001517   Venkatachalapathy R;Veerasingam S;Basavaiah N;Ramkumar T;Deenadayalan K (Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai Univ, Parangipettai, Tamil Nadu-608 502, Email: venkatr5@rediffmail.com) : Environmental magnetic and geochemical charcateristics of Chennai coastal sediments, Bay of Bengal, India. J Earth Syst Sci 2011, 120(5), 885-95.

In this study, environmental magnetic, heavy metal and statistical analyses were conducted on 21 surface sediments collected from Chennai coast, India, to examine the feasibility of heavy metal pollution using magnetic susceptibility. The Chennai coastal sediment samples are dominated by ferrimagnetic minerals corresponding to magnetite-like minerals. The percentage of frequency dependent magnetic susceptibility reflects the presence of super-paramagnetic/single domain magnetic minerals in Chennai harbour, Cooum and Adayar rivers sediments. High pollution load index in sample El, E2, CH7, Cll, C12 and A16 is mainly due to anthropogenic activities such as, harbour activities, Cooum and Adayar rivers input and industrial effluent. Factor analysis shows that the magnetic concentration dependent parameters (x, XARM and SIRM) covary with the heavy metal concentrations, suggesting that the input of magnetic minerals and heavy metals in Chennai coastal sediments are derived from the same anthropogenic sources. Strong correlation obtained between pollution load index (PLI) and concentration dependent parameters (x> XARM and SIRM) for the polluted samples with magnetic susceptibility excess of 50x10^-8 m³kg^-1. Significant correlations between heavy metals and magnetic susceptibility point out the potential of magnetic screening/monitoring for simple and rapid proxy indicator of heavy metal pollution in marine sediments.

14 illus, 27 ref

001516   Udayaganesan P;Angusamy N;Gujar A R; Rajamanickam G V (NO, Alagappa Government Arts College, Karaikudi-630 003, Email: vrajamanickam@hotmail.com) : Surface microtextures of quartz grains from the central coast of Tamil Nadu. J Geol Soc India 2011, 77(1), 26-34.

Quartz grain surface micro textures of 12 samples collected from the beach were examined under scanning electron microscopy to understand the role of coastal processes on their transportation and deposition. The study area has been divided into three sectors on the basis of drainage, geomorphology and nature of the beach and shelf topography. Surface textures of the northern sector display an array of mechanical features like conchoidal fracture, V marks and impact pits, indicating the dominance of mechanical processes. However, silica precipitation in the form of globules indicates an added influence of chemical processes in the Northern sector. The presence of chemical features in northern sector, where energy level is high, corroborates the addition of quartz grains from paleo-sediments, from the nearby Tertiary and Cretaceous formations. Central sector quartz grains display the signatures of chemical and mechanical processes. The presence of step like furrows in southern sector is an indicator of fluvial low energy conditions, and supplements the role of littoral currents in depositing the quartz grains along the coastal region.

4 illus, 1 table, 22 ref

001515   Twumasi Y A;Andrew M;Coleman T L;Merem E C; Osei A (Agricultural Research Unit Dep, Alcorn State Univesrity, MS 39096, U.S.A., Email: yaw@alcorn.edu) : Visualization of the rangeland resources from space: s case of Sahel region, West Africa. Int J Geomatics Geosci 2012, 3(1), 259-68.

Study uses Landsat data and Tasseled Cap Transformation green vegetation index (GVI) technique to assess the condition of rangeland resources in the Sahel region of West Africa. Three representative zones in the sahelian region of Mali, Burkina Faso and Niger were selected for this study. Satellite data covering fifteen years period was used to assess the extent to which rangeland resources have degraded on a country by country basis between 1984 and 1999. The study results show all three countries in the study area experienced vegetation decline. However, loss of vegetation cover was most pronounced in the northern part of the study area than in the south. This decline could be attributed to changing temperature and rainfall gradients.

1 illus, 3 tables, 31 ref

001514   Thakur O P;Dogra N N (Geology Dep, Kurukshetra Univ, Kurukshetra-136 119, Email: thakurop@gmail.com) : Palynofacies characterization for hydrocarbon source rock evaluation in the subathu formation of Marhighat, Sirmaur district, Himachal Pradesh. J Earth Syst Sci 2011, 120(5), 933-8.

This paper deals with the hydrocarbon source rock evaluation of the Subathu Formation exposed at Marhighat on Sarahan-Narag road in Sirmaur district of Himachal Pradesh. Hydrocarbon potential of these sediments is estimated on the basis of palynofacies analysis and thermal alteration index (TAI) values based on the fossil spores/pollen colouration. The analyses are based on the classification and hydrocarbon generation potential of plant derived dispersed organic matter present in the sediments. The palynofacies analysis of Subathu Formation in the area reveal moderate to rich organic matter, with amorphous organic matter constituting the bulk of the total organic matter, followed by charcoal, biodegraded organic matter, fungal remains, spores/pollen and structured terrestrial organic matter. The TAI value for the organic matter in these sediments has been ascertained as 3.00. A dominance of the sapropelic facies (amorphous organic matter) and the measured TAI values for the Subathu sediments in the Marhighat area suggests a good source-rock potential for the hydrocarbon generation.

2 illus, 1 table, 22 ref

001513   Thakur G S;Usmani H U;Gupta S K (Applied Geology Dep, Dr. H.S. Gour Univ, Sagar-470 003, Email: gsthakur_76@hotmail.com) : Bhimkund and Arjunkund dolines, Chhatarpur district, Madhya Pradesh. J Geol Soc India 2010, 76(4), 369-70.

2 illus, 2 ref

001512   Surdas Singh N;Santosh Kumar (Geology Dep, Kumaun Univ, Nainital-263 002, Email: skyadavan@yahoo.com) : Petrology and geochemistry of the Mafic Dyke rocks from precambrian Almora crystallines of Kumaun Lesser Himalaya. J Geol Soc India 2010, 76(5), 437-52.

Mafic dykes of Almora region intrude the Precambrian erystalline rocks of Kumaun Lesser Himalaya. Mafic dykes exhibit fine grained margin and medium to coarse grained core, melanocratic, low to highly ferromagnetic (MS=0.85-38.58x10^-3SI) in nature commonly showing subophitic to ophitic textures with ol-pl-cpx-hbl-bt-mt-ap-sp assemblage, and modally correspond to leucogabbro and olivine gabbro (sensu stricto). Olivine (Fo₆₁-Fo₃₃), clinopyroxene (Wo₄₆-En₄₂-Fs₂₂ to Wo₄₀-En₃₆-Fs₁₅) and plagioclase (An₅₈-An₁₂) have crystallized in the temperature range of ca 1400-980"C at pressure <62>2 kbar in an olivine tholeiitic basalt parent. Low acmite (Na_pfu=0.033-0.025), (Mg*=0.64-0.82), Ti-Al contents of clinopyroxenes and their evolution along enstatite-ferrosilite join (i.e. Mg = Fe substitution) strongly suggest tholeiitic nature of mafic dyke melt with changing activities of alumina and silica. Clinopyroxene compositions of mafic dykes differ markedly as compared to those observed for adjoining Bhimtal volcanics but closely resemble to that crystallized in tholeiitic melts of Deccan province. Observed Cr vs Mg* variation, enriched LILE (Sr, Ba)-LREE and positive Eu-anomaly of the studied mafic dykes are indicative of fractional crystallization of olivine-clinopyroxene -plagioclase from a crustally-contaminated tholeiitic basalt magma derived from enriched mantle source. The mafic dykes of Almora are geochemically identical to mafic dykes of Nainital, but are unrelated to Precambrian mafic volcanic flow and dykes of NW Himalaya and dykes of Salma and Rajmahal regions.

12 illus, 6 tables, 63 ref

001511   Sudarsana Raju G;Ashok Kumar Reddy P T; Shivakumar K N (Geology and Geoinformatics Dep, Yogivemana University, Kadapa-516 003, Email: gsraju05@gnail.com) : Evaluation of aquifer characteristics in and around Kadiri Schist belt of Anantapur district, Andhra Pradesh. Int J Geomatics Geosci 2012, 3(1), 229-38.

Evaluation of aquifer characteristics were carried out for evaluation of groundwater.in and around Kadiri schist belt. The study area comprises mainly acid volcanics represented by rhyolites, rhyodacite, and quartz-sericite schist with subordinate basic volcanics (amphibolites), and is enveloped on all sides by granitoids of peninsular gneissic complex. Evaluation of hydraulic properties of aquifer is one of the important aspects of groundwater assessment of rate of movement of water through an area is a function of the hydraulic properties of the aquifers. Further hydraulic properties like Transmissibility, Storage Coefficient and Specific Capacity were conducted in different locations of the study area.Pumping tests carried out by different methods are used to classify poor, moderate and good aquifer condition.

4 illus, 5 tables, 9 ref

001510   Sreejith K M;Radhakrishna M;Krishna K S; Majumdar T J (Geosciences Div, Marine, Geo and Planetary Sciences Group, Space Applications Centre,, Ahmedabad-380 015, Email: sreejith81@gmail.com) : Development of the negative gravity anomaly of the 85 E ridge, northeastern Indian ocean-a process oriented modelling approach. J Earth Syst Sci 2011, 120(4), 605-15.

