Journal of Geological Society of India (Online archive from Vol 1 to Vol 78) https://www.i-scholar.in/index.php/JGSI <div id="i-scholarabout">The Journal of the Geological Society of India is a premier earth science journal which publishes peer -reviewed articles under the category of Review papers, Research papers, News and Notes, Discussion, Correspondence and Book Review. The articles published deal with all branches of Earth System Science. The journal is published every month constituiting two volumes per year.</div> en-US editorjournalgsi@gmail.com (B. Mahabaleswar) jgsi.jouml@gmail.com (B.R. Krishna) Sat, 01 Sep 2012 00:00:00 +0000 OJS 2.4.2.0 http://blogs.law.harvard.edu/tech/rss 60 Geochemical Behaviour of Vanadium, Chromium, Cobalt, Nickel, and Copper during Progressive Chloritization of Biotites in Granites https://www.i-scholar.in/index.php/JGSI/article/view/183450 Evaluation of the vanadium, chromium, cobalt, nickel, and copper contents of five biotites, chloritized to varying degrees, from a magmatic granitic series of the 2700-million-year-old Giants Range Batholith of Northeastern Minnesota, USA, on the southern margin of the Canadian Shield, determined by wavelength-dispersive x-ray fluorescence spectrometry, shows that, during progressive chloritization of biotites in granites, the content of vanadium decreases and the contents of chromium, cobalt, nickel, and copper increase. The results emphasise the need for great caution when interpreting whole-rock trace-element data in petrological research. S. Viswanathan, Yamuna Singh, B. Mahabaleswar https://www.i-scholar.in/index.php/JGSI/article/view/183450 Sat, 01 Sep 2012 00:00:00 +0000 Efficacy of Electrical Resistivity Tomography Technique in Mapping Shallow Subsurface Anomaly https://www.i-scholar.in/index.php/JGSI/article/view/183451 Electrical Resistivity Tomography is a versatile, fast and cost effective technique for mapping the shallow subsurface anomaly. It covers a wide spectrum of resistivity ranging from &lt;1 Ohm.m to several thousands of Ohm.m. In this paper applications and utility of two-dimensional Electrical Resistivity Tomography (ERT) technique are discussed to look into huge data density coverage, different signal strengths of data from subsurface and their implications in resolving the aquifer zones, related geological structures etc. of the substratum ranging from alluvium to tectonically disturbed hard rock ridge region of the country. The major advantages and flexibility of ERT over conventional resistivity methods are also discussed. Dewashish Kumar https://www.i-scholar.in/index.php/JGSI/article/view/183451 Sat, 01 Sep 2012 00:00:00 +0000 Fractal Analysis of Magnetite Grains - Implications for Interpreting Deformation Mechanism https://www.i-scholar.in/index.php/JGSI/article/view/183452 In the present study, the grain size (d) and shape of 225 magnetite grains, that crystallized at T&gt;600°C in a syntectonic granite (Godhra Granite, India) are evaluated and implications of data to decipher deformation mechanism of magnetite are discussed. Fractal (ruler) dimension (D) analysis of magnetite grains is performed and it is demonstrated that they show fractal behaviour. Smaller magnetite grains tend to be more serrated than the larger ones, which is manifested in the higher fractal (ruler) dimension (D) of the former. Assuming a natural strain rate ranging between 10<sup>-10</sup> s<sup>-1</sup> and 10<sup>-14</sup> s<sup>-1</sup> , the grain size data fall dominantly in the dislocation creep field of the existing deformation mechanism map of magnetite for 630°C. However, SEM-EBSD studies reveal that subgrains are absent in the magnetite grains and they did not undergo dislocation creep. Thus it is inferred that the shape of magnetite grains was not controlled by dislocation creep. It is concluded that the higher serration and increased fractal dimension of finer magnetite grains implies the importance of diffusion creep as an important deformation mechanism at high-T for magnetite in polymineralic rocks. Manish A. Mamtani https://www.i-scholar.in/index.php/JGSI/article/view/183452 Sat, 01 Sep 2012 00:00:00 +0000 Lava Channel of Khedrai Dam, Northeast of Nasik in Western Deccan Volcanic Province: Detailed Morphology and Evidences of Channel Reactivation https://www.i-scholar.in/index.php/JGSI/article/view/183453 The 120 m-wide Khedrai Dam lava channel is one