003187   Thomas H (Applied Geology Dep, Dr. H.S.G. Univ, Sagar, Email: harelthomas@yahoo.com) : Garnetgs.exe: a compatative study of activity of garnet through subregular /regular ternary solution models.. J appl Geochem 2008, 10(2), 31-9.

Geoscientists have proposed different subregular / regular solution models for the calculation of activity of garnet based on thermodynamic variables, empirical and theoretical. These activities are helpful in the calculation of geothermobarometry. The calculation and comparison of the equations of the garnet activity are based on the equations of Ganguly and Saxena (1984) ternary subregular / regular solutions models of garnet and its comparison with other workers equations. From the calculation, it is found that their equations are compatible with others workers equation. The author developed software (GARNETGS.EXE) to calculate the activity of garnet through subregular / regular solution models based on Ganguly and Saxena (1984) equations.

3 tables, 15 ref

003186   Thakur A K;Sarnam Singh;Roy P S (NO, Indian Institute of Remote Sensing (NRSC), 4 Kalidas Road, Dehradun-248 001) : Orthorectification of IRS-P6 LISS IV data using landsat ETM<. Curr Sci 2008, 95(10), 1458-63.

The availability of high-resolution data from IRS LISS IV, IRS Cartosat, QuickBird and IKONOS has added new dimensions to the use of satellite data for cartographic and natural resources management. High-resolution data have high relief displacement in hilly terrains. Therefore, to be able to integrate the dataset generated from coarse and medium-resolution satellite data with that of high-resolution satellite data, high-resolution images need to be orthorectified before they can be used further for long-term bio-resources monitoring. Although the use of stereo images for ortho image generation has been well documented, use of single-frame orthorectification is less known. The acquiring of stereo images is a costly affair. Orthorectification is important for proper geometric registration of LISS IV layers with other ancillary and GIS layers generated from coarse-resolution satellite data. The available orthorectified reference dataset of Landsat ETM^{+ in conjunction with Digital Elevation Model derived from Shuttle Radar Topography Mission (SRTM) have been used to orthorectify high-resolution LISS IV image. This communication discusses the methodology for rectifying high-resolution images using Landsat ETM+ and SRTM data available on the internet. The methodology can be applied in highly complex terrain with high to very high elevation regions like the Himalayas, where contour data are either lacking or not available. The root mean square error is 0.0415 m.}

6 illus, 1 table, 23 ref

003185   Sreekala R;Muthumani K;Lakshmanan N; Gopalakrishnan N;Sathishkumar K (Structural Engineering Research Centre, CSIR Campus, Taramani, Chennai-600 113, Email: kala@sercm.org) : Orthodontic arch aires for seismic risk reduction. Curr Sci 2008, 95(11), 1593-9.

Earthquakes are naturally occurring events demonstrating the power of nature and the catastrophic impact of such power on normal life. Development of new techniques and opting for new materials which are not traditionally used in civil-engineering structures, offer significant promise in reducing seismic risk. Super-elastic Nitinol in the form of wires (orthodontic wires) is a common and well-known engineering material available with dentists all over the world. It belongs to the class of shape memory alloys (SMAs) bearing unique properties such as super elasticity and shape memory effect. The greater flexibility of the material drives many of its applications in the medical industry, but the use of this material in other fields is less known. This communication seeks the suitability of this material for structural applications, especially earthquake risk reduction. A study has been conducted to find the suitability of orthodontic wires in passive vibration control of structures. The super-elastic properties found in these wires are made use of in the development of vibration control devices of re-centering type. Protection of structures from damage during earthquakes can be addressed using passive protection devices designed to provide energy dissipation with re-centering capabilities. Possible application lies in reducing the seismic risk of multi-span bridges, rehabilitation of heritage structures and protection of special structures of national importance.

003184   Sharma N;Jagadeesha D;Joshi P C;Pal P K (Atmospheric Sciences Div, Remote Sensing Applications Area, Space App, ISRO, Ahmedabad-380 015, Email: neerja@sac.isro.gov.in) : Atmospheric stability estimation using radio occultation data over India and surrounding region. Indian J Radio Space Phys 2009, 38(6), 317-25.

Presents analysis of occurrence and intensity of rainfall with the lifted index (LI), total precipitable water (TPW), average relative humidity (ARH) and average refractivity (RI) derived from radio occultation (RO) data. Constellation Observing System has been used for meteorology, ionosphere and climate (COSMIC) refractivity and 1-d variational assimilation retrievals of pressure, temperature and water vapour pressure during May-August 2007 over India and the surrounding region. The results mainly indicate that RO data can be a sensitive measure of rainfall. LI, TPW and ARH together are linked to give 90% probability of occurrence of rainfall events. Almost similar probability of rainfall occurrence and its intensity is captured when RI is used in place of LI. The results emphasize that RO average refractivity (above a certain threshold) is a measure of instability of the atmosphere and can be used as stability index instead of LI. RI in combination with moisture indices is able to give potential signature of rainfall occurrence and its intensity.

003183   Sarwade D V;Mondal N C;Singh V S;Puranik S C (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: ncmngri@yahoo.co.in) : Assessment of groundwater quality in urban area, Belgaum city, Karnataka, India. J appl Geochem 2008, 10(2), 148-65.

Evaluation of the quality and quantity of groundwater is important because its usability is determined by its physical and chemical properties. Considering the significance of water quality in water resources management, Water quality studies are carried out in Belgaum city of Karnataka, where the scarcity of potable water is a major problem due to the population growth and urbanization, The overexploitation of groundwater is leading to the degradation of groundwater quality. In order to assess the deterioration, 44 groundwater samples were collected and analyzed. The results indicate that the groundwater is nearly neutral to mildly alkaline in EC, TH and SO₄ values are comparatively higher in shallow aquifers and Ca, Mg and Na in deep aquifers, while Na, K, Cl, SO₄ are higher in laterite and EC, pH, TH, Ca, Mg, HCO₃ in basalt. The areal distribution of cations and anions show the trend that deterioration of groundwater quality in northeastern, eastern parts of the city. The minor trace elements in shallow aquifer samples contain comparatively higher concentrations deep aquifer. In this area Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Nitrate (NO₃) vary from 4.1 to 5.6 mg/l, 3.0 to 6.5 mg/1, 52.0 to 150.0 mg/l and 35 to 78 mg/l respectively. Except two samples with the highest DO value (5.6 mg/1) in Hindalga village, others have less than 5.0 mg/1. COD values are more than 75 mg/l except in Shahunagar and Hindalga villages. These biological contaminants also show the highest values of BOD, COD and NO, as well as lowest of DO in the southern and southwestern parts of the area.

8 illus, 3 tables, 25 ref

003182   Samuel M P;Satapathy K K (Agricultural Engineering Div, ICAR Research Complex for NEH Region, Umiam-793 103, Email: manojpsamuel@gmail.com) : Concerted rainwater harvesting technologies suitable for hilly agro-ecosystems of Northeast India. Curr Sci 2008, 95(9), 1130-2.

Much of the enormous water resources in India's North-Eastern region remain unutilized and the efficient utilization and management of available rainwater is the core issue if the cropping intensity and production is to be enhanced. The rainwater harvesting can be implemented as a viable alternative to conventional water supply or on-farm irrigation projects. Storing of rainwater can be done in two ways: (i) storing in an artificial storage and (ii) storing in the soil media as groundwater. The rainwater or run-off can be harvested using eco-friendly low-cost technologies such as uv-resistant plastic lined ponds, ferro-cement tanks, etc. and used for multiple purposes.

2 illus, 6 ref

003181   Roy A B (Geology Dep, Presidency College, Kolkata-700 073, Email: obroy_g@yahoo.com) : Critique on the tsunami-arthquake link. Curr Sci 2008, 95(9), 1104.

2 ref

003180   Ratnakar J (Geology Dep, Post-Graduate College of Science, Osmania Univ, Saifabad, Hyderabad-500 004, Email: jrtnkr@yahoo.com) : Nature of precambrian alkaline magmatism in Southern India : nepheline syenite complexes. J appl Geochem 2008, 10(2), 60-75.

