000208   Dickins J M (Innovative Geology, , 14 Bent St., Turner, A.C.T, 2612, Australia) : Nature and problems of the crust and mantle. Himalayan Geol 2001, 22(1), 1-4.

^iia24 ref

000207   Dewaikar D M;Halkude S A (Civil Engineering Dep, Indian Institute of Technology Bombay, Mumbai-400 007) : Actie thrust on retaining wall - point of application and distribution. Indian Geotech J 2003, 33(3), 248-63.

Coulomb's analysis of active thrust on retaining wall with cohesion-less backfill has been extended with emphasis on point of application of the thrust. Using Kotter's Equation, the distribution and point of application of soil reaction on the failure plane are evaluated. Active thrust is obtained using trial and error procedure, in which, the failure plane is identified in such a way that force equilibrium of the failure wedge is satisfied. The distinguishing feature of the proposed analysis lies in its ability to compute the point of application of active thrust using moment equilibrium condition effectively. One of the main deficiencies in Coulomb's theory that, in general, it does not satisfy all the static equilibrium conditions is rectified. The analysis clearly shows that, location point of application of active thrust is dependent upon combinations of several parameters such as angles of soil internal friction, wall from its base. Active pressure distribution on frictional wall is found to be non linear in nature. It is further seen that, there is a reasonably good agreement between the results of proposed analysis and experimental results, in respect of wall rotation about its base.

11 illus, 6 ref

000206   Das B;Talukdar J;Sarma S;Gohain B;Dutta R K; Das H B;Das S C (Tezpur University, , Napaam, Tezpur-784 028) : Fluoride and other inorganic constituents in groundwater of Guwahati, Assam, India. Curr Sci 2003, 85(5), 657-61.

Groundwater quality in Guwahati has been studied with special reference to the presence of fluoride. The Brahmaputra river in the north, hills to the east and south, and alluvial soil to the west surround the city. Fluoride, above the guideline values of WHO, has been found in groundwater of the eastern and southern plains of the city. The fluoride contents have positive correlation with Na⁺, K⁺, total alkalinity and depth of source, and negative correlation with Mg²⁺, Ca²⁺ and total hardness. Negative correlation of fluoride with hardness and absence of any correlation with chloride indicate recharge of the aquifer by the Brahmaputra and/or rain. A few of the samples showed high nitrate and sulphate contents. The sources of fluoride and nitrate are suspected to be minerals from the Precambrian granite, which forms the basement of the city and also outcrops at several places in the city.

3 illus, 2 tables, 21 ref

000205   Christian Smoot N (Geostreams, , Ltd, 104 Williamsburg Rd., Picayune, MS 39466, USA) : Ocean survey program (OSP) bathymetry history : jousting with tectonic windmills. Himalayan Geol 2001, 22(1), 65-80.

The plate-tectonic hypothesis was formulated in the early 1960s .A small scattering of sonar data gave a few megatrends, such as fracture zones and mid-ocean ridges. In 1974, an updated bathymetry set became available. It showed trends going WW-ENE, and trends going NNW--SSE. The data also showed mini-crosstrends passing WNW-ESE. These results were used to show seafloor spreading to the WNW. From 1967 to 1996 multibeam sonar data, called SASS, was collected by the US Navy for the submarine program. In 1989, a stick-figure tectonic diagram of the Atlantic Ocean basin was published, and it showed the megatrends. Geophysical data collected by satellite altimetry, Seasat and GEOSAT, opened up the southern ocean basins to be included in any working hypotheses. This was then compared to the available bathymetry and the tectonic structure was verified. The tracks were shown to be trans-basinal, three complete sets of trends cross the basin. This being a physical impossibility within the constraints of either the plate-tectonic or the Earth expansion hypotheses, placed in a surge tectonic framework, the reasons were apparent. Reactivation causes the implantation of seamounts, the morphology of which are determined by the alignment of the pre-existing fractures. As the planet wobbles, younger surge channels flow, ever eastward, and cross the older, already bathymetrically imprinted surge channels. During the cretaceous, the voluminous igneous outpouring created the large Pacific plateau and rises where several of these surge channel megatrends intersected orthogonally.

^iia2 illus, 91 ref

000204   Choi D R (NO, , 194 McConaghy Street, Mitchelton, QLD 4053, Australia) : Submarine geology of the oceans around Australia. Himalayan Geol 2001, 22(1), 81-90.

Plate tectonics asserts that the oceanic floors around the Australian continent were formed in Cretaceous (Aptian) and Cenozoic by the process of seafloor spreading (Veevers et al., 1991). It claims that India was first separated from Australia in Aptian (Early Cretaceous), followed by Antarctica in Late Cretaceous. The Tasman Sea opened in the latest Cretaceous. However, these plate tectonic stories are refuted by the Precambrian (Proterozoic) contineatal-scale lineaments which harmoniously continue into the ocean floors, implying that the formation of the `oceanic crust' is much older than Cretaceous, probably will be as old as Proterozoic. The prevailing orthogonal fracture pattern well developed both in oceans and continents makes it impossible to move plate blocks anywhere. This alternative interpretation is supported by the dredged Proterozoic and Paleozoic rocks from deep sea floors. It is further supported by seismic data taken across the continental shelf and the slope in the Southern Ocean, in which the Early Cretaceous sediments show conspicuous progradation pattern toward the present land, suggesting that an exposed source area had once existed in the present deep Southern Ocean during the Cretaceous time. No deep sea drillings reached the `oceanic crust' underneath the Mesozoic (Jurassic) and Cenozoic basaltic layers. Basalts encountered at the bottom of the holes are all intrusives or extrusives, and do not form the real`Oceanic crust'.

7 illus, 1 table, 55 ref

000203   Chandel S S;Aggarwal R K;Pandey A N (State Council for Science, Technology and Environment, , Himachal Pradesh, B-34, SDA Complex, Kasumpti, Shimla-171 009) : New approach to estimate global solar radiation on horizontal surfaces from temperature data. SESI Jl 2002, 12(2), 109-14.

A new correlation model for estimating monthly average values of global solar radiation from ambient air temperature data has been presented. The model follows closely to that of Allen's and considers effects of latitude an daltitude of the location. Numerical calculations have been made using the new model corresponding to three locations (viz. Amritsar, Delhi and Shillong) and the results are compared against the measured values and results of other two models.

3 illus, 1 table, 6 ref

000202   Bhat M I (Wadia Institute of Himalayan Geology, , 33, General Mahadeo Singh Road, Dehra Dun-248 001) : Untenability of the Neo-Tethys: Okeanos was not a polygamist. Himalayan Geol 2001, 22(1), 5-15.