of the widest recorded in the Deccan Volcanic Province. Like many recent ones, this channel also has a pair of linear marginal levees made of breccia and confines the channelfill lava. It is resting over a pahoehoe flow (substrate) of basalt studded with plagioclase megacrysts, also known as the Giant Plagioclase Basalt (GPB). The channel-fill lava, which makes the lining at the edges and basal portion of the channel, is a comb-layered basalt (Cl-B) characterized by alternating layers rich in curved, branching augite crystals and laths of plagioclase - a texture indicative of high order of supercooling and rapid cooling rates. The dominant and centrally filling lava of this channel is a plagioclase-phyric basalt (Pp-B) that has a wide variation in phenocryst number from megacryst-poor to megacryst-rich. Occurrence of centimetre to decimetre size angular fragments of Cl-B within Pp-B fill indicates mechanical dislodgements of channel-lining by flowing lava. This also suggests that the channel was reactivated before it finally lost its hydraulic gradient and solidified. Bibhas Sen, A. B. Sabale, P. V. Sukumaran https://www.i-scholar.in/index.php/JGSI/article/view/183453 Sat, 01 Sep 2012 00:00:00 +0000 Petrographic and Depositional Characteristics of Tadkeshwar Lignite Deposits (Cambay Basin), Gujarat https://www.i-scholar.in/index.php/JGSI/article/view/183454 Tadkeshwar lignite deposits are one of the important Lower Tertiary lignite deposits of Cambay Basin, Gujarat. These lignites are rich in huminite macerals followed by liptinite and inertinite with moderate to high proportions of associated mineral matter. Under fluorescence mode these are found to be rich in liptinite macerals, in particular the liptodetrinite and resinite. The type of huminite suggests that the lignite is formed from mixed vegetal source, i.e. woody forest vegetation and herbs, shrubs. The composition of macerals indicates the deposition of lignite in sub-aqueous condition in wet-reducing environment with intermittent exposure and subsidence of the peat surface. The rank of the Main and the Leader seams, determined through reflectance measurement, indicate that the lignite is less mature. The considerable amount of perhydrous huminite may have contributed to the lower reflectance values in some of the samples. Low rank and appreciable amount of mineral matter make the lignite suitable for its utilization in thermal power plants, however when upgraded or mixed with better quality coals it can be used for other industries. Alpana Singh, O. P. Thakur, B. D. Singh https://www.i-scholar.in/index.php/JGSI/article/view/183454 Sat, 01 Sep 2012 00:00:00 +0000 Application of Universal Soil Loss Equation (USLE) to Recently Reclaimed Badlands along the Adula and Mahalungi Rivers, Pravara Basin, Maharashtra https://www.i-scholar.in/index.php/JGSI/article/view/183455 The rapid erosion of soil by wind and water has been a problem since man began cultivating the land. Moreover soil erosion, as a hazard, has always been associated mainly with agriculture in the tropical and semi-arid areas. Soil loss through rill, gully and sheet erosion is a major environmental problem in India. Among all the predictive equations developed to estimate soil loss, the most accepted, used, convenient and suitable technique, for smaller areas like hillslopes and fields, is the <em>Universal Soil Loss Equation (USLE).</em> This method has been applied to the cultivated fields on either side of the gullied banks of the Adula and Mahalungi rivers, to estimate soil loss from fields under different crops. Rainfall data from the IMD has been used for the purpose. Field slope measurements, textural analysis of soil and determination of soil organic matter have also been carried out. Finally the soil loss has been computed from the generated data. The results have been used to ascertain whether the soil loss in the area is within or beyond the tolerance limit. It has been found that the soil loss in these areas have exceeded the tolerance limit and hence require due attention. Debasree Sinha, Veena U. Joshi https://www.i-scholar.in/index.php/JGSI/article/view/183455 Sat, 01 Sep 2012 00:00:00 +0000 Characterization of Bauxite Deposits from Kachchh Area, Gujarat https://www.i-scholar.in/index.php/JGSI/article/view/183456 The bauxites deposits of Kachchh area in Gujarat are investigated to characterize them based on