Mineragraphic Studies of Pb-Zn Ore Deposits of Rampura-Agucha Area, Bhilwara Belt, Rajasthan

Abstract

The Sediment hosted massive Pb-Zn sulfide deposit at Rampura-Agucha area, district Bhilwara, Rajasthan, has been studied. It is in the Mesoproterozoic meta-sedimentary rocks belonging to the Bhilwara supracrustal belt of Aravalli-Delhi orogen. The ore body at Rampura-Agucha is hosted by an enclave of graphite-biotite-sillimanite schist which is found within the garnet-biotite-sillimanite gneiss country rock. It contains bands of amphibolite, pegmatite, calc-silicate rocks and aplite in the proximity of the ore zones. The host and associated rocks encountered in the study area are metamorphosed to mainly upper amphibolite to granulite facies. In this work, an attempt has been made to emphasize on the mineralogy, texture and mode of the occurrence of lead and zinc ore and other ore minerals of the study area. The ore and gangue minerals are identified with the help of the X-ray diffraction analysis and ore microscopic studies. The mineralogical studies of ore samples revealed the presence of sphalerite, galena, pyrite, pyrrhotite, chalcopyrite, arsenopyrite, canfieldite and argentopyrite along with the gangue minerals such as quartz, graphite, kyanite, haycockite as recorded in the X-ray diffraction pattern. Sphalerite and galena are present in most of the samples. The sphalerite is broadly categorized into groups, on the basis of shape, size, and frequency of inclusions and their textural relationships; (a) Sphalerite devoid of inclusions, (b) Sphalerite with minor inclusions of galena, pyrite, and pyrrhotite, (c) Sphalerite with graphite fragments. Existence of deformation texture, brecciated texture and curved cleavage pits in the samples are the suggestive of the post-depositional brittle and ductile deformation in the area.