As proposed by Sengor (1984), the Neo-Tethys ocean, ancestral to the Alpine-Himalayan belt, was born as a result of Late Paleozoic rifting along the northern margin of the Gondwanaland. No ocean or seaway is supposed to have existed in the region of its birth before middle Carboniferous time. The rifting caused separation of a string of continental mass (the Cimmeride continent) whose northward drift, as a result of spreading in the Neo-Tethys ocean, caused the closure of the Paleo-Tethys (a vast, eastward-widening embayment between Eurasia and Gondwanaland) further north, producing the Triassic Cimmeride Orogenic belt. The concept of dual Tethys is supposed to have solved the problem that plate tectonic reconstructions caused by placing large portions of Mongolia and Central Asia within the Tethys. A new variant of the Neo-Tethys model, currently much adhered to, envisages the origin of this ocean in Permian time along the southern margin of a basin that existed since the Precambrian time on the northern margin of the Gondwanaland (e.g., Brookfield, 1993). Neither of the two models, however, stands the stratigraphic and tectonic record of one of the best known segments of the `Neo'-Tethys-the Himalayan belt-where southern passive margin of this ocean preserves a concordant stratigraphy from Late Archean to Eocene time. Following the initiation of the basin formation during a Late Archean rifting event, the sedimentation history reveals a progressive northward shift in the fall line and depocentre.

6 illus, 42 ref

000201   Adachi H (Tokyo Metropolitan Shinobugaoka High School, , 5-1-20 Asakusabashi Taito-ku, Tokyo-111-0053, Japan) : Dynamics of late Miocene tectono-magmatism in the Fossa Magna district, Central Japan. Himalayan Geol 2001, 22(1), 41-9.

Remnants of many late Miocene volcanic collapse basins are recognized to have been formed across the Fossa Magna district at the junction of three island arcs, and preserved from severe erosion due to regional uplift since that time. These remnants should be important clues in understanding the dynamics driving late Miocene tectono-magmatism in the district. The dynamics responsible for the entire hierarchical structure of the three orders is the expansion of elongated molten bodies seated from the lowest crust to the upper mantle. This is because the expansion is considered to have formed regional anticlinal uplifts of the crust surface, while at the same time generating deep echelon fractures that have fed magma chambers aligned in the shallow crust, resulting in the formation of the rows of volcanic collapse basins. Late Cenozoic tectono-magmatism in the southern Fossa Magna is often explained by collision tectonics. However, it would appear to be difficult to explain the formative mechanism of the hierarchical structure of late Miocene volcanic collapse basins, and the tectonic framework consistent before and after the collision event of 5 to 6 Ma with this tectonic scenario.

8 illus, 24 ref

017697   Sreelash K;Mudgal B V (Centre for Water Resources, Anna Univ, Chennai-25, Email: bvmudgal@gmail.com) : Drag characteristics of cylindrical piers with slots and/or collars in subcritical flow. ISH J Hydraul Engng 2010, 16(2), 75-87.

The flow field around a circular bridge pier is a complex three-dimensional phenomenon. Notwithstanding the considerable effort made in the study of local scour by many researchers, an understanding of the mechanics of local scour around a bridge pier remains far from complete. The drag force exerted on the structure is related to the wake. Larger the wake, higher is the drag force and scour potential. Efforts to reduce the drag by reducing/altering the wake structure are widely reported in literature. Use of slot-collar combination is one among them. In this study, an attempt has been made to establish the drag characteristics of cylindrical pier models, with different slot-collar combinations. This experimental study is conducted using a physical hydraulic model operated under clear-water and rigid bed conditions. All the experiments are conducted in a re-circulating tilting flume. Experiments are run for different combinations of slot and collar. Drag coefficient of the pier is computed using the momentum equation. The drag studies indicate that the drag coefficient in general is found to decrease with the provision of slot/collar. The value of drag coefficient is reduced by about 33% for a bottom slot/collar combination.

9 illus, 2 tables, 6 ref

017696   Sethwala R;Agarwal R;Dhodakia M B;Garg J K (NO, L.D College of Engineering, Ahmedabad, Email: gargjk@gmail.com) : Comparative assessment of MXL classifier and knowledge based classifier for delineation of within wetland features using resourcesat-1 Liss-III data. ISH J Hydraul Engng 2010, 16(2), 28-37.

An automated knowledge-based classifier has been developed to decipher wetland features (water, aquatic vegetation- floating as well as submerged, mud flats) in Nal-Sarovar wetland, Gujarat, India from Resourcesat-1 LISS-III data acquired on November 24, 2005. Water has further been classified into three qualitative turbidity classes (low turbid, moderate turbid and high turbid). Same dataset has also been classified for wetland features using Maximum Likelihood classifier. Comparison of the results has brought out that overall accuracy of wetland feature delineation and Kappa statistic of Knowledge based classifier (87.78% and 0.85) are better in comparison to MXL classifier derived wetland features (80.22% and 0.76). Estimated total area of wetland features in Nal Sarovar using knowledge based and MXL classifiers is 106.138 sq. km and 123.951 sq. km respectively out of 139.24 sq. km wetland area.

6 illus, 1 table, 10 ref

017695   Rao S;Shirlal K G;Prashanth S;Varghese R V (Applied Mechanics and Hydraulics Dep, National Institute of Technology Karnataka, Surathkal, Srinivasnagar, D. K. District-570 025, Email: surakrec@yahoo.com) : Laboratory investigation of horizontal and vertical plate breakwaters. ISH J Hydraul Engng 2010, 16(2), 88-98.

Submerged breakwaters are commonly used for coastal protection on many eroding coasts. Plates are proved to induce wave breaking and dissipate wave energy. These have the advantages of low interference with current and sediment transport while saving substantial quantity of material. They permit exchange of surface and subsurface water and living organisms and hence, suitable for ecologically sensitive region. This paper explains the physical model studies to evaluate the transmission coefficients of a rigid submerged horizontal and vertical plate. It is found that the horizontal plate with ds/H_i <60> 1.0 is effective to bring the values of K_t below 0.6 when d/L <62> 0.22. Vertical plate is effective for the entire range of d/L for ds/H_i = 0.

10 illus, 9 ref

017694   Rama Rao V S;Bhajantri M R;Pethe P C (NO, Central Water and Power Research Station, Khadakwasla, Pune-411 024) : Hydraulic model studies for Sewa-II dam spillway, Jammu & Kashmir. ISH J Hydraul Engng 2010, 16(2), 104-15.