mineralogical and petrographic studies. The major bauxitic mineral in these occurrences is gibbsite, with minor concentration of boehmite and diaspore. Apart from the bauxitic minerals, the other associate minerals are kaolin, calcite, alunite and the iron ore minerals such as hematite and goethite and titanium rich anatase. The iron ore minerals (hematite and goethite) are 10-50microns in size and are disseminated throughout the oolitic and pisolitic bauxitic minerals. At places the goethite exhibits colloform texture. The preservation of basaltic texture in some of the samples indicate that the insitu nature of these bauxites, which are formed by the alteration of calcic plagioclase from the parent basalt. Although, the basalt occurs as the main parent rock for these bauxites, the presence of calcite in some of the samples represent the possibility of having a limestone parent rock at least in some of the bauxite occurrences. G. N. Jadhav, N. Sharma, Priyanka Sen https://www.i-scholar.in/index.php/JGSI/article/view/183456 Sat, 01 Sep 2012 00:00:00 +0000 Hydrogeology of a Buried Channel, Village Shenoli, District Satara, Maharashtra https://www.i-scholar.in/index.php/JGSI/article/view/183457 <p>A buried channel has been located, in the basaltic terrain, near village Shenoli, District Satara, Maharashtra. It is composed of a gritty mass formed of a semi-consolidated material. The resistivity value of the semi-consolidated formation is 6.30 Ohm - m whereas the resistivity values of the vesicular basalts range between 18 and 32 Ohm-m. The specific capacity, unit area specific capacity, specific capacity index, transmissivity and hydraulic conductivity, with respect of the buried channel, are 609.07 LPM/m of drawdown, 12.12 LPM/m<sup>3</sup>, 95.47 LPM/m<sup>2</sup>, 353.26 m<sup>2</sup>/day and 55.37 m/day, respectively whereas the values of these parameters for basalt aquifers range from 67 to 117 LPM/m of drawdown, 0.7 to 4.27 LPM/ m<sup>3</sup>, 14.08 to 31.04 LPM/m<sup>2</sup>, 33.5 to 73.71 m<sup>2</sup>/day and 9.44 to 18.32 m/day, respectively. A comparison of the well characteristics and aquifer parameters reveal that the buried channel with semi-consolidated formation has distinctly better groundwater yielding properties.</p><p>The groundwater from the semi-consolidated formation has distinctly different quality. The electrical conductivity (EC) of the water from the basalt aquifers ranges between 417 and 555 micro mhos/cm with a modal value of 430 micro mhos/cm, which is 960 micro mhos/cm at 25° C for the semi-consolidated material forming the buried channel. The plots on the Trilinear diagram show that all the samples fall in field 5 where alkaline earths exceed alkalies and weak acids exceed strong acids but it is clear that the proportion of alkalies and weak acids in the water from the buried channel aquifer is higher than the water from the basalt aquifers.</p> A. K. Sinha, R. P. Singh, P. P. Khanna https://www.i-scholar.in/index.php/JGSI/article/view/183457 Sat, 01 Sep 2012 00:00:00 +0000 Petrological and Geochemical Studies of Paleoproterozoic Mafic Dykes from the Chitrangi Region, Mahakoshal Supracrustal Belt, Central Indian Tectonic Zone: Petrogenetic and Tectonic Significance https://www.i-scholar.in/index.php/JGSI/article/view/183458 A number of Paleoproterozoic mafic dykes are reported to intrude volcano-sedimentary sequences of the Mahakoshal supracrustal belt. They are medium to coarse-grained and mostly trend in ENE-WSW to E-W. Petrographically they are metadolerite and metabasite. Geochemical compositions classify them as sub-alkaline basalts to andesites with high-iron tholeiitic nature. Both groups, i.e. metabasites and metadolerites, show distinct geochemical characteristics; high-field strength elements are relatively higher in metadolerites than metabasites. This suggests their derivation from different mantle melts. Chemistry does not support any possibility of crustal contamination. Trace element modeling advocates that metabasite dykes are derived from a melt originated through ~20% melting of a depleted mantle source, whereas metadolerite dykes are probably derived from a tholeiitic magma generated through &lt;10% melting of a enriched mantle source. Chemistry also reveals that the studied samples are derived from deep mantle sources. HFSE based discrimination diagrams suggest that metabasite dykes are emplaced in