During the Mesoproterozoic to Neoproterozoic (1480-590 Ma), southern peninsular India has experienced Si-undersaturated alkaline magmatism resulting in the emplacement of eight nepheline syenite complexes (NSCs) at Rairakhol, Khariar, Koraput, Kunavaram, Elchuru. Purimetla, Uppalapadu and Sivamalai. The NSCs together cover an area of around 250 sq km in a rift tectonic setting characterized by trans-lithospheric faults, deep fractures and shear zones in the deep continental margin setting. The nepheline syenites of NSCs are composed of orthoclase, microcline, albite, nepheline, diopside, hedenbergite, aegerine-augite, titan-augite, titan-ferro-pargasite, titan-ferro-kaersantite, tarnite, hastingsite, ferro-hastingsite and biotite as essentials and calcite, apatite, sphene, zircon, ilmeno-magnetite, corundum, allanite and garnet as accessories. The major and trace element compositions suggest that the nepheline syenites are of miaskitic type. The NSCs are evolved from volatile-rich hydrous alkaline basic (lamprophyric) parental liquids representing Cpx-Ne-01-Ab equilibria under high P total=(PH₂O+Pco₂). The parental alkaline basic magmas are derived by low degree of partial melting of metasomatically enriched sub-continental lithospheric mantle (SCLM).

7 illus, 2 tables, 31 ref

003179   Rashid S A (Geology Dep, Aligarh Muslim Univ, Aligarh-202 002, Email: rashidamu@hotmail.com) : Major and trace elements distribution in a weathering profile of a granite gneiss at higher altitudes. Curr Sci 2008, 95(10), 1474-8.

The major and trace element geochemistry of a weathering profile from Ranikhet granite gneiss, NW Lesser Himalaya suggests that except for K, other major elements are leached during incipient and intensive stages of weathering, while Al and Fe along with Nb and Sc remained immobile even in extreme stages of weathering. Primary mineral degradation and release of ions to solutions aided by fracture pattern and gneissose structure are the main factors that governed the alteration of the weathering profile. The study reveals that mechanical weathering dominates over chemical weathering, which resulted in the formation of thin soil cover in the region.

3 illus, 1 table, 15 ref

003178   Rama Mohan Rao C;Sahuquillo A;Sanchez J F L (NO, , Geological Survey of India, Hyderabad-500 068, Email: chebrolumohan@hotmail.com) : Comparative study of optimised BCR sequential extraction scheme with various single extractants leaching of elements in different type of soils. J appl Geochem 2008, 10(2), 11-30.

The optimised BCR sequential extraction procedure and partial extractions with various types of single extractants such as unbuffered salt solutions like 0.1M NaNO₃, 0.01M CaCl₂, 1M NH₄NO₃, complexing agents like 0.005M DTPA, and 0.05M EDTA, acid solutions like 0.43M acetic acid and 1M HC1 have been performed on four different types of soil samples like lateritic soil (S-1), in situ natural soil (S-2), soil contaminated by mining activity (S-3) and accidentally polluted soil (S-4) for a suite of 21 elements (Li, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Cd, Cs, Ba, Pb, Bi, Th, U) using ICP-MS. An aqua regia digest on the separate aliquot of samples for their pseudo-total contents had also been carried out for quality assurance purposes. Comparison of the sum of the four BCR fractions, which included an aqua regia digest on the residue, with the pesudo-total values to assess the accuracy of the BCR partioning approach has been undertaken. Partial extraction results with several single extractants have also been reported for the same 21 elements which have been analysed by the optimised BCR procedure. Results obtained after 24 hours extraction with each of the single extractant have also been discussed. The XRF, XRD and SEM studies have also been carried out and an attempt has been made to find out the possible association of the various elements in different phases. The results indicate that accidentally polluted soil shows contrasting behaviour in the recovery of Ga, Sr, Ba, Th, ranging up to 195% in comparison to aqua regia (Pseudo total) value taken as 100%. In all the four soils investigated, exchangeable step released as expected good amount of Cd, Sr Ba and reducing step released the appreciable quantities of Mn, Co, Ga, Ba, Pb and oxidising step accounting for the release of Sc, U in general and Th in particular for the accidentally polluted soil. Major portion of Li, Sc, Ti, V, Cr, Ni, Cu, Zn, As, Rb, Cs, Bi, Th were associated with the residual phase except the accidentally polluted soil wherein Cu, Zn, As were released in all the steps. The single extractants specifically 24 hrs extraction with 1M HC1 released almost similar quantities of most of the elements (except Bi and As) released under the combined steps of 1, 2 and 3 of the BCR sequential extraction for the four different type of soil samples which shows that this reagent can be used successfully to estimate the total extractable contents of different metals in various types of soil samples.

2 illus, 4 tables, 32 ref

003177   Rajendran K;Kitoh A (NO, Meteorological Research Institute, Tsukuba, Japan, Email: rajendrank@hotmail.com) : Indian summer monsoon in future climate projection by a super high-resolution global model. Curr Sci 2008, 95(11), 1560-9.

The impact of future climate change on the Indian summer monsoon has been investigated using a super high-resolution global general circulation model. The model with approximately 20-km mesh horizontal resolution can resolve features on finer spatial scales, which were till now resolved by employing high-resolution regional models. Regional models are known to have high dependency on the lateral boundary forcing and significant inability to represent regional-global scale interactions comprehensively. Another advantage of the 20-km global model is its fidelity in representing the regional distribution of the present-day monsoon rainfall. Super high-resolution future scenario for the Indian summer monsoon shows widespread but spatially varying increase in rainfall over the interior regions and significant reduction in oro-graphic rainfall over the west coasts of Kerala and Karnataka and the eastern hilly regions around Assam. Over these regions, the drastic reduction of wind by steep orography predominates over the moisture build-up effect (that causes enhanced rainfall over other parts) in reducing the rainfall. This indicates that monsoon rainfall is strongly controlled by parameterized physics and high-resolution processes which need to be resolved with adequately high resolution. The model projects substantial, spatially heterogeneous increase in both extreme hot and heavy rainfall events over most parts of India by the end of the century. While fine-scale surface moisture feedbacks influence the response of extreme hot events, extreme precipitation is influenced by fine-scale orography, evaporation, moisture content and circulation. Thus, the results indicate that consideration of fine-scale processes is critical for accurate assessment of local and regional-scale vulnerability to climate change.

9 illus, 32 ref

003176   Raj A;Nath S K;Thingbaijam K K S (Geology and Geophysics Dep, Indian Institute of Technology, Kharagpur-721 302, Email: nath@gg.iitkgp.ernet.in) : Recent earthquakes in the Bengal basin. Curr Sci 2008, 95(9), 1127-9.

3 illus, 1 table, 14 ref

003175   Qaid A M;Basavarajappa H T (Studies in Geology Dep, Mysore Univ, Manasagongtry, Mysore-750 006, Email: aliqaid@yahoo.com) : Integration of geological, geochemical and remote sensing data and evolution of the precambrian rocks, north east of Hajjah, Republic of Yemen. J appl Geochem 2008, 10(2), 76-91.

Precambrian rocks of the study area are represented by metavolcanic and metasedimentary rocks and intruded by post tectonic granites and granodiorites. In the northwest of Yemen where the study is conducted, the basement rocks have a NS to NNW structural trend and a petrogenetic affinity to the accreted arc terrains that constitute the Nabitah erogenic belt of Saudia Arabia, which is an environment of mineralization. These rocks are overlain unconformably by sedimentary Akbra shale, Jurassic Kohlan sandstone and Amran limestone. Field samples Chip, Composite and Grab have been collected. The coordinates of samples are also taken by GPS and integrated with the geological map, and the satellite image (Enhancement Thematic Map ETM+). The chemical analyses show high anomalies of arsenic, copper, nickel and gold. The satellite image was processed by using different programs, which shows that the study area represents an alteration zone and also indicates that the area is the most promising for mineralization.

