Tectonic setting, mineralogy and chemistry of a metamorphosed stratiform base metal deposit within the Himalayas of Pakistan

Publisher Website
Google Scholar
Abstract
Stratiform Zn-Pb mineralization of probable Proterozoic age occurs in a structurally complex area near the northern margin of the Indian plate around Besham in the North West Frontier Province of Pakistan. The sphalerite and galena mineralization is associated with a well-defined stratigraphy of carbonate, layered calc-silicate quartzite, garnet-bearing quartzo-feldspathic gneiss, feldspathic granulite and albite gneiss. Associated with the ore are varying proportions of pyrrhotite, pyrite, baryte, clinopyroxene, quartz, garnet, actinolite, pyroxmangite, feldspar, carbonate and magnetite. The Mn-rich composition of the silicate minerals and the widespread enrichment of Ba in the rocks associated with the ore form a distinctive signature of the mineralization recognizable in reconnaissance exploration. This signature is distinct from that of skarn minerals formed later in carbonate rocks as a result of the intrusion of pegmatites. The recognition of the stratiform nature of the deposits within a well-defined stratigraphy enhances the exploration potential of the mineralization over a much wider area.