Identifying geochemical anomalies associated with Sb–Au–Pb–Zn–Ag mineralization in North Himalaya, southern Tibet

Abstract

The North Himalaya is a prospective area for Sb, Sb–Au, Au, Pb–Zn(−Ag), and Sb–Pb–Zn–Ag mineralization. Geochemical anomalies for mineralizing elements and element associations were identified using concentration–area (C–A) fractal model together with statistical analyses, including the mean±2 standard deviation (Mean+2STD) and the median±2 median absolute deviation (Median+2MAD). The results show that the Mean+2STD for log-transformed data and C–A model could well identify the geochemical anomalies associated with mineralization in the North Himalaya. Sb+Au anomalies show a better spatial association with Sb, Sb–Au, and Sb–Pb–Zn–Ag deposits than those of single Sb element. Au anomalies are associated with all deposits, and Pb+Zn+Ag anomalies are associated with Pb–Zn and Sb–Pb–Zn–Ag deposits. In addition, weak anomalies associated with Sb mineralization can be identified by the singularity method. With the utilization of the Sb+Au, Sb, Au and Pb+Zn+Ag anomalies identified by C–A fractal model and Mean+2STD for log-transformed data, as well as the singularity method, we can facilitate the exploration targeting of various deposits in the North Himalaya. In addition, our results also show that principal component analysis (PCA) of centered logratio (clr) transformed data can accurately recognize three different geochemical assemblage compositions representing three different types of mineralization (i.e., Au, Pb–Zn–Ag and Sb) in the North Himalaya.