005464   Lindstrom M J;Lobb D A;Schumacher T E (USDA-Agricultural Research Service, North Central Soil Conservation Research Laboratory, Morris, MN, USA) : Tillage erosion. Ann Arid Zone 2001, 40(3), 337-49.

Describes soil transport as a function of slope gradient for a variety of tillage operations; however, the gain or loss in soil mass at any point on the landscape is proportional to hillslope curvature. Soil loss from tillage operation takes place on convexities and upper field bonderies, while soil deposition occurs on concavities and lower field bondaries. Soil loss from tillage operations can commonly be greater than what is considered sustainable. As soil is removed from upslope field boundaries or convex slope positions, subsurface soil horizons become exposed. The exposure and subsequent dispersion of this subsoil material, in adition to soil accumulation at lower slope positions, alters soil properties and introduces greater variation in soil properties over the landscape. The recognition of soil translocation by tillage and its subsequent effect on soil properties and variability presents considerable challenges. Soil conservation strategies must be broadened to include tillage erosion to be fully effective.

^iia3 illus, 1 table, 31 ref

005463   Khosla S C;Jakhar S R;Nagori M L;Darwin Felix A;Manisha Kumari (Geology Dep, Mohal Lal Sukhadia University, Udaipur-313 002) : Jurassic ostracode fauna from the type section of Khadir formation, Kachchh and Lophocythere vertipolycostata n. sp.. J Geol Soc India 2003, 61(1), 61-74.

Records for the first time the occurrence of a rich and interesting ostracode fauna from the type section of Kharid Formation, Khadir Island, Rann of Kachchh, Gujarat. The fauna comprises 54 species of which 30 are assigned to the previously known taxa and all these are illustrated herein. Twenty-three species are left under open nomenclature and one species, Lophocythere vertipolycostata, is described as new. Besides Khadir Island, the latter species also occurs in the Khadir Formation of Bela Island and the Fort Member of Jaisalmer Formation, Jaisalmer, Rajasthan. On the basis of these ostracodes, a middle-upper Bathonian to upper Callovian age is proposed for the Kadir Formation.

3 illus, 2 tables, 29 ref

005462   Khan A A;Hoque S;Huq S M I;Kibria K Q;Hoque M A (Geology Dep, University of Dhaka, Dhaka-1000, Bangladesh) : Evidence of bacterial activity in the release of arsenic - a cast study from the Bengal delta of Bangladesh. J Geol Soc India 2003, 61(2), 209-14.

The results presented here indicate that arsenic is released from sediments by the acid formation. The activity is indicated by the decrease of pH value from 7.2 to 7, due to the role played by bacteria that acted on the particulate material present in the sediments. The decrease in pH value in the preliminary experiment indicated the presence of the activity of thiosulphate oxidizers. In a preliminary in vitro study the presence of Thiobacillus activity that was instrumental in lowering the pH by 0.2 unit was noted. However, a detailed microbiological study is yet to be done. The aquifer sediments those contain arsenic, in turn by such release, can contaminate groundwater. It is observed that the values of the incubation study did not show any relationship with the total arsenic content of the sediments. Water extractable fraction of arsenic also did not show any trend with the total arsenic content of the sediments. Water extractable fraction of arsenic also did not show any trend with the total arsenic content of the sediments, probably due to solubility product constant of the arsenic compound in the sediments. However, the arsenic concentration in water treated samples and in thiosulphate treated samples show some correlation. All the samples, except one, show much greater concentration of arsenic in thiosulphate treated samples, thus indicating the release of arsenic from sediment by the acid formation.

^ssc3 illus, 2 tables, 10 ref

005461   Hagen L J (NO, Wind Erosion Research Unit, USDA, ARS) : Processes of soil erosion by wind. Ann Arid Zone 2001, 40(3), 233-50.

The transport capacity of the suspension-size soil is several times larger than the limited transport capacity for the saltation and creep-size component of horizontal soil discharge. Thus, on large fields suspension discharge often exceeds saltation/creep discharge. Sources of saltation/creep discharge include entrainment of loose aggregates and abrasion of immobile clods and crust. Sinks for saltation creep discharge include trapping by surface roughness, interception by standing biomass and breakage to suspension-size. Similarly, sources for suspension discharge include entrainment of loose aggregates, abrasion of clods, and breakage of saltation/creep aggregates. Sinks for suspension include interception by standing biomass and deposition on downwind immobile surfaces. Wind tunnels have been used to directly measure the parameters for the individual wind erosion processes. Moreover, the individual processes can be assembled into physically-based wind erosion models that are applicable to a wide range of surface conditions.

7 illus, 1 table, 58 ref

005460   Goudie A S (School of Geography and the Environment, University of Oxford, Mansfield Road, Oxford, OXI 3TB, UK) : The global distribution of dust storms: patterns and controls. Ann Arid Zone 2001, 40(3), 303-15.

Most storms have important environmental consequences that include climate change, nutrient additions to ocean and terrestrial ecosystems, ocean sedimentation, soil formation and loss deposition. The use of meteorological observations and various satellite-borne sensors (including the Total Ozone Mapping Spectrometer) has enabled the global and regional patterns of dust source areas to be determined. Dust source regions are especially important in the Northern Hemisphere with the Sahara being predominant. Many of the most important sources are very dry areas which are, or have been basins of interior sedimentation.

102 ref

005459   Ghosh G K;Srinivasan C;Benady A S;Sivkumar C (Seismology and Engineering Geophysics Division, National Institute of Rock Mechanics, Champion Reefs Post Office, Kolar Gold Fields, Karnataka-563 113) : Study of background noise and correlation behaviour of seismic noise signal at Kolar gold mining are using broad band seismometer. J Indian Geophys Union 2002, 6(1), 25-41.

