Identifying ore-related anomalies using singularity mapping of stream sediment geochemical data, a case study of Pb mineralization in the Qinling region, China

Abstract

The Qinling region is located in the central part of the China mainland and carries abundant mineral resources. Stream sediment and rock geochemical data of the Qinling region collected from the Regional Geochemistry-National Reconnaissance Project of China and the China Geochemical Baselines Project, respectively, were used to identify the Pb distribution pattern and to explain the geogenic sources of geochemical anomalies. The singularity mapping technique was applied to extract local Pb ore-related geochemical anomalies from complicated geochemical backgrounds. One geochemical mega-province, one geochemical province, and three regional anomalies were delineated in a Pb geochemical map of the Qinling region. The spatial distributions of the regional anomalies are all consistent with that of known Pb metallogenic districts, but only local high anomalous areas in the geochemical province and mega-province contain economic Pb ore deposits. Regions with singularity indices of less than 1.884 occupy 2.70% of the total study area, but contain 60% of the total known Pb deposits in a Pb singularity map of the Qinling region. Targets delineated in the Pb singularity map not only highlighted known areas of Pb mineralization, but also identified areas of high potential for undiscovered ore deposits in the Qinling region.