011903   Srivastava A K;Sinha Ray K C;Kulkarni R (India Meteorological Dep, , Pune-411 005) : Seasonal variations, trend in the tropopause height/temperature over Indian stations and its modulations by SST anomalies of east Pacific Ocean. Mausam 2002, 53(4), 439-46.

Global warming due to increase in the Green House Gases is now well known. There are several studies, suggesting discernible changes over the years in respect of meteorological parameters like, rainfall events, frequency and intesity of tropical cyclone/hurricanes, maximum/minimum temperature, SST of oceans etc, on regional as well as global scale. Study besides finding out seasonal variations in tropopause height and temperature across each 5(F128)(144)(F255) latitude over India based on a longer data set, has demarcated the locations where significant trend in respect of temperature and height was observed over Indian region on annual scale besides investigating the possible causes of this trend. The study has also confirmed significant linear associationship between tropopause temperature/height over Indian stations and SST anomalies of east Pacific Ocean with SST leading by one year.

7 illus, 2 tables, 29 ref

011902   Srivastava A K;Kasturi Lal;Sukhvir Singh;Ram Kishore (Division of Materials Characterization, National Physical Laboratory, New Delhi-110 012) : Preparation and characterization of standard gold resolution test specimen for electron microscopy. MAPAN 2003, 18, 159-64.

The gold (Au) particles have been deposited by thermal evaporation under high vaccum conditions and precise monitoring of different process parameters while deposition on carbon coated 3 mm diameter nickel (Ni) grid. These particles have been examined at its nano-scale by using the transmission electron microscope (TEM) models JEOL JEM 200 CX and JEOL JEM 2000 EX working at the electron accelerating voltages of 200 and 120 kV, respectively. The high magnifications up to 200,000 X under the electron beam has been exploited to reveal the Au particles of an average size between 4 to 8 nm with an interparticle separation of 4 to 6 nm. The selected area electron diffraction patterns confirmed the polycrystalline random distribution of evaporated nano-sized Au. A detailed investigation distinguished the spherical & irregular shapes with the particles of even 2.4 nm in size and inter-particle separation of 2 nm.

3 illus, 7 ref

011901   Shirlal K G;Subba Rao (Dep of Appl Mech and Hydraulics, Karnataka Regional Engineering College, Surathakal, Srinivasnagar, Karnataka) : Laboratory studies on the stability of tandem breakwater. ISH J Hydraul Engng 2003, 9(1), 36-45.

Tandan Breakwater consists of a submerged reef breakwater constructed at some distance in front of a conventional non-overtopping rubble mound breakwater. The submerged reef breakwater breaks the high waves and the stilling basin between two breakwaters attenuates them. Hence, smaller waves approach the non-overtopping rubble mound breakwater and break on it. Therefore, the non-overtopping rubble mound breakwater may be designed for smaller waves, resulting in relatively lighter armour stones. In the model studies, it has been found that for a relative breakwater spacing X/d varying from 3.33 to 4.29 between the brakwater, the damage of a tandem breakwater is 20% to 60% less as compared with a single breakwater for similar operating criteria.

8 illus, 1 table, 8 ref

011900   Sharma S K;Ojha V N;Singh A;Jaiswal S K; Sharma R (NO, National Physical Laboratory, New Delhi-110 012) : Traceability and calibration - a case study. MAPAN 2003, 18, 57-61.

Deals with the traceability and calibration by discussing a case study of the electrical parameters. Also highlighs the role of calibration, intercomparison and metrological timeliness intraceability. the importance of timeliness and factors that effect the periodicity of calibration are also discussed.

1 illus, 11 ref

011899   Santos M S;Bebeachibuli A;Magalhaes D V;Teles F;Bagnato V S (NO, Instituto de Fisica de Sao Carlos, USA) : Stability and reproducibility of a <. MAPAN 2003, 18, 139-45.

