The Manganese deposits of Andhra Pradesh are associated with a thick sequence of Precambrian rocks, belonging to Khondalite and Charnockite groups of Dharwar Supergroup that forms part of 2500 to 3000 m.y. old Eastern...The Manganese deposits of Andhra Pradesh are associated with a thick sequence of Precambrian rocks, belonging to Khondalite and Charnockite groups of Dharwar Supergroup that forms part of 2500 to 3000 m.y. old Eastern Ghat complex of India. The study area is the Manganese deposits of Vizianagram-Visakhapatnam Manganese Belt of Andhra Pradesh. The study area lies about 150 km NE of Visakhapatnam between 18°12′N - 18°30′N and 83°20′E - 83°45′E. The mineralization of Manganese ores is confined to different rock types, belonging to both Khondalite and Charnockite groups, where they are dispersed throughout the country rocks as small lenses, pockets, veins and irregular bodies of varying dimensions. Quartz, garnet, clay, limonite and apatite are the common gangue minerals in the Manganese ores. The presence of quartz, garnet and apatite brings down the grade of the ore. Ferruginous laterite and ochre generally work as capping of the Manganese deposits. The various Manganese ore minerals present in these deposits are indentified as 1) Primary minerals-braunite, bixbyite, vredenburgite, jacobsite and hausmannite, 2) secondary minerals-psilomelane, cryptomelane, hollandite, pyrolusite and wad. The primary ore minerals are considered to be syngenetic and regionally metamorphosed while, the associated secondary ore minerals are formed due to alteration of the primary ores.展开更多
The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground Mine of Sin...The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground Mine of Sindeskar Kalan, Vedanta Group, Rajpura-Dariba-Bethumni Belt which are located at a distance of 76 Kms from Udaipur District (Rajasthan) have been studied. The chief litho units of the group are identified which contain sulfide-bearing calc-silicate and graphite mica schist, dolomite marble, calc-biotite schist and quartzite. Importance to the ore minerals like galena and sphalerite which have been reported in association with the buffer minerals like pyrite and pyrrhotite occurr in the host rocks of the study area. Ore petrography denotes two types of sphalerites, 1) highly deformed and dark brown colour, 2) less deformed and with light yellow colour. Galena shows high reflectance and a network of triangular pits. Pyrite shows high reflectance and anomalous anisotropism because of high brittleness.展开更多
The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground mines of Si...The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground mines of Sindeskar Kalan, Vedanta Group, Rajpura Dariba-Bethumni Belt which were located at a distance of 76 Kms from Udaipur District (Rajasthan) have been studied. The chief litho units of the group were identified which contain sulfide-bearing calc-silicate and graphite mica schist, dolomite marble, calc-biotite schist and quartzite. Importance to the ore minerals like galena and sphalerite which have been reported in association with the buffer minerals like pyrite and pyrrhotite occurred in the host rocks of the study area. The study of melt inclusion (sulfide melt) of sphalerite showed the maximum temperature of melting which was 923°C on the Linkam-TMS94 (the maximum temperature limit of the system is up to 1500°C). The maximum temperature of melting of sphalerite reveals that the dolerite and/or pegmatite intrusion might have supplied sulfide rich melt during the study area in the geological past.展开更多
The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground Mine of Sin...The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground Mine of Sindeskar Kalan, Vedanta Group, Rajpura Dariba-Bethumni Belt which is located at a distance of 76 kms from Udaipur city, Rajasthan have been studied. The chief litho units of the group which contain sulfide-bearing calc-silicate and graphite mica schist, dolomite marble, calc-biotite schist and quartzite are identified. An attempt has also been made to study/or hydrothermal in origin in the different types of fluid inclusions, hosted predominately in Geothermometry viz. heating and freezing study of entrapped palaeo-fluids (such as sedimentary and quartz host grain and a few in sphalerites). The quartz hosts are identified with four types of fluid inclusions, such as 1) monophase (gas/vapour), 2) gas-rich biphase, 3) liquid-rich biphase and 4) polyphase types. The primary types of fluid inclusions show that melting temperature of ice or depression freezing point (DFP) (ranging from -2.5°C to -7.2°C)/(salinity ranging from 4.5 - 13.25 wt% NaCl eq.) and temperature of homogenization into liquid phase (ranging from +188°C to +218°C) have been measured. Data from the fluid inclusions and salinity calculation (low salinity) reveal that rate of cooling is the important mechanism of ore deposition in the study area.展开更多