14 illus, 2 tables, 15 ref

003174   Pandey S K;Shrivastava J P;Roonwal G S (Geology Dep, Delhi Univ, Delhi-110 007, Email: jpshrivastava.du@gmail.com ) : Occurrence of ferroan trevorite within olivine megacrysts of the MORB from olivine megacrysts of the MORB from southern east pacific rise. Curr Sci 2008, 95(10), 1468-73.

Report ferroan trevorite (NiO = 16.22 and FeO_{(Total) = 83.06)} mineral phase that occurs within the olivine megacrysts of the mid-Ocean ridge basalt from the Southern East Pacific Rise, indicative of Ni-enrichment, possibly linked to the heterogeneity in the lower mantle.

4 illus, 4 tables, 23 ref

003173   Nanda Kumar N V;Nagarjuna A;Reddy D C; Rajasekhar M (Zoology Dep, Sri Venkateswara Univ, Tirupati-517 004, Email: venkatananda_7@rediffmail.com) : Satellite remote sensing and field studies on a sea mouth in the northern part of Pulicat lake. Curr Sci 2008, 95(10), 1405-6.

^ssc2 illus, 1 table, 8 ref

003172   Mondal N C;Sxena V K;Singh V S (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: ncmngri@yahoo.co.in) : Experimental study for carbonate scale formation. J appl Geochem 2008, 10(2), 115-17.

A simplified model to explain the carbonate scale formation under laboratory conditions based on solutions of different TH and pH suggests that the carbonate scale is formed primarily due to precipitation of calcium carbonate. The temperature, CO₂ partial pressure, ionic strength, time of interaction and material of reaction vessel used, are the main parameters for the carbonate scale formation. The carbonate scale was formed for the waters of 300 to 700 mg/1 of total hardness (as CaCO₃) at 7.5 and 8.5 pH respectively. Experiment shows that carbonate scale is observed more at pH: 8.5.

1 illus, 2 tables, 11 ref

003171   Mohan P M;Sen S;Johan S (Ocean Studies and Marine Biology Dep, Pondicherry Univ, Brookshabad Campus, Port Blair-744 103, Email: pmmtu@yahoo.com) : Report on rate of sedimentation on corals off Port blais, altermath tsunami. J appl Geochem 2008, 10(2), 108-14.

Study has been carried out over a period of forty five days to understand sedimentation on coral environment of Port Blair region. North Bay and Chidiyatapu were selected to determine the rate of sedimentation on coral environment after 24 December 2004 tsunami. Study shows that this sedimentation is not a long-term process and only a sporadic incidence after tsunami. Also concludes that the subsidence due to this earthquake that causes a new set up of environment has not affected the regular sedimentation rate and hence subsidence may not harm the coral growth in the long run by way of sedimentation rate.

2 illus, 4 table, 6 ref

003170   Mitra A;Chakraborty R;Banerjee K (Marine Science Dep, Calcutta Univ, 45, B.C. Road, Kolkata-700 019) : Monthly variation of Zn, Cu and Pb in and around Indian sundarbans. Proc Natn Acad Sci India-Sect B 2008, 78(Pt III), 234-45.

Deltaic lobe of Sundarbans is one of the most biologically productive, taxonomically diverse and aesthetically celebrated ecotone of the Indian subcontinent, sustaining the famous mangrove gene pool. Due to the existence of highly urbanized cities of Kolkata, Howrah and newly emerging port-cum-industrial complex around the vicinity of this deltaic lobe, the ecosystem is presently under stress. A survey on heavy metal (viz. Zn, Cu and Pb) status was conducted in and around this mangrove ecosystem during 2005 with the aim to establish a baseline data. The order of heavy metal level in the ambient media (both water and sediment) of the selected stations was Zn>Cu>Pb. Highest concentration of these heavy metals was found in the surface water in the months of monsoon, the period characterized by lowest salinity and pH of the ambient aquatic phase. In the premonsoon season, the dissolved metal level was lowest. The biologically available heavy metals from surface sediment of the selected stations showed a complete opposite picture with highest values during premonsoon and lowest during monsoon. The regulatory roles of aquatic salinity and pH in the process of precipitation-dissolution of the selected heavy metals have been statistically confirmed. Significant negative correlations observed between the dissolved metals and sediment metals indicate sharp exchange of heavy metals between the aquatic and sediment compartments under the influence of salinity and pH in the present geographical locale.

30 illus, 1 table, 31 ref

003169   Maitra A;Das S;Shukla A K (Institute of Radio Physics and Electronics, University of Calcutta, Kolkata-700 009, Email: animesh.maitra@gmail.com) : Joint statistics of rain rate and event duration for a tropical location in India. Indian J Radio Space Phys 2009, 38(6), 353-60.

Optimum microwave link design requires the knowledge of rain rate distribution as well as of the duration statistics of the rain events. The rain rates measurements at Ahmedabad, a tropical location in India, are analysed and models for various event parameters are developed using three years of continuous measurements. The average number of cases with at least 1 min event duration shows an exponential dependence on the rainfall rate with a correlation coefficient of 0.93. Also, the average durations for different rainfall rates are found to follow a power law with a correlation coefficient of 0.97. It is found that the average duration more effectively represent the event duration at higher rain rates. The results are compared with those obtained for the temperate and other tropical locations to indicate the distinctiveness of the studied parameters over the location. It has been observed that although the tropical locations show similar qualitative features, the characteristics of the Indian region show quantitative difference from other tropical regions.

003168   Khan H F;Khaki S B (Geology Dep, A.M.U., Aligarh-202 002, Email: farahimkhan@hotmail.com) : Geochemistry and petro-mineralogy of phosphate bearing sedimentay rocks around Pahalgam, district Anantnag, Jammu and Kashmir. J appl Geochem 2008, 10(2), 40-50.

The phosphate bearing sedimentary rocks (Limestone, Shale and Sandstone) of Permian age overlain by Post Permian Panjal volcanics are exposed in Aru valley about 102 km from Srinagar in the North-West of Pahalgam town along the West of the Lidder river. Petromineralogical studies show that phosphate minerals (cellophane) in the form of pellets and showing replacement textures and the carbonate minerals constitute about 7-9% in the upper band of Permian limestone. Other minerals are calcite (60-70%), quartz (3-5%), dolomite (5-7%), iron minerals (4-6%) and clay, limonite, biotite (10-14%). Selected samples (7) from the lower and upper (7) bands of the Permian limestone were chemically analysed for major and trace elements and there is striking difference between lower and upper limestone beds in the area. Trace element geochemistry reveals that the rocks are enriched in Sr, Cr, Ni and Cu and depleted in Cd, Zn and Pb and biogenic, physico-chemical processes, and principal adsorbents like clay, iron oxides and silicate minerals have influenced the distribution of the trace elements. Presence of pyrite and variation in iron content in these rocks suggests a change in the environmental conditions. From the study of forms of phosphate minerals, lithological, chemical and mineralogical assemblages, it is inferred that the deposition of phosphatic sediments was influenced by the physico-chemical characters of the medium such as Eh-pH, supply of the material, lithological facies variation and some biogenic factors.

8 illus, 2 tables, 10 ref

003167   Jagannadha Rao M;Jaya Raj A A;John Paul K (Geology Dep, Andhra Univ, Visakhapatnam-530 003, Email: mjrao_isa@yahoo.co.in) : Occurrence of zincian ilmenite from sirkurmam placer sand deposit, Andhra Pradesh, India. Curr Sci 2008, 95(9), 1124-7.

3 illus, 3 tables, 9 ref

003166   Frincy R M;Anirudhan S;Thrivikramaji K P; Jijikumar S (Geology Dep, Kerala Univ, Kariavattom, Thiruvananthapuram-695 581, Email: frincyrm@gmail.com) : Bidecadal change in irriational suitability of river water - a case study from Neyyar river, Southern Kerala. J appl Geochem 2008, 10(2), 118-31.