The perennial Himalayan rivers provide potential for large scale hydro power generation. These rivers carry heavy sediments because of steep slopes and young geology consisting of soft, friable rock. This is further aggravated by the seismic character of the Himalayan zone. The rivers during flooding time carry with them lot of sediment which ultimately gets collected in the reservoir. Spillways in Himalayan region are designed for handling both flood releases and flushing of the sediment. Breastwall/sluice spillways have been widely recognized as the most appropriate spillways for dual purpose of flood disposal and flushing of sediment. Present paper describes the hydraulic model studies conducted for Sewa dam spillway, to study the suitability of spillway by assessing the discharging capacity of spillway, performance of stilling basin, flow conditions upstream, downstream of spillway and in front of power intake.

7 illus, 6 ref

017693   Prakash H (NO, CWPRS, Khadakwasla, Pune-411 024, Email: hprakash_bhoora@yahoo.com) : Velocity approach for incipient motion. ISH J Hydraul Engng 2010, 16(2), 47-57.

Velocity of flow for incipient motion condition of sediment particles is the fundamental parameter required for use in studies on Fluvial Hydraulics. Using the data for average critical velocity for different sediment sizes collected by different investigators, a single functional relationship has been obtained between dimensionless critical velocity.

4 illus, 1 table, 26 ref

017692   Mazumder S K (NO, Aquagreen Engg. Mgt. (P) Ltd., ICT Pvt. Ltd. & SWI (P) Ltd., New Delhi, Email: somendrak64@rediffmail.com) : Critical tractive stress in straight and surved channels with non-cohesive soil. ISH J Hydraul Engng 2010, 16(2), 38-46.

Estimation of critical tractive stress in an open channel is important for finding bank stability and for the design of stable channels. It is also vitally needed for finding bed load transport. Shields' study is applicable for non-cohesive soil on flat surface. Lane made exhaustive study on critical tractive stress for both flat and inclined surfaces and contributed immensely for the design of stable channels. All these studies are, however, applicable for straight channels only. Starting from fundamentals, author has derived equations for critical tractive stresses both for straight and curved channels. It has been shown that the shear stress induced by secondary current in a typical curved channel e.g. in a meandering bend, reduces significantly the critical tractive stress on the outer side of bend. If the stress due to secondary current is very high due to strong flow curvature, critical tractive stress may vanish and the outer bed and bank may cave in even with insignificant forward drag.

4 tables, 12 ref

017691   Kumar C P;Mittal S (NO, National Institute of Hydrology, Roorkee-247 667) : Determination of soil hydraulic properties in a part of Hindon river catchment using soilprop software. ISH J Hydraul Engng 2010, 16(2), 13-27.

Mathematical models of hydrologic and agricultural systems require knowledge of the relationships between soil moisture content (6), soil water pressure (h) and unsaturated hydraulic conductivity (K). To model the retention and movement of water and chemicals in the unsaturated zone, it is necessary to know the relationships between soil water pressure, water content and hydraulic conductivity. It is often convenient to represent these functions by means of relatively simple parametric expressions. The problem of characterizing the soil hydraulic properties then reduces to estimating parameters of the appropriate constitutive model. A number of models for water retention function and unsaturated hydraulic conductivity are well reported in literature, the most popular being van Genuchten model and Brooks-Corey model. In general, the van Genuchten model matches experimental data more satisfactorily than Brooks-Corey model. However, the functional form of van Genuchten model is complicated and limits its usefulness for large number of analytical solutions available for infiltration and drainage problems. On the other hand, Brooks-Corey model yields conductivity and water retention functions that are easy to manipulate mathematically. For this study, 27 soil samples were collected from various locations as well as depths in different villages, namely Aurangabad, Kamalpur, Budhakhera, Gagalheri, Dudhil Bukhara in the upstream part of Hindon river catchment and laboratory investigations were carried out to determine bulk density and grain size distribution. Using these data as input to the SOILPROP software, van Genuchten and Brooks-Corey parameters (α and n & h_d and λ) were determined to derive the retention characteristic and unsaturated hydraulic conductivity. The values of a and n (van Genuchten parameters) were found to vary from 0.00004 to 0.00078 and 1.19 to 1.65 respectively. The values of h_d and λ (Brooks-Corey parameters) were found to vary from 860 to 20200 cm and 0.189 to 0.538 respectively. These results (as necessary input for unsaturated zone modelling) will be helpful for prediction of soil moisture flow and groundwater recharge in the Hindon river catchment.

6 illus, 1 table, 9 ref

017690   Khelchandra Singh K;Manihar Sharma B;Usha K H (Ecology Laboratory, Life Science Dep, Manipur Univ, Canchipur, Imphal-795 003, Email: k_khel@yahoo.com) : Ecology of Kharungpat lake, Thoubal, Manipur, India: part-I water quality status. Ecoscan 2011, 4(2-3), 241-5.

The study attempts to examine some of the physico-chemical parameters of the water samples of Kharungpat lake, Thoubal district, Manipur. The lake is a shallow rainfed lake and is located at a distance of about 30 km from the Imphal town. Various physico-chemical parameters (Viz., temperature, transparency, total dissolved solids, pH, electrical conductivity, dissolved oxygen, free carbon dioxide, chloride, total alkalinity and total hardness) were analysed during 2008 at monthly intervals by following standard methods. Among the various parameters recorded, the overall surface water temperature ranged from 15.5 (December) to 31.3°C (May); transparency from 16.5 to 62.5 cm; total dissolved solids from 35 mg L-1 (December) to 416 mg L-1 (July); pH from 6.1 to 7.9; electrical conductivity varied from 94.0 S cm ^-1 to 289.0 Scm^-1 dissolved oxygen from 1.4 to 7.8 mg L^-1 free carbon dioxide ranged from 7.0 to 37.0 mg L^-1; while chloride values ranged from 21.27 to 113.46 mg L^-1; total alkalinity varied from 38.0 to 226.0 mg L^-1; total hardness ranged from 88.0 to 220.0 mg L^-1. The physico-chemical characteristics of the different sites varied considerably during the study period. The high values of the physico-chemical parameters obtained in the present study sites indicate the hyper-eutrophic status of the Lake.

1 table, 46 ref

017689   Karmakar S;Sirajul Haque S M;Mozaffar Hossain M (NO, Degradation of Upland Watershed in Bangladesh, Bangladesh, Email: shamifescu@yahoo.com) : Silation in Kaptai reservoir of Shittagong hill tract Bangladesh. J Indian Wat Wks Ass 2009, 41(4), 275-8,283-4.

