Compositional balance analysis: A novel method for tectono-geochemical anomaly identification and blind ore deposit prediction

Abstract

Tectono-geochemical exploration always involves the study of tectono-geochemical primary halos. From the perspective of compositional data analysis, this study introduced how to use compositional balance analysis (CoBA) method to recognize tectono-geochemical anomalies and infer blind ore deposits in the deep. A case study for prediction of concealed Pb–Zn ore deposits based on tectono-geochemical data in the Huangzhuguan ore cluster, Gansu Province, China, was employed to demonstrate the potential applications of the CoBA method. First, an optimal element combination (i.e., Pb–Zn –Cd) related to near-ore halo was determined by means of CoBA method and receiver operating characteristic curve analysis. Then, according to the element zonation sequences of the primary halo in the hydrothermal deposit, the front halo element combination (i.e., As–Sb–Hg) and the tail halo element combination (i.e., W–Sn–Mo–Bi) were selected for compositional balance analysis. Finally, based on knowledge-driven CoBA method, three types of tectono-geochemical primary halos were customized to evaluate blind Pb–Zn deposits in the Huangzhuguan ore cluster. The results indicate that the CoBA method combined with the superimposed characteristics of tectono-geochemical primary haloes, proves to be effective and straightforward in interpreting Pb–Zn mineralization-related anomalies and predicting hidden Pb–Zn targets.