The 85°E Ridge extends from the Mahanadi Basin, off northeastern margin of India to the Afanasy Nikitin Seamount in the Central Indian Basin. The ridge is associated with two contrasting gravity anomalies: negative anomaly over the north part (up to 5°N latitude), where the ridge structure is buried under thick Bengal Fan sediments and positive anomaly over the south part, where the structure is intermittently exposed above the seafloor. Ship-borne gravity and seismic reflection data are modelled using process oriented method and this suggest that the 85°E Ridge was emplaced on approximately 10-15 km thick elastic plate (Te) and in an off-ridge tectonic setting. We simulated gravity anomalies for different crust-sediment structural configurations of the ridge that were existing at three geological ages, such as Late Cretaceous, Early Miocene and Present. The study shows that the gravity anomaly of the ridge in the north has changed through time from its inception to present. During the Late Cretaceous the ridge was associated with a significant positive anomaly with a compensation generated by a broad flexure of the Moho boundary. By Early Miocene the ridge was approximately covered by the post-collision sediments and led to alteration of the initial gravity anomaly to a small positive anomaly. At present, the ridge is buried by approximately 3 km thick Bengal Fan sediments on its crestal region and about 8 km thick pre- and post-collision sediments on the flanks. This geological setting had changed physical properties of the sediments and led to alter the minor positive gravity anomaly of Early Miocene to the distinct negative gravity anomaly.

5 illus, 1 table, 37 ref

001509   Som S K;Shivgotra V;Saha A (Earthquake Geology Div, Geological Survey of India, Salt Lake City, Kolkata-700 091, Email: sksom@rediffmail.com) : GPS derived co-seismic and post-seismic effects of recent earthquakes on peninsular Indian shield and its tectonic implications. J Geol Soc India 2010, 76(5), 485-92.

Several major earthquakes affected the stable continental Indian peninsular shield in recent past due to the activity of fault movements. This necessitates identifying the active faults in the region for future monitoring. The far field co-seismic and post-seismic effects of recent major earthquakes occurred at Sumatra, 2004, Pakistan, 2007 and Indonesia, 2007 on HYDE and IISc IGS GPS stations were studied by small span GPS analysis. Different type of movement pattern on displacement components ensure the reactivation of existing fault planes signifying an integral relationship between GPS displacement vectors and geological structure of the region.

5 illus, 1 table, 15 ref

001508   Som A;Sai Baba M;Jeyagopal A V;Shobhita K; Mohanty R;Maithani P B (Atomic Mineral Directorate for Exploration and Research, Begumpet, Hyderabad-560 629, Email: som.anjan@gmail.com) : Occurrence of uranium in metasedimentary enclaves within basement granite, near Peddur and Kottur, Karimnagar district, Andhra Pradesh. J Geol Soc India 2010, 76(3), 247-50.

Several radioactive anomalies due to uranium and thorium, associated with the mesedimentary enclaves (Archaean) within granite (Archaean to Early-Proterozoic) have been recorded in parts of Karimnagar Granulite Terrain, Karimnagar Dist. At Peddur and Kottur, Uraninite has been identified in the samples of metasediments. The mctasediment from these two places have been subjected to granulite facies of metamorphism and host high values of uranium with negligible thorium. In Peddur, samples of metasediments have assayed as high as 1.96% U₃O₈ with negligible thorium, and in Kottur up to 0.059% U₃O₈. Leaching studies on these samples have indicated that most of the U₃O₃ present is leachable. This discovery has opened up the possibility of finding uranium mineralisation in Archaean metasediments and thus provides a thrust for uranium exploration in similar geological environs in India. Further, the basement granite along with the metasedimentary enclaves has the potential to act as a provenance for a possible unconformity type or sandstone type U-deposit in the rocks of overlying Pakhal and Gondwana Supergroup, in Pranhita-Godavari Basin, situated to the east of this area.

4 illus, 2 tables, 7 ref

001507   Singh R K;Tiwari R N (Geology Dep, Government Science College, Rewa-486 001) : Sectoral zoning in natural fluorites from carbonatite rocks of Ambadongar, Gujarat. J Geol Soc India 2010, 76(3), 244-6.

Examines the presence of various types of zoning and spatial distribution of luminescence activating trace elements including REEs in natural fluorites from carbonatite rocks of Ambadongar, Gujarat. At Ambadongar, fiuorite occurs as veins and vugs in different colours e.g. blue, yellow, green and purple associated with carbonatite and alkaline rocks. Cathodoluminescence microscopy was used to study the internal morphology including growth sectors, growth bands and concentric zoning patterns in fiuorite crystals.

1 illus, 10 ref

001506   Singh M K (Centre for Advanced Study in Geology, Banaras Hindu Univ, Varanasi-221 005, Email: manojgeology78@rediffmail.com) : Assessing the relative packing behaviour of Chandarpur and Khairagarh sandstones of proterozoic Chhattisgarh basin. J Geol Soc India 2011, 77(1), 35-41.

The paper concerns mainly with properties of packing of the Proterozoic Chandarpur and Khairagarh sandstones of Chhattisgarh Basin. An attempt has been made to decipher the nature of boundary between Chandarpur Group and overlying Raipur Group on the basis of grain packing. For the purpose of study based on eight representative thin sections of Chandarpur and Khairagarh sandstones, measurements of grain size distribution, types of grain contacts, packing density (Pd), packing proximity (Pp) and linear regression analysis has been carried out. The relation of packing density with packing proximity of Khairagarh sandstone shows positive correlation coefficient (r) with linear regression equation (y) and no clear trend in packing proximity (Pp) vs grain size (Is) is observed whereas Chandarpur sandstone shows packing density increases and packing proximity decreases with linear regression equation (y) and correlation coefficient (r). Chandarpur grain size tends to increase with packing density (Pd) whereas packing proximity (Pp) increases but Khairagarh sandstone packing density (Pd) decrease with increase of grain size (Is) and packing proximity (Pp) tends to increase with decrease in grain size. Above study indicates that packing behaviour of Chandarpur sandstones and Khairagarh sandstones are entirely different.

7 illus, 4 tables, 22 ref

001505   Shekhar S;Bhola A M;Saklani P S (Geology Dep, Delhi Univ, Delhi-110 007, Email: shashankshekhar01@gmail.com) : Kink bands in thrust regime: examples from Srinagar-Garhwal area, Uttarakhand, India. J Earth Syst Sci 2011, 120(5), 939-48.

This paper deciphers the late stress systems involved in the development of kink bands in the perspec-Hive of thrust regime. In kink bands, the correlation coefficient for α-β plots is positive near thrusts and negative away from thrusts. The plots show nearly linear relationship near thrusts and non-linear relationship away from thrusts. The rotation was prominent mechanism of kink band formation near thrusts and rotation coupled with shearing, along the kink planes away from thrusts. Along thrusts a1 is horizontal E-W trend and it rotates to horizontal N-S trend away from the thrust. The proposed model establishes that (1) the shearing along kink planes led to angular relationship, β <60> α and (2) the kink planes of conjugate kinks could be used for paleostress analysis even in those cases where shearing along these planes has occurred.

7 illus, 59 ref

001504   Sharma A;Tiwari K N;Bhadoria P B S (Civil Engineering Dep, BRCM College of Engineering & technology, Bahal, Bhiwani-127 028, Email: arbind_78@rediffmail.com) : Determining the optimum cell size of digital elevation model for hydrologic application. J Earth Syst Sci 2011, 120(4), 573-82.

Scale is one of the most important but unsolved issues in various scientific disciplines that deal with spatial data. The arbitrary choice of grid cell size for contour interpolated digital elevation models (DEM) is one of the major sources of uncertainty in the hydrologic modelling process. In this paper, an attempt was made to identify methods for determining an optimum cell size for a contour interpolated DEM in prior to hydrologic modelling. Twenty-meter interval contour lines were used to generate DEMs of five different resolutions, viz., 30, 45, 60, 75, and 90 m using TOPOGRID algorithm. The obtained DEMs were explored for their intrinsic quality using four different methods, i.e., sink analysis, fractal dimension of derived stream network, entropy measurement and semivariogram modelling. These methods were applied to determine the level artifacts (interpolation error) in DEM surface as well as derived stream network, spatial information content and spatial variability respectively. The results indicated that a 90 m cell size is sufficient to capture the terrain variability for subsequent hydrologic modelling in the study area. The significance of this research work is that it provides methods which DEM users can apply to select an appropriate DEM cell size in prior to detailed hydrologic modelling.

7 illus, 2 tables, 28 ref

001503   Shamaun Kabir A S M;Hossain D;Abdullah R (NO, Bangladesh Petroleum Exploration and Production Company Ltd. (BAPEX), Dhaka-1217, Email: shamaunm@yahoo.com) : 2-D electrical imaging in some geotechnical investigation of Madhupur city, Bangladesh. J Geol Soc India 2011, 77(1), 73-81.

