016044   Sharma M D;Saini T N (Department of Mathematics, Kurukshetra University, Kurukshetra-136 119) : Velocity anomalies in a cracked poroelastic region. Indian J pure appl Math 2001, 32(3), 331-41.

Elastic and dynamical parameters used in Biot's theory of wave propagation in poroelastic solids are modified for the introduction of cracks. The possible interconnection between cracks are also taken into account while modifying these parameters. During the process of stress accumulation, pores are assumed to be squeezing after draining their liquid to keep the cracks fully saturated. The effects of variations in crack density and increase in width of cracks on wave velocities are observed numerically. Variations in velocity ratio are also observed for different values of crack density, aspect ratio of cracks and for different regimes of connections between cracks. The velocity anomalies observed before an earthquake are linked with modifications in cracks. A hypothetical earthquake preparation process is suggested to explain these velocity anomalies.

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016043   Pitchumani N K;Madhav M R (Department of Civil Engineering, Indian Institute of Technology, Chennai-600 036) : Lateral displacement interaction between soil and reinforcement strip. Indian Geotech J 2000, 30(2), 108-30.

The shear interaction between a reinforcing strip and soil within a reinforced foundation bed is considered. The theory on which the formulation is based is that the lateral deformations, which result from the surface loaded area, are resisted by reinforcing strips placed below the loaded area within the soil. The amount of resistance offered depends on the axial stiffness of the strip. Consequently, shear stresses are developed at the interface. These shear stresses in turn push the soil above the strip upward resulting in a heave of the surface. Thus the strip helps in reducing the surface settlements. The elastic continuum approach is resorted to evaluate the shear stresses mobilised at the soil-reinforcement interface and the surface heave resulting thereof. For evaluating the horizontal displacements at the interfaces due to the surface load, the Boussinesq's equation is used while the Mindlin's equation is used for evaluating the deformations at the interface due to the mobilised shear stresses. The displacement compatibility is satisfied at the interface and the resulting equations are solved simultaneously for the shear stresses. A parametric study brings out the effect of the length, depth of placement and stiffness of the strip on the stress mobilised at the interface and the settlement reduction of points on the surface. Optimum locations and length of the reinforcement are suggested to achieve full benefit of strip reinforcements placed beneath a rectangular.

016042   Manoharan N;Dasgupta S P (Department of Civil Engineering, Indian Institute of Technology, , Kharagpur-721 302) : Large deformation consolidation analysis. Indian Geotech J 2000, 30(2), 146-73.

Starting with the variational formulation proposed by Sandhu and Wilson (1969), a finite element formulation of large deformation consolidation analysis is developed. The formulation results in a coupled problem, which is to be solved numerically. Coupled large deformation analysis using an updated Lagrangian algorithm of both strip and circular footings on Mohr-Coulomb soil has been carried out. Formulations and the developed computer codes, presented in flowchart form, are validated by comparing the results obtained in the present study with the solutions reported in the literature. Analysis reveals that footings experience more displacements and difference between small and large deformation analyses increases in the case of an elasto-plastic modelling. Geometrical nonlinearity increases the soil stiffness and reduce the footing displacement to some extent. Results have been discussed and presented graphically.

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016041   Maitra S N;Midya S K;Tarafdar G;Bhattacharjee B;Chatterjee S S (NO, Jalpaiguri Polytechnic Inst., Post Danguajhar, Dist. Jalpiguri) : Antarctic ozone sink, its covariation with solar parameter and possible effects on environment. Asian J Microbiol Biotechnol envir Sci 2000, 2(3-4), 105-12.

Atmospheric Ozone is a very minor constituent, but it plays an important role to absorb solar U.V. radiations, which are lethal to earth's environment. But the O3 Concentration is declining throughtout the world. Investigates the variation of O3 Concentration at MCMurdo in Antarctica with the variable and basic components of 10.7 cm. Solar flux. A critical study has been made and interesting results are obtained; Correlation coefficients between O3 Concentration and each of two components of radio flux during late winter to spring are maximum the O3 depletion in Antarctica is independent of solar parameters and it can severely affect the biological system.

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016040   Dodagoudar G R;Venkatachalam G (Department of Civil Engineering, I.I.T. Bombay, Mumbai-400 076) : Slope stability evaluation using fuzzy sets. Indian Geotech J 2000, 30(2), 131-45.