tectonic environment similar to the N-type mid-oceanic ridge basalts (N-MORB) and the metadolerite dykes exhibit tectonic setting observed for the within-plate basalts. These inferences show agreement with the available tectonic model presented for the Mahakoshal supracrustal belt. The Chitrangi region experienced N-MORB type mafic magmatism around 2.5 Ga (metabasite dykes) and within-plate mafic magmatism around 1.5-1.8 Ga (metadolerite dykes and probably other alkaline and carbonatite magmatic rocks). Rajesh K. Srivastava https://www.i-scholar.in/index.php/JGSI/article/view/183458 Sat, 01 Sep 2012 00:00:00 +0000 Interpretation of Aero-Magnetic Data and Satellite Imagery to Delineate Structure - A Case Study for Uranium Exploration from Gwalior Basin, India https://www.i-scholar.in/index.php/JGSI/article/view/183459 The Paleo-Meso Proterozoic Gwalior basin (E - W), lying to NW fringe of Bundelkhand massif is represented by litho-package of lower arenaceous Par Formation and upper chemogenic Morar Formation. It is bounded by Indo- Gangetic alluvium in north and east, Kaimur sediments in west and Bundelkhand granitoids in south. Gwalior Basin has been the exploration target for uranium mineralization right from early 60's. Surface radioactivity anomalies due to uranium has been reported in both Par and Morar Formations of Gwalior Group and Vindhyan sediments. Besides presence of syngenetic uranium in the system, presence of post-depositional faults and fractures are the favorable factors. Aeromagnetic survey was carried out by AMD in 2002 with N-S lines of 500 m interval covering 9406 line km. The data with sampling interval of 0.1 sec was corrected for spikes, diurnal variation, IGRF, heading and lag. Final processed images are prepared after suitable leveling and gridding. First vertical derivative of TMI-RTP and tilt-angle derivative images are used to map the litho-contacts, lineaments and structural features. Numerous NE-SW trending low amplitude and NW-SE trending high amplitude magnetic linears corroborate with quartz reefs and basic dykes respectively. Besides, E-W to WNW-ESE and ENE-WSW trending fractures are also evident from the processed image maps. Further, the Euler's depth solution of gridded aeromagnetic data calculated for structural indices of 0 and 1 are very consistent in locating the position of the causative sources. Based on the amplitude and textural character of processed aeromagnetic data, alteration zone is delineated well within the Morar Formation. Enhanced Thematic Mapper (ETM+) image with 30m resolution was merged with IRS PAN 1D (5.8 m resolution) for better spatial/radiometric resolution to extract lithocontacts and lineament patterns. Merged PAN band-4 after linear contrast and edge enhancement techniques deciphered detailed lineament pattern, which corroborate the magnetic data. Merged ETM+ (RGB 751) and PC (PC1-PC2-PC5) images depict litho-logical contrast. Integration of aeromagnetic and satellite imagery data helped in understanding the structural fabric of the Gwalior Basin and to identify favorable loci of uranium mineralization. A. Markandeyulu, I. Patra, B. V. S. N. Raju, A. K. Chaturvedi, P. S. Parihar https://www.i-scholar.in/index.php/JGSI/article/view/183459 Sat, 01 Sep 2012 00:00:00 +0000 Earthquake Forerunner as Probable Precursor - An Example from North Burma Subduction Zone https://www.i-scholar.in/index.php/JGSI/article/view/183460 The Burmese Arc seismic activity is not uniform for its ~ 1100 km length; only the Northern Burmese Arc (NBA) is intensely active. Six large earthquakes in the magnitude range 6.1 - 7.4 have originated from the NBA Benioff zone between 1954 -2011, within an area of 200 × 300 km<sup>2</sup> where the Indian plate subducts eastward to depths beyond 200 km below the Burma plate. An analysis on seismogenesis of this interplate region suggests that while the subducting lithosphere is characterized by profuse seismicity, seismicity in the overriding plate is rather few. Large earthquakes occurring in the overriding plate are associated with the backarc Shan-Sagaing Fault (SSF) further east. The forecasting performance of the Benioff zone earthquakes in NBA as forerunner is analysed here by: (i) spatial earthquake clustering, (ii) seismic cycles and their temporal quiescence and (iii) the characteristic temporal b-value changes. Three such clusters (C1- C3) are identified from NBA