Electrical imaging or electrical tomography is a survey technique suitable for the investigation of areas of shallow complex geology, where the use of other electrical and electromagnetic techniques is less effective. An electrical image has been delineated at a site located in front of the Department of Geological Sciences, Jahangirnagar University, Dhaka, Bangladesh. 16 soil samples were collected from two boreholes located on the image line and geotechnical parameters such as unit weight, water content, grain size, plastic limit, liquid limit and plasticity index were measured in the laboratory. These geotechnical parameters were compared with the measured electrical resistivity.

7 illus, 1 table, 19 ref

001502   Shahi N R;Agarwal N;Mathur A K;Sarkar A (Atmospheric and Oceanic Sciences Group, Space Applications, Centre (ISRO), Ahmedabad-380 015, Email: navenshahi@gmail.com) : Atmospheric correction for sea surface temperature retrieval from single thermal channel radiometer data onboard kalpana satellite. J Earth Syst Sci 2011, 120(3), 337-46.

Atmospheric correction method has been applied on sea surface temperature (SST) retrieval algorithm using Very High Resolution Radiometer (VHRR) single window channel radiance data onboard Kalpana satellite (K-SAT). The technique makes use of concurrent water vapour fields available from Microwave Imager onboard Tropical Rainfall Measuring Mission (TRMM/TMI) satellite. Total water vapour content and satellite zenith angle dependent SST retrieval algorithm has been developed using Radiative Transfer Model [MODTRAN ver3.0] simulations for Kalpana 10.5-12.5 μm thermal window channel. Retrieval of Kalpana SST (K-SST) has been carried out for every half-hourly acquisition of Kalpana data for the year 2008 to cover whole annual cycle of SST over Indian Ocean (IO). Validation of the retrieved corrected SST has been carried out using near-simultaneous observations of ship and buoys datasets covering Arabian Sea, Bay of Bengal and IO regions. A significant improvement in Root Mean Square Deviation (RMSD) of K-SST with respect to buoy (1.50-1.02 K) and to ship datasets (1.41-1.19 K) is seen with the use of near real-time water vapour fields of TMI. Furthermore, comparison of the retrieved SST has also been carried out using near simultaneous observations of TRMM/TMI SST over IO regions. The analysis shows that K-SST has overall cold bias of 1.17 K and an RMSD of 1.09 K after bias correction.

6 illus, 4 tables, 30 ref

001501   Sethupathi A S;Lakshmi Narasimhan C; Vasanthamohan V (NO, Infosys Technologies Ltd, Bangalore-560 100, Email: lakshmina_c@yahoo.com) : Evaluation of hydrogeomorphological landforms and lineaments using GIS and Remote Sensing techniques in Bargur - Mathur subwatersheds, Ponnaiyar River basin, India. Int J Geomatics Geosci 2012, 3(1), 178-90.

Landsat ETM satellite data is used to demarcate hydrogeomorphological landforms and lineaments to evaluate groundwater potential of the study area. The Bargur - Mathur subwatersheds of Ponnaiyar river basin is occupied mostly by hard rocks and half of the portion in the study area is covered mainly by both wet and dry cultivation. The major hydrogeomorphic units identified in the area are, Structural Hills, Denudational Hills, Residual Hills, Inselberg, Pediments, Buried Pediment Inselberg Complex, Pediplains, Valley Fills, Linear Ridges, Boulders and Rocky Knobs. Most part of the study area is occupied by pediplains with various thicknesses and the ground water potential is directly related to thickness of pediplain. Field observations showed that ground water occurs under unconfined conditions with water table at shallow to deep depth. From the lineament map, the lineament density and lineament intersection maps prepared to understand the impacts on groundwater percolation. Finally, the hydrogeomorphology and Lineament maps are overlaid following the weighted index overlay method, which delineates groundwater potential zones. An integrated remote sensing and geographic Information System (GIS) based approach has been used for demarcating groundwater potential zones in the study area.

6 illus, 20 ref

001500   Senthilvelan A;Ganesh A;Banukumar K (Geography Dep, Government Arts College, Kumbakonam, Email: kbanukumar@gmail.com) : Markov chain model for probability of weekly rainfall in Orathanadu taluk, Thanjavur district, Tamil Nadu. Int J Geomatics Geosci 2012, 3(1), 191-203.

It is necessary to know the sequence of dry and wet periods for successful agricultural management and planning of soil and water conservation measures. Probability analysis is a very useful tool for making important decisions in agricultural operation. In the study, Markov Chain Model has been extensively used to study spell distribution. For this purpose a week period was considered as the optimum length of time. The present study has been carried out to find the probabilities of occurrence of wet week (W), wet week preceded by wet week (W/W) at different threshold limits of 10 and 20 mm. On the basis of the analysis the following conclusions are made: (a) the 3 and 31/2month varieties are best suited for Vettikkadu region; (b) 3^1/2 and 4 months paddy varieties can be successfully grown in Neivasal Thenpathi area and (c) 4 and 4^1/2 months paddy varieties are favourably grown in Orathanadu region.

3 illus, 5 tables, 27 ref

001499   Sen K;Sharma R;Arora B R;Gupta V (NO, Wadia Institute of Himalayan Geology, 33, GMS Road, Dehradun-248 001, Email: koushik.geol@gmail.com) : Influence of magnetic fabric anisotropy on seismic wave velocity in paramagnetic granites from NW Himalaya: results from preliminary investigations. J Geol Soc India 2010, 76(4), 322-30.

Anisotropy of Magnetic Susceptibility (AMS) and seismic wave velocity studies of some paramagnetic Himalayan granitoids show good correlation between magnetic fabric anisotropy and P wave velocity (Vp). Vp shows strong positive correlation with magnetic lineation (L) and degree of magnetic anisotropy (P1) having correlation coefficient (r) values of 0.93 and 0.89 respectively. Both Vp and Vs show positive correlation with the SiO₂ content of Proterozoic and Paleozoic granitoids. Velocity of S wave (Vs) shows negative correlation with mean magnetic susceptibility (K_m) having 'r' value of 0.86. The correlation between Vs-K_m, Vp-P', Vp-L also shows <62>95% probability in Spearman's rank correlation. Based on the results from the present sample size it is suggested that, in paramagnetic granites, Vp is proportional to intensity of deformation and preferred orientation of minerals as well as the mineralogy. On the other hand, Vs is more dependent on the mineralogy alone.

6 illus, 3 tables, 27 ref

001498   Selvam S;Sivasubramanian P (Geology Dep, V.O. Chidambaram College, Thoothukudi, Tamil Nadu, Email: geoselvam10@gmail.com) : Groundwater potential zone identification using geoelectrical survey: a case study from Medak district, Andhra Pradesh, India. Int J Geomatics Geosci 2012, 3(1), 55-62.

Geoelectrical resistivity survey using Vertical Electrical Soundings (VES) was carried out in Medak District, Andhra Pradesh, India, in order to assess the subsurface geology and groundwater potential zones. Twenty six vertical electrical soundings were recorded with Schlumberger electrode configuration with current electrode spacing (AB/2) half ranging from 1 to 150m. The field data has been primarily interpreted using curve matching and electrical imaging computer software IPI2WIN. The curves are prominently of A and H type indicating the presence of three layers followed by combination of curves AK, HA, KH, HK, AH indicating the four layer followed by combination of curves HAA, HAK, AKH, QHA, AAA indicating the presence of five layer sub-surface layers. Interpretations revels the number of subsurface layers, their thickness and their water bearing capacity within the study area. The best layer which acts as the good aquifer of Medak districts is the second layer which consist the fracture/weathered rock formations at the depth between 5 to 15 m.

4 illus, 2 tables, 13 ref

001497   Sarate O S (NO, Birbal Sahni Institute of Palaeobotany, 53, Univ Road, Lucknow-226 007, Email: ossarate@yahoo.co.in ) : Petrographic charcateristics of coal from Mailaram coalfield, Godavari valley, Andhra Pradesh. J Geol Soc India 2010, 76(6), 557-64.

The quantitative maceral study of the Queen seam from Mailaram coalfield of Godavari valley has displayed alternate coal bands rich in vitrinite/liptinite or inertinite. The random vitrinite reflectance (R_o max. %) of these coals, from top part ranges from 0.50 to 0.64%. However, the bottom part of the seam has indicated lower reflectance, between 0.49 and 0.52%. Thus, the Queen seam, in general, has attained high volatile bituminous C rank. The study indicates that the depositional site has been a slowly sinking basin that witnessed alternate dry (oxidizing) and wet (reducing) spells. This subsequently caused fluctuation in water table of the basin and the formation of oxic and anaoxic moor condition, where accumulated vegetal resource transformed into mixed and fusic coal types in due course of time. Being high in liptinite and vitrinite contents and low mineral matter, the Queen seam of Mailaram coalfield has high economic potential.

5 illus, 3 tables, 27 ref

001496   Sarate O S (NO, Birbal Sahni Institute of Palaeobotany, 53, Road Univ, Lucknow-226 007, Email: ossarate@yahoo.co.in ) : Petrological characteristics of coal deposits from Marki-Jhari-Jamni area, Wardha valley coalfield, Maharashtra. J Geol Soc India 2010, 76(4), 361-8.