To measure impact of ecological change in Chittagong Hill Tracts after the installation of dam at Kaptai in 1955 on siltation, Bangladesh Water Development Board has conducted siltation study several times from 1978. In 1983 and 2001 more comprehensive survey had done on 67 cross-sections, repeating 42 cross-sections of 1978 and in 1986 a partial survey done on 20 cross-sections by echo sounding method and found total silt loads were higher in upstream silt ranges than downstream of Kaptai Reservoir. In reservoir, total siltation load was 1.25xl0⁸m³in 1983-2000 of 67 cross sections with a siltation rate of 41361.82m³/km²/yr. Apart from this, suspended sediment (SS) in Kaptai reservoir was studied independently in September 2007 and April 2008 in rainy and dry season, respectively by grab sampling at 0.8 and 0.2 fractional depths at six different points in the reservoir. The upstream locations comprised high SS concentration than downstream locations and rate of discharge was not affecting the SS concentration significantly. Silting up of the river created island in many places signaling further worsening of overall conditions of the region which may impede hydroelectricity generation, navigation, fishing habitat, and waters supply for irrigation and domestic for which dam was created in this torrent river.

3 illus, 2 tables, 5 ref

017688   Gupta L D (NO, Central Water and Power Research Station, Pune-411 024) : Investigation of dynamic response characteristics of gravity DAMS by sub-structure approach. ISH J Hydraul Engng 2010, 16(2), 1-12.

In the sub-structure approach for dynamic response analysis of gravity dams the dam-foundation rock and the dam-reservoir water interaction forces are first estimated by solving the wave equation for the foundation-rock and the reservoir domains with suitable boundary conditions, and the response of the dam by treating it as a separate sub-structure with the earthquake and the interaction forces applied externally. Using this approach, the effect of various controlling parameters on the dynamic response of the tallest monolith of Koyna dam has been investigated with the accelerogram of the M6.5 earthquake of 10 December 1967 as input excitation. Nine different combinations of the Young's modulus of foundation rock, water level in the reservoir, thickness of the sedimentary deposits in the reservoir, and the Young's modulus of the rock underlying the sedimentary layer have been considered to investigate the significance of each of these parameters on the dam response. It has been established that the sub-structure approach is able to predict the response of gravity dams by accounting for the effect of various interaction forces in a quite realistic way, provided the foundation can be approximated to be a half-space.

5 illus, 4 tables, 10 ref

017687   Dutta S P S;Jandial N;Khajuria M (Environmental Sciences, Jammu Univ, Jammu-180 004, Email: nidhijee@hotmail.com) : Water quality at two spring sites and at sites before water discharge into Nagrota Nullah, near Kashmir migrant quarters, Nagrota, Jammu. Ecoscan 2011, 4(2-3), 227-34.

Water quality parameters viz., temperature, turbidity, pH, DO, COD, BOD, HCO₃, Ca ++ Mg ++ total Hardness, Na + K+, Silicate, Phosphate, Nitrate, electrical conductivity and TDS were analysed for one year viz. January, 2003 - December, 2003 at two spring sites and at sites away from springs, before water discharge into Nagrota nullah, jammu and have been described. Comparison of water quality parameters with national and international standards has revealed these within optimum limits for consumption.

2 illus, 6 tables, 33 ref

017686   Bhattacharya D (NO, , C/O Radha Krishna, Kedar Gouri Road, Bhubaneswar-751 002) : Effects of very severe tropical cyclone : select short perspectives. J Instn Engrs-Pt AR 2010, 91(Apr), 26-32.

Very severe tropical cyclonic storms (VSCSs) are extremely high impact natural hazards that inflict severe disasters and needs to be managed on war footing. The Mahanadi-Brahmani delta-valley region of the Indian sub-continent act as one of the naturally preferred inland ingression gateway for at least one VSCS/year. It has experienced the sole super cyclone (SC) in living memory. In the year 2006, out of the 16 depressions that ingressed into the Indian peninsula, 14 had ingressed inland through this gateway. Microbursts causes tree break, fall and loosening of embankments. Microbursts are constituent members and not the cause factor or maintainer of VSCS. Induces swing and delayed action mechanism induced synchronous swing in the electrical high-tension scopes which trigger tower collapse that causes introduction of swing propagation cancellor. Futher, angled flow of rain drops induces mud house wall collapse. Rural building engineering suggests cyclone resistant preferred shape and evolutionary design. Bernoulli's effect associated with microbursts causes acute pressure contrast, triggers (asbestos and tin) roof blow-offs. Tightly closed shutters have been suggested as saviour of asbestos roofed tenements.

9 illus, 17 ref

016431   Sahu D D;Chopada M C;Kacha H L (Agrometerology Cell, Agronomy Dep, Junagadh Agricultural Univ, Junagadh, Email: ddsahu1950@yahoo.co.in) : Verification of medium range rainfall forecast under south Saurashtra agro climatic zone, Gujarat. J Agrometeorol 2011, 13(1), 65-7.

2 table, 9 ref

016430   Pradhan S;Sehgal V K;Das D K;Singh R (Agricultural Physics Dep, Indian Agricultural Research Institute, New Delhi-110 012, Email: sanatan28@gmail.com) : Analysis of meteorological drought at New Delhi using SPI. J Agrometeorol 2011, 13(1), 68-71.

^ssc1 illus, 3 tables, 3 ref

016429   Jemimah M L;Rajput C;Machiwal D;Sharma A (College of Technology of Engineering, MPUAT, Udaipur-313 001) : Detection of heat wave trends in semi-arid climate of Udaipur, Rajasthan. J Agrometeorol 2011, 13(1), 62-4.

^ssc2 illus, 2 tables, 6 ref

015389   Vu T T A;Liwei H;Wang B;Deng N (NO, Institute of Marine Geology and Geophysics-Vietnam Academy of Science, Hanoi, Vietnam, Email: nsdengwhu@163.com) : Photodegradation of tetracycline in water in the presence of ferric-oxalate complex. Res J Chem Envir 2010, 14(2), 93-5.

Photodegradatidn of tetracycline in aqueous solution was investigated under UV-Vis light (A, ≥ 365 nm) in Fe(III)/oxalate system in this work. After 15 min of irradiation with C(Fe(IH)) = 10.0μM, C(oxalate) =100 μM, 10.0μM tetracycline could totally degrade at pH 4.7. The influence factors of light source, pH value, Fe(III)/oxalate ratio as well as the chemicals adding sequence on tetracycline photodegradation efficiency were studied.

5 illus, 17 ref

015388   Shrestha R A;Kafle B K;Sillapaa M (School of Science, Kathmandu Univ, P.O. Box: 6250, Kathmandu, Nepal, Email: mka.sillapaa@uef.fi) : Water quality of Dhulikhel area, Nepal. Res J Chem Envir 2010, 14(2), 36-8.