Three component Broad band waveforms are studied for background noise of the Kolar Gold Mining area and the statistical behavior of noise signal recorded by broad band seismometer. The data were recorded to calibrate the noise of the Kolar Gold fields area for the period of two months (February to April, 2000) with sample rate 100 Hz in continuous mode, four sample in a day, once in a week for total 10 minutes duration of data which gives total number of 60000 data points. The noise behaviour has been closely studied with time correlation of lag interval from zero to 20,000 ms. The auto correlation coefficients (ACC) and the cross correlation coefficients (CCC) are calculated for 100 ms lag interval and calculated maximum lag up to 20,000 ms. All these three ACC and three CCC versus time lag are plotted and observed that there are several node points where the signal itself has minimum correlation. The statistical behaviour of the noise has been correlated and the properties of these three components as Vertical, North-South and East-West are studied. The average three components of auto correlation coefficients and three components of cross correlation coefficients of the noise signal are studied in detail. The calculated raw seismograms recorded along with noise are converted into the velocity and displacement seismograms. The power density spectrums and the peak ground acceleration are also calculated. The average and the maximum background noise calculated are 17 nm and 35 nm respectively at the Central Seismic Station, Kolar Gold Fields. The continuous study of background noise of the area can play an important role to find out the precursors of earthquake and to study signal behaviour recorded using short period and telesismic earthquake data.

16 illus, 15 ref

005458   Fryrear D W;Chen W;Lester C (NO, Research Engineer for Custom Products, 7204 S, Service Road, Big Spring, Taxas, USA) : Revised wind erosion equation. Ann Arid Zone 2001, 40(3), 265-79.

The technology in RWEQ emphasizes that to effectively control wind erosion and minimize land damage efficient wind erosion control pracrics must be in peace over the entire field. When erosion does occur, soil losses are greatest within a few tens of meters of the upwind boundary. Measured annual soil losses at Crown point, Indiana, were 31.21 kg m^-2, WEQ technology estimated 0.00 kg m ^-2 erosion, and RWEQ estimated 25.24 kg m^-2 erosion. With the RWEQ technology, land managers can be confident that they can plan erosion control systems for their farmlands that will be effective. In addition, the wind barrier routine, hill effects, and field length equations will estimate erosion within the field and the quantity of material that will be leaving the downwind field boundary.

2 illus, 1 table, 38 ref

005457   Dewashish Kumar;Krishnamurthy N S;Ahmed S; Jain S C;Dhar R L (NO, National Geophysical Research Institute, Hyderabad-500 007) : Mise-a-masse technique in establishing the lateral extension of fractures in hard rocks. J Geol Soc India 2003, 61(2), 185-94.

Mise-a-la-masse technique has been applied to map water filled fractures struck in bore wells in a small watershed near Hyderabad. The area consists of hard crystalline rock mainly granite where groundwater is mostly tapped from fractured rock. In the watershed, 25 wells have been drilled fairly distributed over the area on the basis of results of Vertical Electrical Soundings (VES) to study the groundwater conditions in the weathered/fractured aquifer system. Mise-a-la-masse and Spontaneous Polarization (SP) investigations were carried out at five out of these 25 sites, to delineate the lateral extension of fractures. The anomalies are clearly indicative at four locations and some indication is seen at the fifth location. Two bore wells drilled on the basis of these results have encountered fractures at the same depth as at the experimental site. It is conlcude that mise-a-la-masse technique supplemented with S.P. investigations could be helpful in delineating the extension of fractures.

10 illus, 17 ref

005456   Chattopadhyay A;Khan A S;Huin A K; Bandyopadhyay B K (NO, Geological Survey of India, Seminary Hills, Nagpur-440 006) : Reinterpretation of stratigraphy and structure of Sausar group in Ramtek-Mansar-Kandri area, Maharashtra, central India. J Geol Soc India 2003, 61(1), 75-89.

Geological mappingand structural analysis of the manganese-bearing Sausar Group and associated rocks in Ramtek-Mansar-Kandri area, Maharashtra, have also led to reinterpretation of stratigraphy and structure. A local stratigraphic succession for the Sausar supracrustal rocks, giving due weightage to lithologic criteria and structural considerations, has been proposed which is different from the existing divergent lithostratigraphic successions suggested by different workers at different times. The lithologic unit interpreted as a conglomerate horizon by some workers, near the contact of the granite gneiss and the Sausar Group in Mansar-Kandri area, has been reinterpreted to be a tectonic origin. Sausar Group preserves evidence of four generations of folding (F₁ to F₄). The map pattern is controlled by F₂ and F₄ whereas F₁ and F₃ have developed only on hand specimen to outcrop scale. Ramtek synform, the major structural feature in the area, is a polyharmonic, second-generation fold with shallow southeasterly plunge and a steep to subvertical, WNW-ESE striking axial plane. It is not a large scale non-plane, non-cylindrical superposed fold (F₂ to F₁), as interpreted earlier. Regional metamorphism of pelitic-psammopelitic rocks possibly reached amphibolite facies with peak metamorphic condition post-dating D₁ deformation.

10 illus, 1 table, 24 ref

005455   Chandramohan T;Venkatesh B;Jain S K (NIH Regional Centre, , Hanuman Nagar, Belgaum-590 001) : Rainfall-runoff modelling based on GIUH approach in a GIS environment. J Instn Engrs-Pt CI 2002, 83(Nov), 180-5.

Geomorphological Instantaneous Unit Hydrograph (GIUH) is a physically based rainfall-runoff modelling approach, appropriate for ungauged catchments. Here, the characteristics of the instantaneous unit hydrograph (IUH) are related to the geomorphological characteristics of the basin. A mathematical model, which enables the evaluation of parameters of the Clark model for derivation of the IUH using geomorphological characteristics was applied to a small catchment, Barchi, which lies in the North Kanara district, Karnataka. Observed hourly rainfall-runoff records were used to check the applicability of this method. The geomorphological parameters and time-area diagram form important input for the GIUH baed Clark model and these parameters for the catchment were generated using a GIS software Integrated Land and Water information system (ILWIS). From the hourly rainfall-runoff records, eight events were extracted for the analysis. The GIUH based Clark model simulated these events quantitatively as well as qualitatively. Further, the use of GIS has provided a great automation and efficiency in the estimation of the gemorphological parameters required for the model application.

4 illus, 3 tables, 9 ref

005454   Biswas S (Geophysical Div, State Water Investigation Directorate, Bikash Bhavan, 4th Floor, Salt Lake, Kolkata-700 091) : Groundwater flow direction and long term trend of water level of Nadia district, West Bengal: a statistical analysis. J Geol Soc India 2003, 61(1), 22-36.

