Delineation of geochemical haloes using the developed zonality index model by multivariate and fractal analysis in the Cu-Mo porphyry deposits

Abstract Main aim of this study is to propose a developed zonality index for Cu-Mo porphyry deposits based on staged factor analysis with Number-Size (N-S) fractal model. This method was used in an Iranian porphyry system as named Serenu (SE Iran). The developed zonality index was a ratio between factors related to major and minor ore elements based on in-situ soil samples. In this study, two factors were extracted after three stages of factor analysis including F1-3 (Pb, Zn, Au, Ag, Mn, Cd, As) and F2-3 (Cu-Mo). Based on these factors, F 1 − 3 F 2 − 3 is determined as a developed zonality index. Furthermore, conventional zonality index was calculated on the basis of ( P b × Z n ) ( C u × M o ) . Then, these zonality indexes were classified by the N-S fractal modeling. Results obtained by the fractal modeling indicates that the main anomalies for the developed zonality index is correlated with plutonic units, mineralized rock samples and exploratory boreholes especially in the central and SE parts of the studied area. This methodology can be utilized for other types of ore mineralization.