Presents the proposed method for stability analysis of slopes incorporating fuzzy uncertainty. The method seeks to develop a new approach for taking into account the uncertainties in evaluating the stability of slopes. Like the probabilistic approach, fuzzy set theory seeks to describe and express explicitly the uncertainties related to the calculation variables introduced in the limiting equilibrium. Fuzzy set theory is isued to encode system uncertainty in a slope reliability analysis. Fuzzy uncertainty is incorporated in the estimated probability of failure. Fuzzy failure probabilities are the fuzzy numbers. A numerical example of finite earth slope problem illustrates the methodology and compares the results with those obtained from a probabilistic analysis. A comparison between two approaches indicates the usefulness of the fuzzy approach. The approach will allow to assess the likelihood that a particular slope section will have a higher failure probability than a critical value.

016039   Bhattacharya G;Pan S (Department of Civil Engineering, Bengal Engineering College (Deemed University), Howrah-711 103) : Passive earth pressure coefficients by generalized procedure of slices. Indian Geotech J 2000, 30(3), 73-85.

The study pertains to the development of a generalized procedure for computation of passive earth pressure coefficients based on limit equilibrium method of slices. The developed procedure does not make any a priori assumption regarding the shape of the potential slip surface and can handle any heterogeneous soil and pore pressure conditions, irregular ground surface and superimposed loads. The problem has been cast as a mathematical programming problem wherein the critical slip surface is found out which minimizes the passive earth pressure subject to some behavioural and side constraints. Janbu's Generalized Procedure of Slices has been adopted as the method of analysis and the solution has been obtained using the well known sequential unconstrained minimization technique of nonlinear programming. The study reveals unconstrained minimization technique of nonlinear programming. The study reveals that for purely frictional soils the classical assumption of a log spiral composite failure surface may lead to non-conservative values of passive earth pressure coefficients.

016038   Anvar Batcha S M (NO, Environmental Sciences Research Centre, Plot No. B-7, Khajamalai Dargha Road, Tiruchirapalli-620 023) : Studies on sediments of north Vembanad lake. Asian J Microbiol Biotechnol envir Sci 2000, 2(3-4), 167-77.

Sediment samples from 18 stations of North Vembanad Lake have been collected from December 1977 to December 1978 (except August 1978) after the construction and commissioning of the Thanneermukkam bund. The sand, silt and clay percentage composition during different seasons have been studied at length. The difference in the composition of the three different components of the sediment samples in different stations have been discussed in detail with reference to their location. The change from primary type of sediments to secondary type, time of shifting and completion is also explained.

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015083   Zhang K J (Department of Earth Sciences, Nanjing University, Nanjing-210 093) : Is the songpan-Ganzi terrane (central China) really underlain by Oceanic crust?. J Geol Soc India 2001, 57(3), 223-30.

The Songpan-Ganzi terrane of central China has long been believed to be floored by oceanic crust. However, several recent deep seismic profiles across the terrane reveal that it could be underlain by Precambrian continental crust. In general, the upper crust of the terrane with a P velocity of less than 6.35 km/s is about 29-32 km thick and could consist of Mesozoic and Paleozoic sedimentary rocks and Precambrian basement. Within the terrane there exist two suites of Permo-Triassic sedimentary rocks in tectonic contact with each other.

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015082   Vinodarao T (Department of Geology, Andhra University, Visakhapatnam-530 003) : Occurrence of fluoride bearing ground waters in western parts of Ongole, Prakasam district, Andhra Pradesh. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 87.

'Fluorosis' a dreadful water borne crippling disease is prevalent among the rural people in western parts of Ongole area, Prakasam district, Andhra Pradesh, as a result of prolonged ingestion of excessive amounts of fluoride bearing waters. A hydrogeochemical survey was carried out in the Western parts of Ongole area to study the distribution of fluoride both in surface and shallow ground waters and to trace the source of fluoride enrichments in waters. The analytical results reveal that the concentrations of fluoride in surface waters is below 1.0 ppm while that in ground waters at some locations increases upto 8.0 ppm. The high concentrations of fluoride can be attributed to the presence of fluorite in granites and gneisses constituting the nearby hills, which is being leached down to the saturated zones by recharge and irrigation return flows. Suggestions have been made for defluoridation of water for drinking water supply and stress to need for detailed study in the area.