The chemistry of Neyyar River Water is examined for its irrigational suitability by estimating Kelley's Ratio, SAR, RSC, SSP and Mg- hazard, which is compared with the data for the year 1984. The river flows through the capital city of Kerala and has been affected substantially due to the anthropogenic activities like sand mining from channel bed and flood plains, hard rock quarrying, check dams and channel diversion activities over the last two decades. Change in land-use pattern had enormously modified the quality and quantity of water resources of the basin over this period. There is an overall increase in Na⁺, K⁺, Cl^-, HCO₃^- and SO₄^2- ions in river water over the last two decades. The potability of groundwater of the basin is also studied.

3 illus, 5 tables, 15 ref

003165   Dwivedi S B;Lalnunmawia J (Civil Engineering Dep, Institute of Technology, Banaras Hindu Univ, Varanasi-221 005, Email: sbdcharu@yahoo.com) : Mineral chemistry and P-T condition of metamorphism of leptynite from the area around north-east of Dumka, Jharkhand. J appl Geochem 2008, 10(2), 51-9.

The area around NE of Dumka (latitude N24°14' to N24°18'42" and longitude E87°15' to E87°18') represents the eastern margin of Chhotanagpur-granulite-gneiss-complex (CGGC). It includes the highest-grade regionally metamorphosed rocks like khondalite and leptynite. Leptynite shows coarse band of garnet that is associated with biotite and defines the schistosity. Leptynite contains garnet-biotite-plagioclase-perthite-quartz, garnet-biotite-quartz-K-feldspar-plagioclase and garnet-biotite-K-feldspar-plagioclase-quartz. Garnet content of the leptynite varies from 73.4 to 75.1mole% almandine, 20.2 to 22.6 mole% pyrope, 3.7 to 4.3mole% grossularite and 0.3 to 0.5 mole% spessartite. The X_Mg content of biotites ranges from 0.734 to 0.7500. The Al^IV content in biotites varies from 2.4877 to 2.5737 p.f.u and Al^VI ranges between 0.1979 and 0.2373. TiO₂ contents of biotite varies from 4.169 to 4.923 wt%. The higher content of TiO₂ in biotite (4.923wt%) is similar to other granulite facies terrain of the World. The average temperature and pressure of the leptynite estimated by garnet-biotite Fe-Mg exchange geothermometer and garnet-biotite-plagioclase-quartz geobarometers is 636 ± 26°C/ 5.2 kbar.

4 illus, 2 tables, 14 ref

003164   Das S S;Maurya A S;Pandey A C;Bhan U;Rai A K (Earth and Planetary Sciences Dep, Nehru Science Centre, Allahabad Univ, Allahabad-211 002, Email: siddharthasankar_das@yahoo.co.in) : Influence of sediment source and monsoonal variations on the late quaternary clay mineral assemblages at ODP site 728A, northwestern Arabian sea. Curr Sci 2008, 95(9), 1320-6.

Clay mineral assemblages of the terrigenous fraction of 39 samples from ODP site 728A, located on the continental margin of Oman, northwestern Arabian Sea, have been analysed to understand the influence of sediment source, possible transport pathways and palaeoclimatic conditions during the late Quaternary. Illite, palygor-skite and chlorite were the most dominant clay minerals, with minor amount of kaolinite and smectite. Quartz, plagioclase feldspar and dolomite were the other detri-tal minerals. The terrigenous content showed antithetic relationship with the biogenic carbonate, and was high during the glacial stages mainly due to low sea level and erosion of exposed continental shelf by wind and/or fluvial processes. The high biogenic carbonate during the interglacial periods has been correlated to intense monsoonal activity and surface productivity. The study suggests that the detrital minerals are largely aeolian derived from the adjoining Arabian Peninsula, Persian Gulf and Iran-Makran regions and transported to the northwestern Arabian Sea by northwesterly winds. It appears that the cold and dry periods during the glacial times were responsible for physical weathering and contribution of higher amounts of chlorite and dolomite. The warm and humid interglacial period caused extensive chemical weathering and contribution of kaolinite.

7 illus, 41 ref

003163   Chatterjee S;Ghosh S;De U K (Atmospheric Science Research Group, School of Environmental Studies, Jadavpur University, Kolkata-700 032, Email: deutpal2003@yahoo.com) : Reduction of number of parameters and forecasting convective developments at Kolkata (22.53°N, 88.33°E), India during pre-monsoon season: An application of multivariate techniques. Indian J Radio Space Phys 2009, 38(5), 275-82.

Aims at the formation of a statistical index using the most effective parameters out of primarily selected 20 parameters to predict the convective development at Kolkata (22.53°N, 88.33°E), India during the pre-monsoon season along with a multivariate statistical analysis of 20 different thermodynamic and dynamic parameters. In the first phase, linear discriminant functions formed with the help of linear discriminant analysis (LDA) of 20 parameters derived from the radiosonde observations at 0000 and 1200 hrs GMT during 1985-1996 at Kolkata produced 42.8 and 72.7% correct prediction for fair weather and convective development in next 12 hrs for the years 1997 to 1999 whereas in the evening the respective correct results are 50.8 and 56.6%. In the second phase, an attempt has been made to reduce the number of parameters using eigenvector analysis and correlation study between 20 original parameters and significant principal components. Here, again LDA has been performed with the parameters thus selected. The study reveals that for morning and afternoon, the number of parameters can be reduced to 6 and 7, respectively. The accuracy of predictions is also found to improve as compared to the first phase. However, it may be mentioned that total number of days involved in the study is much less than the total number of days in the entire pre-monsoon season from 1985 to 1999 due to the unavailability of basic data needed to compute the required parameters.

003162   Charles Jeeva J;Vasanthakumar J; Balasubramaniam S;Geethalakshmi V (NO, Central Institute of Fisheries Technology, Matsyapuri P.O., Cochin-682 029) : Technology development efficiency and socio personal characteristics of researchers in marine fisheries. Fish Technol 2009, 46(2), 185-92.

Deals with the assessment of the technology development efficiency among the researchers in marine fisheries and identification of the influencing socio-personal characteristics. The study was conducted among 72 researchers of two premier fisheries research Institutions. The results revealed that the technology development efficiency index was 88.51 ± 10.01. Among the 15 variables studied, the variables viz., communication behaviour, extent of linkages with extension and clientele systems, time utilization in research, participation in professional bodies, in-service training undergone, job satisfaction, job performance and technologies generated had positive and highly significant relationship with the technology development efficiency. The R^{2 value indicated that all the variables taken together served as cause for explaining 57.60 % of variation in the efficiency level in the technology development process. The present results establish that the technology development process is efficient in marine fisheries.}

4 tables, 5 ref

003161   Chakravarthi V (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: vcvarthi@rediffmail.com) : Gravity inversion of 2.5D faulted beds using depth-dependent density. Curr Sci 2008, 95(11), 1618-22.

A gravity inversion using Marquardt algorithm to simultaneously estimate four parameters of a 2.5D faulted bed in addition to regional gravity background is presented. The density contrast along the structure varied continuously with depth based on a parabolic function. Analysis of gravity anomalies over a synthetic fault structure using the present inversion unravelled the fact that the estimated parameters of a fault structure were independent of its strike length, as long as the profile bisected the fault plane. In case the profile failed to bisect the strike length, then the offset of the profile from the origin of the fault plane must be considered for reliable interpretation. A simulated parabolic density function of the Chintalpudi sub-basin in India, was used to interpret the gravity anomalies of the Aswaraopet master fault. The estimated structure yielded a geologically plausible model that is consistent with borehole information.

5 illus, 2 tables, 17 ref

003160   Bikramaditya Singh R K;Gururajan N S; Krishnakanta Singh A (NO, Wadia Institute of Himalayan Geology, Northeast Unit, Itanagar-791 113, Email: kk_luwang@rediffmail.com) : Petrology and geochemistry of amphibolites of the Bomdila group, western Arunachal Himalaya. J appl Geochem 2008, 10(2), 92-107.

