Copper deposits in Khetri copper belt are hosted in the proterozoic sequence of rocks belonging to Ajabgarh group of Delhi supergroup situated in foot hill zone of Aravalli mountain range North-West, India. Khetri copper belt is about 100 km long NE-SW trending metallogenic province, starting from Singhana in the north to Sangarava in the south. The study area is the northern Khetri copper belt 190 km SW of Delhi, the capital city of India. In the present work an attempt has been made to determine the mode of occurrence and nature of mineralization with special emphasis on mineragraphic study of copper ores. The ore bodies are found in the form of multiple lodes regionally but locally in the forms of veins, stringers, dissemination, sporadic, cavity filling and replacement. Enriched mineralized zones are localized along the contact of Alwar and Ajabgarh group. Copper, the main entity in the belt occurs dominantly as sulphides, oxides, carbonates and sulphosalts mineral hosted in pelitic and psammitic rocks. Pyrrhotite, pyrite, magnetite and sphalerite are the other ore mineral associated with the copper ore in a considerable amount. From the textural, structural and multigenerational minerals, mineral assemblage studies, it is assumed that deposit has undergone metamorphism and multi-stage mineralization. Replacement has a profound influence on mineralization in the northern Khetri copper deposits.

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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.

The present study is to confine the Rampura-Agucha area, Bhilwara district, Rajasthan, which occurs in Bhilwara Super group at the contact with Banded Gneissic Complex. The Bhilwara belt is a thick pile of metasedimentary rocks in the eastern part of Aravalli-Delhi belt that consists dominant litho-units viz: graphite-sillimanite-garnet schist, garnet-biotite-sillimanite gneisses with garnet-bearing leucosomes as well as amphibolites, pegmatites and some scattered calc-silicates while the Pb-Zn ore deposit mainly occurs within graphite-biotite-sillimanite schist. The mineralogical assemblages of host rocks explain that they are formed under the high grade of metamorphism, primarily upper amphibolite to granulite facies condition. These Pb-Zn bearing ore are intimately associated with schist. The inclusions of quartz are common in garnets, while ore minerals also contain the inclusion of quartz and feldspar. The highly fractured grains of garnet, hornblende and pyroxene due to deformation, and pressure are observed in these host rocks while the contact between the quartz grains is of suture type in the calc-silicate rock.