015081   Tyagi A;Nagar S G;Seetharamayya P (NO, , AF Station, Pune-411 032) : Variations of thermodynamic parameters in the planetary boundary layer over Calcutta with different intensities of convection. Vatavaran 1999, 23(1), 1-11.

Characteristic features of Planetary Boundary Layer (PBL) over Calcutta during dry, moderate and deep convection have been examined using radiosonde data. Conserved variables have been employed to determine the top of the PBL and to identify the type of convective processes in different phases. Mean profiles for each phase, based on a 5 - day period have been prepared and changes in the thermodynamic parameters (θv,θe,θes, P^*-P and q) between the dry and deep convective phases are discussed. A vertical time section analysis of wind fields for the period 10 June to 30 June 1981 has been carried out to study the relationship between wind field and boundary layer characteristics.

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015080   Tewari V C (NO, Wadia Institute of Himalayan Geology, Dehra Dun-248 001) : Revised chronostratigraphy, macrobiota, ichnofacies and isotopic signatures of the Garbyang formation, Tethyan basin, Garhwal Himalaya. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 92.

015079   Talapatra A K (Monitoring Division, , GSI CHQ, Calcutta-700 016) : A scheme of computer-based mineral deposit modelling and resource evaluation of precambrian terrains. J Geol Soc India 2001, 57(3), 231-7.

A significant part of Precambrian metallogenic provinces in India is covered by soil, sand alluvium or weathered material, where the likely occurrences of concealed ore deposits do not show any surface signature of mineralisation. In fact, continuous exposures of fresh in situ rock are generally very difficult to find in such areas. Even if such exposures are found, these do not normally show any surface indication of mineralisation that was not known earlier. Under such circumstances, indirect non-conventional methods of exploration with the help of computer-based multivariate statistical analyses may provide modelling techniques by establishing the characteristic inter-relationships of geological, geophysical and geochemical parameters to enable prediction of new exploration targets at low cost. Focuses attention on the development of such computer-based statistical models and their utility in various modelling in reconnaissance stage, deposit modelling in regional exploration stage, and ore-body modelling in detailed exploration stage. An attempt has been made to present a holistic scheme of such modelling. Finally, the use of geostatistics with quantitative parameters of regional and detailed exploration stages has been suggested for computer-aided resource evaluation of different deposits and re bodies in a metallogenic province. This is possible through the use of Geographic Information System (GIS) integrating different input data layers to g

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015078   Subudhi C R;Pani B K;Mohanty S K;Senapati H K;Senapati P C;Behera B (Dryland Agricultural Research Project, Orissa University of Agriculture and Technology, Phulbani-762 001) : Rainfall characteristics at Nuagaon of Kandhamal district, Orissa, India. Envir Ecol 2000, 18(4), 1033-5.

On the basis of rainfall data (1975-97) the average annual rainfall of Naugaon is 1,617.3 m n. It has been observed that 85% of the annual rainfall is received from June to September. Frequency analysis for maximum annual rainfall data was done by using Weibull technique. Expected maximum annual daily total rainfall for different return periods was incorporated. Frequency analysis for monthly, seasonal and annual rainfall was carried out and values at 70% probability level were estimated. The kharif season received 1,093.7 mm rainfall. June, July, August and September received 143.6, 272.4, 292.8, 149.5 mm rainfall, respectively. Selection of crop varieties with growing period of four months from June to September is advisable for Nuagaon, under rainfed conditions.

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015077   Subudhi C R;Mohanty S K;Pani B K;Senapati H K;Senapati P C;Behera B (Dryland Agricultural Research Project, Orissa University of Agriculture and Technology, Phulbani-762 001) : Rainfall pattern for Kandhamal district of Orissa, India. Envir Ecol 2000, 18(4), 1039-41.

Rainfall data of Kandhamal district of Orissa was collected and used for the purpose. Annual rainfall at 50% probability levels were computed for all the blocks of the district and block wise rainfall pattern of Kandhamal district was prepared. The rainfall distribution varies with a minimum of 1,306.3 mm (at Tikaballi) to 1,647.3 mm (at Nuagaon). Further, most of the rain occurs in the monsoon period. (June to September). Hence for better yield, crop planning may be taken on the basis of rainfall distribution pattern.

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015076   Srivastava D C (Department of Earth Sciences, University of Roorkee, Roorkee-247 667) : Deformation pattern in the precambrian basement around Masuda, central Rajasthan. J Geol Soc India 2001, 57(3), 197-222.