Groundwater utilization of Nadia district, West Bengal has been emerging rapidly in the wake of increasing urbanization and production of agricultural commodities and it is, therefore, necessary to evaluate the existing trend and availability of groundwater in time and space for space for proper planning in near future. Historical groundwater level records, in this respect, provide an important data base for reckoning long term changes in groundwater regime which may be an useful tool for judicious future planning of groundwater utilization. Strives to analyze the long term (1984-1998) trend of pre- and post-monsoon water table through the 53 Permanent Hydrograph Stations, distributed all through Nadia district. Satistical analysis shows that, although, most part of the district experiences a declining trend in water table or depletion of groundwater resources in pre-monsoon period to cope up with ongoing demand, the post-monsoon water table shows generally a rising trend of water table i.e. more input of water in the underground aquifer. As the influx of water primarily depends on the replenishment of the aquifer from the prime source of rain water, a correlation of yearly rainfall trend and pre- and post-monsoon water table trend has been for the specified period and a positive correlation is observed for the district.

8 illus, 2 tables, 5 ref

005453   Bin Xia;Heng-Xiang Yu;Hou-Jun-Mei;Gen-Wen Chen;Liang QI (Guangzhour Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou-510 640) : Geochemistry of basalts: evidence for formation of Dazhu ophiolite, Tibet (China), in a supra-subduction zone environment. J Geol Soc India 2003, 61(1), 7-15.

The Dazhu ophiolite of Tibet is characterized by a complete sequence of lithological assemblages comparable with the typical ophiolites worldwide. Geochemical studies show that basalts in the Dazhu ophiolite are LREE-depleted, low-K thioleiites and thier ∑REE, the extent of REE depletion or enrichment and the REE distribution pattern are close to those of N-MORB (normal mid-oceanic ridge basalt). However, relative to the typical MORB, their large ion lithophile elements (LILE) and high field strength elements (HFSE) have experienced varying degree of differentiation. Their trace element distribution patterns are different from those of the typical MORB. It is characterized by strong depletion of Nb and Ta, slight depletion of K and Ba, enrichment of Th and Rb, and relatively high Th/Ta and La/Ta ratios. It is deduced that ophiolite was formed in a supra-subduction zone (SSZ), representing a relic of the oceanic crust of a small-sized spreading forearc basin.

1 table, 34 ref

005452   Bielders C L;Lamers J P A;Michels K (Environmental Sciences and Land Use Planning Dep, Universite Catholique de Louvain, Louvain-la-Neuve, Belgium) : Wind erosion control technologies in the West African Sahel: The effectiveness of windbreaks, mulching and soil tillage, and the perspective of farmers. Ann Arid Zone 2001, 40(3), 369-94.

Wind erosion constitutes a major threat for the sustainable use of land resources in the Sahel. It is favored by a long dry season, low vegetation cover, sandy soils and the occurrence of strongly erosive winds at critical times of the year. Wind erosion can result in considerable losses of soil and nutrients at the plot and field scale and impart significant damage to crops through sand blasting and seedling burial. Current land management such as land clearing practices also largely favors the occurrence of wind erosion, forcing farmers to actively implement conservation measures that reduce the potential impact of wind erosion. As a rule, such measures need to be low cost, rely on local skills and knowledge, and typically present multiple benefits besides wind erosion control such as soil fertility improvement or the production of products for household consumption. Reviews the current knowledge about the extent and severity of wind erosion in the Sahel at scales up to village land units, and discusses some of the technological options that are available to farmers for reducing the impact of wind erosion on agricultural land. Emphasis is laid both on the technical and socio-economic feasibility of the techniques.

6 illus, 2 tables, 75 ref

005451   Barker R;Venkateswara Rao T;Thangarajan M (NO, University of Birmingham, Birmingham B15 2TT, UK) : Application of electrical imaging for borehole siting in hardrock regions of India. J Geol Soc India 2003, 61(2), 147-58.

Much of the seventy five percent of India that is underlain by shallow granitic and gneissic basement suffers from a shortage of water, but it is precisely these areas where siting successful boreholes for water supply is a difficult problem. Geophysical methods, especially resistivity sounding, are commonly employed to improve the drilling success rare, but the techniques are time consuming, subject to considerable ambiguity and still have scope for considerable improvement. Tested new electrical tomography (imaging) techniques to provide detailed `pictures' of the sub-surface that show variations in the bedrock topography and the nature and thickness of the overburden. The resulting images can be used to plan borehole investigations more cost effectively.

14 illus, 1 table, 13 ref

004367   Subrahmanyam M;Radha Krishna M;Prakasa Rao T K S (Geophysics Dep, Andhra University, Visakhapatnam-530 003) : Crustal section across Cauvery - Palk basin as modelled from gravity and magnetic data. J Indian Geophys Union 2001, 5(2), 107-15.

Free-air gravity and total magnetic intensity data along a near E-W section in the vicinity of 10° 20' N latitude in the Cauvery Palk Basin region extending from 36 km cast of the coast upto 82° E longitude is considered for modelling the deep crustal and sedimentary structures across the transition zone. The initial model is arrived at on the basis of characteristic free-air and magnetic anomaly signatures. The free-air anomaly profile exhibits a high over the outer shelf which rapidly decreases over the continental slope and attains a minimum at the seaward end of the slope. The total intensity magnetic anomaly profile presents a characteristic rise over the continental shelf and the anomaly decreases rapidly over the continental slope and forms a deep magnetic low at its base with a small peak within the low. In between the coast and the crustal transition zone, the magnetic anomaly profile indicates the presence of intrusions into the basement and block displacements which do not have surface expression owing to the sedimentary cover. A notable feature is the east coast magnetic anomaly (-270nT) which indicates the position of continent - ocean boundary. The magnetic low of about -575 nT probably marks the hinge zone which is underlain by a change in depth of Moho. Nature of the free-air gravity anomaly occuring to the east of the lower slope indicates a ridge-like feature while magnetic anomalies indicate irregular basement with surface which probably corresponds to the northward extension of Sri Lanka Archaean massif in the subsurface. The crust - uppermost mantle models worked out are in agreement with the anomaly characteristics and the inferred features of the continental margin.

5 illus, 39 ref

004366   Srivastava A K;Tewari R (NO, Birbal Sahni Institute of Palaeobotany, 53, University Road, Lucknow-226 007) : New gulate megaspore from the Satpura Gondwana basin. J Palaeont Soc India 2002, 47, 93-6.