Benioff Zones I&amp;II that are capable of generating earthquakes in the magnitude ranges of 7.38 to 7.93. Seismic cycles evidenced for the Zone I displayed distinct quiescence (Q<sub>1,</sub> Q<sub>2</sub> and Q<sub>3</sub>) prior to the 6<sup>th</sup> August 1988 (M 6.6) earthquake. Similar cycles were used to forecast an earthquake (Dasgupta et al. 2010) to come from the Zone I (cluster C1); which, actually struck on 4 February 2011 (M 6.3). The preparatory activity for an event has already been set in the Zone II and we speculate its occurrence as a large event (M &gt; 6.0) possibly within the year 2012, somewhere close to cluster C3. Temporal analysis of b-value indicates a rise before an ensuing large earthquake. Sujit Dasgupta, Basab Mukhopadhyay, Manoj Mukhopadhyay https://www.i-scholar.in/index.php/JGSI/article/view/183460 Sat, 01 Sep 2012 00:00:00 +0000 Late Holocene Storm Records from Lower Reaches of Narmada Valley, Western India https://www.i-scholar.in/index.php/JGSI/article/view/183461 Storms from the Arabian Sea are the most significant meteorological feature in western India that brings extreme rainy days together with catastrophic flooding. The present study reports two such palaeo-storm horizons at 1.16 m and 3.2 m above the present day water level in the Narmada channel, 56 km inland based on sedimentology and foraminiferal records. Both the horizons show similar sediment facies and foraminiferal assemblage. The present findings instigate to look for such new sites and build palaeo-storm records for western India. Prabhin Sukumaran, C. Rajshekhar, Dhananjay A. Sant, K. Krishnan https://www.i-scholar.in/index.php/JGSI/article/view/183461 Sat, 01 Sep 2012 00:00:00 +0000 Paleoenvironment of Deposition of the Dupi Tila formation, Lalmai Hills, Comilla, Bangladesh https://www.i-scholar.in/index.php/JGSI/article/view/183462 The Dupi Tila Formation is composed of yellow to light brown medium to very fine moderately hard to loose sandstone, siltstone, silty clay, mudstone and shale with some conglomerates with clasts of petrified wood. The lithofacies of matrix supported conglomerate, trough cross bedded conglomerate, massive sandstone, trough cross bedded sandstone, planar cross bedded sandstone, ripple cross laminated sandstone-siltstone, flaser laminated sandstone-shale, lenticular laminated sandstone-siltstone-shale, parallel laminated sandstone-siltstone, wavy laminated shale, parallel laminated blue shale, and mudstone are delineated within this formation. Based on the grain size, sedimentary structures, water depth and genesis of individual facies, facies are grouped into three types of facies associations like (i) coarse-grained conglomerate facies association in relation to tractive current deposits of alluvial fan set up at the base of litho-succession (FAC), (ii) medium to fine-grained sandstone-siltstone-mudstone facies association or facies association in relation to strong tide (FAT) characterizing the middle part of litho-succession, (iii) very fine-grained sandstone-siltstone-mudstone facies association in relation to less frequent weak tide or heterolithic facies association (FAHL) characterizing upper part of litho-succession and shallow marine facies association (FASM) composing the uppermost litho-succession. Presence of gluconite indicates that the depositional environment was shallow to deep marine. The dominant paleoflow direction during the deposition of Dupi Tila Formation was toward southeast to southwestern direction. The rivers were of braided type at the piedmont alluvial depositional set up at the lower part, which later changed to estuarine-tidal flat type environmental set up in the middle part to upper part and paleo-environment was shallow marine in the uppermost part. Mrinal Kanti Roy, Syed Samsuddin Ahmed, Tapas Kumar Bhattacharjee, Sultan Mahmud, Md. Moniruzzaman, Md. Masidul Haque, Sudip Saha, Md. Ismail Molla, Pulan Chandra Roy https://www.i-scholar.in/index.php/JGSI/article/view/183462 Sat, 01 Sep 2012 00:00:00 +0000 Geological Modeling and Short-Term Production Planning of Dimension Stone Quarries Based on Market Demand https://www.i-scholar.in/index.php/JGSI/article/view/183463 In order to obtain minimum amount of ore wastage and maximum profitability in dimension stone quarries an optimal short-term production planning procedure has been established here according to the market demand. As