Amphibolite boudins occurring within the Bomdila Group of Lesser Himalaya in Arunachal are regionally metamorphosed in the upper greenschist to lower amphibolite fades. These intrusive rocks exhibit sharp contact with the host rock without any signature of assimilation and predominantly consist of hornblende with plagioclase, quartz, actinolite, epidote and chlorite with Fe-Ti oxides as minor constituents. Geochemical studies indicate that they are high-Ti to low-Ti, ortho-amphibolites enriched in light rare earth elements (LREE) and large ion lithophile elements (LILE) and resemble Within Plate Basalt. Similarity in major and trace element compositions together with normalised spidergram and REE patterns suggest that both the high-Ti to low-Ti amphibolites are generated from an enriched mantle source by varying degrees of partial melting with crystal fractionation at various sub-lithospheric levels.

7 illus, 3 tables, 41 ref

003159   Bhattacharya S;Purohit P K;Gwal A K (Space Science Lab, Physics Dep, Barkatullah University, Bhopal-462 026, Email: sbhattacharya_82@yahoo.co.in) : Ionospheric time delay variations in the equatorial anomaly region during low solar activity using GPS. Indian J Radio Space Phys 2009, 38(5), 266-74.

Ionosphere can be a greatest variable source of error in precise time transfer using GPS satellites. The proposed navigation concept requires that a user measures the time-delay that satellite emitted signals experience in traversing the distance between satellite and user. The difference between the apparent range and the true range, or the free space velocity and the true velocity, is the quantity of interest. This quantity is directly proportional to the total electron content along the path of propagating signal. Thus, if the total electron content is known or is measured, a perfect correction to ranging could be performed. The equatorial anomaly region, Bhopal (geographic latitude. 23.2°N, longitude 77.6°E), India with dual frequency from the GSV4004A GPS Ionospheric Scintillation and TEC Monitor (GISTM) receiver have demonstrated a high degree of accuracy in measuring the ionospheric group delay. The diurnal and seasonal variations of ionospheric time delay have been studied during the solar minimum period January to December 2005. It was found that diurnal variation of ionospheric time delay is maximum in the month of April and minimum in the month of December. The study reveals that during low solar activity, equinox season shows the maximum delay while summer gives the moderate and winter shows the minimum delay. The ionospheric time delay was also studied during magnetic storm conditions for the same period and the occurrence of daily maximum ionospheric time delay as a function of day during this period.

003158   Bajpai R K (Back End Technology Development Div, Bhabha Atomic Research Center, Trombay, Mumbai-400 085, Email: rkbajpai1@gmail.com) : Geochemical perturbations induced by radioactive waste emplacement in host rocks and their impact on environmental safety. J appl Geochem 2008, 10(2), 1-10.

Radioactive wastes are generated in various steps of nuclear fuel cycle commencing from mining and milling of uranium ore, followed by fuel fabrication and its application in nuclear reactors. The spent fuel recovered from these reactors is subjected to aqueous reprocessing for recovery of valuable radioisotopes like that of plutonium, uranium, strontium, cobalt etc. for their subsequent use as fuel in advanced reactors as well as other industrial, agricultural and medicinal applications. Reprocessing of spent fuel produces maximum quantity of radioactive waste of different category. The low level and intermediate level wastes (1% of total radioactivity) which are of very large volume, after suitable treatment and conditioning, are disposed in very shallow engineered facility in mostly unsaturated zones of subsurface strata. These included 4 to 5 m deep Reinforced Concrete Trenches as well as metal lined tile holes. As most of the radioisotopes disposed in these facilities are of short half lives (~30 years), this period of environmental safety in such cases is of the order of 300 years. India has seven such operating facilities in different parts of the country. The, high level radioactive waste (upto gross activity 1000ci/L) produced during the reprocessing of spent fuel, though very small in volume (~700 L/tone fuel), poses major technological challenges to geologists and geochemists, so far as their safe disposal is concerned. The radioisotopes in this category mainly include corrosion products (Fe, Ni, Cr, Mn), fission products (90Sr, 106Ru, 137Cs, 144Ce etc), actinides (241Am, 244Cm, un-recovered U and Pu) and account for almost 99% of the total radioactivity handled in the entire nuclear fuels cycle. Due to their very long half-lives, they need special conditioning and disposal. There is consensus worldwide that such wastes can be confined and isolated from the environment over a minimum period of 20,000 years to about 0.1 million years by disposing them in deep geological repository in suitable host rocks like granites, basalts, salt domes, clays etc. in the depth range of 500-700 m. There has been enormous work in the field of site selection and characterization for locating potential sites for development of such geological repositories worldwide in the last two to three decades especially in USA, Canada, Sweden, Finland and Germany etc. In India, granites have been chosen as host rock for geological disposal of radioactive wastes. A programme of systematic screening of stable granitic regions of India is being pursued for the last two decades. Indian geological disposal concept involves immobilization of wastes in glass or crystalline matrix placed in steel canisters (10mm thick and 2m long), providing another protective layer of steel in the form of over packs, and disposing these units at about 400-500m depth in granites. Additional layers of smectite clays and clay sand mixtures are proposed to be placed between steel overpacks and host rocks. The migration of radioisotopes from waste overpacks to environment during the period of projected safety is the main safety issue and will essentially be through groundwater pathways. The geochemical transport of radio elements through host rock in the case of granite would be essentially controlled by mineralogy of fracture fillings and host rock, groundwater chemistry, temperature, Eh and Ph of the near field geochemical environment. Thus, geocehmical evolution of the near field environment has been considered as one of the most important phenomena that will control movement of radionucilde through biosphere and also design of the geological repository. Emplacement of heat emitting radioactive wastes at ~500m depth in granite rocks will generate thermal field around them. In Indian case, it has been estimated that temperature in deep geological repository will at no point of time exceed 100° C. The thermal phase, caused mainly by isotopes of Cs and Sr will disappear after about 300 years. During this period, a combination of geochemical, mechanical, radiological and thermal processes will operate together to control near field geochemical environment. Analysis of combined effects of these processes on radio nuclide transport reveal that mostly reducing environment will exist around disposed wastes that will facilitate reduction of high valence radioisotopes of Pu, Am, U, Np, Tc etc and retard their transport substantially. The Ph of the groundwater has also been estimated to be alkaline after initial acidic phase. The high Ph environment arrests the migration of radionuclides substantially. Field and laboratory based experiments on such transport reveal that waste elements have not migrated more than a few meters in years. These observations have been corroborated from observations in natural analogue sites at Oklo, Gabon as well as in many Indian sites. The use of 50cm thick layer of smectite clays around waste provides additional geochemical barrier against any possible migration of waste species. These clays by processes of cation exchange and surface adsorption limit the radionuclide transport significantly. It is estimated that most of the radioactive isotopes barring long-lived actinide, will decay in clay barriers. Besides migration, hydrothermal alteration of host rock, waste glass, clay layers and steel overpack constitute another very important aspect of environmental safety, as it will control the confinement of waste in its place of emplacement. Studies reveal that presence of minerals like pyrite in clays will speed up corrosion of steel overpacks due to acid production. Similarly, geochemical transformation of swelling clays i.e. smectite to illite under the influence of temperature and presence of potassium in granite groundwater, has also emerged as major factor controlling degradation of swelling and retardation properties of clays. The presence of a number of other constituents like calcite, organic material, gypsum, biotite etc. in host rock as well as clays has been found to exert a significant control on near field geochemistry. The estimation of evolution of geochemical changes around disposed waste and migration of radionuclides in laboratory based experiments or small scale field experiments, provides some level of confidence in safety of waste disposal, but the extrapolation of the results of these short duration experiments over time scales of thousands of years remains a major challenge. There are geochemical computer codes that use experimental results as input to define changes in system as a function of time.

3 illus, 1 table, 6 ref

003157   Arora B R;Kamal;Amit Kumar;Rawat G;Naresh Kumar;Choubey V M (NO, Wadia Institute of Himalayan Geology, Dehradun-248 001, Email: arorabr@wihg.res.in) : First observations of free oscillations of the earth from Indian superconducting gravimeter in Himalaya. Curr Sci 2008, 95(11), 1611-17.