Presents the progress made in the last year on Brazilian scientific time and frequency program. In our last evaluatin comparing frequency standard with a HP 5061-B obtained the Allan standard deviation σ_y(τ)=(1.8±0.2)x 10^-11τ^-0.5. Applied the method described by Makdissi et. al. adn Shirley et. al. to determine the major frequency shift like the second -order Zeeman shift, magnetic field inhomogeneity along the rf-cavity, rabi and cavity pullin in order to characterize our standard.

4 illus, 5 ref

011898   Sangam Kumar;Rashmi Ranjana (Dep of Phy, B R A Bihar Univ, Muzaffarpur) : Influence of earth's magnetic field and air resistance on a system of two cable-connected artificial satellites. Proc Math Sci 2001, 17, 59-65.

Using the equation of relative motion with respect to the centre of mass of orbiting system, Lagrangian equation of the first kind for the centre of mass of the system has been obtained. Central gravitational force of the earth is the predominating force. The perturbing forces are earth's magnetic field and air resistance. By normalizing the equation of the relative motion, it is transformed in the rotating frame of reference and thereafter Nechvill's co-ordinate system.

2 ref

011897   Rao K R (NO, , ) : Remote sensing and GIS based approach for sustainable waste land development. Sapper 2002, 13(5), 53-9.

2 illus, 4 ref

011896   Rai K;Sarkar A K;Mitra A P (Analytical Chemistry Section, National Physical Laboratory, New Delhi-110 012) : Characterization of aerosols in an urban residential environment. MAPAN 2003, 18, 147-51.

Delhi, capital of India, one of the highly polluted cities in the world, is causing a great concern to the environmentalist because of high pollution level. A regular monitoring of the pollutants like suspended particulate matter (SPM), sulphur dioxide (SO₂), nitrogen oxides (NO₂), organic carbon (OC) and black carbon (BC) is needed as these are playing a major role on the health of habitants in Delhi. Efforts have been made to evaluate the concentrations of these pollutants in ambient air at NPL (residential complex) through out the year from may 2001 to April, 2002. It was observed that the SPM, SO₂, NO_@ varied from 116-300 μg m^-3, 8.0-21 μg m^-3 and 23-113 μg m^-3 respectively. The carbonaceous speices show no clear seasonal variation at this location but concentration during winter are generally slightly higher than summer and monsoon concentration. For the analysis of toxic and heavy metals viz. Al, Cr, Pb, Cd, Ni, Mn, Fe, Cu in the SPM, the particulate samples have been digested with conc. HNO₃ (AR grade) and filtered. Each element is determined in the filterate by Graphite Furnance Atomic Absorption Spectrophotometer (GFAAS) in their respective principle resonance line after doing the calibration with each standard.

2 illus, 2 tables, 6 ref

011895   Panda D (Indira Gandhi Govt. College, , Tezu, Dist. Lohit-792 001) : Spatial distribution of soils in the Rushikulya basin. Indian J Landsc Syst ecol Stud 2000, 23(2), 24-38.

Soils are the essential components of the earth's surface which influence the sustainance of life in various forms. Soils are very much influenced by the existing parent materials of the region. An attempt has been made to classify the spatial distribution of soils in the Rushikulya basin by using the latest USDA 1992 soil taxonomic classification system. The Rushikulya river basin of southern Orissa located in the east coast of India and covers about 8402 Sq. km area. On the basis of analysis the soil scapes of the basin have been broadly classified under three geological formations i.e. Eastern Ghat granite gneiss. Dharwar system and coastal plain. As per the soil taxonomy USDA, 1992. 30 different soil scapes belonging to 4 orders, 7 suborders, 11 great groups, 19 sub groups and 31 family types. The soils of the basin belong to the 4 main orders of Entisols, Inceptisols, Alfisols and Vertisols. These soil orders are found both independently as well as in association with other others. Inceptions is the most widely occurring soil found in association with other soils and accounts for about 93.1% of the basin area. Alfisols in association with other soils occupy about 63.84% of the basin area, Vertisols in association with other soils occupy 5.34,37> of the basin area and Entisols in association with other soils occupy about 5.52% of the basin area. The study is based on both primary and secondary data like collection and analysis of soil samples and use of satellite imagery etc.