Detailed study of maceral composition and vitrinite reflectance of the coal deposits from Marki-Jhari-Jamni area, situated in the northwestern extremity of Wardha valley coalfield, Yeotmal district, Maharashtra has been carried out with special reference to their depositional set up. These coals have two distinct types of maceral organization, one having significantly high distribution of the vitrinite group of macerals (35-41%) and the other containing the dominance of inertinite (26-49%). Liptinitc maceral group is recorded between 14 and 24%, barring a few coal bands having liptinite maceral group as high as 33-37%. The vitrinite reflectivity ranges from 0.38-0.43%. Thus, they have attained sub-bituminous C rank. Mineral matter in these coals varies between 15 and 22%. The present study suggests that the basin primarily experienced cold climate having intermittent brackish water influx with alternating dry oxidizing spells.

7 illus, 2 tables, 20 ref

001495   Sapra R;Dhaka S K;Panwar V;Bhatnagar R; Praveen Kumar K;Shibagaki Y;Venkat Ratnam M;Takahashi M (Radio and Atmospheric Physics Lab, Physics Dep, Rajdhani College, Delhi Univ, New Delhi, Email: skdhaka@gmail.com) : Long-term variations in outgoing long-wave radiation (OLR), convective available potential energy (CAPE) and temperature in the tropopause region over India. J Earth Syst Sci 2011, 120(5), 807-23.

Relationship of outgoing long-wave radiation (OLR) with convective available potential energy (CAPE) and temperature at the 100-hPa pressure level is examined using daily radiosonde data for a period 1980-2006 over Delhi (28.3°N, 77.1°E) and Kolkata (22.3°N, 88.2°E), and during 1989-2005 over Cochin (10°N, 77°E) and Trivandrum (8.5°N, 77.0°E), India. Correlation coefficient (R_xy) between monthly OLR and CAPE shows a significant (<126>-0.45) anti-correlation at Delhi and Kolkata suggesting low OLR associated with high convective activity during summer (seasonal variation). Though, no significant correlation was found between OLR and CAPE at Cochin and Trivandrum (low latitude region); analysis of OLR and temperature (at 100-hPa) association suggests that low OLR peaks appear corresponding to low temperature at Delhi (R_xy<126>0.30) and Kolkata (R_xy<126>0.25) during summer. However, R_xy between OLR and temperature becomes opposite as we move towards low latitudes (<126>8°-10°N) due to strong solar cycle influence. Large scale components mainly ENSO and quasi-biennial oscillaton (QBO) that contributed to the 100-hPa temperature variability were also analyzed, which showed that ENSO variance is larger by a factor of two in comparison to QBO over Indian region. ENSO warm conditions cause warming at 100-hPa over Delhi and Darwin. However, due to strong QBO and solar signals in the equatorial region, ENSO signal seems less effective. QBO, ENSO, and solar cycle contribution in temperature are found location-dependent (latitudinal variability) responding in consonance with shifting in convective activity regime during El Nino, seasonal variability in the tropical easterly jet, and the solar irradiance.

13 illus, 5 tables, 23 ref

001494   Santosh Kumar;Pieru T (Geology Dep, Kumaun Univ, Nainital-263 002, Email: skyadavan@yahoo.com) : Petrography and major elements geochmeistry of microgranular enclaves and neoproterozoic granitoids of south Khasi, Meghalaya: evidence of magma mixing and alkali diffusion. J Geol Soc India 2010, 76(4), 345-60.

Neoproterozoic (690±19 Ma) felsic magmatism in the south Khasi region of Precambrian northeast Indian shield, referred to as south Khasi granitoids (SKG), contains country-rock xenoliths and microgranular enclaves (ME). The mineral assemblages (pl-hbl-bt-kf-qtz-mag) of the ME and SKG are the same but differ in proportions and grain size. Modal composition of ME corresponds to quartz monzodiorite whereas SKG are quartz monzodiorite, quartz monzonite and monzogranite. The presence of acicular apatite, fine grains of mafic-felsic minerals, resorbed mafic-felsic xenocrysts and ocellar quartz in ME strongly suggest magma-mixed and undercooled origin for ME. Molar A1₂O₂/ CaO+Na₂O+K₂O (A/CNK) ratio of ME (0.68-0.94) and SKG (0.81-1.00) suggests their metaluminous (I-type) character. Linear to sub-linear variations of major elements (MgO, Fe₂O₃¹, P₂O₅, TiO₂, MnO and CaO against SiO₂) of ME and SKG and two-component mixing model constrain the origin of ME by mixing of mafic and felsic magmas in various proportions, which later mingled and undercooled as hybrid globules into cooler felsic (SKG) magma. However, rapid diffusion of mobile elements from felsic to mafic melt during mixing and mingling events has elevated the alkali contents of some ME.

14 illus, 5 tables, 80 ref

001493   Sanislav I V;Shah A A (School of Earth and Environmental Sciences, James Cook Univ, Townsville, QLD 4811, Australia, Email: ioan.sanislav@jcu.edu.au) : Problem, significance and implications for metamorphism of 60 millions years of multiple phases of staurolite growth. J Geol Soc India 2010, 76(4), 384-98.

Microstructural measurements of FIAs in staurolite reveal at least 3 periods of growth in the Proterozoic Colorado Front Range and 5 in the Paleozoic Western Maine. Dated monazite inclusions in staurolite have an absolute age of 1760±12 Ma (FIA 1), 1720±7 Ma (FIA 2), 1682±18 Ma (FIA 3) in Colorado, and 408±10 Ma (FIA 2), 388±8 Ma (FIA 3), 372±6 Ma (FIA 4), 352±4 Ma (FIA 5) in Maine, supporting the multiple periods of deformation and metamorphism indicated by the FIA succession in each region. Multiple phases of growth by similar reactions in the same as well as in diverse adjacent rocks in both regions suggest that PT and X are not the only factors controlling the commencement and cessation of metamorphic reactions. The FIAs preserved by the staurolite porphyroblasts indicate that the local partitioning of deformation at the scale of a porphyroblast was the eventual controlling factor on whether or not the staurolite forming reactions took place.

9 illus, 4 tables, 60 ref

001492   Samal A S;Sengupta R R;Fifarek R H (Geology Dep, Southern Illinois Univ, Carbondale, IL 62901-4324, USA, Email: arsamal@yahoo.com) : Modelling spatial anisotropy of gold concentration data using GIS-based interpolated maps and variogram analysis: implications for structural control of mineralization. J Earth Syst Sci 2011, 120(4), 583-93.

Linear trends of anomalously high gold values in the Florida Canyon gold deposit, Nevada have been identified using a combination of contour maps of gold (Au) concentration developed with a geographic information system (GIS) and variogram maps created using a geostatistical analysis package. These linear trends arc interpreted to represent major fault zones that exerted a prinicipal control on gold mineralization and therefore imparted a spatial anisotropy to gold concentrations. Oxidation state information such as oxide, sulfide or mixed was used initially to map and contour the lower limit of the oxidation zone. Linear trends on this surface suggest the location and trend of major structural elements in the deposit that guided late oxidizing fluids. Subsequently, four contour maps of gold concentrations in oxidized rocks were produced, each map representing 500 ft vertical intervals starting at 3500 ft above mean sea level (msl). Relatively high concentrations of Au that form linear trends on these maps suggest the presence of structural features, such as shear zones that controlled mineralization. Finally, to validate the observed trends, variogram maps of gold concentrations were derived through geostatistical analysis and the major axes of anisotropy were determined for each map. The results that emerge suggest linear trends of northeast, northwest and, less prominently, north-south orientations. The north-south and northeast trends match those of known and mapped major structures associated with the Florida Canyon deposit. However, the results imply a stronger control on mineralization by northwest-trending structures than previously recognized and the location of possible structures of all trends not previously mapped. They also serve to identify faults that controlled both early hydrothermal fluids and late oxidizing fluids since the gold distribution represents the time integrated effects of both fluid events. The linear trends derived by spatial analysis (contour maps, variogram maps) of geochemical data (i.e., gold concentration), combined with the results of the field observations prove to be advantageous in understanding the structural control of gold mineralization. Such spatial analyses of geochemical concentration data are particularly useful in the field of mineral exploration.

6 illus, 1 table, 31 ref

001491   Sajan C P;Basavalingu B;Ananda S;Byrappa K (DOS in Earth Science, Mysore Univ, Manasagangothri, Mysore-570 006, Email: kbyrappa@gmail.com) : Comparative study on the photodegradation of indigo caramine dye using commercial TiO₂ and natural rutile. J Geol Soc India 2011, 77(1), 82-88.

