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K. S. Balasubramaniam ¹, V. Panchapakesan ¹, K. C. Sahu ¹

Affiliations
1 Indian Institute of Technology, Bombay, IN

Abstract

The homogenisation studies of gas-liquid fluid inclusions in fluorites from Handev Dongar-Ambadongar (Gujarat) and Kahela-Mandokipal (Rajasthan) carried out with a fabricated heating stage corroborates the earlier view that both the deposits are typically of a low hydrothermal origin.

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K. C. Sahu ¹, V. Panchapakesan ¹, R. R. Patil ¹

Affiliations
1 Geology Section, Indian Institute of Technology, Bombay 400076, IN

Abstract

Fluid inclusion studies were carried out on the milky white vein qurtz intimately associated with Kolihan sulphide assemblage. The studies reveal that the deposition should have taken place at a temperature higher than 350°C and the ore-bearing solutions could have had a very high degree of salinity approaching the condition of a 'hydrosaline melt' with 33% NaCI and 17% KCl by weight.

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B. K. Nayak ¹, V. Panchapakesan ²

Affiliations
1 Wadia Institute of Himalayan Geology, Dehra Dun 248001 (U.P.), IN
2 Department of Earth Sciences, I.I.T., Bombay 400076, IN

Abstract

The thermodynamical calculations for the oxygen and sulphur fugacities of Mosaboni mineralisation have been made based on the equilibrium reactions for various mineralogical associations like, (a) bornite-pyrite-chalcopyrite. (b) pyrite-pyrrhotite. (c) pyrite-magnetite, (d) pyrrhotite-magnetite and (e) pyrite-pyrrhotite-magnetite and the temperatures determined by fluid inclusion studies. The association of pyrite-pyrrhotite-magnetite indicates that oxygen fugacity was 10^-24.3 atmosphere at 450°C and this got reduced to 10^-32.5 atmosphere at 300°C. Presence of bornite in place of magnetite shows that there was fluctuation in the fugacity of sulphur. This might be varying from 10^-6.3 to ^-1.6 atmosphere at 450°C and from 10^-11.6 to 10^-6.4 atmosphere at 300°C.

Keywords

Fluid Inclusion, Thermodynamics. Mosaboni, Sulphide Mineralization, Bihar.

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B. K. Nayak ¹, V. Panchapakesan ²

Affiliations
1 Wadia Institute of Himalayan Geology, Dehra Dun 248 001 (U.P.), IN
2 Department of Earth Sciences, LLT., Bombay 400 076, IN

Abstract

There exists a strong control of fluid inclusion homogenization temperature on the assay of copper ore in the Mosaboni mine. The ores, having copper assay greater than or equal to 1.5%,are more or less confined to a homogenization temperature range of 320° and 360°C. This also reflects that these ores were precipitated within narrow salinity limits of 38.6 and 42.8 equivalent wt. per cent NaCl. The homogenization temperature varied between 275° and 420°C with the highest recorded temperatures at the bottom levels indicating that the ore-forming fluids came from below and migrated upward precipitating various grades of ores at favourable sites under suitable physico-chemical conditions.

Keywords

Fluid Inclusion, Economic Geology, Mosaboni Mine, Singhbhum, Bihar.

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B. K. Nayak ¹, V. Panchapakesan ²

Affiliations
1 Wadia Institute of Himalayan Geology, Dehra Dun - 248 001 (U.P.), IN
2 Department of Earth Sciences, I.I.T. Powai, Bombay - 400076, IN

Abstract

The equation, N = 2πX²/√3, has been derived to find out the number of hexagonally distributed points (N), in a given circle of radius 'R' and the point-point distance 'd'. where X = R/d. For a given set of microscopic conditions, the above equation is applied to construct 4 standard circular graphic charts. An, attempt has been made to use these charts to study the population of fluid inclusions, by visual comparison, in the quartz samples intimately associated with the sulphides collected from the Mosaboni mine of Bihar.

Keywords

Fluid Inclusion, Mosaboni, Bihar.

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B. K. Nayak ¹, V. Panchapakesan ²

Affiliations
1 Regional Research Laboratory, Bhubaneshwar, Orissa 751013, IN
2 Dept. of Earth Science, IIT, Bombay-400076, IN

Abstract

Distribution pattern of fluid inclusion homogenisation temparatures and assay of copper ores hove been uscd to ascertain the mineralising fluid ascent direction. Thetrigonametric relationships to calculate the parameters of this direction have been derived which show that the bearing of ascent of ore fluids isN 53.°E-S 53°W having plunge 38° and rake 77°. There is high probability of encountering rich ores underneath 30th level in a direction opposite to fluid ascent at selected locations.

Keywords

Fluid inclusions, Ecodornic Geology, Sulphide Deposits, Mosnboni, Bihar.

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D. Narasimhan ¹, N. Krishna Rao ¹, V. Panchapakesan ², K. C. Sahu ²

Affiliations
1 Ore Dressing Section, Bhabha Atomic Research Centre, Begumpet, Hydembad - 500016, IN
2 Department of Earth Sciences, Indian Institute of Technology, Powai, Bombay - 400076, IN

Abstract

Fluid inclusion study has indicated two distinct stages of mineralisation: one with higher T_H and lower salinity (greisens) and the other with lower T_H and slightly higher salinity (quartz vein) conditions. These mark the formation conditions of wolframite and scheelite respectively.

Keywords

Economic Geology, Fluid Inclusions, Tungsten, Wolframite, Maharashtra.

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