A new gulate megaspore Satpurapora is described from the Barakar Formation (Lower Permian), Rawanwara Colliery, Pench Valley Coalfield, Satpura Gondwana Basin, Madhya Pradesh. The megaspore has been observed under light and scanning electron microscopes and its exosporium is characterised by the presence of elongate, furcate process with pointed apices.

2 illus, 8 ref

004365   Sridhar S G D;Hussain S M;Kumar V;Periakali P (Applied Geology Dep, School of Health and Atmospheric Sciences, University of Madras, Guindy Campus, Chennai-600 025) : Recent benthic ostracoda from Palk bay off Rameswaram, southeast coast of India. J Palaeont Soc India 2002, 47, 17-39.

Fifty two bottom sediment samples were collected over a year from the inner-shelf off Rameswaram, Tamil Nadu and the detailed systematic study of Ostracoda was made. A total of 48 species belonging to 39 genera, 19 families, 3 superfamilies, 2 suborders of the Order Podocopida were identified and described with SEM photomicrography. Among these, 3 species belong to Platycopa and the rest of Podocopa. Kotoracythere inconspicua, Neocythretta snellii and Paradoxostoma subtile are recorded for the first time from the Indian waters and four species are recorded for the first time from the east coast. The assemblage of the fauna shows a close similarity to the Indo-Pacific region. A relatively faster rate of sedimentation is deduced based on the occurrence of carapace and value ratio, in the study area.

5 illus, 83 ref

004364   Sivabalan R;Rengaraj S;Arabindoo B;Murugesan V (Chemistry Dep, Anna University, Chennai-600 025) : Fluoride uptake characteristics of activated carbon from agricultural-waste. J scient ind Res 2002, 61(12), 1039-45.

Removal of excess fluoride from ground water to within the permissible limits of 1.0-1.5 mg/L is the only way to control fluorosis. Batch and column type experiments were carried out for the adsorption of fluoride using activated carbon prepared from palm seed coat (PSCC) by dolomite process. In the batch study, influence of pH, adsorbent dose, contact time and initial fluoride concentration was investigated. Adsorption of fluoride was pH dependent and higher removal efficiencies were observed in the pH range of 4.8. Fluoride removal increased with dosage of carbon. A low concentration aluminium sulphate solution (2 per cent) effectively regenerated the exhausted carbon bed. The adsorption process obeyed Freundlich adsorption isoltherm. The kinetic studies revealed that the forward rate constant was comparatively much higher than the backward rate constant. Continuous flow experiments in fixed bed columns were carried out with ground water in order to assess the feasibility of this carbon for field application. The performance of the carbon in fluoride removeal was studied as a function of flow rate, initial fluoride level and particle size of the adsorbent. Fluoride removal increased with decreasing particle size of the carbon. The interesting feature of the study was that the defluoridation capacity increased with increase in the initial fluoride ion concentration.

6 illus, 1 table, 24 ref

004363   Shroff J J (NO, The Arvind Mills Ltd, Naroda Road, Ahmedabad-380 025) : Meritocracy and menace of ozone. Colourage 2002, (14-15 Dec), 45-8.

004362   Sharma R;Pervez S (Chemistry Dep, Government V.Y.T. Postgraduate Autonomous College, Durg-491 001) : Spatial variability of ambient particulate matter around a phosphatic fertilizer plant in India. J scient ind Res 2002, 61(12), 1077-83.

Monitoring of ambient PM₁₀ and SPM levels in the vicinity of a phosphatic fertilizer plant located at Kumhari, Chhattisgarh was carried out using two sets of Respirable Dust Sampler (RDS) and High Volume Sampler (HVS). The specific objectives were the determination of spatial and seasonal variability of levels of ambient particulates, and their relationship with the phosphatic fertilizer plant emissions. Samples were collected in post-rainy, winter and summer seasons (September 2000-June 2001). The results have shown a marked seasonal trend and spatial variability of ambient particulate levels in the study area that were higher in winter and lower in summer while in post-rainy period, levels were far less than other two seasons. Higher concentrations of ambient PM₁₀ and SPM were found in downwind monitoring stations compared to upwind direction. Seasonal variation in transport pattern of PM₁₀ and SPM was also observed. Monitoring stations at a distance of 4km downwind have shown highest susceptibility of PM in post-rainy and summer seasons while in winter it was found at 2 km downwind. In the case of SPM, highest susceptible location was found at 2km downwind in all the three seasons. Ratios of PM₁₀ to SPM and correlation coefficient values between both size of particulate matter along with meteorological parameters were also worked out.

2 illus, 3 tables, 27 ref

004361   Sharma A;Khokale D;Budholia M;Sharma A;Sharma V K;Rajput S (Bacteriology Lab, Bioscience Dep, Rani Durgavati University, Jabalpur-482 001) : Prevalence and distribution of aeromonads in different chlorinated water samples. Indian J envir Hlth 2002, 44(4), 314-19.

Four different sites were selected for sampling of water samples - river, pond, hand-pump, and municipal water. These were analyzed for physico-chemical and bacteriological parameters with special reference to aeromonads following standard methods. Chlorinated disinfectants in the form of powder and liquid (drops) were used for the treatment. Out of these powdered forms were found to be more effective. Although chlorination reduced the density of aeromonads to some extent, but still its presence could not be prevented.

5 illus, 2 tables, 25 ref

004360   Rao M V M S;Adesh Kumar;Murthy D S N;Nagaraja Rao G M;Udaykumar S;Mohanty S K (NO, National Geophysical Rseearch Institute, Hyderabad-500 007) : Deformation and failure behaviour of deccan rhyolites under unconfined stress : an experimental study. J Indian Geophys Union 2001, 5(2), 83-91.

Performed uni-axial compression tests on deccan rhyolites, and monitored their stress-strain behaviour and the associated acoustic emission activity. The experimental tests were made at a constant loading rate using a servo-controlled testing machine, and the data were recorded, processed and analyzed using PC-based systems. The results obtained from linear regression analysis of the stress-strain data and the AE signatures of dilatancy in terms of hit rate and b-value are presented and discussed. The results show that the pre-failure deformation of rhyolite is largely controlled by the compaction mechanism which will not only delay the onset of dilatancy but also influence its progress (stable and unstable cracking). The microstructure and model data of the samples were found to have a strong bearing on the deformation and failure behaviour of rhyolites.