The photocatalytic degradation of Indigo Caramine dye using commercial TiO₂ and fine grained natural rutile has been carried out. The commercial TiO₂ and natural rutile were characterized using powder X- ray diffraction (XRD) and Fourier transformed infra red spectroscopy (FTIR). The study on the photodegradation of Indigo Caramine dye using commercial TiO₂ and natural rutile were investigated both under Solar and UV irradiation. The degradation of Indigo Caramine dye was checked by the following parameters like Chemical Oxygen Demand (COD), %T, irradiation time and duration. In both cases using commercial TiO₂ and natural rutile, the COD of the dye solution was reduced from 288 mg/L to less than 20 mg/L, and similarly the %T was increased from 76% to 97% and the percentage decomposition upto 97% within the irradiation duration of 3.5 hrs. The preliminary results obtained on the photodegradation of Indigo Caramine dye are highly encouraging and further work is being carried out for the use of the natural rutile or anatase sources for the other organic decomposition and treatment of industrial effluents.

10 illus, 1 table, 22 ref

001490   Saini S S;Kaushik S P (Geography Dep, Kurukshetra University, Kurukshetra-136 119, Email: saini.surjit@gmail.com ) : Risk and vulnerability assessment of flood hazard in part of Ghaggar Basin: a case study of Guhla block, Kaithal, Haryana, India. Int J Geomatics Geosci 2012, 3(1), 42-54.

Ghaggar River in Haryana-Punjab plains, northern India presents a challenge in terms of repeated flash flood hazard. Although a long history of flood control management in the basin for more than 2 decades, the river continues to bring a lot of gloom through extensive flooding. Reconsiders the flooding problem in the Ghaggar River basin and presents an in-depth analysis of flood hydrology. Authors integrate the hydrological analysis with a Geographic Information System (GIS) based flood risk mapping in the middle parts of the basin. Typical hydrological and environmental characteristics of the study area include drainage congestion, drainage confluence, very high discharge variability, gentle slope, and agricultural practices. Besides, proximity to high slope of upper catchment area and disturbance of natural drainage channels due to human intervention, are identified main factors increasing vulnerability to flood hazard. Annual peak discharges often exceed the mean annual flood and the low-lying areas of the alluvial plains are extensively inundated year after year. The main objective of the study is to assess the risk and vulnerability based on multi-criteria assessment. In this study Rank Sum method is used to calculate the weights of factors contribute to flood hazard. Study limited to environmental factors such as hydrology, slope, soil type, drainage density, landform and land use/ land cover to propose a Flood Risk Index (FRI). GIS techniques shown efficient role in the process of derivation, integration, and analysis of spatial data. The approach resulted in three classes of flood risk mapping ranging between low to high vulnerable area. GIS produced flood risk map is validated with recent flood occurred in July 2010 inundation data collected from irrigation department of the concerned district. Finds out that GIS based long-term inundation maps can offers a cost-effective solution for planning mitigation measures and preparedness in flood prone areas.

6 illus, 11 tables, 8 ref

001489   Saha O;Shukla U K;Rekha Rani (Centre for Advanced Study in Geology, Banaras Hindu Univ, Varanasi-221 005, Email: shukla_umakant@yahoo.com) : Trace fossils from the late cretaceous lameta formation, Jabalpur area, Madhya Pradesh: paleoenvironmental implications. J Geol Soc India 2010, 76(6), 607-20.

In Jabalpur area about 18 m to 45 m thick Lameta Formation is stratigraphically divisible into five lithounits namely, Green Sandstone, Lower Limestone, Mottled Nodular Beds, Upper Limestone and Upper Sandstone. Having differentiated lithofacies constitution and here grouped as facies associations, these units are intensively burrowed and sparingly fossiliferous. Ichnogenera including Arenicolites, Calycraterion, Fucusopsis, Laevicyclus, Macanopsis, Ophiomorpha, Paleomeandron, Rhizocorallium, Stipsellus, Thalassinoides and Zoophycos are recovered from the Lower Limestone, Mottled Nodular Beds and Upper Limestone associations of the Lameta Formation of Jabalpur area. Among these, Arenicolites, Calycraterion, Laevicyclus, Ophiomorpha, Rhizocorallium, Stipsellus and Thalassinoides belong to mixed Skolithos and Cruziana ichnofacies and indicate sandy backshore to sublittoral condition of deposition. Additionally rhyzocretes, some times chertified, are also present in different parts of the Lameta Formation. Ichnofacies assemblage supported by sedimentological information suggests that the Lameta Formation of Jabalpur area was deposited in coastal marine settings where sediments were subaerially exposed intermittently.

5 illus, 1 table, 67 ref

001488   Roy P S;Roy A (Indian Institute of Remote Sensing, NRSC, ISRO, 4, Kalidas Road, Dehradun, Email: psroy13@gmail.com ) : Land use and land cover change in India: a remote sensing & GIS prespective. J Indian Inst Sci 2010, 90(4), 489-502.

Land use and land cover change have been among the most important perceptible changes taking place around us. Although perceptible, the magnitude, variety and the spatial variability of the changes taking place has made the quantification and assessment of land use and land cover changes a challenge to scientists. Furthermore, since most of the land use and land cover changes are directly influenced by human activities, they rarely follow standard ecological theories. The Remote Sensing and Geographic Information System has proved to be very important in assessing and analyzing land use and land cover changes. Satellite-based Remote Sensing, by virtue of its ability to provide synoptic information of land use and land cover at a particular time and location, has revolutionized the study of land use and land cover change. The temporal information on land use and land cover helps identify the areas of change in a region. The use of Geoinformatics has enabled us to assign spatial connotations to land use land cover changes, namely, population pressure, climate, terrain, etc which drive these changes. This has helped scientists to quantify these tools and to predict various scenarios. This article gives a overview of the current trends in land use and land cover changes along with two case studies on the same subject, one case study on geospatial LULC change modeling and one on agent based land use and land cover change modeling.

^iia 11 illus, 30 ref

001487   Ray J;Saha A;Ganguly S;Balaram V;Keshav Krishna A;Hazra S (Geology Dep, Calcutta Univ, 35, Ballygunge Circular Road, Kolkata-700 019, Email: asaha.geocal@gmail.com) : Geochemistry and petrogenesis of neoproterozoic mylliem granitoids, Meghalaya plateau, Northeastern India. J Earth Syst Sci 2011, 120(3), 459-73.

The Mylliem granitoids of the Meghalaya Plateau, northeastern India, represent one of the disharmonic Neoproterozoic igneous plutons, which are intrusive into low-grade Shillong Group of metasediments. Field studies indicate that the Mylliem granitoids cover an area of about 40 km² and is characterized by development of variable attitude of primary foliations mostly marked along the margin of the pluton. Xenoliths of both Shillong Group of metasediments and mafic rocks have been found to occur within Mylliem granitoids. Structural study of the primary foliation is suggestive of funnel-shaped intrusion of Mylliem granitoids with no appreciable evidence of shearing. Petrographically, Mylliem granitoids are characterized by pink to white phenocrysts of prismatic microcline/perthite and lath-shaped plagioclase (An₂₀-An₂₉). Groundmass material is characterized by quartz, microcline, plagioclase, muscovite and biotite. Sphene and apatite occur as accessory minerals. Petrographically Mylliem granitoids have been discriminated as granite and granodiorite according to IUGS system of classification. Critical evaluation of geochemical data and variation trends of major oxides/trace elements suggests a significant role of fractional crystallization in the evolution of Mylliem pluton. Th/U ratios (3.22-6.77) indicate a relatively higher abundance of Th over U. Chondrite-normalized REE diagram characteristically shows an enriched LREE pattern and prominent negative Eu anomaly (Eu/Eu* = 0.16-0.42) indicating the significant role of plagioclase fractionation from the parent magma. An overall strong REE fractionation pattern has been envisaged for Mylliem granitoids. The strong REE fractionation of the Mylliem granitoids is depicted by (Ce/Yb)_N values, which show a range of 1.39 to 1.65. The aluminium saturation index (ASI) (ranging from 1.0 to 1.3), A/CNK ratios (ranging from 1.4 to 2.11) and A/NK ratios (ranging from 1.75 to 2.43) provide evidences for the peraluminous, S-type nature of the Mylliem granitoids. The peraluminous, S-type character is further supported by geochemical parameters such as Fe* and MALI (modified alkali lime index). Normative corundum <62>1.0 wt.% is suggestive of the S-type nature of Mylliem granitoids. This is indicative of parent melt-extraction from metasedimentary source rocks by partial melting. Distinct geochemical parameters suggest a post-orogenic tectonic environment for the Mylliem granitoids. The peraluminous, calc-alkalic to alkali-calcic, post-orogenic Mylliem granitoids are geochemically correctable with the post-orogenic Caledonian granitoids of Ireland and Britain.

9 illus, 3 tables, 46 ref

001486   Ratheesh Kumar R T;Maji T K;Kandpal S C; Sengupta D;Nair R R (Ocean Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: rajeshnair.iitkgp@gmail.com) : Elastic thickness estimates at northeast passive margin of North America and its implications. J Earth Syst Sci 2011, 120(3), 447-58.