2 illus, 1 table, 12 ref

011894   Pal S;Das J;Sengupta P;Banerjee S K (Electronics and Communication Science Unit Dep, Indian Statistical Institute, Calcutta) : Short term prediction af atmospheric temperature using neural networks. Mausam 2002, 53(4), 471-80.

A neural network based forecasting model for the maximum and the minimum temperature for the ground level is proposed. A backpropagation method of gradient-decent learing in multi-layer perceptron (MLP) type of neural network with only one hidden layer is considered. This network consists of 25 input nodes and two output nodes. The network is trained with a varying number of nodes in the hidden layer using a set of training sample and each of them is tested with a set of test sample. It accepts previous two consecutive days information (such as pressures, temperatures, relative humidities, etc.) as inputs for the estimation of the maximum and the minimum temperature as output. The network with 20 or less neurons in the hidden layer is found to be "optimim" and it produces an error within+-2° C for 80% of test cases.

13 illus, 2 tables, 7 ref

011893   Neeraj Kumar;Sharma R C (Zool Dep, Meerut Coll, Meerut-250 001) : Water quality of river Krishni 1. Physico-chemical characteristics]. J Nat Conserv 2002, 14(2), 273-97.

Water quality of river Krishni has been studied at 8 sampling points fixed at 70 kilometers stretch. The river received about 50 to 67 causec. of domestic and industrial waste water via three waste water channels containing high amount of total solids, dissolved solids, suspended solids, bio-chemical oxygen demand (BOD), chemical oxygen demand (COD), albuminoid nitrogen, ammonical nitrogen, nitrate nitrogen, sulphate, phosphate and chlorides. These waste contents of the waste water have changed the characteristics of the river water to great extent.

22 illus, 9 tables, 15 ref

011892   Nandankar P K (Regional Meteorological Centre I, , Colaba, Mumabi-400 005) : Assimilative capacity of the atmosphere at Gorakhpur with respect to air pollution. Mausam 2002, 53(4), 481-6.

Aims at seasonal and diurnal pollution potential at Gorakhpur in east Uttar Pradesh. To assess the pollution potential, meteorological data for five year period (1982-86) of Gorakhpur have been analyzed for four seasons vis; winter (December-February), summer (March-May), monsoon (June-September) and post monsoon (October-November). Season wise wind roses, stability, stability wind roses have been prepared adn season wise diurnal variation of mixing height and ventilation coefficient have also been worked out. It is fount that Gorakhpur has a better duffucsion capacity in summer and poor in post monsoon followed by winter. Afternoon hours are better for verticla mixing. The winds are predominantly from southwest to west in all seasons except in monsoon when it blows from northeast to east. Based on this study, an appropriate location for industrialization has been suggested.

4 illus, 1 tables, 20 ref

011891   Mohapatra M (Meteorological Centre, , Bhubaneswar) : Recent trends in climate of Bangalore. Mausam 2002, 53(4), 425-38.

The linear in the monthly, seasonal and annual mean maximum temperature, minimum temperature, average temperature, diurnal range of temperature, rainfall, relative humidities at 0830 7 1730 hr IST of Bangalore city and airport have been analysed based on the data for the period from 1960-95. The variation in surface wind over Bangalore during above period has also been studied to find out impact of urbanisation on weather parameters. It is found that Bangalore city is becoming warmer in terms of mean maximum & mean minimum temperatures. Rate of increase is significantly higher over Bangalore city (central observatory) that over airport during winter months. Similarly the rising trend of average temperature of Bangalore city is higher than of Bangalore airport during October to April being significantly so during winter season. Also the diurnal range of temperature of Bangalore is becoming larger in winter months with the rising trend being higher over Bangalore city than over airport. Even though rainfall does not show any significant trend, the rising trend during monsoon & falling trend during post monsoon season over Bangalore city are higher than that of Bangalore airport. Also though both Bangalore city & airport show maximum rising trend in mean relative humidity at 0830 hr IST during winter, the rate of rise is less over Bangalore city. Similarly though the relative humidity at 1730 hr IST shows decreasing trend during all the seasons, the rate of decrease is less over Bangalore city for all seasons except post monsoon season. The mean maximum, minimum and average temperature and relative humidities show cyclic variation of their monthly trend coefficients during the year.