The first Indian superconducting gravimeter (SG) was installed in March 2007 at the Multi-Parametric Geophysical Observatory of the Wadia Institute of Himalayan Geology, in the Himalaya near the Main Central Thrust at Ghuttu, Uttarakhand, India. Almost immediately after installation, the free oscillations excited after the Solomon Islands earthquake (M = 8.1) were well recorded on the SG. The frequency and amplitude of several of these oscillations have been estimated in the present study and compared with the earlier global observations. The results are in tandem with similar studies carried out using a global dataset from the seismometers and SG. The present study validates the quality of the recorded data to search minute (submicrogal) coseismic/precursory gravity signals to large earthquakes and sets the background for future low-frequency seismological research in the country. Some new applications of SG data are also discussed.

6 illus, 1 table, 29 ref

003156   Aravind Kumar N;Ashalatha B;Sinha B;Thakur N K (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: nkthakur46@yahoo.com) : Estimates of geothermal gradients from bottom simulating reflectors. Curr Sci 2008, 95(10), 1463-7.

Multi-channel seismic reflection data from two different tectonic regimes over the continental margins of India have been studied to identify the bottom simulating reflector (BSR), a prime indicator for the presence of gas hydrates in a region. The probable depth of occurrence of these BSRs is estimated. The estimated depths were projected on plots of hydrate stability zones calculated for different geothermal gradients. The projected depths show scatter over curves of geothermal gradients. Best-fit curves were obtained from the datasets to arrive at geothermal gradients over the two regions. The estimated geothermal gradient for Kerala-Konkan is of the order of 0.05°-0.055°C/m and for Andaman region it is in the range 0.015°-0.02°C/m. The estimated geothermal gradient over Kerala-Konkan indicates normal value, whereas for the tectonically active Andaman region, it is lower. Utilizing the published values of thermal conductivities for hydrated sediments we have determined the heat flow values. The estimated heat flow value for Kerala-Konkan region seems to be normal with hydrated sediments, whereas the value obtained for the Andaman region seems to be significantly low. Possible explanation for this anomalous behaviour has been attempted.

5 illus, 24 ref

003155   Ahmad S;Hasnain S I (Geology Dep, AMU, Aligarh, Uttar Pradesh, Email: Sarfaraz71@yahoo.com) : Pattern of a glacial steam chemistry in Ganga headwater, Garhwal Himalaya, India. J appl Geochem 2008, 10(2), 132-47.

Purpose of this study was to determine the processes controlling stream water chemistry in high altitude, central Himalayan catchment. Plots of water chemistry versus time were used to assess seasonality and hysteresis diagrams were used to describe processes affecting water chemistry through the relationship of stream discharge. Studies reveal the importance of snowmelting and rainfall on chemistry of glacial - fed streams. The major ions exhibit seasonality, high concentrations in early spring and low concentrations in summer, except chloride and hydrogen ion concentration, which were higher during summer period. The hysteresis between discharge and stream water chemistry can be categoried as open clockwise loop, counter-clockwise and open "complex" loops.

7 illus, 3 tables, 31 ref

002147   Yang D X;Zhang D L (Institute of Crustal Dynamics, Chinese Earthquake Administration, Bejing -100 085, Email: yangdx@mail.igcas.ac.in) : CE/SE scheme for incompressible flows through porous media. Indian Miner 2008, 61-2(3-4,1-4), 223-32.

An improved two-dimensional space-time conservation element and solution element (CE/SE) method with first-order accuracy is applied to simulate flow in porous media, using Brinkman-Forchheimer-extended Darcy models. The numerical result of lid-driven cavity flow demonstrates the availability of the CE/SE method for numerical simulation of flow in porous media, somewhat similar to those obtained by Ghia. After investigating the effect of Darcy number and its anisotropy as well as porosity on flow, it's found that Darcy number has determinant influence on flows in porous media.

6 illus, 16 ref

002146   venkateswarlu P;Kiran K;Ramamohan Y;Anji Reddy M (Centre for Environment, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad-500 072) : Integrated micro level watershed management for drought-prone rural areas: remote sensing approach. Bull pure appl Sci-Sect F 2008, 27(1-2), 53-68.

Application of remote sensing and GIS for the development of an action plan at micro level for appropriate management of land resources of a Watershed in a drought -prone region of Andhra Pradesh in India forms the theme of this paper. Using IRS-IC-LlSS111 data .landuse j landcover, hydrogeomorphology and soil maps were generated. In addition, slope and drainage maps were prepared from survey of India tope- sheets. Based on the computerized database created Using ARC/INFO software, information derived in terms of the land resources and their spatial distribution was then integrated with the socio-economic data to formulate an action plan. Such [, plan is useful for the watershed management and for improving the socio-economic status of rural population on a sustainable basis.

5 illus, 9 table, 7 ref

002145   Tian Y;Zhao D;Liu C;Teng J;Sun R (College of GeoExploration Science and Technology, Jilin Univ, Changchum-130 026, Email: tianyou@jlu.edu.cn) : Three-dimensional P-wave velocity structure of the crust and upper mantle under the Changbai volcanic area in Northeast China. Indian Miner 2008, 61-2(3-4,1-4), 1-8.

Determined 3-D P-wave velocity structure of the crust and upper mantle under the Changbai volcanic area in northeast China by applying a tomographic method to a large number of arrival times from regional earthquakes and teleseismic events. A prominent low-velocity anomaly is clearly imaged in the crust and upper mantle down to 400- km depth beneath the Changbai volcano. A high-velocity anomaly is revealed in the mantle transition zone and deep earthquakes occurred actively there, suggesting that the stagnant Pacific slab exists in the mantle transition zone under the Changbai volcano. Our results suggest that the origin of the Changbai volcano is related to the deep dehydration of the subducted Pacific slab and corner flow in the big mantle wedge above the stagnant slab.

7 illus, 35 ref

002144   Tejale P M;Sinha A K (NO, Geological Survey of India, Kolkata-700 016) : Co-linearity of important lead-zinc deposits of Rajasthan and its airborne geophysical signatures. Indian Miner 2008, 61-2(3-4,1-4), 233-46.

Rajasthan having high basemetal potential constitutes a part of the western Indian Shield comprising several Archaean and Proterozoic belts. At present, Rajasthan contains more than 90% of the known economically viable Zn-Pb resources of India. In the shield area of south-central Rajasthan, there are three known major basemetal deposits viz., the largest and intensively exploited Zn-Pb Zawar deposit (24°22'N:73°42'E), the polymetallic ore deposit at Rajpura-Dariba (24°58'N:74°08'E) and Zn-Pb deposit at Rampura-Agucha (25°49'N: 74°44'E). These three deposits account for the maximum production of lead and zinc metals, with silver as a bi-product. The above three deposits are distributed in diverse geological milieu i.e. Agucha deposit occurs in Mangalwar Complex (>2500 Ga), Rajpura-Dariba deposit in Bhilwara Supergroup (2200 to 2600 Ga) and Zawar in Aravalli Supergroup (1800-2200 Ga). In spite of different geological and geochemical set-up, they are having similar metallogeny. In addition to their different geological ages, they are all considered to be stratabound. The co-linearity with some similarity and dis-similarity have attracted the attention of authors as because the studies may lead to prognostication of more target areas, hitherto buried in between the known deposits. Deals with the geological parameters of and geophysical signatures over the deposits and their surrounding areas.

10 illus, 1 table, 35 ref

002143   Subhadra N;Padhy S I;Sesunarayana T; Vijayaraghavan R (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: padhys@rediffmail.com) : Synthesis of exoected ground motion using semi-empirical green's function approach and its comparison with observed accelerations in Garhwal Himalaya. Indian Miner 2008, 61-2(3-4,1-4), 201-12.