Detailed mapping of the Precambrian rocks around Masuda in central Rajasthan reveals that the basement is made up of a granulite-granitoid terrane and a sheared gneiss-migmatite terrane. The gneiss-migmatite terrene mainly comprises a multimade of the monzoranite gneisses, amphibolites and migmatised biotite schists. These gneissic-migmatitic rocks are repeatedly mylonitised and folded at scales ranging from thin section to map. The granulite-granitoid terrane consists of massive bodies of granulite and granitoid hosting numerous enclaves of gneiss, monzogranite porphyry and mafic-ultramafic rock. Two successive groups of folds (F1 and F2), each containing two or more sets of co-axial folds are common in the gneiss-migmatite terrane. Whereas the interference between different fold sets belonging to the individual groups has resulted in type 3 interference patterns, the superposition of F2 group folds on F1 group folds has resulted in type 2 interference patterns. Several lines of evidence suggest that F1 and F2 groups of folds have evolved as sheath folds during two phases of ductile shearing, respectively. It is primarily due to the isoclinal nature of the late folds that both the early and late folds display similar style and coplanar relationship in most of the area. A critical comparison reveals that the gneiss-migmatite terranes in the southern and central Rajasthan are different from each other with respect to style of deformation.

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015075   Srivastava A K (NO, Birbal Sahni Institute of Palaeobotany, 53, University Road, Lucknow-226 007) : Glossopteris flora : the source material for the formation of Indian coal. Minetech 2000, 21(5-6), 28-31.

015074   Singh P;Das M;Sahoo N K;Acharya S (P.G. Department of Geology, Utkal University, Bhubaneswar-751 004) : Pillow lava and associated sedimentary rocks of Daitari-Tomka iron ore belt, Jaipur dist., Orissa. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 88-9.

015073   Singh A K (Remote Sensing Application Centre, , U.P. Sector-G, Jankipuram, Kursi Road, Lucknow-226 021) : Ground water appraisal of area around Robertsganj, Sonebhadra district (U.P.) using remote sensing and geophysical studies. Minetech 2000, 21(5-6), 21-6.

015072   Singarasubramanian S R;Mani R;Manoharan K (Department of Geology, Annamalai University, Annamalai Nagar) : Sedimentological history and environmental interpretations of the cretaceous outcrops of Pondicherry area. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 94.

015071   Sethna S F;Kothare P;Sethna B S;Javeri P (Department of Geology, St. Xavier's College, Mumbai-400 001) : Geology and petrography of the intrusives in the Deccan trap of central and south-eastern Saurashtra, India. J Geol Soc India 2001, 57(3), 249-56.

Forty-five major dykes intruding the Deccan trap were studied in the central and south-eastern parts of Saurashtra. There are some distinct structural differences seen between the area north of Amreli and that south of Amreli. The lava flows north of Amreli are practically horizontal, while south of Amreli they seem to be forming a major southerly-plunging antiform. In the area north of Amreli, dolerite dykes are invariably enriched in fresh olivine and are associated with one ankaramite dyke, a hybrid monzodolerite and a stock-like body of essexite (foid monzogabbro). In the area south of Amreli, dolerites are generally olivine free but in a few samples altered olivine is present. These dolerites are associated with rhyolitic dykes, which invariably contain microphenocrysts of quartz and are thus described as quartz porphyries.

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015070   Sarate O S (Birbal Sahni Institute of Palaeobotany, , 53 University Road, P.B. 106, Lucknow-226 007) : A distribution pattern of micro-constituents in the coals of Kondha and Nandori blocks, Wardha valley coalfield, Maharashtra, India. Minetech 2000, 21(5-6), 33-47.

015069   Reddy P R;Koteswara Rao P;Prasad A S S S R S (NO, National Geophysical Research Institute, Hyderabad-500 007) : Delineation of sub-trappean low velocity formations. J Geol Soc India 2001, 57(3), 263-71.

Skips/shadow zones in the first arrival travel seismic time data (refraction) help in delineating hidden low velocity formations sandwiched between two high velocity zones. Efficacy of this processing methodology has been successfully tested utilising analog refraction data acquired along a profile located in the Deccan Trap country. The 2D velocity depth details also suggest probable presence of hidden Sub-Trappean Gondwana formations.