3 illus, 7 tables, 6 ref

011890   Modawai O S;Al-Mull A H;Govind Rao P (Civil Aviation Authority, P.O.Box 3000, DOHA-State of Qatar P, , ) : Comparative study of temperatures of direct sunlight and air temperatures in a standard screen measured at Doha International airport-a pilot study. Mausam 2002, 53(4), 529-32.

An observational campaign was conducted at Doha International Airpost, Arabian Gulf to find out difference between air temperature in a standard screen and direct sunlight. Difference between screen temperature (ST) and outside temperature (OT) in respect of all hourly data in the above period from 0600 to 1800 hrs of local time have been computed and analysed. In order to examine the difference before sunrise and after sunset, observations were also made during 1900-0500 hrs of local time form 1st to 18th of July 1998. Results of the study revealed that the magnitude of the differences between OT and ST is not as high as expected. The highest difference observed was 5.1° C on 16th July 1999 at 0900hrs. As anticipated, the temperature of direct sunlight between 0600 hr and 1700 hr were always higher than the screen temperature. However, after 0500 pm of local time, the screen temperatures are found to be higher than outside temperature though the sunset time in these months are after 0600 pm. The mean difference between ST and DT in June, July and August respectively found to be 1.43° C, 1.53<144>C and 1.67°C. The highest defference observed in these months was 3.8° C, 5.1° C and 4.1° C respectively. Indicated that the difference between OT and ST is generally higher during 0900-1000 hrs of local time and lower during two hours before sunrise sunset.

1 illus, 3 tables, 2 ref

011889   Mahesha A;Mohan Babu (Dep of Applied Mechanics and Hydraulics, Karnataka Regional Engg. College, Surathkal) : Effectiveness of subsurface barrier on salt water intrusion. ISH J Hydraul Engng 2002, 8(1), 60-7.

The effect of subsurface barrier on the motion of the sea water-fresh water interface in coastal aquifers is analysed for sudden freshwater drawdown conditions. A Galerkin finite element model is used for this purpose to carry out the parametric studies of the effect of location, width and hydraulic conductivity of the barrier. The results indicated marked variations in the interface profile as compared to no barrier condition. The width and hydraulic conductivity play a decisive role in delaying the interface response for any drawdown situations. Among the various barrier locations considered, the barrier at initial length of intrusion L₀ was found to be most effective in checking the salt water intrusion.

5 illus, 2 tables, 6 ref

011888   Kulkarni M N (NO, , ) : Deformation studies using the global positioning system. Sapper 2002, 13(5), 39-46.

2 illus, 10 ref

011887   Karmakar S;Roy G B (Faculty of Agricultural Engineering, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia) : Watershed approach for sustainable development in tribal hilly area of southern Rajasthan. Indian J Landsc Syst ecol Stud 2000, 23(2), 70-2.

Soil erosion and land degradation threatens long-term ability to sustain production of food and fibre. The watershed management on sound principles of soil and water conservation in the only way to reverse this trend of land degradation. Keeping this in view, effort has been made to prepare a watershed management plan for Nayakhera Village, Udaipur District, Rajasthan, taking the economical parameters into consideration. The proposed technology comprises of Puerto Rico Terrace, Stone wall terrace, Loose stone check dam and afforestation. These measures will not only increase the crop production per unit area, but will greatly help to improve the socio-economic condition of the tribal farmers. After evaluation the benefit-cost ratio works out to be 1.27:1.

2 tables, 3 ref

011886   Kane R P (Instituto Nacional de Pesquisas Espaciais Dep, Sao Jose dos Campos, SP, Brazil) : Antarctic ozone recovery. Mausam 2002, 53(4), 487-502.

