Multivariate Analysis of Stream Sediment Geochemical Data for Gold Exploration in Delijan, Iran

Abstract

Muteh is a major Iranian gold mine that is located in Delijan, within in the Sanandaj-Sirjan metallogenic zone. Previously, the gold mineralization in Muteh was interpreted to be formed in Precambrian. However, recent geological models propose younger age, i.e., late Eocene, for the gold mineralization, therefore, the geologic units of age and older than late Eocene can be considered as targets for gold exploration. The objective of this paper is to investigate Muteh type gold mineralization potential in the area with respect to the new geological models. Statistical analysis of 644 stream sediment samples was used to determine anomalous concentrations Au and elemental correlations of Au geochemical pathfinders. Using the factor analysis, an eight-factor model was established for the stream sediment geochemical data explaining 74.76% of the total variance. Factor 4 was found to be representative of Al-Ca-Na-K-P, which defines the lithological variation in the data. Factor 6 represents the variation of Pb-Ag-Sb-Ba-Tl, which is related to the hydrothermal mineralization. The factor 7 includes Au-S-Mo and is representative of regional geochemical patterns of gold. The correlation of Au with S and Mo signifies the inclusions of Au in pyrite minerals of Muteh mine. Factor 7 specifies three exploration targets. Moreover, the fourth prospective area representing significant geochemical signatures for gold mineralization was not detected in factor analysis. The results show that data reduction techniques, such as factor analysis, have great potential for geochemical applications; however, it is essential to perform careful analysis in addition to using these techniques. Factor analysis highlights the regional geochemical patterns and may slight the smaller subsystems.