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015068   Ray M;Lahiri S C (Department of Chemistry, Kalyani University, Kalyani-741 235) : Sediment quality of the river Ganga in the deltaic region and its utilisation. Proc Indian Sci Congr Ass - Pt III(YS abstr), Sect-I 1997, (NULL), 133.

Enormous sediment transport of the River Ganga has been causing extensive damage to the ecosystem by carrying huge amounts of exchangeable ions and nutrients like N and P to the sea. The damage aused may be partially resorted by properly utilising the sediment in agronomy.

015067   Rastogi B K (NO, National Geophysical Research Institute, Hyderabad-500 007) : Erattupetta earthquake of 12 December 2000 and seismicity of Kerala. J Geol Soc India 2001, 57(3), 273-4.

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015066   Rajani (NO, Government P.G. College, Kaladera, Jaipur) : Quantitative assessment of ground water as a media for mineral exploration in arid and semi-arid region of western Rajasthan. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 70-1.

The chemical analysis of ground water for major cations and anions of Padru, Mithura, Loharwa and Bhedana villages of arid and semi-arid region of Barmer district of Rajasthan shows that the water is saline and potassium and nitrate are comparatively in higher proportions. Though the water is slightly to moderately saline in nature, but with the presence of high potassium and nitrate content, the water can be profitably utilised for growing salt tolerant crops. The chemical analysis results of ground water may be utilised as a potential tool for exploring the area to quantify the hidden evaporite deposits for economical recovery of potassium nitrate as an import substitute.

015065   Parihar S M;Parihar P K (Department of Geography, Kirori Mal College, University of Delhi, Delhi) : Spatial evaluation of scenic resources for development in mountanous region - a case study of Bhagirathi basin. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 93.

015064   Panjikar J;Ramachandran K T (NO, Gemmological Institute of India, Mumbai) : Synthetic diamond and natural diamonds in the present context. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 90-1.

015063   Panjikar J;Ramachandran K T (NO, Gemmological Institute of India, Mumbai) : Role of gemmology the gemstone science in the 21st century. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 91.

Gemmology is one of the most recent branches of the earth system science. It is the science which involves the rough gem minerals, the gem deposits, the scientific cutting of gems, grading and assortment of stones, the study of the properties of gem species, synthesis of gemstones, various treatments to gemstones to enhance their appearance and their identification. It is the science which is indirectly responsible for the large export earnings in gem and jewellery industry.

015062   Nandi B;Ravi N;Hota M K;Srivastava A;Nanjappa M T (NO, , ) : On some aspects of axis of monsoon trough based on satellite imageries. Vatavaran 1999, 23(1), 21-33.

The positions of axis of monsoon trough (AMT) at surface, 700 hPa and 500 hPa levels were correlated to the monsoon trough as indicated by visible INSAT imageries of 0600 or 0900 UTC. The trough was marked as a line demarcating bright cloud masses and cumuliform clouds in the zonally arranged cloud band. It was found that when the width of intense convective clouds was less than 200 km, the 700 hPa trough matched with this line. The 500 hPa trough matches it when the width of intense clouds in the band is wide and more than 200 km. The AMT on surface generally was found to be better correlated with relatively cloud free-zone.

015061   Mukherjee A (Department of Geological Sciences, Jadavpur University, Calcutta-700 032) : Landslides as natural hazard occuring around Ambootia tea garden in the Darjeeling Himalayas. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 91-2.

015060   Mehrotra N C;Swamy S N;Rawat R S (Oil and Natural Gas Corporation Limited, KDM Institute of Petroleum Exploration, Dehra Dun-248 195) : Reworked carboniferous palynofossils from panna formation, Bombay offshore basin : clue to a hidden target for hydrocarbon exploration. J Geol Soc India 2001, 57(3), 239-48.

A reworked Carboniferous palynofossil assemblage from the subsurface sections of the Early Eocene basal clastics of Panna formation, Bombay offshore basin has been discovered. This assemblage is recorded at various stratigraphic levels of the studied well sections along with the indigenous Early Eocene dinoflagellate cysts and spore-pollen taxa. Initial studies have suggested more than one possibility of explaining the provenance of reworked sediments containing the carboniferous palynofossils. One possibility is that these might have been derived from the erosion of Early Palaeozoic sediments present in the Deccan volcanic province. Alternatively, these sediments could result from long distance transport of reworked material from Saudi Arabia-Africa region in the west which were deposited in the Bombay offshore region during Early Eocene. Available evidences, for and against these two possibilities are discussed. Our studies show that the carboniferous reworked assemblage is confined to the Heera-Bassein block. The reworking in the Panna formation might have taken place by palaeorivulets cutting through the thin Deccan trap flows, exposed in the faulted blocks. A model explaining the mechanism of reworking has been presented. Organic matter studies indicate the presence of mature sediments below the Deccan Trap, which suggest a possible hidden basin to be a new exploration target for hydrocarbon.