This study consisted of the determination of the physiochemical properties of different types of untreated water in Dhulikhel area of Nepal. The aim was to ascertain the quality of river water, ground water and pond water. Only the concentration of chloride exceeded the permissible limits of the World Health Organization drinking water quality guidelines. The four out of five ponds had very low dissolved oxygen content. On an average, the water in this area was slightly polluted. A simple pre-treatment is enough to make the water potable.

1 illus, 1 table, 33 ref

015387   Sadi T;Arzhani Z (NO, Khuzestan Water and Power Authority Co., Ahwaz, Iran, Email: tofigh_sadi@yahoo.com) : Effect of ENSO on precipitation based on ONI (Case study for the region of Shahr-e-Kord in Iran). Res Crop 2009, 10(3), 755-8.

One of the affecting atmospheric events causing worldwide climatic variability is El Nino Southern Oscillation (ENSO) phenomena which demonstrates a teleconnection pattern on a global scale and influences the whole southern hemisphere and a great part of northern hemisphere beyond countries and continents. The present research investigates the impacts of this phenomenon on precipitation in Shahr-e-Kord region, south-west Iran using Oceanic Nino Index. Monthly precipitation records of Shahr-e-Kord gauging station for a period of 1956-2005 were gathered for the purpose of this study and the results showed that the a significant correlation of 0.01 and 0.05 existed for precipitation data of several months of the year over specific time periods. This correlation is positive which emphasizes the fact hat the El Nino event is usually followed by a wert year and the La Nina phenomenon reduces the precipitation in the region.

8 illus, 1 table, 7 ref

024980   Verma V K;Sharma P K;Singh V;Patel L B;Toor G S (Punjab Remote Sens Cent, PAU Campus, Ludhiana, Punjab) : Hydrochemical facies of groundwaters of southwestern Punjab, India in relation to their suitability for irrigation. Asian J Microbiol Biotechnol envir Sci 2004, 6(3), 379-81.

A systematic study was conducted to ascertain the hydrochemistry of ground waters in southwestern part of Pubjab, in relation to their suitability for irrigation and evaluate their effect on crop growth and chemical properties of soils. The ground water samples from running tubewells were collected and analysed for various chemical constitutents. Based on their major cation and anion content, five hydrochemical facies have been identified and mapped. Majority of ground waters occur as Na⁺-SO^2-₄-Cl^- HCO^-₃. The composition generally changes from HCO^-₃-Cl^-SO^2-₄ to Cl-SO^2-₄-HCO^-₃ and SO^2-₄-Cl^--HCO^-₃ as we move from high to low rainfall areas.

1 illus, 7 ref

023898   Teressa S;Mohan Kumar G;Sampath S (Atmospheric Sciences Division, Centre for Earth Science Studies, Akkulam Thiruvananathapuram-695 031) : Ultraviolet transmission through a few edible oils in the context of changing solar insolation. J Indian Geophys Union 2004, 8(4), 267-71.

A study carried out to ascertain qualitatively whether the medium of the applicant has any protection from the UV insolation. The UV transmission characteristics of edible oils were obtained using a dual beam UV -Visible spectrophotometer. UV transmission profiles of these oils smeared on quartz disks were taken. In UV-B (280-320 nm), coconut oil does not absorb much. But, neem-seed oil absorbs heavily in the lower wavelength and its absorption decreases to about 50% at 320 nm. Sesame oil, on an average, has absorption of about 45% in the UV-B. Applying these oils on the skin reduces the UV dose absorbed in the epidermal and subcutatious layers. Results of the study are presented and discussed. To evaluate the efficacy of these oil as UV screens, their Sun Protection Factors are to be estimated involving more quantitative studies.

3 illus, 7 ref

023897   Sen A K;Sharma P K;Mohanty D;Ghosh T K (Earth Sciences Dep, Indian Insitute of Technology, Roorkee-247 667, Email: senakjes@iitr.ernet.in) : Composition of Cr-spinel - an ore genetic indicator of kathpal chromite deposit, Sukinda ultramafic complex, Orissa, India. Curr Sci 2005, 88(10), 1547-50.

2 illus, 1 table, 17 ref

023896   Sampath S;Murali Das S;Sasi Kumar V (Atmospheric Sciences Division, Centre for Earth Science, Akkulam Thivandrum-695 031) : Ambient noise levels in major cities in Kerala. J Indian Geophys Union 2004, 8(4), 293-8.

As a first step towards assessment of noise pollution, measurement was taken up with emphasis on traffic noise. Measurements of noise levels were carried out in the three major cities in Kerala, viz. Thiruvananthapuram, Kochi and Kozhikode to assess noise pollution. Two type of instruments with acalibration source were used for measurement. One Integrating Precision Sound Level Meter was used for measuring the equivalent continuous level (L ) and the spectrum of sound. A second instrument, a Noise Dose Meter, was used for continuous monitoring. Both instruments were calibrated before each field session using a secondary standard. All measurements were A weighted. Measurements of noise levels were carried out in the commercial zones of the three cities. The results indicate that the noise levels are higher than the limits prescribed by the Ministry of Environment & Forests, Government of India. The silence zones in the cities also showed higher levels. The measured sound level inside residential buildings at night during festival time exceeds the prescribed limit by 30 to 40 dB. Announcements from vehicles fitted with public address systems can cause sound levels above 100 dB A at distances of 10 to 15 metres.

2 illus, 2 tables, 8 ref

023895   Reddy P R;Rao G K;Behera L;Prasad A S S S R S;Sridhar V (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007) : Actuve seismics. J Indian Geophys Union 2004, 8(4), 309-10.

023894   Reddy P R (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: paravata@yahoo.com) : Crustal velocity structure of western India and its use in understanding intraplate seismicity. Curr Sci 2005, 88(10), 1652-7.

Intraplate seismicity is random in distribution and understanding of its genesis needs proper knowledge of various data sets including subsurface crustal images, stress field characteristics and spatial-temporal seismic pattern. An attempt is made to provide one important input in the form of seismicity and P-wave velocity-depth relationship, covering aseismic and seismic zones of western India.

3 illus, 15 ref

023893   Rastogi R G;Yumoto K;James M E;Kitamura K (NO, Physical Research Laboratory, Ahmedabad-380 009) : Geomagnetic storm effect at Equatorial electrojet stations. J Indian Geophys Union 2004, 8(4), 299-307.

The studies of the geomagnetic H and D data from the Kyushu University network of stations has confirmed the suggestions made by Rastogi et al (2001) that during the magnetic storms the deviations of horizontal field (H) and the eastward field (Y) are related by ΔY/ΔH = sin (Ψ-D) where Ψ is the dipole declination and D is the ground (dip) declination at the station.

