Application of multifractal and local singularity analysis method to the identification of deep-level geochemical anomalies in the Duolong mineral district, Tibet, China

Objective As one of the most crucial information carriers for predicting mineralized geological bodies, exploration geochemical data play a significant role in the identifying and extracting mineralization-associated anomalies as well as in analyzing deep-level mineralization information. Methods Based on the scale invariance and generalized self-similarity characteristics of the spatial distribution of geochemical elements, this paper uses Cu and Au in the 1:50 000 exploratory geochemical data of the Duolong mineral district as an example and conducts a study using fractal/multifractal and singularity theories to identify the spatial distribution patterns of ore-forming elements and extract anomalies. The multifractal spectrum which is derived by the exploratory moment method for the whole study area, the fault buffer zone and the stratigraphic zone, is used to describe the relative enrichment and depletion of elements in the local area and to analyze the local singularity of Cu and Au mineralized elements, so as to identify and extract weak and low anomalies of mineralized elements and delineate potential mineralization zones. Results Both Cu and Au exhibit mineralization-favoured patterns in the Duolong mineral district, with the Cu showing weak enrichment in the region and Au being over-enriched on a local scale. The intersections of the east-west and northeast-trending faults, as well as the Jurassic strata, are identified as the most promising locations for mineralization in this region. Conclusion The spatial distribution of the local singularity index is mapped to characterize the distribution features of Cu and Au geochemical anomalies, therefore, the central and northern regions of the ore district are subsequently identified as potential areas for mineralization.