Since 1976, and more so since 1985, the Antarctic ozone level has suffered considerable depletion (termed as Antarctic ozone hole), attributed to the destructive effects of CFC compounds leaking into the atmosphere from man-made gadgets. The 12-month running means of South Pole Dobson ozone (monthly means, upto 1999 end only) were subjected to spectral analysis, which showed considerable, significant for QBO (Quasi-biennail, 2-3 year) and QTO (Quasi-triennaial, 3-4 years) oscillations, with a total range of 20-30 DU. When subtracted from the original values, a failly smooth variation was seen, with a decrease from-260 DU in 1986 to -230 DU in 1996 (-12 decrease in 12-month running means), and an almost steady level thereafter. Thus, the net ozone variation at South Pole consists of two parts, a long-term monotonically downward trend upto 1996 and a steady level thereafter and a superposed QBO-QTO oscillation. The chemical destruction effect is not likely to disappear soon, and may even increase if greenhouse effects, major volcanic eruptions or enhanced stratospheric cooling intervene. If the long-term level remains steady, an extrapolation of the QBO-QTO patterns indicates that the ozone level is due for an increase from about 1999 end to about 2001 beginning. The purpose of the analysis is to point out that, if such an increase of 20-30 DU occurs, it should not be misinterpreted as due to a decrease in chemical destruction, which scientist are eagerly awaiting due to the indication of a reduction in the halogen load in recent years due to adherence to the Montreal Protocol. After one of two years (in 2002), the extrapolated QBO-QTO oscillation may bring down the ozone level back again to the 1999 end level, and the apparent recovery may turn out to be a false signal.

6 illus, 3 tables, 48 ref

011885   Hari Krishan;Ram J;Singh B;Chadha D (NO, National Physcial Laboratory, New Delhi-110 012) : Vapour pressure calculations based on the international temperature scale (ITS-90) used in the computation of relative humidity. MAPAN 2003, 18, 35-42.

The saturatin vapour pressures at different temperatures is evaluated using Sonntag's equations in accordance with the International Temperature Scale of 1990 (ITS-90). Reports the values of saturatin vapour pressures of water, calculated by a program writtenin C⁺⁺ language in the temprature range from 0<144>C to 100°C at an inerval of 0.1<144>C, used in computation of relative humidity. This tabulation finds immense use to the researches working in the humitidy area and employing psychrometric technique for computation fo RH.

2 tables, 10 ref

011884   Hari Krishan;Ram J;Singh B;Chadha D (NO, National Physcial Laboratory, New Delhi-110 012) : Vapour pressure calculations based on the international temperature scale (ITS-90) used in the computation of relative humidity. MAPAN 2003, 18, 35-42.

The saturatin vapour pressures at different temperatures is evaluated using Sonntag's equations in accordance with the International Temperature Scale of 1990 (ITS-90). Reports the values of saturatin vapour pressures of water, calculated by a program writtenin C⁺⁺ language in the temprature range from 0° C to 100°C at an inerval of 0.1°C, used in computation of relative humidity. This tabulation finds immense use to the researches working in the humitidy area and employing psychrometric technique for computation fo RH.

2 tables, 10 ref

011883   Ghosh U (Physics Dep, Shillong College, Shillong-793 003) : Variation of V<. Mausam 2002, 53(4), 515-28.

V^pV^s, ratios for the granitic layers in Shillong Plateau and the partially overlapping Tezpur seismic area, have been calculated from Wadati diagrams drawn on the basis of seismic phase data.From Shillong plateau the average of 23 readings for some months of 1979 for V^p/V^s is found to be 1.71. For Tezpur area the average of 29 readings of V^p/V^s for 1991-92 is found to be 1.73, but for 1995-96, the average V^p/V^s from 49 reading is found to be 1.68. The overall average from 78 readings for this area is 1.70. The low V^p/V^s for 1995-97 seems to be precursory. For the granitic layer, taking V^p=5.92 kms/s and V^p/V^s=1.70. We get V^s-3.48 km/s for NE India.Values of V^p/V^s ratios and number of shocks per day are plotted against time and are shown to undergo sudden loweing before many M(F128)(147)(255)4.2 earthquakes. V^p/V^s is generally lowerd below 1.60 in such cases.In Shillong plateau the number of shocks per day for 1979 is found to be three times the number in the adjoining Tezpur area, for 1991-97.