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015059   Mandal D K (Department of Geography and Applied Geography, North Bengal University, West Bengal) : Geological consequence on landslide in the Himalaya. Proc Indian Sci Congr Ass - Pt IV, Sect-I 1997, (NULL), 89-90.

015058   Majumder A;Mazumder G;Ghosh A (Department of Agricultural Statistics, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur-741 252) : Statistical characteristics of rainfall distribution in different agro-climatic zones of West Bengal. Envir Ecol 2000, 18(4), 865-8.

Statistical characteristics, randomness and weekly pattern of rainfall distribution in West Bengal are studied extensively over 11 meteorological stations of West Bengal. The meteorological stations are selected from six agro-climatic zones of West Bengal. Old alluvial, new alluvial and coastal and saline zones experience similar types of weekly rainfall pattern. The weekly rainfall pattern of other three zones are different.

015057   Keerthiseelan K;Kapoor S L;Suresha A;Prakash T R (Central Ground Water Board, , South-Western Region, Bangalore-560 011) : Salinity intrusion from tidal recharge and its impact on groundwater quality in Goa state. J Geol Soc India 2001, 57(3), 257-62.

Chemical analysis of water samples collected from streams, borewells and dugwells tapping a shallow zone in Goa indicate that some groundwater occurring in dug wells as well as bore wells is influenced by salinity due to tidal recharge along the river Chapora near the coast. The contamination of groundwater is more pronounced in dry season than in wet season and in areas close to the stream courses. Moreover, the groundwater adjacent to stream course in the NE of Panjim is polluted with domestic sewage in addition to high salinity. The ionic ratios, such as Na⁺/Cl^-, Cl^-/CO2-3 + HCO3^-, Na⁺/Ca²⁺+Mg²⁺ and Br^-/Cl^- of Type III waters, in which strong acids and alkalies exceed weak acids and alkaline earths respectively, are comparable to the ionic ratios of average seawater. However, some well waters have shown secondary salinity, which can be attributed to reverse ion exchange undergone by the intrusive seawater before meeting the groundwater. Fluoride contents of these contaminated waters which is higher than the average fluoride concentration in the groundwater of the area also suggest the mixing of intrusive water with fresh groundwater.

015056   Gupta H K;Harinarayana T;Kousalya M;Mishra D C;Indra Mohan;Purnachandra Rao N;Raju P S;Rastogi B K;Reddy P R; Sarkar D (NO, National Geophysical Research Institute, Hyderabad-500 007) : Bhuj earthquake of 26 January, 2001. J Geol Soc India 2001, 57(3), 275-8.

015055   Dugam S S;Kakade S B (NO, Indian Institute of Tropical Meteorology, Pune-411 008) : The relationship of north Atlantic oscillation and southern oscillation with northeast monsoon. Vatavaran 1999, 23(1), 34-8.

Analysis of Northeast monsoon (NE) rainfall and two low-frequency atmospheric oscillations, namely North Atlantic Oscillation (NAO) and Southern Oscillation (SO), is carried out. For this analysis 108 years (1881-1988) data have been used. The analysis reveals that NAO in the month of April is showing an inverse relationship with NE monsoon rainfall activity. The relationship is statistically significant at 1% level. The SO in the month of May shows a direct relationship with NE monsoon rainfall. Analysis is also carried out on decadal and climatological scale.

013997   Yedekar D B (School of Earth Sciences, SRTM University, Vishnupuri, Nanded-431 606) : Petrology and geochemistry of the felsic volcanics of the Sakoli group. Indian Miner 2000, 54(1-2), 1-34.

