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M. Satish Kumar ¹, M. Santosh ¹

Affiliations
1 Centre for Earth Science Studies. P.B.7250, Akkulam, Thuruvikkal Post, Trivandrum 695 031, IN

Abstract

The granite pluton at Kalpatta in northern Kerala is a member of the Late Precambrian magmatic suite emplaced proximal to transcrustal faults in southern India In this study. we report the find of fluorite mineralization within late pegmatite phase associated with the granite. Both purple and colourless fluorites are associated, with X-ray diffraction pattern indicating perfect crystalline nature. Wet chemical analyses show CaF₂ contents of 92 and 96 % for purple and transparent fluorites respectively. Primary fluid inclusions in both fluorite categories belong to aqueous bi-phase type, with T_h between 150-180° C, and salinity in the range of 3 to 9 wt. per cent NaCl equivalent. Qurtz associated with fluorite contains CO₂-H₂O inclusions with T_h(C02) between 8 to 15° C (density 0.85-0.90 g/cm³). The nature of mineralizing fluids suggests that fluorite crystallization occured from low temperature hydrothermal solutions derived as end-products of the frctionation of volatile- and alkli-enriched felsic magma. The mineralization is regarded as a finger-print of the alkaline affinity of Pan-African magmatism in Kerala.

Keywords

Fluorite, Fluid Inclusions, Kalpatta Granite, Kerala.

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M. Satish Kumar ¹, M. Santosh ¹, S. Yoshikura ², M. Yoshida ¹

Affiliations
1 Department of Geosciences, Osaka City University, Osaka 558, JP
2 Department of Geology, Kochi University, Kochi 780, JP

Abstract

Colour-coded compositional mapping under an electron microprobe provides useful information on chemical gradients within the domain of individual minerals. Here we apply this technique to granulite facies reaction textures from a calc-silicate-charnockite interface at Nuliyam, southern Kerala, to understand the element mobility patterns and mass balance related to fluid-induced metasomatism during deep crustal metamorphism. The contact zone assemblage at Nuliyam is characterized by plagioclase + quartz symplectites after K-feldspar. From element mapping of this reaction interface on micron - scale, and from quantitative analyses of the individal mineral phases under an electron microprobe, we trace the diffusion of K, and addition of Na and Ca, through an open system migration dUling the influx of externally-derived CO₂-rich fluids. Our study provides the first direct evidence for microscale chemical diffusion associated with CO₂-induced charnockite formation in southern Kerala, and illustrates the potential of colour-coded compositional mapping in tracing element mobility patterns.

Keywords

Metamorphic Petrology, EPMA - Compositional Mapping, Calc-Silicate, Charnockite, Nuliyam, Southern Kerala.

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Shubhadeep Ghosh ¹, M. V. Hanumantha Rao ¹, M. Satish Kumar ¹, V. Uma Mahesh ¹, M. Muktha ¹, P. U. Zacharia ²

Affiliations
1 Visakhapatnam Regional Centre of Central Marine Fisheries Research Institute, Visakhapatnam 530 003, IN
2 Central Marine Fisheries Research Institute, Cochin 682 018, IN

Abstract

The contribution of marine fisheries in Visakhapatnam at all stages of its life cycle to climate change during 2010-2012 was studied by determining its carbon footprint. Pre-harvest phase consisted of vessel construction and maintenance and provision of fishing gear; harvest phase included harvest from mechanized and motorized craft and post-harvest phase involved fish transportation and fish processing. The functional unit selected was 1 kg of marine fish to the consumer. Fuel and electricity consumption was 0.48 l/kg and 0.255 kWh/kg of fish. The C and CO₂ emitted were 0.382 kg C/kg and 1.404 kg CO₂/kg of fish. The highest consumption of energy and the highest emissions of CO2 were observed from the harvest phase. The fuel and electricity consumption and C and CO₂ emissions were high for mechanized landings and low for motorized landings. Reduction in energy consumption and subsequent emissions is possible in mechanized craft by increasing the fuel efficiency of marine diesel engines, controlling craft speed, using large propeller with lower revolutions and reducing the craft drag.

Keywords

Carbon Footprint, Co₂ Emission, Energy Consumption, Lifecycle Analysis, Marine Fisheries.

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K. R. Hari ¹, M. Satish Kumar ², M. Santosh ³, Suneet Kumar Rai ¹

Affiliations
1 Government Arts and Science College, Durg, Madhya Pradesh 491 001, IN
2 Department of Geoscience, Osaka City University-559, JP
3 Centre for Earth Science Studies, P.B.No. 7250, Akkulam, Trivandrum - 695 018, IN

Abstract

Carbonate-rich rocks occur as E-W trending dyke-like bodies in the Deccan 'basalts at Chhaktalao area in the lower Narmada valley and show a structurally controlled mode of emplacement. Modal composition shows calcite as the dominent mineral (∼90%). Ankerite, apatite, altered olivine, augite and opaques account for the remaining percentage. Geochemically, these rocks show high CaO (>50%) with low SiO₂, TiO₂, FeO* and K₂O. Trace element concentrations are low compared to average carbonatites. Stable isotope studies show that δ¹³C(-1.74‰ to -2.8‰) and δ¹⁸O(+12.75‰ to +13.35‰) values do not compare with those of "primary igneous carbonatites" eventhough they fall within the wide range of "igneous carbonatites". These rocks can be considered only as carbonate-rich rocks and not as true carbonatites.

Keywords

Petrology, Carbonate-Rich Rocks, Stable Isotope, Nannada Valley, Madhya Pradesh.

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M. Satish Kumar ¹, M. Santosh ¹, H. Wada ²

Affiliations
1 Department of Geosciences, Osaka City University, Sugimoto cho, Sumiyoshi ku 3-3-138, Osaka-558, JP
2 Institute of Geoscience, Shizuoka University, Ohya 836, Shizuoka 422, JP

Abstract

Calcite-graphite isotope exchange thermometer is a useful tool in elucidating the peak metamorphic temperatures in regionally metamorphosed marbles, for which normal cation exchange thermometers are not available.

Keywords

Isotope Thermometry, Granulites, Marbles, Geochemistry, Kerala.

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