4 illus, 2 tables, 8 ref

011882   Dimri A P;Jain V K;Dash B B (Indian Institute of Technology I, , New Delhi) : Effect of dust aerosol layer on vertical temperature profile. Mausam 2002, 53(4), 539-42.

^ssc3 illus, 1 tables, 13 ref

011881   Dhanny H (NO, , ) : Disaster management during natural calamities. Sapper 2002, 13(5), 3-24.

1 illus, 1 table,

011880   Devendra Mohan;Sharma Y (Zool Dep, Jai Narain Vyas Univ, Jodhpur-342 001) : Trace metals in a few water bodies of Pali (Rajasthan). J Nat Conserv 2002, 14(2), 363-6.

Trace metals Cu, Zn, Pb, Cd, CO, and Ni were estimated in a few fesh bodies of Pali during 1999-2000 and the results were compared with the drinking water standards of WHO. The water of Lakotia lake and Hemawas dam is used for the civil supply in which the mean concentration of Pb was found higher through out the studies while other metals were within the limits. Seasonal river Bandi receives the total industrial waste of the city in which Pb, Cd, Ni were found higher through out the study while Zn and Co were within the WHO limits. This river has also contaminated the wells of this region.

1 table, 15 ref

011879   Chaudhuri S;Chattopadhyay S (Centre for Atmospheric Sciences Dep, University of Calcutta-700 009, ) : Multi layer perceptron model in pattern recognition of surface parameter during pre monsoon thunderstorm. Mausam 2002, 53(4), 417-24.

The concept of Multi Layer Perceptron and Fuzzy logic is introduced to recognize the pattern of surface pertaining to forecast the occurrence of pre-monsoon thunderstorms over Kolkata (22° 32', 88°20'). The results reveal that surface temperature fluctuates significantly from Fuzzy Multi Layer Perceptron (FMLP) model values on thunderstorm days whereas on non-thunderstorm days FMLP model fits well with the surface temperature. The results further indicate that no definite pattern could be made available with surface dew point temperature and surface pressure that can help in forecasting the occurrence of these storms.

4 illus, 14 ref

011878   Bhunya P K;Mohapatra P K (NO, National Institute of Hydrology, Roorkee) : Computation of runoff in hypothetical microcatchment using dynamic routing. ISH J Hydraul Engng 2002, 8(1), 1-12.

The runoff in an independent hypothetical micro-catchment due to rainfall is computed using a mathematical model. One-dimensional Saint Venant equations are used as the governing equations. These equations are solved numerically by an explicit finite-difference method-McCormack Scheme. The analysis is performed for different intensitiesof rainfall, perviousness coefficients and cloud movement. The results are also compared with the hydrograph derived using discrete kernel approach for all rainfall intensities.

4 illus, 3 tables, 15 ref

011877   Balaram V (NO, National Geophysical Research Institute, Hyderabad-500 007) : Quality Management in Geochemical Analyses. MAPAN 2003, 18, 1-6.

Presents scientific and technological challenges,both in basic and applied earth science studies rely heavilyon the fundamental support lent by the science of measurement in general and analytical geochemistry in particular. For a thorough exploitation of this discipline, both external checks such as, use of certified references materials, proficiency tests and accreditation, and internal checks such as, use of blanks, duplicates, recovery tests, control samples and control chards are a prerequisite inaddition to the utilization of state-of-the-art analytical and sample preparation techniques. Describes the usefulness of such inernational proficiency test trials, collaborative studies and accreditation processes in general in obtaining highly precise and accurate geochemical date.

2 tables, 4 ref

010686   Wen Su;Zengqiu Zhong;Bolin Cong;Weiping Wu; Yonghong Shi (NO, , ) : Geochemical variations of jadeite-quartzite in the dabie mountains, Eastern China, during retrograde metamporphism. J Geol Soc India 2003, 61(5), 588-94.