6 illus, 15 ref

004359   Patel M E;Prabhakar B C;Lokesh K N (Applied Geology Dep, Kuvempu University, Karnataka) : Drainage characteristics of Hirehalla basin, Shimoga district, Karnataka. Indian J envir Hlth 2002, 44(4), 303-07.

In order to understand the dynamics of Hirehalla watershed, an attempt has been made to study drainage characteristics. The linear, areal and relief aspects of the basin have been analysed and compared with other climatic factors.

2 illus, 1 table, 5 ref

004358   Murali Das S;Sasi Kumar V;Sampath S (Atomospheric Sciences Div, Centre for Earth Science Studies, PB No 7250, Akkulam, Thiruvananthapuram-695 031) : Atmospheric electrical conductivity measurements as an indicator of natural radioactivity. J Indian Geophys Union 2001, 5(2), 93-101.

Cosmic rays render the air in the lower layers of atmospheric slightly conductive. Near dip equator, the vertical profile of conductivity has a minimum near the surface and then increase with altitude. At those regions where radioactive mineral deposits exist, it causes more ionization, resulting in an increased conductivity of air near the surface. In other words, a higher conductivity near the surface points to the presence of a radioactive deposit. The Gerdien Condenser is a well known instrument used for the measurement of atmospheric electrical conductivity. Response time of the measurement system is limited only by the time constant of the associated electronics and so it detects changes in conductivity almost instantancously. Therefore, a jeep or aircraft borne system detects the presence of a deposit when driven past. Measurements of atmospheric electrical conductivity in regions of known radioctivity like Chavara, Kollam and Manavalakurichi, using jeep and aircraft borne Gerdien Condenser will be presented. Simultaneous measurements of conductivity using a Gerdien Condenser and radioactivity using an environmental radiation monitor will be presented to indicate the use fulness of conductivity measurements as a technique for the exploration of radioactive mineral deposits.

8 illus, 12 ref

004357   Muraleedharan G;Unnikrishnan Nair N;Kurup P G (Physical Oceanography, Cochin University of Science and Technology, Fine Arts Avenue, Cochin-682 016) : Predicting the shallow water wave heights using a modified Weibull model. J Indian Geophys Union 2001, 5(2), 103-6.

Prediction of design wave heights in shallow waters is an important aspect with varied ocean engineering applications. A Modified Weibull Model is suggested for maximum wave heights in shallow waters by accommodating a depth factor to incorporate the shallow water wave height transformations. A 90.0% agreement is found using (χ²-test at 0.05 level of significane. Prediction formulae for extreme wave heights and probability of realising a wave height less than a designated return period have been derived and tested using recorded wave data at Valiathura, SW coast of India. The height wave recorded in a period of 5 years is in the range 3.7-4.1m, which is in agreement with the wave height predicted for 5years-(4.0 m). The scale parameter (2.59) and shape parameter (3.07) are the average values for the active monsoon season as high waves are frequent during this period. Prediction formulae for mean wave height, mean maximum height and most frequent maximum wave height has also been presented.

2 illus, 2 tables, 17 ref

004356   Kant Y;Krishna Prasad V;Badarinath K V S (Space Dep, National Remote Sensing Agency, Goverment of India, Balanagar, Hyderabad-500 037) : Surface energy balance components using mid-day surface temperature from satellite thermal infrared data. J Indian Geophys Union 2001, 5(2), 73-81.

Evaportanspiration are very useful in micrometeorologic and climatologic studies as well as in estimating water balances in hydrologic studies. Describes the estimation of surface energy components at local and regional scales by combining satellite based spectral data with ground-based meteorological data. Surface temperature can provide useful information in deriving surface energy components. Remote sensors can provide information on surface emissivity, surface temperature, albedo. The remaining variable in the energy balance equations must be measured at ground level, estimated or modeled. A simlified model has been used to calculate the surface temperature over heterogencous areas taking into consideration the derived narrow-band emissivity at the sensor's resolution. The theoretical expression for the compitation of mid-day surface temperature from the instantaneous measured value at any instance of time has been presented that would provide a resonable estimate to the daily evapotranspiration value suggesting the possible use of approach for regional scale studies on evapotranspiration.

3 illus, 31 ref

004355   Kalia P;Pande P (Geology Dep, University of Delhi, Delhi-110 007) : Early palaeocene planktic foraminiferal assemblages and biostratigraphy at site 237, central western Indian ocean. J Palaeont Soc India 2002, 47, 1-15.

Seven early Plaeocene planktic foraminiferal genera and their fourteen species have been identified using wall texture criterion in combination with test architecture at DSDP Site 237, Western Tropical Indian Ocean. This is a significant improvement over the record of six species in the previous work. The wall texture criterion is included for taxonomy of planktic foraminifers obtained from the siliceous nannochalk, affected by different levels of diagenetic alteration. It has been observed under SEM that diagenesis does not affect the wall texture in smooth wall normal perforate tests; in microperforate pustulose tests the diagenetic overprinting is directed by the original pattern of ornamentation, whereas remains of cancellate texture are recognizable in the specimens affected by dissolution and overgrowth. To differentiate the cancellate spinose from cancellate nonspinose (premuricate wall texture) forms the disposition of ridges is a clue, but for observing the presence or absence of spine holes good preservation is a prerequisite. Based on the assemblages of species, their ranges and FAD/LAD biochrons, biozones P1b-P2 have been demarcated with redefined boundaries. It is inferred that lower palaeocene rocks underlain by Upper Cretaceous rocks are likely to be present in the unpenetrated interval of strata above the basement at the DSDP Site 237. Globocomusa daubjergensis, earlier recorded mainly from high latitudes, occurs commonly at Site 237.

6 illus, 24 ref

004354   Jain R L (NO, , 111/106, GSI Colony, Malviya Nagar, Jaipur) : Echinoids from the Gaj formation (early and middle Miocene) of Kathiawar, Gujarat, India. J Palaeont Soc India 2002, 47, 107-35.

