Enhancing deep orebody prediction and localization through the revelation of geochemical primary halo patterns in drill holes

Abstract

Geochemical primary halos play a crucial role in mineral exploration as they provide valuable insights into the dispersion of ore materials, identification of concealed deposits, and determination of ore deposit dimensions. The Naruo mining area in the Duolong mineral district, northern Tibet, China well-known for its worldclass porphyry-epithermal Cu–Au deposits is currently chosen as the study area. We employ statistical and nonlinear methods to analyze geochemical data from drill holes. Specifically, R-type cluster analysis is utilized to evaluate element affinity and concentration index, while an improved Grigorian zoning index is employed to delineate the vertical zoning sequence of the primary halo. These methodologies significantly enhance our understanding of element enrichment within geological contexts and greatly contribute to mineral resource evaluation. Based on these results, we have constructed a vertical zonation index model of denudation coefficient tailored to the geological characteristics of mineralization within the study area. This model effectively represents the vertical variation of the ore body. Our findings reveal a decrease in this zoning index towards the central region of deep ore bodies which correlates with deep granodiorite porphyry occurrences. Furthermore, we observe increasing concentrations of Cu, Ag, and Au with depth in specific sections of drill holes indicating promising exploration potential. Supplementary short-wave infrared data suggests the presence of a deep hydrothermal center in drill hole RNZK2404 which tentatively infers concealed porphyry bodies. Notably, the reversal observed at 4200 m on RNZK2404's zoning index hints at a possible hidden ore body at great depths. Finally, three-dimensional visualization techniques effectively illustrate spatial patterns for elements thereby paving way for future endeavors in mineral exploration.