Results of ground-motion attenuation relations in Garhwal Himalaya. A semi-empirical Green's Function approach based on envelope summation technique of Midorikawa (1993) was used to model the ground motions. In this approach, the fault of the large earthquake is divided into a certain number of elements (sub-faults). Our model assumes each sub-fault as point source in uniform Earth structure. The acceleration envelope waveforms, instead of time histories, from such elements are determined using empirical relations. The envelope from each element are lagged and summed at the receiver to get the resultant envelope of a large earthquake. The resultant envelope is multiplied with filtered white Gaussian noise to synthesise the acceleration at a given site. The methodology was applied to predict the strong motion records and to calculate the peak ground acceleration (PGA) from the aftershocks of 1999 Chamoli earthquake. The results show a reasonably good agreement between theoretical and recorded waveforms and their spectra at high frequencies. Significant discrepancies between the spectra at low frequencies may be attributed to the effects of source or medium in the simulation process. The PGA values are found to be ~3 m/s^{2 at 15km and decays to ~1.5 m/s2 at 80km distance. Our result shows a rapid decay of ground-motion amplitude with distance, similar to that found in other tectonically active regions like Himalaya.}

7 illus, 1 table, 50 ref

002142   Srivastava D K;Gupta A;Jauhri A K (Centre of Advanced Studies in Geology, Lucknow Univ, Lucknow-226 007, Email: sirdkdr@rediffmail.com) : New regular echinoid from the middle eocene of Kachchh, Western India. J Palaeont Soc India 2008, 53(1), 107-10.

A phymosomatoid cchinoid genus Kachchhia n. gen. (referable to K. krohi n. sp.) is described and illustrated from the middle Eocene rocks of south western Kachchh, India.

^ssc1 illus, 23 ref

002141   Singh O P;Chowdhuri S N;Gaonkar S G (Central Geophysics Div, , Geological Survey of India, 27, J.L. Nehru Road, Calcutta-700 016, Email: op_singh9@hotmail.com) : Site response study in the eastern part of Guwahati city (Assam) using ambient seismic noise analysis. Indian Miner 2008, 61-2(3-4,1-4), 141-8.

North-east region of India is notoriously seismic prone and Guwahati in the state of Assam is arguably the largest city in that region. The results of site response study in the eastern part of Guwahati using ambient seismic noise carried out from Geological Survey of India as a part of a multi-institutional project are analysed and presented here. The average relative spectral ratio of horizontal to vertical component (H/V) was calculated using the Nakamura technique. The maximum site amplification factor and corresponding peak frequency maps are prepared. In this study, we compared the noise observations with spectral-ratio site response estimates using microearthquakes recorded at some sites to test the validity of the noise survey method. Our analysis shows that the site amplification factor varies from 1 to 10, while the peak frequency varies from 1 to 16 Hz. The highest amplification factor that range from 7 to10 is observed in the southeastern part of the study area (eastern part of Guwahati). The highest peak frequency has values that vary from 8 to 16 Hz, in central part of the survey area with amplification factor of 2-3. These findings may be useful for designing the building code as well as for evolving earthquake hazard mitigation model for the city. Our study concludes that the Nakamura's method may be a reliable procedure for determining the fundamental resonant frequency of sedimentary deposits from ambient noise of the site.

6 illus, 1 table, 22 ref

002140   Singh A P;Bhonde U;Rastogi B K;Jaiswal R K (Institute of Seismological Research, , Raisan, Gandhinagar-382 009, Email: apsingh07@gmail.com) : Possible inundation map of coastal areas of Gujarat with a tsunamigeni earthquake. Indian Miner 2008, 61-2(3-4,1-4), 59-64.

The western Indian peninsula experienced the most destructive tsunami ever recorded in the Arabian Sea by the 28th November 1945 earthquake (Mw 8.1) in Makran region. The run-up height during the tsunami was of 17m at Makran coast and 11 to 11.5m in Gulf of Kachchh region. Seismic gap area along the subduction zone of Makran is possible site of future great earthquake, which could generate tsunamigenic condition along western Indian coast. Determination of run-up elevation is important aspect to study the inundation in any region, which get affected by offshore and on-shore geomorphological conditions i.e. bathymetry and near-shore topography. Inundation maps are prepared using Shuttle Radar Topographic Mission (SRTM) data and ETOPOv2v to show the possible areas of inundation due to different wave heights along coastal parts of Gujarat state. Results shows that more than 2 m run-up elevation is showing possibility of inundation in Jakhau and Kandla areas of Gulf of Kachchh region whereas, the Saurashtra region shows less possibility of inundation. As the state has important installations like ports, jetties, industries along the coast and also other socio-economical perspective which can be affected by such an event, hence the demarcation of possible inundation areas is important for determination of future tsunami hazard demanding more detailed work.

6 illus, 9 ref

002139   Ramasamy V;Ponnusamy V;Gomathi S S;Jose M T (Physics Dep, Annamalai University, Annamalainagar-608 002) : Glow curve characteristics of dolomitic rocks. Bull pure appl Sci-Sect F 2008, 27(1-2), 43-7.

Therrmostimulated luminescence (TSL) glow .curve characteristics of ten dolomitic crystals of Salem and Namakkal districts of Tamilnadu are put to analysis. The natural thermoluminescence (NTL) measurement were carried out for all the samples and shows two peaks at 270°C and 335°C. The sample irradiated with a gamma dose of 200 Gy shows an additional peak at I80°C, when recorded with linear heating rate of 10°C/sec. At the same time, the NTL peak at 270°C is shifted to 260°C with increasing in intensity and there is no change in the peak position of 335°C. The annealed sample also shows the same trend.

2 illus, 11 ref

002138   Panigrahi R K;Guruvittal U K;Gupta P;Prasad P S;Mathur S (Geotechnical Engineering Division, CRRI, New Delhi) : Geomechanic classification of rocks for hill slope failure at Km.45.0 on NH-150, Mizoram. Indian Min Engng J 2008, 47(9), 22-32.

Reveals the outcome of field and laboratory investigations of landslide at Km.45 of NH-150, Mizoram showing the engineering properties of the rocks. Geomechanical classification of rocks of study area was carried out based on rock mass rating method as suggested by Beniawski in his number of publications. It helps to characterize the slope and indicate the causes of slope failure in this location. Slope stability Analysis was carried out and along with other studies to evolve a set of suitable remedial measures suggested for implementation to attain a long term remediation of this slope.

2 illus, 4 table, 3 ref

002137   Pandey D K;Kondo Y;Jain R L;Tej Bahadur; Pradhan V R (Geology Dep, Rajasthan Univ, Jaipur-302 004, Email: dhirendrap@satyam.net.in) : Microfacies and depositional environmental of the Gaj formation (Miocene) exposed near Bhatia, district Jamnagar, Saurashtra. J Palaeont Soc India 2008, 53(2), 131-45.

Complex tectonic features surround the Saurashtra Peninsula of the Gujarat state on the western extremity of India, a consequence of the breaking up of Gondwanaland in the Triassic. The arching up of the Saurashtra peninsula was a result of pre-Eocene thermal expansion of the crust while moving northeastward over the Reunion hot spot. This, together with lower eustatic sea level during the Eocene in comparison to higher global sea level in the Miocene, has resulted in the absence of Eocene sediments from the Saurasthra upland. The oldest sediments deposited at the northwestern coast of Saurasthra, which forms the Palaeogene-Neogene pericratonic sedimentary basin, belong to the Miocene. These Miocene sediments of Saurashtra have been, lithostratigraphically, grouped into the lower Ashapura Clay Member and the upper Ranjitpur Limestone Member of the Gaj Formation. Fossil records suggest a marine environment of deposition, however, rapid temporal change of fades can be attributed to fluctuating depositional environments. In the present paper, a 1.5 m thick section of the Ranjitpur Limestone Member exposed along a ridge near Bhatia, district Jamnagar, Saurashtra, has been investigated and interpreted to represent nearshore to subtidal environments.

3 illus, 3 tables, 37 ref

002136   Mishra O P;Zhao D;Wang Z (NO, Geological Survey of India, Culcutta-700 016, Email: niom_mishra2005@yahoo.co.in) : Genesis of the 2001 Bhuj, India Earthquake (Mw 7.6): a puzzle for peninsular India?. Indian Miner 2008, 61-2(3-4,1-4), 149-70.