5 illus, 1 table, 13 ref

023892   Rastogi B K;Bergman E A;Engdahl R E (National Geophysical Research Institute, , Hyderabad-500 007, Email: brastogi@ngi.res.in) : Improved earthquake locations and estimation of Pn and Sn path anomalies for India, using multiple event relocation and reference events. Curr Sci 2005, 88(10), 1586-91.

Combines local seismic network data and a groomed ISC/NEIC database of phase arrivals at regional and teleseismic distances to determine accurate hypocenters and origin times for 224 earthquakes that are clustered in three regions of India (Koyna, Chamoli Uttarkashi and Kutch). Multiple event relocation of these clusters of events, combined with highly accurae reference event locations from local network data, is used to improve relative and absolute locations of all cluster events. The improved accuracy of the locations obtained for mainshocks, early aftershocks and other earthquakes in these regions offers insights into the regional seismotectonics. The observed arrival time data for these cluster, calibrated by the reference events, provide a valuable data set for estimating Pn and Sn travel time anomalies beneath India, which in turn are used to develop constraints on models of the crust and upper mantly for that region. In particular, observes largs (up to 12 seconds early) path anomalies for Sn on paths across the Indian shield, suggesting significantly higher shear velocities than predicted by the average global model ak135.

3 illus, 2 tables, 6 ref

023891   Prasad N;Sarma A D (R & T Unit for Navigational Electronics, Osmania University, Hyderbad-500 007) : Ionospheric time delay estimation using IDW grid model for GAGAN. J Indian Geophys Union 2004, 8(4), 319-27.

To facilitate the accuracy required for Category-1 (CAT-1) precision approach landing of aircrafts, augmentation of GPS is planned through regional SBAS called 'GAGAN' by Indian Space Research Organization (ISRO) and Airport Authority of India (AAI). In GAGAN, ionospheric time delay is one of the predominant errors that limit the range accuracy of the user. Even though several analytic function based models are available for ionospheric error corrections, grid based models are preferred due to their greater accuracy and less complexity. The accuracy of modeled vertical ionospheric delays at the IGPs, user's IPPs and GIVE are the functions of IPP density, grid size, input data and measurement update rates. The ionospheric vertical delays and error bound GIVE estimated using Inverse Distance Weighted with Klobuchar model is presented. The results are encouraging and this model is a good contender for implementation in GAGAN System.

7 illus, 3 tables, 17 ref

023890   Paikarasy S;Banerjee S;Mukherjii S (Earth Sciences Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076, Email: mitras@iitb.ac.in) : Sorption of arsenic onto Vindhyan shales: role of pyrite and organic carbon. Curr Sci 2005, 88(10), 1580-5.

Batch isotherms for aresenic sorption on Vindhyan shales were compared with arsenic sorption on black cotton soil. High sorption was observed on pyrite-rich shales and the Freundlich capacity constant K_F yielded a good correlation with sediment pyrite content. Shales with high organic carbon sorbed more arsenic; however, the organic carbon-rich soil demonstrated significantly lower sorption. This difference may be due to the condensed nature of organic carbon in shale, which may have facilitated formation of organio-arsenic complexes. The pyrite content was also strongly correlated with the organic carbon content, possibly due to microbial synthesis during shale diagenesis.

2 illus, 4 tables, 31 ref

023889   Mukhopadhyay P (NO, Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan Pune-411 008) : Idealized simulation of a thunderstorm over Kolkata using RAMS. J Indian Geophys Union 2004, 8(4), 253-66.

An idealized simulation of a thunderstorm is attempted using Regional Atmospheric Modelingy System (RAMS). The storm was reported on 1200 UTC of 14 July 1998 over Kolkata station. The upper air sounding data collected over Kolkata station at 0600 UTC under GEWEX Asian Monsoon Experiment is perturbed with a warm bubble to trigger the convection. Subsequently the model is run for 12 hour in forecast mode with two horizontal resolutions namely 5 km and 1 km. Analyzing different forecast fields such as temperature, total cloud condensate, vertical velocity, rainfall, it is found that 5 km grid has produced a strong convection after one hour model run. However it could not generate the convection around 1200 UTC which is the time of actual report of the thunderstorm. On the contrary, the 1 km simulation showed formation of storm after one hour integration and also at 1100 UTC i. e. after five hour of integration. The time of simulated convection by 1 km grid at 1100 UTC is very close to that of actual report. As such this study indicates that cloud resolving grid length of 1 km has better simulated the thunderstorm compared to the 5 km grid resolution.

9 illus, 1 table, 15 ref

023888   Mooney W D;Vijaya Rao V;Reddy P R;Chulick G S;Detweiler S T (US Geological Survey, , Middlefield Road. Menlo Park, Califormia 94025, USA, Email: vijayraov@yaloo.co.in) : Comparison of the deep crustal structure and seismicity of North America with the Indian subcontinent. Curr Sci 2005, 88(10), 1639-51.

Summarises geophysical information from North America and India, and find many similarities in the deep crustal structure of the two continents. From this, infer that similar processes have operated, particularly in the accretion and stabilization of the crationic regions. Seismic images and other data suggest that plate tectonic processes have been active, both in the North American and Indian shields, Since the late Archean. Precambrian orogens and high-pressure gramulite terrains of both regions have developed nearly identically through time since about 2500 Ma. Such similarities invite direct comparisons of deep crustal structure. Presents results from work in North America including; maps of crustal thickness, maps of average p-wave velocity of the crystalline crust, maps of average P_n (sub-Moho) velocity, and statistical analysis of crustal properties.

11 illus, 1 table, 44 ref

023887   Mall D M;Singh A P;Sarkar D (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: malldm@rediffmail.com) : Structure and seismotectonics of Satpura, Central India. Curr Sci 2005, 88(10), 1621-7.

Each intracontinental region of epeirogenic uplifts in Indian shield is a composite of smaller wavelength features of uplift, separated in some areas by sharp lowlying tectonic lineaments. Despite the large dimension, considerable uplift and high seismicity associated with the Satpura orogenic belt, its seismogenic character is not well understood. A close look at the spatial distribution of moderate earthquakes in pensinsular India, considered as a `Stable Continental Region', reveals a relatively higher level of seismicity associated with the narmada Son Lineament (NSL). The seismicity pattern of the elevated Pachmarhi plateau (a part of Satpura range) shows the concentration of the sesmicity at the boundary of the Satpura Gondwana basin, which is uplifted more than 500m along its boundary faults. They are predominantly associated with strike-slip or thrust mechanism; consistent with the compressive stresses transmitted from the plate boundary. Besides, the influence of uplifting process that possibly origimates through lithosphere-mantle interaction could be a significant contributor; perhaps not uniform in magnitude and direction as the plate tectonic stress. The plateau forming processes and the 3-D character of distensional tectonics that epeirogenic uplift imposes on an otherwise compressive domain are proposed as a mechanism for the present-day seismicity of the region.