A new collection from the early and middle Miocene of the Gaj Formation in Kathiawar has yielded 27 echinoid species. Of these, 10 species were already known previously from the study area. 11 species were known from outside the study area of Kathiawar and remaining six have been named here as new species. Already recorded species are figured, described their additional characters and registered better types. Duncan and Sladen (1883, p. 86-87) had wrongly assigned the material of the genus Maretia from the present study area under Eupatagus patellaris d'archiae, 1850. Since Eupatagus patellaris d'Archiae, 1850 is a valid species for Kachchh and Sind, the present collection of Maretia from Kathiawar is described as a new species. The new species are Fibularia depressa, Mortonia lowraliensis, Brissus daviesi, Maretia rajnitpurensis, Metalia harshadi and Clypeaster kurangaensis. Temnechinus costatus (d'Archiae & Haime), T. rousseaui (d'Archiae), T. tuberculosus (d'Archiae & Haime) and T. affinis Duncan & Sladen have been described under the genus Opechinus Desor. Cidaris granulata Duncan & Sladena and Cidaris excelsa Duncan & Sladen have been put under the genus Prionocidaris. Cidaroid spines mostly belong to the genus Prionocidaris and Eucidaris.

8 illus, 1 table, 26 ref

004353   Hussain M F;Ahmad I (Chemistry Dep, North Eastern Regional Institute of Science and Technology, Nirjuli (Itanagar)-791 109) : Variability in physico-chemical parameters of Pachin river (Itanagar). Indian J envir Hlth 2002, 44(4), 329-36.

The concentration of water quality parameters in river and heavy metals in the bed sediment were measured for Pachin River for the three major flow periods. The pH, temperature (°C), conducity (μS cm^-1), DO, COD, NH₃, PO₄, total hardness and alkalinity (mg/L) were found in the range of 12 to 22, 6.90 to 7.69, 25 to 211, 5.0 to 12.5, 10-115, 1.2 to 12.0, 0.05 to 0.62, 14 to 45, and 12 to 35, respectively. The heavy metals as Zn and Se showed an enrichment of 1 to 25, and 5 to 120, with concentration (μg/g) range of 8 to 385 and 0.5 to 6.0, for the respective metal, in the labile fraction of the bed sediment. The variability in the physico-chemical parameters for different flow periods may be assigned to dilution of river water by direct runoff, human activities and organic load. The correlation study of physico-chemical parameters shows that their source of entering the river system is the same whether it may be a natural or anthropogenic or both.

3 illus, 5 tables, 14 ref

004352   Durga Rao K H V;Ambesh Kumar Singh;Hari Prasad V (NO, Indian Institute of Remote Sensing, 4-Kalidas Road, Dehradun-248 001) : Study of water quality parameters in Bhopal upper lake using landsat 5 TM satellite data. J Indian Wat Resour Soc 2002, 22(4), 165.

Focuses on studying the possibility of developing regression models between different water quality parameters and satellite remote sensing data of Bhopal upper lake in India and to estimate the sediment concentration rate within the lake in spatial domain. Water samples at different locations of the lake have been collected and its locations were identified using Global Positioning System (GPS) instrument. These samples were tested and analyzed to know its quality parameters. Different image processing techniques have been applied on LANDSAT 5 TM satelite digital data (except thermal band), at each stage correlation between different bands of satelite data and water quality parameters have been studied. Correlation between radiance values of band2 and suspended sediments is found to be good, positive and a linear equation found to fit best. Correlation between radiance values of band2 and sechi depth is found to be negative. It has been observed that other water quality parameters do not follow any relationship with the satellite data. Radiance image of band 2 of the satellite data has been classified into seven classes and average suspended sediment rate has been calculated for each class using the developed regression model.

4 illus, 1 table, 5 ref

004351   Charatkar S L;Radhakrishnan K V (Fisheries Resources and Management Dep, College of Fisheries, Mangalore, Karnataka-575 002) : Coastal attrition of Dakshina Kannada district using remote sensing and GIS. Indian J envir Hlth 2002, 44(4), 270-81.

Mangalore is one of the important coastal towns in Dakshina Kannada along the west coast of India situated at the mouth of Nethravathi-Gurpur estuary. The remote sensing and GIS (Geographical Information System) is a powerful tool to monitor coastal changes by continuous observation. Study has been carried out on the shoreline changes and coastal processes operating in the Dakshina Kannada coast using remote sensing and GIS technique. Survey of India topographical map of 1967 and IRS 1B, LISS II 1993 imagery (Geocoded) both on the scale of 1:50000 has been analysed to elucidate and quantify erosion and accretion in the study area. Erosion is observed at southern spit (Ullal) upto Talapadi and also northern spit (Bengre) upto New Mangalore Port. Accretion is observed at north of New Mangalore Port. Gradual shifting of the estuarine mouth of Nethravathi-Gurpur to the north is also observed. The changes could be attributed to human interference by way of constructing coastal structures.

4 illus, 5 tables, 17ref

004350   Ali S;Patnaik U S;Praksh C (NO, Central Soil and Water Conservation Research and Training Institute, R, Kota-324 002) : Frequency analysis of one day and consecutive days maximum rainfall of Eastern Ghat high land zone of Orissa for marshy watershed management planning. J Instn Engrs-Pt AG 2002, 83(Dec), 33-6.

Annual 1 day and 2 to 4 consectuve days maximum rainfall data of six stations in Eastern Ghat high land (EGHL) zone of Orissa State were analyzed. Five probability distribution was found to be the best fit frequency distribution function for the region. Simple regression models were developed for 1 day as well as 2 to 4 consecutive days maximum rainfall for the region. Thein's U-static indicated that conseutive days maximum rainfall model estimate was not statistically different from a 2-parameter log-normalestiamte.

2 illus, 5 tables, 16 ref

004349   Agarwal B N P;Shaw R K;Majumder M (Applied Geophysics Dep, Indian School of Mines, Dhanbad-826 004) : A hybrid technique to invert gravity anomaly over a faulted slab. J Indian Geophys Union 2001, 5(2), 117-22.

Simulated Annealing (SA) and non-linear curve fitting (NCF) techniques have been combined to evolve a hybrid strategy for inversion. The energy of the analytic signal computed from the gravity anomaly over a faulted slab has been inverted for source parameters. SA is exceuted for a small number of iterations and the models having errors less than a pre-specified value are considered as the guess models for NCF. This strategy enhances the probability to explore the neighbourhood of the global minimum from different directions in the parameter space.

3 illus, 3 tables, 14 ref

003437   Yaacob R;Azhar N;Shamsuddin M S A;Lokman M H; Siti Zauyah D I;Nor Antonina A;Kamaruzzaman B Y (NO, Institute of Oceanography, University College of Science and Technolog, Malaysia 21030 Kuala Terengganu, Malaysia) : Grain-size distribution of the south China sea continental shelf sediments off the coast, Peninsular Malayasia. Ultra Scient phys Sci 2002, 14(3), 413-24.