The influence of an active plate boundary on the stress field of the Bhuj tectonics and its analogies with other intraplate earthquakes associated with ancient rift basins have generated interest among the scientific community. A number of hypotheses on the genesis of the 2001 Bhuj earthquake (Mw 7.6) in the peninsular India have already been put forth by several researchers without a common consensus on the issue. Despite no evidence of plate collisional - subduction tectoaics and magmatic eruption in the peninsular India the region is being marked with a frequent occurrence of several damaging earthquakes in the recent past, which has become a great puzzle to the geoscientists. The aim is to identify the key processes involved in the geneses of the 2001 Bhuj earthquake and its aftershocks within the ancient Kutch rift basin, thereby providing an interpretational framework for three-dimensional (3-D) seismic velocity and Poisson's ratio structures of the source area using high-quality P- and S-wave arrival time data from the best located Bhuj aftershocks using the double difference method of relocating earthquakes. The Bhuj mainshock is located in a distinctive zone, characterized by high P-wave velocity (high-Vp), low S-velocity (low-Vs) and high Poisson's ratio (high-a), while areas with high aftershock activity are mainly associated with low Poisson's ratio (low-o). An integration of the simulated seismotectonic model and existing geo-scientific observations with Vp, Vs and o tomograms of the source area suggests that a deep-seated intersecting geometry of hidden faults at the base of paleo-rift zone associated with fluid-filled, fractured mafic rock matrix might have contributed to the initiation of the Bhuj earthquake in the intraplate region of western India. The present study infers that the Bhuj mainshock was triggered neither by the north-dipping Kutch mainland nor by the south-dipping North Wagad pre-existing faults. Fluid pressure in the fractured rock matrix at the mainshock hypocentre might have played a key role in the earthquake generating processes, which may have built up differently, possibly in response to dissolution-recrystallisation processes, or thermal processes to initiate the brittle failure in a stable tectonic context by influencing the variations in pore-pressures and thermo-mechanical properties of the continental lithosphere.

14 illus, 2 tables, 97 ref

002135   Mishra H P;Lahiri A K;Acharya R S;Syiem S M (Geological Survey of India, North-Eastern Regions, Shillong-793 003, Email: hpmishra50@rediffmail.com) : Assessment of groundwater potential and its potability in sukhatal area, Nainital, Uttaranchal estimated using electrical resistivity techniques. Indian Miner 2008, 61-2(3-4,1-4), 117-22.

Nainital hill resort faces acute shortage of groundwater in peak period of tourist season. In search of an alternative reservoir for fresh groundwater, geophysical survey was conducted in Sukhatal depression which remains dry throughout the summer, acts as seasonal lake and is situated slightly on higher elevation than Nainital town in Nainital district, Uttaranchal. The objective of the survey was to configure the fresh and potable groundwater aquifer. Resistivity survey depicted a zone 30 to 55 m thick having resistivity of 50-125 Ohm-m of saturated sand layer which was interpreted as fresh water zone lying at depth of 4-8 m bgl. The lateral extent of the aquifer was 200 m in east-west and 50 m in north-south direction. Assuming the formation resistivity factor for medium to clean sand to be between 3 and 3.5, it was estimated that the amount of total dissolved solid (TDS) in that aquifer may be very less and of the order of 100-180 mg/l NaCl equivalent which is well within the permissible limit as per the standards of World Health Organization (WHO). A drill hole was recommended in the middle of the area where the aquifer thickness was found to be maximum. It has been reported that substantial amount of potable water is being extracted through the tubewell from Sukhatal.

4 illus, 1 table, 1 ref

002134   Mishra H P;Babu Lal;Regar R L;Singh S K;Amar Singh;Sharma P (Geophysics Div, Western Region, Geological Survey of India, Jaipur-302 004, Email: hpmishra50@rediffmail.com) : Geophysical studies for configuring the bedrock profile along Jhiri Dam alignment, Par-Tapi-Narmada link project, Nasik District, Maharashtra. Indian Miner 2008, 61-2(3-4,1-4), 113-16.

Presents the results of geophysical surveys conducted along the Jhiri dam alignment in district Nasik, Maharashtra at the request of the Par-Tapi-Narmada Link Project of National Water Development Agency (NWDA). National Water Development Agency (NWDA) is the first Water Resources Management Scheme involving interbasin transfer of Par, Nar, Tan, Ambika, Khapri and Purna rivers through Tapi (Ukai reservoir) and Narmada (Sardar Sarovar reservoir) to Kutch region in the state of Gujarat. Under this programme, geophysical surveys employing seismic, electrical resistivity and magnetic techniques were conducted for the delineation of bedrock configuration and the geological structural features, if any, present in the vicinity of the dam alignment. The Jhiri dam site is located across river Par near village Jhiri which is situated about 3 km west of village Jhiri in Nasik district. The depth to the bedrock at dam site varies between 2.9 m and 20 m showing P-wave velocity ranging between 5000 to 5100 m/s.

4 illus, 2 ref

002133   Kumar G (Geology Dep, BIT Sindri, Dhanbad-828 123) : Waste water utilization concept & practices. Indian Min Engng J 2008, 47(8), 28-31.

Water for domestic consumption is an essential right of society, which must be over secured. Water reclamation and reuse provides a unique and viable opportunity to augment traditional water supplies. As a multi-discipline and important element of water resource development and management, water reuse can help to close the loop between water supply and wastewater disposal. Effective water reuse requires integration of water and reclaimed water supply functions.

12 ref

002132   Khurshid S;Kulshrestha P (Geology Dep, Aligarh Muslim University, Aaligarh-202 002, Email: khurshid_shadab@yahoo.com) : Groundwater resource and development potential in parts of central Ganga basin, Aligarh, (UP), India. Bull pure appl Sci-Sect F 2008, 27(1-2), 1-11.

Rapid Agricultural growth and urbanization requires systenmatic groundwater planning to increase efficiency, save energy and to manage groundwater pumpage. For current assessment of groundwater potential of a region, the storage and transmissibility coefficients of an aquifer are the important characteristics. They are essential parameters in the economic development of groundwater potential of a region. A better understanding of these aquifer parameters are of much significant. The present study utilizes premonsoon and post-monsoon water level to determine water level fluctuations in the area. Borehole data have been collected to study technological units and on the basis of lithological units a correlation has been made to demarcate the disposition of aquifer system. The ground recharge has been estimated by the water level fluctuation and specific yield method. The rain fall data have been used to correlate the impact of water level fluctuation and assessment of recharge and discharge conditions.

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002131   Khan P K;Chakraborty S;Srivastava V K;Prasad R (Applied Geophysics Dep, Indian School of Mines Univ, Dhanbad, Email: pkkhan_indica@yahoo.com) : Seismicity, source parameters and scaling relationships for the eastern part of eastern Indian shield region. Indian Miner 2008, 61-2(3-4,1-4), 65-74.

The study area comprises the eastern part of eastern Indian shield, and lies between latitude 22.5° and 26°N and longitude 85° and 88.3°E. The region has a very complex Precambrian history, evolving through a number of orogenic cycles. A total of 46 local microearthquake events were recorded during 2007 by a three-component broadband digital seismometer installed in the seismological observatory of the Indian School of Mines University at Dhanbad in the state of Iharkhand and analysed under the present study. Epicentral and source parameters of these 46 events were computed using the SEISAN 8.1.3 software. The seismicity and source parameters for this area have been interpreted in the backdrop of Bouguer gravity anomaly and tectonic setup and this preliminary understanding provides invaluable information of the subsurface geological processes. The study area recorded low-magnitude earthquakes not more than Mw = 3.7 during 2007. Seismic moments lie between 0.06 x 10^{18 and 15.40 x 1018 dyne-cm and source radius varies from 100 to 500 m. Plot of seismic moment (Mo) against moment magnitude (Mw) shows a positive correlation. However, the moment magnitude significantly appears to contrast sharply with stress drop (Δσ) and source radius (r). Seismicity of this area is mainly confined to the Damodar basin and little activities are apparent in southern and northern parts of this basin. These observations might be due to the presence of sub surface lateral heterogeneities in these areas. Localized strain along pre-existing fractures/shear zones causes either ductile o, brittle failure of rocks at shallow level through several fluid-induced processes at elevated temperature. High heat-flow and presence of several hot springs in these areas possibly corroborates these views.}

5 illus, 2 tables, 22 ref