Sokoli Group forms roughly a triangular outcrop in central Indian shield. Felsic volcanics are exposed mainly in the southwestern part of this exposure in association with pelitic metasediments. The felsic volcanics comprise pyroclastics, massive lavas and conduit lavas with pyroclastics forming more than 95% of the felsic volcanic suite. The studies suggest that the eruptive centre for the felsic volcanics of the Sakoli Group was in the southwestern part of the basin in Goharli-Gothangaon area. The felsic volcanics are calc-alkaline in character. The trace-elemental and REE characteristics of the volcanics suggest that the felsic melt was generated by interaction of enriched partial melt from mantle and subsequent progressive partial melt at deep crustal levels caused by it. The composition was controlled more by partial melting rather than olivine-orthopyroxene fractionation. Resultant melt had short crustal residence and some fractionation/differentiation at shallow crustal levels. Relationships of Ta, Yb, Th, La, and Ce suggest that the first eruptive phase (pyroclastics of Garara Nerla area) came up without much differentiation/fractionation. The second eruptive phase (pyroclastics and massive lavas) came after a small time gap with the melt being enriched in incompatible elements due to differentation/fractionation. The third phase of eruption (conduit lavas) was relatively depleted due to continued differentiation/fractionation in LREE as well as to some extent HREE. A mixed continental marginal to back-arc tectonic setting is suggested for the felsic lavas.

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013996   Upadhye S N;Tarafdar P;Das D P (Geological Survey of Inida, , Nagpur) : Gold mineralisation in Pandripani area, Raigarh District, M.P. Indian Miner 2000, 54(1-2), 119-26.

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013995   Thakre R;Sarangi B K (Land Environment Management Division, National Environmental Engineering Research Institute, Nagpur-440 020) : Coastal geological alterations. Indian Min Engng J 2000, 39(11), 15.

The coastline is a dynamic environment, which gives rise to specific natural hazards which may affect development. Coastal hazards can be divided into those which are essentially `quiet' and progressive, such as coastal erosion and those which are `dramatic' events such as coastal flooding. In this paper a case study of Gujarat coast line has been highlighted which stretches to about 1600 km. It is quite distinct from the rest of the West Coast of India. The coastal zone of Gujarat is characterised by a variety of geomorphic forms and geological features evolved under different structural controls during the Quaternary period. The present coastline shows much variation in its trend, shoreline features and the near shore and off shore characters. The paper presents the problems of coastal erosion, and salinity ingress in the coastal part, mechanism of sea water intrusion and mitigation strategy for the protection of coastal erosion and flooding.

013994   Srikantappa C;Suresha K J;Shankara M A; Basavalingu B (Department of Geology, University of Mysore, Manasagangotri, Mysore-570 006) : P-T paths, CO2-brine and melt inclusions in the deep crustal rocks from Madurai block, Tamil Nadu, India. Indian Mineralogist 2000, 34(1), 29-31.

013993   Srikantappa C;Srinivas G;Basavarajappa H T; Prakash Narasimha K N;Basavalingu B (Department of Studies in Geology, University of Mysore, Manasagangotri, Mysore-570 006) : Metamorphic evolution and fluid regime in the deep continental crust along the N-S geotransect from Vellar to Dharapuram, southern India. Indian Mineralogist 2000, 34(1), 32-7.

013992   Singh S B;Ashok Babu G;Singh K P;Srinivas Y; Stephen J;Singh U K;Janna Reddy E (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007) : Deep resistivity sounding studies in the south Indian granulite terrain along Kuppam - palani geo - transect. Indian Mineralogist 2000, 34(1), 48-51.

013991   Sidheswaran P;Bhat A N (NO, Hindustan Lever Research Centre, Chakala, Andheri (East), Mumbai-400 099) : Influence of kaolinite calcination temperature on the synthesis of zeolite 4A. Clay Res 2000, 19(1), 35-47.

Effect of kaolinite calcination temperature on the nature and behaviour of zeolite formed in the subsequent hydrothermal synthesis has been explored in the study. Effort has been made to identify the degree of crystallinity, the particle size by SEM and calcium exchange capacity of the resulting zeolite.

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013990   Siddharth S;Jamal A (Department of Mining Engineering, Institute of Technology, Banaras Hindu University, Varanasi-221 005) : Impact of overburden geochemistry on the quality of mine effluent. Indian Min Engng J 2000, 39(11), 34.

