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Chakraborty, S. K.
- Petrology of Early Palaeozoic Lamprophyres from Schirmacher Oasis, East Antarctica
Authors
1 Antarctica Division, Geological Survey of India, NH 5P, N.I.T., Faridabad- 121001, IN
2 Central Petrological Laboratory, Geological Survey of India, 15 A & D Kyd Street, Calcutta-700016, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 56, No 6 (2000), Pagination: 593-604Abstract
Lamprophyre dykes are conspicuous within the Proterozoic high-grade metamorphic rocks of Schirmacher Oasis. These dykes have been classified chemically into alkaline and calc-alkaline types on the basis of K2O/Na2O ratio and CIPW norm. The close association, age and geochemical similarities of both the-lamprophyres and melasyenite in thc area indicale their consanguinity and derivation from same source region. These lamprophyres have a high concentration of incornpatible elements like Ba, Rb, Sr and Zr. These rocks also have a high Mg# and depict a negative Ta-Nb-Ti anomaly. The chondrite normalised REE patterns show fractionated trends with large variation in LREE and small variation in HREE concentration in both the rock groups. The calc-alkaline lamprophyre is more enriched in LREE than the alkaline lamprophyre.
It is proposed that metasomatised phlogopite-bearing enriched mantle source has undergone partial melting to generate lamprophyric magma. This magma is generated in a continental within-plate tectonic setting. The collision of East and West Gondwana during Pan-African orogeny, resultant overthickening of continental lithosphere and generation of widespread magmatic activity in the region due to partial melting has culminated in the intrusion of lamprophyres around 450 Ma ago.
Keywords
Lamprophyre, Melasyenite, Schirmacher Oasis, East Antarctica, Pan-African Orogeny.
- Depositional Architecture of Mio-Pliocene Sequences in Offshore Bengal Basin
Authors
1 Reliance Industries Ltd , Mumbai, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 67, No Spl Iss 5 (2006), Pagination: 575-583Abstract
Bengal Basin located along the northeast coast of India has a thick pile of MIO-Pliocene sediments fed by a number of large rivers like Ganga, Brahmaputra, Mahanadi and smaller rivers like Subarnarekha, Baitaram and Brahmani. The basin covers an area of 40,000 sq km in the Bay of Bengal. The sediments in the present day shelf area exhibit a complex deposition history with unique juxtaposition of shallow and deep water sediments in the form of deltas, distributary channels, Pro-Delta sediments and incised canyons, filled up with channel-levee complex deposits.A detailed study was carried out on the morphology and architecture of the different depositional elements and units utilizing different vintages of 2D/3D seismic and data from drilled wells Geo-Body mapping and attribute studies reveal finer details of the complex system Special seismic attributes such as spectrally decomposed amplitude, waveform classifier and 'sweetness' (amplitude by square ischolar_main of frequency) were quiet helpful in understanding the morphological details of the system. The following depositional elements have been brought out
•Delta-Distributary channel complex associated with incised valley and tidal inlets.
•Shelfal Canyon cut and fill sequences.
o Simple canyon fills Simple "V" shaped cuts with fills in the form of low to moderate sinuous.
channels.
o Complex Canyon cut and fills Numerous, repeated canyon cuts caused by Mass-Wasting with intervening fills in the form of deep water to Sub-Aerial channels and deltaic progradational deposits.
•Deep-Water Channel Complex Fed by large canyon up-dip. These depositional elements do not form part of the canyon fill, but occur down-dip.
The sand and si1t lithological distribution in the above depositional complexes form the predominant hydrocarbon reservoir units. The numerous reservoir bodies within the above units of varying lateral and vertical extents, are expected to hold the future exploration potential in this frontier basin.
Keywords
Morphology, Architecture, Bengal Basin.- Alkali Basalt of Kachchh: its Implication in the Tectonic Framework of Mesozoic of Western India
Authors
1 Geochronology and Isotope Geology Division, Geological Survey of India, 15 A & B, Kyd Street, Kolkata - 700 016, IN
2 Geological Survey of India, Operation Gujarat, Gandhinagar - 382 093, IN
3 Central Petrological Laboratories, Geological Survey of India, 15 A & B, Kyd Street, Kolkata - 700 016, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 66, No 5 (2005), Pagination: 599-608Abstract
Field evidences in Kachchh show that alkali basalts occur as flows over Mesozoic sediments. The top parts of Mesozoic Bhuj Sandstone often carry scoria and lapilli related to alkali basalt magmatism indicating that alkali magmatism and sedimentation went side by side. Tholente flows occur as blanket over both Mesozoic sediments and alkali basalt bodies.Evidences are provided to show that alkali basalt magmatism in Kachchh was not only an earlier episode than tholente emplacement, it also predates the closing of Kachchh Mesozoic basin and seems to support a protracted period of Deccan magmatism (70 - 60 Ma). The study also shows that huge concentration of alkali basalt in the western Kachchh mainland is associated to a zone of transtension related to the rifting of Kachchh basin. Alkali basalt bodies and whole of Mesozoic sequence were affected by reverse faults related to closure of Kachchh basin with development of series of hanging wall anticlinal and footwall synclinal structures.
