-Mo-Zn-W-Sb-Bi-As)与N2(Au-Bi-As),新变量中各元素权重根据主成分分析所得特征向量值大小决定;运用分形含量-面积法提取新变量异常下限并生成综合异常图。结合野外地质检查,成功圈定两处成矿潜力区,为下一步工作提供有力依据。

A new principal component analysis-based method for lineation of geochemical anomalies: A case study of detritus data (1/50 000) of Western Junggar,Xinjiang

Detritus data (1/50 000) from Akebasitao, western Junggar, Xinjiang were processed with Pearson correlation analysis and R-type cluster analysis and the ore-forming elements portfolio of the study area are determined to be Cu-Mo-Zn-W-Bi (Cu-Mo mineralization) combination and Au-As-Bi-Ag(Au mineralization)combination. The two elements combinations are re-combined with principal component analysis and two linear combined variables N₁(Cu-Mo-Zn-W-Sb-Bi-As) and N₂(Au-Bi-As) are obtained. the authority value of each element of these variables is determined by its eigenvector value. According to the work done above, the lower limits of geochemical anomalies of two new variables are determined by content-area method based on fractal theory and a integrated anomly map is drawn with two mineralization targets lineated for further exploration.