Geochemistry of coal/ore and associated overburden along with the grain size and morphology of reactive/non reactive minerals are the important parameters which governs the ultimate quality of mine effluent. In the case of open cast coal mining, mining operations make the availability of rocks at or near the earth surface. These rocks are vulnerable to attack by both physical and chemical processes and accelerates the movements of minerals and degraded product into hydrological cycle. The quality of drainage in coal mines is generally governed by the mineralogical composition of rocks and many other factors (e.g. chemistry of ground water, volume of water, geological structure and relative proportion of each rock type. The study shows that the ratio of acid producing (pyritous rocks) and acid neutralizing (carbonate rocks) rocks ultimately decides the fate of sump water quality (acidic or alkaline) in a mine.

013989   Sengupta S;Sarkar G;Ghosh Roy A K;Bhaduri S K;Gupta S N;Mandal A (Geological Survey of India, , Calcutta-700 016) : Geochemistry and Rb-Sr geochronology of acid tuffs from the northern fringe of the Singhbhum craton and their significance in the precambrian evolution. Indian Miner 2000, 54(1-2), 43-56.

Acid volcanic rocks of tuffaceous nature occur interlayered with metasediments and basic - ultrabasic rocks between the Dalma volcanic belt to the south and the Chotanagpur Gneissic Complex to the north. Inspite of the low-grade metamorphism suffered by the rocks, certain textural - mineralogical attributes, abundance of high field strength and rare-earth elements and primary isotopic signature have remained unaffected. All the samples represent evolved composition but samples from Chandil and Ankro are interpreted to have crystallised from primary melts generated from variable source compositions. On the basis of the nature of isochron, the age of 1484±44 Ma is inferred to be the age of eruption of the acid volcanics. This constrains the age of the metasediments and the basic - ultrabasic rocks occurring conformably interlayered with the acid volcanics and reports for the first time the presence of a mild-Proterzoic sequence in eastern Indian craton. The initial Sr ratio of 0.708545 for the Chandil samples is not very high. It is inferred to be largely dominated by Sr from mantle-derived components and the acid volcanics may be products of differentation from some mantle-derived basic magma.

33 ref

013988   Santosh M (NO, Centre for Earth Science Studies, P B 7250, Akkulam, Thuruvikkal Post, Trivandrum-695 301) : Palaeoproterzoic accretion, pan-african reworking and fluid-driven processes in the continental deep crust of southern India. Indian Mineralogist 2000, 34(1), 22-8.

013987   Saha A K;Mohan M (Geaological Survey of India, , Nagpur-440 006) : Geological and genetic aspects of tungsten mineralisation in Sakoli supracrustals. Indian Miner 2000, 54(1-2), 35-42.

Tungsten mineralisation is widespread in the Sakoli Group of supracrustals forming a prominent fold belt in the eastern parts of Maharashtra State. Tungsten mineralisation in three distinct geological setups is recorded here especially from the south-western parts of the fold belt. The most-developed wolframite-scheelite mineralisation is found in `greisen veins' within the mica schists enclosed on all sides by granite gneisses. The best deposits are found in patches over a strike length of over 16 km between Kuhi in the west to Agargaon in the east. The next dominant type of mineralisation is in the `hydrothermal quartz veins' occurring in swarms within a country of amphibolite and metachert to the west of Kolari-Bhaonri. The least established and explored scheelite mineralisation is recorded in the `lime-skarn' lenses within Umrer granite around Umrer, Phegar and Shikarpur. Scheelite mineralisation with the basemetal sulphides has also been reported recently in major quartz veins in Parsori area emplaced both in phyllite and meta-acid volcanics. The varying geological environment and setup of tungsten mineralisation in the south-western part of the fold belt is discussed and the possible genetic link to a tungsten-enriched pranitic activity is suggested.

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013986   Reddy P R;Misra D C;Sarma S V S;Harinarayana T;Divakara Rao V;Narayana B L;Singh S B (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007) : Subsurface configuration of the southern high grade granulite terrain-inferences from integrated geological/geochemical/seismic/magneto telluric deep resistivity and gravity studies. Indian Mineralogist 2000, 34(1), 41-7.

013985   Ray L;Senthil Kumar P;Reddy G K;Roy S;Rao G V;Srinivasan R;Rao R U M (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007) : Geothermal regime of the southern granulite province, peninsular India. Indian Mineralogist 2000, 34(1), 19.

013984   Rajaram M;Harikumar P;Balakrishnan T S (NO, Indian Institute of Geomagnetism, Colaba, Mumbai-400 005) : Implications of the aeromagnetic data for the southern granulite terrain. Indian Mineralogist 2000, 34(1), 39-40.