Global estimates of the elastic thickness (Te) of the structure of passive continental margins show wide and varying results owing to the use of different methodologies. Earlier estimates of the elastic thickness of the North Atlantic passive continental margins that used flexural modelling yielded a Te value of <126>20-100 km. Compares these estimates with the Te value obtained using orthonormalized Hermite multitaper recovered isostatic coherence functions. Discussed how Te is correlated with heat flow distribution and depth of necking. The E-W segment in the southern study region comprising Nova Scotia and the Southern Grand Banks show low Te values, while the zones comprising the NE-SW zones, viz., Western Greenland, Labrador, Orphan Basin and the Northern Grand Bank show comparatively high Te values. As expected, Te broadly reflects the depth of the 200-400°C isotherm below the weak surface sediment layer at the time of loading, and at the margins most of the loading occurred during rifting. These low Te measurements indicate Te frozen into the lithosphere. This could be due to the passive nature of the margin when the loads were emplaced during the continental break-up process at high temperature gradients.

7 illus, 3 tables, 59 ref

001485   Rashid M;Lone M A;Romshoo S A (NO, National Geophysical Research Institute, Hyderabad-500 606) : Geospatial tools for assessing land degradation in Budgam district, Kashmir Himalaya, India. J Earth Syst Sci 2011, 120(3), 423-33.

Land degradation reduces the ability of the land to perform many biophysical and chemical functions. The main aim of this study was to determine the status of land degradation in the Budgam area of Kashmir Himalaya using remote sensing and geographic information system. The satellite data together with other geospatial datasets were used to quantify different categories of land degradation. The results were validated in the field and an accuracy of 85% was observed. Land use/land cover of the study area was determined in order to know the effect of land use on the rate of land degradation. Normalized differential vegetation index (NDVI) and slope of the area were determined using LANDSAT-enhanced thematic mapper plus (ETM+) data, advanced space-borne thermal emission and reflection radiometer, and digital elevation model along with other secondary data were analysed to create various thematic maps, viz., land use/land cover, geology, NDVI and slopes used in modelling land degradation in the Kashmir Himalayan region. The vegetation condition, elevation and land use/land cover information of the area were integrated to assess the land degradation scenario in the area using the ArcGIS 'Spatial Analyst Module'. The results reveal that about 13.19% of the study area has undergone moderate to high degradation, whereas about 44.12% of the area has undergone slight degradation.

6 illus, 6 tables, 35 ref

001484   Ramesh Kumar K;Pande D;Misra A;Nanda L K (NO, Atomic Minerals Directorate for Exploration and Research, Western Region, Sector-V, Pratap Nagar Extn, Jaipur-302 030, Email: rkumark2002@yahoo.com) : Playa sediments of the Didwana lake, Rajasthan: a new environment for surficial-type uranium mineralisation in India. J Geol Soc India 2011, 77(1), 89-94.

The Didwana playa, the second largest playa in the eastern part of the Thar desert, is 5.6 km long and 2.4 km wide and supports commercial salt production. The thickness of lake sediment package is reported to be 20 m and comprises fine grained clays and silts, with abundant calcite, gypsum, and halite.associated with hypersaline water. Isolated hills of graphitic phyllite and quartzite are seen on the western side of the lake. During the course of investigations for uranium in surficial environment of semi-arid terrain of Rajasthan, ground water sampling defined a NE-SW trending uranium halo encompassing the Didwana playa. Subsequent sampling of unlined dug wells, up to water table in central part of the playa, indicated uranium values up to 190 ppm and 2072 ppb in lake sediments and brine respectively. These values arc of the order of 21 ppm and 192 ppb towards the southwestern periphery of the lake. The average uranium content, as inferred from 12 samples in the central part of the lake, is around 60 ppm over a thickness of 5 m. It appears that the uranium is loosely bonded to the sediments in amorphous form and is, hence, easily leachable. Samples of brine (n=10), from both the central and southwestern portions of the lake, analysed high (1,67,500-3,00,000 mg/1) TDS, HCO₃^- (1128-8395 mg/1), and SO4 (30,536-88,000 mg/1). These are of alkaline (pH: 7.2-9.3) and reducing (Eh: -200 to -340 mV) nature. Under these Eh-pH conditions below the groundwater table, and for such uranium bearing groundwater, precipitation of primary uranium is expected. It is, therefore, modelled that uranium in lake sediment package above water table is concentrated by evaporation process and by chemical reduction below the water table. As the sampling is so far confined to zones above water table, the above possibility is still to be examined. Features like high intrinsic uranium in lake (playa) sediments as well as groundwater, the alkaline and reducing nature of groundwater, which may facilitate precipitation of primary uranium below water table, and the large extent of the lake sediments (10 sq km x 20 m thickness) make the Didwana Lake, a potential candidate for hosting a surficial-type uranium occurrence of significance, for which samples below water table need to be generated. These studies are expected to establish the lake sediment environment in semi-arid tracts of Rajasthan as a new target horizon for locating surficial-type uranium mineralisation in India.

5 illus, 17 ref

001483   Rajput P;Ram Mohan Rao K;Sidda N K (Geoinformatics Div, Indian Institute of Remote Sensing, Dehradun, Email: naveensidda@yahoo.co.in) : Development of an economical spatial health information system. Int J Geomatics Geosci 2012, 3(1), 97-110.

Study outlines the economical development of Dehradun Malaria Information System (DMIS) using open source internet GIS technologies and concepts. The application is developed with three objectives i) real time updating of malaria data from various health centers in Dehradun, India into one central information system ii) providing access and dissemination of the data in a spatial interactive environment iii) Usage of various state of art freely available technologies in building an information management system economically. The web application development is instrumental in the malaria research, control and health service communities at different locations for effective planning and operational activities.

14 illus, 1 table, 10 ref

001482   Purohit M K;Prajapati K K;Trivedi R K (Applied Geology Dep, Dr. H.S. Gour Univ, Sagar-470 003, Email: mpk09@rediffmail.com) : Conjugate faulting along pre-existing fractures in Bundelkhand granite, Hirapur, Central India. J Geol Soc India 2010, 76(5), 479-84.

Re-examination of the outcrop of conjugate of strike-slip faults mapped by Roday et al. (1989) near forest rest house at Hirapur reveals that the main dextral strike-slip fault that strikes N35°E and is a manifestation of the earliest NE-SW trending subhorizontal σ₁ that produced extensional reef system in the Bundelkhand massif. Although the change in the stress system though 90° rotation of the principal compressive stress σ₁ and σ₃ (with σ₂ maintaining near vertically) is correct, another point of interest is that the σ₁, for the system of faults bisects the obtuse angle between the two sets and not an acute one as required by the brittle failure criterion. The sinistral strike-slip faults were probably formed by rejuvenation of the initial dextral strike-slip faults that were generated when the maximum principal compressive stress was oriented NS. The reversal of fault displacement is seen on all scales in the Bundelkhand massif. The dextral strike-slip fault related to the late stress system was preferentially produced along pre-existing tensile fractures that were generated under NE-SW directed subhorizontal σ₁. Some of these fractures were converted into sinistral strike-slip faults under NS directed maximum principal compression acting subhorizontally.

5 illus, 5 ref

001481   Preethi B;Revadekar J V;Kripalani R H (NO, Indian Institute of Tropical Meterology, Dr. Homi Bhabha Road, Pune-411 008, Email: preethi@tropmet.res.in) : Anomalous behaviour of the Indian summer monsoon 2009. J Earth Syst Sci 2011, 120(5), 783-94.

The Indian subcontinent witnessed a severe monsoon drought in the year 2009. India as a whole received 77% of its long period average during summer monsoon season (1 June to 30 September) of 2009, which is the third highest deficient all India monsoon season rainfall year during the period 1901-2009. Therefore, an attempt is made in this paper to study the characteristic features of summer monsoon rainfall of 2009 over the country and to investigate some of the possible causes behind the anomalous behaviour of the monsoon. Presence of El Nino like conditions in the Pacific and warming over the equatorial Indian Ocean altered the circulation patterns and produced an anomalous low level convergence and ascending motion over the Indian Ocean region and large scale subsidence over the Indian landmass. Furthermore, the cross-equatorial flow was weak, the monsoon was dominated by the slower 30-60 day mode, and the synoptic systems, which formed over the Bay of Bengal and the Arabian Sea, did not move inland. All the above features resulted in less moisture supply over the Indian landmass, resulting in subdued rainfall activity leading to a severe monsoon drought during 2009.

10 illus, 37 ref

001480   Prakash D (Center of Advanced Study in Geology, Banaras Hindu Univ, Varanasi-221 005, Email: dprakashbabu@yahoo.com) : New SHRIMP U-Pb zircon ages of the metapelitic granulites from NW of Madurai, Southern India. J Geol Soc India 2010, 76(4), 371-83.