文摘The Manganese deposits of Andhra Pradesh are associated with a thick sequence of Precambrian rocks, belonging to Khondalite and Charnockite groups of Dharwar Supergroup that forms part of 2500 to 3000 m.y. old Eastern Ghat complex of India. The study area is the Manganese deposits of Vizianagram-Visakhapatnam Manganese Belt of Andhra Pradesh. The study area lies about 150 km NE of Visakhapatnam between 18°12′N - 18°30′N and 83°20′E - 83°45′E. The mineralization of Manganese ores is confined to different rock types, belonging to both Khondalite and Charnockite groups, where they are dispersed throughout the country rocks as small lenses, pockets, veins and irregular bodies of varying dimensions. Quartz, garnet, clay, limonite and apatite are the common gangue minerals in the Manganese ores. The presence of quartz, garnet and apatite brings down the grade of the ore. Ferruginous laterite and ochre generally work as capping of the Manganese deposits. The various Manganese ore minerals present in these deposits are indentified as 1) Primary minerals-braunite, bixbyite, vredenburgite, jacobsite and hausmannite, 2) secondary minerals-psilomelane, cryptomelane, hollandite, pyrolusite and wad. The primary ore minerals are considered to be syngenetic and regionally metamorphosed while, the associated secondary ore minerals are formed due to alteration of the primary ores.
文摘The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground Mine of Sindeskar Kalan, Vedanta Group, Rajpura-Dariba-Bethumni Belt which are located at a distance of 76 Kms from Udaipur District (Rajasthan) have been studied. The chief litho units of the group are identified which contain sulfide-bearing calc-silicate and graphite mica schist, dolomite marble, calc-biotite schist and quartzite. Importance to the ore minerals like galena and sphalerite which have been reported in association with the buffer minerals like pyrite and pyrrhotite occurr in the host rocks of the study area. Ore petrography denotes two types of sphalerites, 1) highly deformed and dark brown colour, 2) less deformed and with light yellow colour. Galena shows high reflectance and a network of triangular pits. Pyrite shows high reflectance and anomalous anisotropism because of high brittleness.
文摘The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground mines of Sindeskar Kalan, Vedanta Group, Rajpura Dariba-Bethumni Belt which were located at a distance of 76 Kms from Udaipur District (Rajasthan) have been studied. The chief litho units of the group were identified which contain sulfide-bearing calc-silicate and graphite mica schist, dolomite marble, calc-biotite schist and quartzite. Importance to the ore minerals like galena and sphalerite which have been reported in association with the buffer minerals like pyrite and pyrrhotite occurred in the host rocks of the study area. The study of melt inclusion (sulfide melt) of sphalerite showed the maximum temperature of melting which was 923°C on the Linkam-TMS94 (the maximum temperature limit of the system is up to 1500°C). The maximum temperature of melting of sphalerite reveals that the dolerite and/or pegmatite intrusion might have supplied sulfide rich melt during the study area in the geological past.
文摘The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground Mine of Sindeskar Kalan, Vedanta Group, Rajpura Dariba-Bethumni Belt which is located at a distance of 76 kms from Udaipur city, Rajasthan have been studied. The chief litho units of the group which contain sulfide-bearing calc-silicate and graphite mica schist, dolomite marble, calc-biotite schist and quartzite are identified. An attempt has also been made to study/or hydrothermal in origin in the different types of fluid inclusions, hosted predominately in Geothermometry viz. heating and freezing study of entrapped palaeo-fluids (such as sedimentary and quartz host grain and a few in sphalerites). The quartz hosts are identified with four types of fluid inclusions, such as 1) monophase (gas/vapour), 2) gas-rich biphase, 3) liquid-rich biphase and 4) polyphase types. The primary types of fluid inclusions show that melting temperature of ice or depression freezing point (DFP) (ranging from -2.5°C to -7.2°C)/(salinity ranging from 4.5 - 13.25 wt% NaCl eq.) and temperature of homogenization into liquid phase (ranging from +188°C to +218°C) have been measured. Data from the fluid inclusions and salinity calculation (low salinity) reveal that rate of cooling is the important mechanism of ore deposition in the study area.