5 illus, 42 ref

023886   Kumar V V R;Reddy U V B (11-3-366/4A, Laxmi Apartments Opp. Methodist Church, Srinivasa Nagar, , Secunderabad 500 061) : Multivariate analysis applied to the geochemistry of soils, Patancheru industrial belt, A. P., India. Ecol Envir Conserv 2004, 10(3), 329-32.

Multivariate analysis has been applied on the pedogeochemical data of 100 samples collected from Patancheru Industrial Belt (PIB) in order to know the factors dominating the chemistry of soils. A four factor model of factor analysis has been choosen and it is observed that the chemistry of soil is dominated by lithology and changes brought by anthropogenic activities. Factor 4 is loaded with pH and Na for which a detailed study of Na compounds is needed for the establishment of their relationship.

4 illus, 4 tables, 7 ref

023885   Kishore R K;Rao R (NO, National Geophysical Research Institute, Hyderabad-500 007) : Basement characteristics of papaghin basin of Eastern Dharwar Craton (India)- An inference from aeromagnetic study. J Indian Geophys Union 2004, 8(4), 311-17.

Analysis of the aeromagnetic map of a part of granite-green stone terrain west of the Precambrian Cuddapah Basin (2000-600Ma) has been made to delineate possible lithological variations with in the basement of the oldest Papaghni sub-basin. Three magnetically different zones with in the basement have been inferred where each zone is separated by deep fault/contact. The northern part of the basement (A) is of more felsic nature compared to the middle part (B) which is occupied by older metamorphics. The southern part (C) of the basement is severely affected by mafic intrusions. Analysis of magnetic Profiles yielded a total thickness of 1300mts for the Papaghni rocks and 5.3km for the entire suite of Papaghni & Chitravati group of rocks which is in aggrement with the earlier studies.

5 illus 16 ref

023884   Jose M K;Sastry R G (NO, National Institute of Hydrology, Jalvigyan Bhawan, Roorkee-247 667, ) : Analytical computation of aquifer potenials in a three-layered porous medium. J Indian Geophys Union 2004, 8(4), 243-52.

Layered aquifer systems are common. Seepage from surface water bodies can recharge a layered aquifer system depending upon the hydrogeological set up. In artificial recharge practices, which are on the rise all over the world, it is useful to have a prior understanding of the aquifer system. It may be helpful in planning sustainable watershed development projects in complex terrains. In this context, analytical solutions are presented for steady state hydraulic heads at any point within a three layered aquifer system. The analytical solutions are obtained with a point source of known strength, on the earth's surface. The recharging due to the point source would result in the buildup of hydraulic potentials in the layers beneath. By considering the analogy between electrical flow and groundwater flow, the geoelectric principles have been suitably invoked in formulating the presented methodology. An algorithm has been designed to compute the hydraulic potentials. The mode requires only recharge rate of the source, (aquifer) grid dimensions, hydraulic parameters for layers and depth to the various layers. Several examples are provided to demonstrate the effectiveness of the analytical solutions. Performance of the analytical model compares well with that of a numerical model, MODFLOW. The algorithm presented is much faster and easy to execute.

5 illus, 1 table, 10 ref

023883   Jena M S;Rudramuniyappa M V;Misra S K;Biswal S K (NO, Gulbarga University, Karnataka-583 119) : Characterisation and beneficiation study of typical coal sample from Talcher by flotation technique. SGAT Bull 2004, 5(1), 25-33.

Investigations were carried out to characterise and evaluate the possibility of treating -1 mm size fraction of non-coking coal of South Bolanda, Talcher coalfield by flotation in cell and column. Black oil that was used as promoter to enhance the floatability worked satisfactorily when added to normal flotation process. The overall ash percentage of concentrate is around 31% with 92% combustible recovery in case of cell flotation. The petrographic study on bulk sample, flotation concentrate, middlings and tailings were carried out to find out the role of macerals in flotation. The vitrinite and liptinite (exinite) have well responded to the flotation in comparison to inertinite. A part of same sample was also subjected to column flotation study. The overall ash percentage of concentrate in this case is around 26% with 82% combustible recovery, which is comparatively better than the results of cell flotation.

10 illus, 4 table, 6 ref

023882   Hough S E;Bilham R;Ambraseys N;Feldl N (United States Gseological Survey, , 525 S. Wilson Avenue, Pasadena, CA 91106, USA, Email: hotgh@usgs.gov) : Revisiting the 1897 Shillong and 1905 Kangra earthquakes in northern India: site response, moho reflections and a triggered earthquake. Curr Sci 2005, 88(10), 1632-8.

Re-evaluated intensity distributions for the 1897 M_w 8.0 Shillong and the 1905 M_w 7.8 Kangra earthquakes, combined with geodetic constraints on rupture geometries, allow us to compare observed distributions of intensity with theoretically predicted shaking. The difference between predicted and observed shaking is interpreted in terms of the site response of the Ganges and Brahmaputra basins. These comparisons identify regions of enhanced shaking along main rivers, revealing amplifications of 1-2 intensity units, roughly an amplification of 2-4 in acceleration. Also finds two unexpected results in analysis of the Kangra earthquake: (i) The epicentral region is surrounded by a halo of enhanced intensity at 150-200 km radius and (ii) The Dehra Dun region was the locus of a broad region of anomalously high intensities. Interpret the former result as the signal frompost-critical Moho reflections and the latter observation as a probable second large earthquake (M<62>7) at 30-50 km depth triggered within minutes of the 1905 main shock. These results have important consequences from future earthquakes in the Himalaya.

6 illus, 31 ref

023881   Gupta H K (Ocean Development Dep, , Block-12, CGO Complex, Lodhi Road, New Delhi-110 003, Email: dodsec@dod.delhi.nic.in) : Artificial water reservoir-triggered earthquakes with special emphasis at Koyna. Curr Sci 2005, 88(10), 1628-31.

Globally, about one hundred sites are known where filling of artificaial water reservoirs triggered earthquakes. It is noteworthy that a majority of the sites where triggered earthquakes exceeding magnitude 5 have occurred are in Stable Continental Regions. The triggered seismicity at Koyna, india is a classical example where such events have continued to occur for over 41 years since impounding of the Shivaji Sagar Lake in 1962. Detailed investigations in the Koyna region have shown that triggering of earthquakes is influenced by rate of loading, the highest water levels reached and the duration of retention of high water levels as well as Kaiser effect. It is also proposed that increase in heterogeneity in the Koyna region and occurrence of 18 earthquakes of magnitude 5 or more may not have left a large enough fault segment for re-occurrence of another M 6.3 earthquakes will continue to occur here for another 3 to 4 decaedes making this an ideal site for monitoring eqrthquake precursos, which may lead to forecast of M - 5 earthquakes. This optimism is based on the fact that earthquakes in the Koyna region are restricted to a small area pof 30 x 20 km and within a focal depth of 12 km, and there are no other seismically active regions in the near vicinity.