Zircon cathodoluminescent imaging and SHRIMP U-Pb dating were carried out for metapelitic rocks sapphirine-bearing granulites and garnet-cordierite gneisses) from the NW of Madurai, Southern India. The cathodoluminescence images reveal the complex, inhomogeneous internal structure having irregular-shaped core and overgrowths. Zircon grains have obliterated oscillatory zoning. SHRIMP U-Pb chronological results yield ages of 550±15 Ma and 530±50 Ma as a time of metamorphic overprint, and the age of 2509±12 Ma and 2509±30 Ma corresponding to a timing of protolith formation for sapphirine-bearing granulites and garnet-cordierite gneisses respectively. Zircon ages reflect that continental crust in the NW of Madurai region resulted from the recycling of Archaean protolith of an igneous origin similar to the preserved crust in the southern part of Dharwar craton. The present SHRIMP U-Pb zircon ages are in close agreement with earlier published Nd isotopic data which suggest an extended precrustal history of their protoliths. The abraded zircon grains indicate multiple recycling and repeated metamorphism that has ultimately resulted in present day continental crust exposed in Madurai region. These SHRIMP U-Pb zircon ages from metapelitic UHT granulites are also significant to understanding the architecture of the SGT during the amalgamation of Gondwana in Neoproterozoic time.

5 illus, 2 tables, 49 ref

001479   Pegahfar N;Bidokhti A A;Zawar-Reza P;Farahani M M (Institute of Geophysics, Tehran Univ, Tehran, Iran, Email: pegahfar@ut.ac.ir) : Vertical wind profiles in an urban area with complex terrain (Tehran). J Earth Syst Sci 2011, 120(5), 825-41.

In this paper monthly trends of vertical wind profiles within and above an urban area with complex topography (Tehran) have been investigated using data from a Sodar, a 100-m and two 28-m towers and some surface stations. It includes the occurrence, evolution, dissipation time, peak time and maximum height for katabatic-anabatic winds due to topography, return flow and urban circulation. Vertical distributions of wind and the heat and momentum fluxes up to 600 m were also considered. The vertical wind profiles which have diurnal and seasonal variations show southwesterly daily anabatic wind and northeasterly nocturnal katabatic wind. Daily vertical wind profile structure which has two layers and two jets contains a decrease approximately at 300-400 m which may be due to the return flow and a daily thermal convective flow in the urban convergent terrain. At night the nocturnal wind profile structure, in the majority of months, has two layers and sometimes three layers containing northeasterly flows. In two layers structure, a decrease can be seen between two layers. In three layers structure, the middle layer has a different direction that indicates the return flow and urban circulation more clearly. Katabatic flows also develop in successive phases varying from 1 to 3 phases in different months. Investigation on surface wind demonstrates that in cold months a drainage flow from a valley located in the west of the station can affect wind speed and direction especially at evening transition time. These flow patterns can influence the way air pollutants disperse in this area.

14 illus, 1 table, 47 ref

001478   Pawar S D;Murugavel P;Gopalakrishnan V (NO, Indian Institute of Tropical Meterology, Pune) : New particle formation by ion-induced nucleation during dissipation stage of thunderstorm. J Earth Syst Sci 2011, 120(5), 843-50.

Case of new particle formation observed during dissipation stage of a thunderstorm at a tropical station, Pune, India on 3 June 2008 is reported. The flash rate and rainfall intensity increased as high as 110 flashes per 5 minutes and 150 mm hour^-1 respectively during the active stage of thunderstorm, and then gradually decreased during the dissipation stage. The number concentration of particles in the size range of 10-100 nm sharply increased from 350 particles cm^-3 to <126>8000 particles cm^-3 during the dissipation stage of a thunderstorm and grew to larger diameter subsequently. Observations suggest that the atmospheric conditions such as (i) reduced background aerosol concentration after heavy rain, (ii) high humidity condition, and (iii) increased ion concentration during the dissipation stage by corona discharges, favoured generation of new particles by ion-induced nucleation (IIN). Observations also suggest that generation of unipolar ions by corona discharges may be more favourable for UN and subsequent growth of the particles.

5 illus, 43 ref

001477   Paul S (Post Graduate Geography Dep, Krishnagar Government College, Krishnagar, Nadia, West Bengal, Email: suman.krish.2007@gmail.com) : Location allocation for urban waste disposal site using multi-criteria analysis: a study on Nabadwip Municipality, West Bengal, India. Int J Geomatics Geosci 2012, 3(1), 74-88.

Solid waste materials in cities are the natural outcome of human activities. Most of our cities and municipalities in third world countries like India is a major concern of the government due to the health problems associated with improper disposal of waste. Several factors are considered in site selection for waste disposal. Provision of such system appears to be a major problem due to the complication and the wide nature of waste production. Due to the different parameters involved, deciding upon a suitable location is also very complicated, costly and time consuming. Geographic Information System (GIS) allows users to view, understand, question, interpret and visualize spatial and non-spatial data in many ways that reveals relationships, patterns and trends in the form of maps, reports and charts. This study investigated most suitable site(s), as a waste disposal site(s) for Nabadwip Municipality which is located in the extreme west of Nadia district, West Bengal. Suitable disposal site must follow environmental safety criteria and attributes that will enable the wastes to be isolated so that there is no unacceptable risk to people or the environment. Criteria for site selection include natural physical characteristics as well as socioeconomic, ecological and land-use factors. Multi-criteria analysis has been done for solid waste disposal site selection in this study. The Geographical Information System (GIS) can provide an opportunity to integrate field parameters with population and other relevant data or other associated features, which will help in selection of suitable disposal sites.

7 illus, 1 table, 24 ref

001476   Paul A (NO, Wadia Institute of Himalayan Geology, Dehradun-248 001, Email: ajaypaul@wihg.res.in) : Evaluation and implications of seismic events in Garhwal-Kumaun region of Himalaya. J Geol Soc India 2010, 76(4), 414-18.

The Garhwal-Kumaun region continues to accumulate the built-up of strain energy like the other regions of the Himalaya. But this sector unlike the other sectors is yet to release this accumulated strain energy which can be in the form of great earthquake. The region has sufficient strain energy to generate earthquake of M>8. The analysis of seven hundred ten local events, recorded by ten station broad band network between August'07 to February'10 shows that most of the seismic events recorded in this region continue to occur from shallow depths (<60> 25 km). The evaluation of source parameters from p-wave spectral analysis indicates that the events have low stress drop values. The region continues to release energy in the form of smaller magnitude earthquakes. The epicentral location map indicates that Munsiari Thrust, which is located south of the Main Central Thrust is more active.

1 illus, 1 table, 25 ref

001475   Patel R C;Adlakha V;Singhl P;Yogesh Kumar;Lal N (Geophysics Dep, Kurukshetra Univ, Kurukshetra-136 119, Email: patelramesh_chandra@rediffmail.com) : Geology, structural and exhumation history of the higher Himalayan crystallines in Kumaon Himalaya, India. J Geol Soc India 2011, 77(1), 47-72.

The crystallines in the Kumaon Himalaya, India are studied along Goriganga, Darma and Kaliganga valleys and found to be composed of two high-grade metamorphic gneiss sheets i.e. the Higher Himalayan Crystalline (HHC) and Lesser Himalayan Crystalline (LHC) zones. These were tectonically extruded as a consequence of the southward directed propagation of crustal deformation in the Indian plate margin. The HHC and its cover rocks i.e. the Tethyan Sedimentary Zone (TSZ) are exposed through tectonic zones within the hinterland of Kumaon Himalaya. The HHC records history of at least one episode of pre-Himalayan deformation (D₁), three episodes of Himalayan deformation (D₂, D₃, D₄). The rocks of the HHC in Kumaon Himalaya are thoroughly transposed by D₂ deformation into NW-SE trending S_m (S₁+S₂). The extent of transposition and a well-developed NE-plunging L₂ lineation indicate intense strain during D₂ throughout the studied portion of the HHC. Ductile flow continued, resulting in rotation of F₁ and F₂ folds due NE-direction and NW-SE plunging F₃ folds within the HHC. The over thickened crystalline was finally, superimposed by late-to-post collisional brittle-ductile deformation (D₄) and exposed the rocks to rapid erosion. Apatite Fission Track (AFT) and Zircon Fission Track (ZFT) studies from the Kumaon Himalaya suggest reactivation of the Main Central/Munsiari Thrust (MCT/MT) and Vaikrita Thrust (VT), rapid exhumation and a system that has been in topographic and exhumation steady-state since at least 4 Ma.

9 illus, 4 tables, 133 ref

001474   Pandit M K;DeWall H;Daxberger H;Just J; Bestmann M;Sharma K K (Geology Dep, Rajasthan Univ, Jaipur-302 004) : Mafic rocks from erinpura gneiss terane in the Sirohi region: possible ocean-floor remnants in the forland of the Delhi fold belt, NW India. J Earth Syst Sci 2011, 120(4), 627-41.