Keywords
Alkali Basalt, Tholente, Flow, Plug, Releasing Bend, Kachchh.- Chemistry of Blotites from Pelitic Schists and Granitic Rocks of McCluskieganj, District Palamau, Bihar
Authors
1 Department of Geology, Patna University, Patna, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 17, No 3 (1976), Pagination: 322-331Abstract
Composition of biotites from the pelitic schists and granitic rocks of McCluskieganj indicate that the former is rich in magnesium and the latter in iron; their Mg-Fe content is controlled by the composition of the respective host rock. The study of biotite of granitic rocks suggests that oxygen fugacites which prevailed during crystallization closely followed the QFM buffer. Positive correlation of Na between the co-existing K-feldspar and biotite in the granitic rocks, indicates that equilibrium conditions had reached during crystallization of these minerals. Experimental results of a porphyritic granite show that the rock was formed at the 'minimum melt' condition (655°C at PH20 = 4 kb).- Effect of Integrated Nutrient Supply on Growth, Leaf Yield and Field Performance of Mulberry (Morus alba) under Semi Irrigated Lateritic Soil Condition of West MidNapur District, West Bengal
Authors
1 Department of Zoology, Vidyasagar University, West Midnapur, West Bengal, IN
2 Central Sericultural Research and Training Instiitute, West Bengal, IN
Source
Journal of Environment and Sociobiology, Vol 5, No 2 (2008), Pagination: 221-226Abstract
A field experiment was conducted during 2004-06 to study the effect of organic manures along with bio-fertilizers and reduced doses of chemical fertilizers on growth and leaf yield of mulberry, belonging to the variety S1635 in lateritic soil condition with limited irrigation of West Midnapur areas having around pH 5.6. However plant height, number of tiller, leaf area, leaf yield, leaf moisture and total soluble protein were found high owing to application of different organic residues along with biofertilizers and reduced doses of chemical fertilizers. Among organic manures poultry litters along with biofertilizers with reduced dose of mineral fertilizers significantly increased leaf yield (11446.50 kg/ha/year) which is 5.76% over control. Application of organic manure like poultry litter on S1635 mulberry variety can reduce nitrogenous fertilizers (168 kg/ha/year) and 60% phosphatic fertilizers (60 kg/ha/year) over recommended dose (336 kg/ha/year, 180 kg/ha/year respectively) without any detrimental effect and could save Rs. 2440.00 /ha/year by curtailing the cost of cultivation by 6.75%.Keywords
Mulberry, Vermicompost, Poultry Manure Azotobactor, Arbuscular, Micorrhizal Fungi.- A Study of Transport Related Noise Pollution in Asansol Town, West Bengal Using Modelling Techniques
Authors
1 Department of Physics, Banwarilal Bhalotia College, Asansol-71304, W.B., IN
Source
Nature Environment and Pollution Technology, Vol 6, No 4 (2007), Pagination: 601-607Abstract
With rapid urbanization of our cities and towns and resultant increase in the number of vehicles on roads, noise pollution is growing at an alarming rate. About 60% of total noise in the any urban environment can be credited to road traffic. The objective of the present study was to model and predict the road traffic noise and compare the results with observed values in an urban environment. Two models, namely, 'Calculation of Road Traffic Noise' (CORTN of U.K.) and 'Federal Highway Administration' (FHWA of U.S.A.) were used in the study. The study area selected for the investigation was Asansol town, an urban-industrial town, situated in eastern India. The values predicted by each of the models were analysed and compared with observed data collected at ten locations in the study area. Three tests, namely, 't'-test, correlation coefficient (r) and deviation between predicted and observed values was used to validate the modelling results. Based on the test criterions, statistical validation and comparison with other similar works, it can be said that both models gave acceptable results under Indian road conditions, with certain degree of error. The CORTN model (r = 0.8313) provided better prediction than the FHWA model (r = 0.8031). The deviation range of the CORTN was also lower 1- 4 db(A) against the FHWA predicted range of 1-6 db(A). Refinement of the model inputs is required as per Indian road conditions to enhance the quality of prediction.Full Text
- Education, Technology and Development: An Approach
Authors
1 Assistant Professor of Education, NITTTR, Kolkata-700 106, IN
2 Director, NITTTR, Kolkata-700 106, IN
3 Senior Lecturer of Mechanical Engineering, NITTTR, Kolkata-700 106, IN
Source
Indian Science Cruiser, Vol 18, No 4 (2004), Pagination: 36-44Abstract
"Existing educational Institutions were created to meet the need of a society that Is first disappearing. We need new educational organizations that can exploit the new technologies to meet the needs of twenty-first century Economic development win depend as much on the success of creativity and supporting such organizations, as on establishing the technological Infrastructure, it is critical to get this right because those countries that harness the power of multimedia communication for education and training purposes will be the economic powerhouses of the twenty-first century. The development of modern communications and Information technologies is becoming a major Instrument for widening access to education and training on a cost-effective basis while also enhancing its quality."Keywords
No Keywords.References
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