2 illus, 1 table, 30 ref

023880   Gangopadhyay A;Talwani P (Geological Sciences Dep, University of South Caroina, Columbia, SC 29208, USA, , Email: talwani@geol.sc.edu) : Fault intersections and intraplete seismicity in charlestion South Carolina: insights from a 2-D numerical model. Curr Sci 2005, 88(10), 1609-16.

A simple 2-D numerical model was developed to explain the current seismicity in Middleton Place Summerville Seismic Zone, near Charleston, South Carolina. The model comprises blocks representing the structural framework with elastic properties corresponding to known geology. The blocks were subjected to tectonic loading for seven days along the direction of the maximum horizontal stress field ad the resulting pattern of shear stresses, and block rotations successfully duplicated the observed seismicity and fault motion. These results support the idea that in a localized volume of pre-existing weak crust, fault intersections act as stress concentrators, and cause anomalous stress build-up in their vicinity, resulting in the observed seismicity.

2 illus, 32 ref

023879   Ganer D W;Deo A A;Salvekar P S (NO, Indian Institute of Tropical Meteorology, Dr.Homi Bhabha Road, Pashan, Pune-411 008) : Investigation of upper ocean temperature in response to cyclonic circulations over tropical Indian Ocean using satellite winds. J Indian Geophys Union 2004, 8(4), 283-91.

In the study a 2 1/2-layer thermodynamic ocean model over the region 35°E -115°E, 30 °S -25 °N is used to simulate the thermal structure during the passage of cyclonic circulations as revealed from daily SSM/I winds. The simulation of Sea Surface Temperature (SST) over the Tropical Indian Ocean with interannually varying daily SSM/I surface winds is in close agreement with observed SST. The daily surface wind data for the year 1994, 1995 and 1996 is examined for the cyclonic vortex during the period of all the cyclonic storms over tropical Indian Ocean. The wind speed however, is less as compared to the real storms. The simulated SST anomalies show cooling of sea surface of the order of 0.5 to 1 °C within a week after the cyclonic circulation has passed over that region. This magnitude of cooling is much smaller due to less wind speed as compared to the earlier model studies and observations reported for cyclone period. The model results for each case are discussed in detail.

5 illus, 1 table, 9 ref

023878   Dimri V P;Vedanti N;Chattopadhyay S (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: vpdimri@ngri.re.in) : Fractal analysis of aftershock sequence of the Bhuj earthquake: a wavelet-based approach. Curr Sci 2005, 88(10), 1617-20.

Wavelet-based fractal analysis of the aftershock data of the disastrous Bhuj earthquake (26, January 2001) has been carried out to understand the behaviour of the aftershocks. The Omori's curve suggests that the decay of aftershocks follows a power law relation with time. The p-value, known as `decay constant' is found to be 0.88. The b-value of the region as obtained by wavelet variance analysis is close to 1, which is in agreement with normal the value for tectonically active regions. The results obtained from the multi-scale analysis of the aftershock sequence using the wavelets indicate that the fractal behaviour of aftershock data sustains up to certain scales only. Using the wavelet variance, the fractal dimension of the source is obtained as 2.06, which indicates that it is a 2D plane that is being filled up by the source fractures. The slip ratio that determines the fraction of total slip occurring on the primary fault is computed to be 0.48, which reveals that 48% of the total slip has occurred on the primary fault.

4 illus, 30 ref

023877   Das S K;Nayak B K;Sahoo B N;Sahoo R K (NO, Regional Research Laboratory, Bhubaneswar-751 013) : Characterisation of Dholkata bauxite, Keonjhar district, Orissa. SGAT Bull 2004, 5(1), 10-24.

The Dholkata bauxite deposits of Keonjhar district occurs over metabasaltic rocks of Early Proterozoic age. The bauxite occurs as segregations, irregular bodies, patches and lenses of variable thickness from 0.2 m to 10 m averaging 3 m. The metabasaltic rock is composed of augite (altered to actinolite) and feldspar (both phenocrysts and microlites). Characterisations of bauxite along two vertical profiles and the basement rock are reported. Microscopic, X-ray, DTA and SEM studies reveal that the laterites and bauxites are composed of gibbsite, kaolinite, hematite and goethite with trace amounts of boehmite, diaspore and anatase. In KD/4 profile, gibbsite content increases from 11% at the top to about 68% in the bauxite layer at about 3.0 in depth. In KD/2 profile, bauxite layer is present at the top with 53% Al₂O₃ and grades to aluminous laterite at depth having about 45% A1₂O₃. Laterite-bauxites are enriched in Fe, Al, V, Cr and Ga and depleted in Si, Ba, Sr, Cu and Zn. Chondrite normalized REE patterns of laterite-bauxite indicate strong LREE enrichment with LREE/HREE ratio varying between 9.47 to 12.71. EPMA results indicate that goethite is non-aluminous (max. Al₂O₃ = 1.3%). Laterite and bauxite are formed through Residual Enrichment ofironand alumina and derived from a basaltic parentage.

20 illus, 2 table, 14 ref

023876   Chinthalu G R;Seetaramayya P;Nagar S G (NO, Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune-411 008) : Role of heat, moisture and momentum transport across the air-sea interface in the off-shore trough over the Eastern Arabian sea during (IOP 22 July - 4 August) ARMEX-2002. J Indian Geophys Union 2004, 8(4), 273-82.

The day-to-day variability in the synoptic and sub-synoptic weather conditions is responsible for the development, intensification and dissipation of the offshore troughs. The evolutionary processes have been examined using recent surface meteorological data recorded onboard ORV Sagar Kanya, during an intensive observation period (IOP 22 July-4 August) of ARMEX-2002. Indian daily weather summary (IDWS) have also been consulted. Bulk formulae have been used to compute surface fluxes. The parameter D_Q (= difference between saturation specific humidity at sea surface temperature and specific humidity of air at 10m height) is used to assess the moist spells. It is observed that the marine atmosphere near the sea level over the eastern Arabian Sea has become dry (D_Q4 g.kg^-1) due to the weakening of the offshore trough and tends to become moist (D_Q4 g.kg^-1) due to the intensification of this offshore trough.

7 illus, 2 tables, 8 ref