Presents a systematic pattern of sedimentological characteristics and particle size distribution of the South China Sea continental shelf sediments off East Coast Peninsular Malaysia, after the northeast monsoon. Results showed that generally, sediments in the study area are finer, poorly sorted and positively skewed. With respect to distance from the shorelines, nearshore sediments are coarser than the middle and offshore sediments.

8 illus, 8 tables, 13 ref

003436   Tuli N K;Mohinder Singh;Kanwar R C (CAS in Geology, Punjab University, Chandigarh - 160 014) : Petrochemistry and tectonic environment of granitoids of saranh area, Lesser Himalayas. Bull Indian Geol Ass 1999, 32(2), 21-37.

The granitic rocks occurring at Saranh are mainly of foliated and non-foliated type, which have intruded into the garnet mica schist of the Jutogh formation. Both the types of granite show similar concentrations of major, minor and trace elements. They are considered to have crystallised from the granitic melts which were generated at a temperature of 620°-700° and pressure 2-4 kb through the process of partial melting of the crustal rocks. The chemical parameters indicate that the Saranh granites are continental collision granite.

6 illus, 2 tables, 13 ref

003435   Synudeen Sahib S (PG & Research Department of Zoology, S N College, Kollam-691 001) : Impact of Thenmala dam on the water quality of the Kallada river. Uttar Pradesh J Zool 2002, 22(2), 167-9.

Kallada river was one of the highly polluted rivers in Kerala till 1987. The closure of the Punalur paper mill consequent to a lockout and the commissioning of the dam at Thenmala almost around this time have created an altogether new situation on the river tract. Although data are available on the ecology of the river systems in kerala, virtually no information is available on the post-impoundment changes in downstream river tracts. Monthly data on temperature. pH, light penetration, total hardness, dissolved oxgen, nitrate, nitrite, phosphate and silicate collected from four stations (Station I-Thenmala dam, Sation II-Ottakal weir, Station III-Perumthottam and Station IV-Kadapuzha) have been presented.

1 tables, 7 ref

003434   Srivastava H B;Thomas T (Geology Dep, Banaras Hindu University, Varanasi - 221 005) : Structure and deformation history of a part of dudatoli crystallines around tamadhaun, Dist. Almora. Bull Indian Geol Ass 1999, 32(2), 1-14.

The rocks of Dudatoli Crystallines in Inner Lesser Himalaya of Kumaun and Garhwal occur as a synform trending in NW-SE direction. The Tamadhaun area which forms a part of southern extension of Dudatoli Synform exhibit very complicated structures due to repeated phases of deformations. The detailed study of small-scale structures of the area reveals that the rocks of Dudatoli Crystallines have suffered four phases of tectonic deformations which have been chronologically named as D₁D, D₂, D₃ and D₄. D₁ phase is probably Precambrian in age which is indicated by metamorphism of Dudatoli Crystallines, D₂ to D₄ deformations have occurred during Tertiary period related to the Himalayan Orogeny.

1 table, 7 illus, 41 ref

003433   Sridharan M;Ramasamy A M S (IIG Magnetic Observatory, , Pondicherry-605 014) : Multidimensional scaling technique for analysis of magnetic storms at Indian observatories. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(4), 459-65.

Multidimensional scaling is a powerful technique for analysis of data. The latitudinal dependence of geomagnetic field variation in horizontal component (H) during magnetic storms is analysed by employing this technique.

3 illus, 11 ref

003432   Sircar A (NO, , ) : Tomographic inversion of focusing operators. Indian J Petrol Geol 2001, 10(2), 19-22.

One Common Focal Point (CFP) approach towards velocity model estimation consists of two, basically independent processes. The first process is a fully data- driven focusing operator updating scheme, it can be shown that correct operators relate to focal points at reflecting boundaries. The scheme will determine a set of operators, which will provide the necessary one - way traveltime data to be used in the second process. This process uses the traveltime to estimate a velocity model via transmission tomography. Apart from inversion, process is illustrated using a theoretical dataset.

2 illus, 7 ref

003431   Singh T P;Singh S;Roy P S;Rao B S P (Geo-engineering Dep, College of Engineering, Andhra University, Visakhapatnam-530 003) : Vegetation mapping and characterization in West Siang district of Arunachal Pradesh, India - a satellite remote sensing-based approach. Curr Sci 2002, 83(10), 1221-30.

The vegetation cover types extracted from classification showed good relationship with altitudinal zones. Correspondence with field-gathered GPS points for vegetation classes showed 85.29 percent overall accuracy. Hybrid classification approach gives an opportunity to refine the classification to acceptable limits for various activities related to management and planning.

7 illus, 3 tables, 18 ref

003430   Siddiquie F N (Geology Dep, A.M. U., Aligarh) : On the occurrence of Lepocinclis form Khondalites of Srikakulam District (A.P.). Bull Indian Geol Ass 2000, 33(2), 63-8.

The algal limestone is reported from the Khondalite Group in Garividi, Srikakulam District (A.P.). The algae occur as thalloid bodies with well preserved cellular structures. Besides, unicellular green algae refereable to Lepocinclis have been recorded from Koduru Main quarry. The find of the algae from the Khondalite Group suggests a possible Proterozoic age for the sequence in the Eastern Ghats.

4 illus, 6 ref

003429   Shukla A D;Shukla P N (Physical Research Laboratory, , Ahmedabad-380 009) : Comments on `No K/T boundary at Anjar, Gujarat, India-Evidence from magnetic susceptibility and carbon isotopes. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(4), 489-91.

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003428   Sharma M;Dogra R;Dadwal V (C.A.S. Geology, Punjab University, Chandigarh) : Potassium pollution of groundwater, its source and variation with depth, Faridabad district, Haryana, (India). Bull Indian Geol Ass 1998, 31(1-2), 83-9.

