Antimony, lead, and zinc mineralization in the Kamol Gol, Awrit Gol, and Barum areas, Chitral district, Pakistan

Abstract

A comprehensive study was conducted to investigate the geochemical characteristics of Sb, Pb, and Zn deposits in various regions of Chitral district. The primary objective was to identify the source and chemical composition of the metal-bearing fluids, which currently remain unidentified. Field research revealed the presence of stibnite (Sb), galena (Pb), and sphalerite (Zn) ores, accompanied by small amounts of chalcopyrite and pyrite. These deposits were found to be associated with the Reshun fault/shear zone, and secondary minerals such as quartz and calcite were observed. Ore petrography, in combination with SEM-BSE and SEM–EDS analysis, confirmed the presence of magnetite, chamosite, stibnite, fahlore, galena, litharge, sphalerite, arsenopyrite, zinkenite, chalcostibite, boulangenite, pyrite, as well as a few gangue minerals (specifically quartz and calcite). Atomic absorption spectroscopy (AAS) was employed on four cross-sections to determine the concentrations of the metal-bearing elements. The results revealed varying concentrations of Sb (ranging from 0.001 to 24%), Pb (ranging from 0.006 to 24.1%), Zn (ranging from 1.2 to 158,000 ppm), and Cu (ranging from 0.2 to 2730 ppm). Gold (Au) and silver (Ag) concentrations were predominantly below the detection limit (BDL), except for the Barum Ghari section, where gold concentrations ranged from 0.0 to 0.38 ppm. Integration of field observations, ore petrography, and SEM analysis suggested that the deposition of ores was influenced by metamorphic fluids generated during the progressive metamorphism of sedimentary layers. Furthermore, the AAS results demonstrated an increasing concentration of metal-bearing elements from the lower to the upper Chitral region.