the base of this procedure geological modelling has been first created and smoothing of ore-body boundaries was done. Then, an economical block model has been provided. In the next step, all probable shapes of minable-blocks were specified and their priorities in assignment were done according to desired size of the blocks by market demand. Finally, searching from a base sub-block was started in order to find the optimal plan. The procedure has been used for a dimension marble quarry located in northwest of Iran. It demonstrates a decrease about 26% of ore wastage and 21.3% of diamond wire assumption with comparing to the existent traditional procedure. J. Abdollahisharif, E. Bakhtavar, A. Alipour, M. Mokhtarian https://www.i-scholar.in/index.php/JGSI/article/view/183463 Sat, 01 Sep 2012 00:00:00 +0000 Characterization of Clay Minerals in the Sundarban Mangroves River Sediments by SEM/EDS https://www.i-scholar.in/index.php/JGSI/article/view/183464 Clay minerals, byproducts of chemical weathering, are important group of minerals found in rivers, estuaries, and marine sedimentary environments, which include mudstones, clay stones, and shales. In the present study, FTIR and SEM investigation on the clay minerals in Sundarban mangrove core sediments collected from Moipith Matla and Belamati Island are carried out. The study indicated the dominant association of kaolinite with subordinate amount of quartz, illite and chlorite. The abundance of kaolinite, illite chlorite and clay with quartz helps in increasing sediment in the islands region. The geochemical and mineralogical evolution of mangrove sediments are results of the interaction of biotic and abiotic parameters, whose balance is conditioned by the climate that governs the hydrologic regime, the sedimentation dynamics and the organic matter. This study on the charaterstation of clay provides us with substantial impact in the water holding capacity, productivity and mineralogical and chemical transformation in order to establish much more and intermediate equilibrium between marine influence and continental contribution, as part of the estuarine environment, than to the tropical climate conditions. K. Rajkumar, Al. Ramanathan, P. N. Behera https://www.i-scholar.in/index.php/JGSI/article/view/183464 Sat, 01 Sep 2012 00:00:00 +0000 Reservoir Induced Landslide at Assar, Jammu and Kashmir: A Case Study https://www.i-scholar.in/index.php/JGSI/article/view/183465 In February 2009, a huge landslide occurred at Assar in Doda district of Jammu and Kashmir state. The slide triggered after the reservoir level of the Baglihar dam increased from initial water level of 850 m to 870 m. The impounding of reservoir water created high angle scarps at number of fossil slide sites on either side of the river within the reservoir area. One such scarp (about 250 m long) at Assar caused a huge landslide washing out about 150 m road stretch. The sliding material is dominated by finer fraction (71.5 %) of micaceous silty sand and coarser fraction of gravel to boulder size. Over saturation of the slope forming material, weak rocks and high absorption and swelling nature of the soil, high slope angle and toe cutting by the water are the main reasons that triggered this slide. Yudhbir Singh, G. M. Bhat, Vinay Sharma, S. K. Pandita, K. K. Thakur https://www.i-scholar.in/index.php/JGSI/article/view/183465 Sat, 01 Sep 2012 00:00:00 +0000 Foundation Day of Geological Society of India: Group discussion on Mining and Environment https://www.i-scholar.in/index.php/JGSI/article/view/183466 No Abstract. S. V. Srikantia https://www.i-scholar.in/index.php/JGSI/article/view/183466 Sat, 01 Sep 2012 00:00:00 +0000 Petrology and Geochemistry of the Vivekananda Rock at Kanniyakumari, Tamil Nadu, Southern India https://www.i-scholar.in/index.php/JGSI/article/view/183467 No Abstract. C. Bhattacharyya, U. Tickha https://www.i-scholar.in/index.php/JGSI/article/view/183467 Sat, 01 Sep 2012 00:00:00 +0000 Relevance of Philately in Earth Science and its Significance in Paleontology https://www.i-scholar.in/index.php/JGSI/article/view/183468 No Abstract. Ajit V. Vartak https://www.i-scholar.in/index.php/JGSI/article/view/183468 Sat, 01 Sep 2012 00:00:00 +0000 Greenland's Ancient Impact https://www.i-scholar.in/index.php/JGSI/article/view/183469 No Abstract. https://www.i-scholar.in/index.php/JGSI/article/view/183469 Sat, 01 Sep 2012 00:00:00 +0000