Potassium plays a vital role in plant metabolism and its deficiency causes low protein higher amino-acid concentrations and also disturbs carbohydrate metabolism. Excessive concentrations of potassium are harmful for the human system and are cathartic. The groundwater from several places like Seoli, Pingor, Tumsara, Aurangabad, Andhop etc. in district Faridabad, Haryana State, India, has moderate to high levels of potassium ranging between 286 to 891 mg/1. Distribution of potassium in groundwater from all the five administrative blocks, namely, Hodal, Hathin, Palwal, Ballabhgarh and Faridabad of district Faridabad. Major sources of potassium, and changes with depth of potassium concentration have also been studied Potassium levels in groundwater from natural sources are generally very low due to resistance of potash bearing minerals to weathering and dissolution. In view of absence of major natural sources of potassium in the area, its high levels in groundwaters at several places may be due to leaching of fertilizers which are extensively used in the study area. This is corroborated by the fact that potassium concentrations at deeper levels are quite low (ranging between 3.7 and 39 mg/1) as compared to the shallow depths (ranging between 0.1 and 891 mg/1). Study also highlights polution abatement measures like utilizing high potassium water for irrigation and proportionately reducing the quantity of potash fertilizers, etc., which would not only help in preventin

2 illus, 3 tables, 6 ref

003427   Shalivahan;Bhattacharya B B (Applied Geophysics Dep, Indian School of Mines, Dhanbad-826 004) : Implications of novel results about Moho from magnetotelluric studies. Curr Sci 2002, 83(10), 1259-64.

Moho boundary is well established on the basis of seismological studies. Magnetotelluric (MT) studies have not been able to establish this boundary due to the presence of highly conducting continental lower crust (CLC). MT studies over the Eastern Indian (3.3 Gyr) and Slave (4.03 Gyr) cratons resolve the crust-mantle boundary due to the absence of highly conducting CLC. The upper mantle beneath these two cratons cannot be of pure olivine as resistivity of the uppermost mantle is much less than the laboratory studies on pure olivine. From these two studies it can be speculated that a dynamics other than the plate tectonics possibly existed up to the mid-Archaean.

4 illus, 2 tables, 34 ref

003426   Sen G;Sheth H C (Geology & Geophysics Dep, School of Ocean & Earth Science & Technology (SOEST), University of H, Manoa, Honolulu HI-96822 U.S.A) : Comments on `Generation of Deccan trap magmas'. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(4), 483-5.

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003425   Sen G (Florida Center for Electron Microscopy, Florida International University, University Park, Miami, FL-33199) : Giant plagioclase basalts, eruption rate versus time : response to Sheth's comments and some additional thoughts. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(4), 487-8.

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003424   Sarma K P;Dey T (Geological Sci Dep, Gauhati University, Guwahati - 781 014) : Fold morphology and strain history of the precambrian rocks around Chandrapur - Narengi area, Kamrup District, Assam, India. Bull Indian Geol Ass 1998, 31(1-2), 47-53.

Evidence for three phases of ductile deformation and late stage of crustal instability leading to the development of numerous small scale faults and fractures of extensional and contractional tectonism is studied. Multilayered sequence of varied lithology showing different rheological properties bear the testimony of strain variation which is worked out from analysis of folds of different generation (F₁ and F₂). Fold asymmetry is used as a key to reveal the shear sense and shear strain but the shear sense is changed subject to progressive increase in strain in some narrow zones of ductile shearing. The t¹/α plot for different values of λ₂/λ₁ show usual variation from 0.2 to 0.9 (for F₁) and 0.4 to 1.00 (for F₂) and they belong to class IA to 3 types of Ramsay with exception which falls in strongly convergent isogon field class IA₃.

3 illus, 16 ref

003423   Sarma H R N;Ahmed F (Geology Dep, Nagaland University, Kohima) : Significance of amount of quartz in the disang and barail groups of sediments, Kohima, Nagaland : A statistical study. Bull Indian Geol Ass 1999, 32(2), 37-42.

A quantitative evaluation of amount of quartz in Disang and Barail Groups of sediments exposed in and around Kohima suggests that there exists some similarity in the form of amount of quartz and their distribuiton pattern in the environmental set ups of the two groups as well as in the sources. There also appears to exist a statistically significant negative relationship between the set of data of the two groups. This may suggest that the sediments came from different sources and were deposited in two different environments.

1 illus, 1 table, 10 ref

003422   Sam N V;Vittal Murty K P R (Centre for Atmospheric Sciences, Indian Institute of Technology, Hauz Khas, New Delhi-110 016) : Characteristics of monsoon low level jet (MLLJ) as an index of monsoon activity. Proc Indian Acad Sci-Earth Planet Sci 2002, 111(4), 453-7.

Temperature and wind data are used to describe variation in the strength of the Monsoon Low Level Jet (MLLJ) from an active phase of the monsoon to a break phase. Also estimated are the characteristics of turbulence above and below MLLJ.

1 illus, 1 ref

003421   Ruby B S;Punj N K (Geological Survey of India, SCO: 98-100, 17/C, , Chandigarh - 160 017) : Geo-environmental Hazards of Amritsar district, Panjab with special reference to environmental potential of Amritsar city. Bull Indian Geol Ass 1999, 32(2), 21-36.

The toxic metal content in the shallow aquifers have values above desirable limits of F, Cl, NO₃, SO₄, Cr, Mn, and Fe in the southwestern part of the district (i.e. Khemkaran-Patti belt), rendering it unpotable. Values above desirable limits of Cu, Pb, Fe, Mn, Mg, F, Cl, So₄ and NO₃ are recorded in a few pockets around Amritsar, Tarn Taran, Jandiala Guru and Kirishahi in the central part of the district i.e. Amritsar-Jandiala Guru-Kirishahi area whereas higher values of Fe, Mnn, F, Cl, and NO₃ observed in a few pockets restricted to northern part of the district i.e. around Ajnala. SAR and EC values when plotted on US Salinity chart indicate that the groundwater in the western half of the district has medium to high salinity thus rendering it unsuitable for irrigation. In almost entire district, the soil samples show Cu, Pb, and Co values higher than the typical values after Bowen, 1966. Ni shows higher values above the typical in a few pockets only. The flood plains of the Ravi, Satluj and the Beas rivers are prone to inundation during rainy season. Besides this, intense gully erosion marks the banks of the Beas and the Ravi rivers. Phenomenal urban growth coupled with haphazard industrialisation has brought Amritsar city under intense environmental strain. Further accelerated urbanisation is presently making inroads into wherever vacant land is available towards northeast up to the bypass. Certain drains carrying untreated sewerage and indust

3 illus, 5 tables, 11 ref