A small isolated mafic body occurs to the south of Sirohi near village Daba within the Neoproterozoic Erinpura Granite in the southern sector of the Proterozoic Delhi Fold Belt in NW India. This mafic body occurs close to a 100 m wide NE-SW trending shear zone (Daba Shear Zone) which overprints the felsic rock fabrics. Further south, a small mafic body near village Kui was also sampled which forms the southern limit of the Phulad Ophiolite Suite which is a 300 km long major NE-SW trending lineament, described as Western Margin Fault. Some of the lithological components of the Daba mafic body show locally preserved magmatic fabric but completely transformed mineralogies under lower amphibolites facies metamorphic conditions where two-stage deformation has been inferred. Magnetic fabric analysis underlines a general correspondence of structural elements in both felsic and mafic lithologies. Binary correlations of Zr with other high field strength elements underline fractionation as the main process in the evolution of Daba arid Kui rocks. Geochemical characteristics indicate subalkaline tholeiitic basalt affinity for these mafic rocks. The trace element characteristics, such as enriched LIL elements, high Th, absence of negative Nb anomalies and depletion in compatible elements in Daba samples suggest an enriched mantle source and lower degree of melting. The trace and rare earth element characteristics for Kui (Th anomaly, Nb-Ta trough and less spiked patterns, flat REE trends) indicate derivation from a refractory mantle source affected by fluids derived from subduction. Distinct differences in trace and REE characteristics between Daba and Kui can be interpreted in terms of different stages of ophiolite development.

11 illus, 2 tables, 47 ref

001473   Paliwal B S (Geology Dep, Jai Narain Vyas Univ, Jodhpur-342 005, Email: paliwalbs.geology@gmail.com) : Unusual calcareous concretions from the palaeocene grey-black shales of palana formation at hadla bhatiyan southwest of Bikaner, Rajasthan. J Geol Soc India 2010, 76(5), 518-24.

During the search of some plant and animal fossils a variety of calcareous concretions were collected from the carbonaceous grey-black shales of Palana Formation of the Palaeocene age in a dug well section at Hadla Bhatiyan village Southwest of Bikaner in Rajasthan. The concretions range in size from a few millimetres to 30 centimetres in diameter. These structures exhibit a variety of shapes ranging from spherical, botryoidal, flattened and dumbbell shaped. The calcareous concretions observed here show an unusual internal structure. On the outer surface they show straight laminations but inside these laminations form slump structures. In many cases the central portion of the slump structures has been detached and rotated due to the gravity effect. Secondly, laminations on the outer surface exhibit continuity irrespective of the shape of the concretions.

12 illus, 17 ref

001472   Pal S C;Shit M (NO, Visva-Bharati, Santiniketan, West Bengal, Email: geo.subodh@gmail.com) : Geo-hydrological study of Gandheshwari sub-watershed using remote sensing and GIS techniques. Int J Geomatics Geosci 2012, 3(1), 204-18.

Study was conducted on Gandheshwari sub-watershed situated in Bankura district of West Bengal. The remote sensing and GIS techniques have been proved to be very efficient in identification geo-hydrological aspects of the study area. The various thematic maps have been generated like Geology, geomorphology, hydro-geomorphology, geo-hydrology, structure, soils and land use land cover helped in identification of the potential zones for development planning and forecasting. Lineaments and their intersections appear to be potential sites for groundwater. The study shows that the integration of all attributes provide more accurate results in identification of geo-hydrological characteristics.

13 illus, 2 tables, 15 ref

001471   Pal D C;Sarkar S;Mishra B;Sarangi A K (Geological Sciences Dep, Jadavpur Univ, Kolkata-700 032, Email: dcpal@geology.jdvu.ac.in) : Chemical and sulphur isotope compositions of pyrite in the Jaduguda U (-Cu-Fe) deposit, Singhbhum shear zone, Eastern India: implications for sulphide mineralization. J Earth Syst Sci 2011, 120(3), 475-88.

The Jaduguda U (-Cu-Fe) deposit in the Singhbhum shear zone has been the most productive uranium deposit in India. Pyrite occurs as disseminated grains or in sulphide stringers and veins in the ore zone. Veins, both concordant and discordant to the pervasive foliation, are mineralogically either simple comprising pyrite ± chalcopyrite or complex comprising pyrite + chalcopyrite + pentlandite + millerite. Nickel-sulphide minerals, though fairly common in concordant veins, are very rare in the discordant veins. Pyrite in Ni-sulphide association is commonly replaced by pentlandite at the grain boundary or along micro-cracks. Based on concentrations of Co and Ni, pyrite is classified as: type-A - high Co (up to 30800 ppm), no/low Ni; type-B - moderate Co (up to 16500 ppm) and moderate to high Ni (up to 32700 ppm); type-C - no/low Co and high Ni (up to 43000 ppm); type-D - neither Co nor Ni. Textural and compositional data of pyrites suggest that the hydrothermal fluid responsible for pre-/early-shearing mineralization evolved from Co-rich to Ni-rich and the late-/post-shearing fluid was largely depleted in minor elements. Sulphur isotope compositions of pyrite mostly furnish positive values ranging between -0.33 and 12.06%o. Composite samples of pyrites with only type-A compositions and mixed samples of type-A and type-B are consistently positive. However, pyrite with mixed type-A and type-C and pyrite with type-D compositions have negative values but close to 0%o. By integrating minor element and sulphur isotope compositions of pyrite in conjunction with other published data on the Jaduguda deposit, it is proposed that reduced sulphur for the precipitation of most pyrites (type-A, type-B) was likely derived from isotopically heavy modified seawater. However, some later sulphur might be magmatic in origin remobilized from existing sulphides in the mafic volcanic rocks in the shear zone.

6 illus, 2 tables, 31 ref

001470   Ogungbe A S;Onori E O;Olaoye M A (Physics Dep, Lagos State University, Ojo, Lagos, Nigeria, Email: ogungbea@yahoo.co.uk) : Application of electrical resistivity techniques in the investigation of groundwater contamination: a case study of Ile - Epo Dumpsite, Lagos, Nigeria. Int J Geomatics Geosci 2012, 3(1), 30-41.

2D resistivity imaging and vertical electrical sounding (VES) surveys were integrated in the study of the investigation of the level of groundwater contamination at Ile - Epo dumpsite in Agbado Oke-Odo Local Council Development Area (LCDA), Lagos State, Southwestern, Nigeria. A total of nine vertical electrical soundings and four 2D electrical imaging using Wenner configurations was used for the study. Out of these, six VES and three 2D electrical imaging were carried out on the dumpsite while three VES and one 2D imaging were carried out in a school 100m away from the dumpsite in order to serve as control. The result of interpretation of both data suggests that the study area is underlain by sand and clay formations. Results of the resistivity Imaging delineated the contaminant plume as low resistivity zones (0.5 - 48 αm). This was also correlated with the VES values of 0.1 to 31.6 Wm which indicate contaminant plume. This was observed to have infiltrated to a depth of about 50m which poses serious health risks to the inhabitants of that area.

15 illus, 16 ref

001469   Nayak T;Verma M K;Hema Bindu S (NO, National Institute of Hydrology Regional Centre, Manoraa Colony, Email: trnnca@gmail.com) : SCS curve number method in Narmada basin. Int J Geomatics Geosci 2012, 3(1), 219-28.

SCS-CN method is an event-based model developed by the USDA Soil Conservation Service (SCS). The Curve Number (CN) is a land-cover index for a given land and soil type to determine the amount of rainfall that infiltrates into the ground and the amount that becomes runoff for a specific storm event (USDA, 1986). The hydrological response of watershed is usually altered due to revolution in the watershed development. Thus it is necessary to quantify the likely changes in the surface runoff in a watershed as an impact of the planned or unplanned changes made in the land use. The Uri river watershed in Lower Narmada basin in Central India has been chosen to investigate the effects of land-use change on surface runoff. Satellite imageries pertaining to two different periods, i.e. year 2001 and 2007 have been interpreted in ILWIS GIS platform for preparation of land use/cover maps, analysis of their spatial distribution and changes between the two periods. The weighted average Curve Numbers (CN) for both the year calculated on the basis of land use/cover type and hydrologic soil class in the catchment area. The direct surface runoff volume computed by the SCS Curve Number method have been compared with the observed runoff calculated from recorded hydrograph at G&D site for the selected rainfall events. It was shown from the results that the agricultural area have been increased drastically and forest area has reduced considerably resulting in 20-40% increased surface runoff volume in recent years (i.e. 2007) in comparison to those in 2001 for the similar rainfall events.

4 illus, 4 tables, 12 ref

001468   Nayak S (NO, Earth System Science Organization, Delhi-110 003, Email: shailesh@moes.gov.in) : Societal benefits of earth system science. J Indian Inst Sci 2010, 90(4), 503-13.

Climate prediction over India is focused on the monsoons and has a history of well over a century. Weather forecast efforts span over 7 decades. As climate change issues take center stage, the need for a deeper understanding of the components of earth systems is recognized as critical for learning how the earth is changing. The long-term measurements, both in situ and satellite are crucial for improved predictive capability to forecast weather, climate and hazards. Capacity building in climate change research is also paramount for responsible stewardship of the Earth as an integrated and it is an investment that will pay dividends for generations to come. A number of programs focused on monsoons to earthquakes to energy and ecosystems are being planned to tackle these important issues. The success of these programs depends not only on technology and infrastructure but on people, an education system that produces the scientists and managers needed for implementing such an approach and news need to build effective communication with various stake-holders including policy-makers.

^iia6 illus, 1 table, ref