Petrographical and geochemical studies show that during retrograde metamorphism there are major. trace and rare earth element geochemical variations of the jadeite-quartzite form the Chanpu district of Dabie Mountains, EasternChina. The elements such as SiO₂, FeO, Ba, Zr, Ga, La, Ce, Pr, Nd Sm and Eu increase gradully from the jadeite-quartzite to retrograded jadeite-quartzite and to gneiss, whilst TiO₂, Na₂, O, Fe₂, O3, Rb, Y, Nb, Gd, Tb, Dy, Ho, Er, Tm, Yb decrease gradually. Such changes are not only controlled by element transfer within mineral phase, but are also closely related to the fluid-rock interaction during the decompressive retrograde metamorphic processes.

6 illus, 2 tables, 20 ref

010685   Wanju B;Liangqian G;Guiying D;Xiwei X;Shao'an S (NO, First Crustal Deformation Monitoring Center, CSB, Tianjin, 300180, China) : A seismogenic pattern akin to `Dam Bursting'. J Geol Soc India 2003, 61(5), 549-56.

A new hypothesis of seismogenic pattern has been proposed based on the data obtained from gravity surveys, cross-fault mobile measurements, large-area levelling, GPS measurements, field investigations of great earthquakes and characteristics of seismic phenomena in the continent of China. It is considered that this is one of the main patterns that play a vital role in earthquake generation.

6 illus, 16 ref

010684   Vishwakarma R K;Bristow J W (NO, Investigation Div.,NMDC Ltd,, Masab Tank, Castle Hills, Hyderabad-500 028) : Exploration of diamondiferous kimberlite:consideration from geology and mineral chemistry. Indian J Geochem 2002, 17, 151-62.

Exploration is key to the long-term success and development of mining companies. Be it through brown-field concept or green-field concept, large mining companies have to operate exploration for prioritized mineral commodities in large number of areas by proper thorough going preliminary investigations. Kimberlite-related exploration for diamonds, commonmly known as the king of gems, can provide excellent financial rewards for companies. Systematic field exploration comprising sampling, geophysical programme, HIM recovery and analysis, microprobing and mineral interpretation are all established tools in undertaking cost effective diamond exploration. Particularly the regional scale heavy indicator mineral (HIM) analysis in conjunction with aerial photo-interpretation could be considered as a good start of exploration venture. Added to this, petrographic and chemical parameters are effectively used as guideline in assessing the economic viability of kimberlite. While comprehending the'high interest kimberlite' there has to be appreciable proportion of HIM, and at the same time, the chemistry of any particular HIM must have back up of other supporting indicator mineral(s) as well.

5 illus, 1 tables, 12 ref

010683   Verma S P (NO, Centro de Investigacion en Energia, UNAM, Priv. Xochicalco S/No.,Apartado Postal 34, Temixco, Mor. 62580, Mexico) : Geochemical and sr-nd isotopic evidence for a rift -related origin of magmas in tizayuca volcanic field, central mexican volcanic belt. J Geol Soc India 2003, 61(3), 257-76.

New geochemical and Sr and Nd isotope data are presented on six selected rock samples of hy-normative late Quaternary basalt, basaltic trachyandesite, basaltic andesite, andesite, and dacite from Tizayuca Volcanic Field (TVF), located in the state of Hidalgo, Maxico, at the central part of the Mexican Volcanic Belt (MVB). This province (MVB) is a modern volcanic zone (Miocene to Recent), which inspite of ongoing subduction, presents widespread magmas whose origin is showed to be unrelated to subduction. The initial isotopic ratios of the sampled rocks, practically identical to their measured ratios, range a sfollows: ⁸⁷Sr/⁸⁶Sr 0.70390-0.70540and ¹⁴³Nd/¹⁴⁴Nd 0.512598-0.512907. There is a general increase in ⁸⁷Sr/⁸⁶Sr and a decrease in ¹⁴³Nd/¹⁴⁴Nd with increasing SiO₂ and decreasing MgO contents. The combined geochemical and isotopic evidence supports the generation of these magmas from the mantle or even in lower crust, and subsequent modification through crustal assimilation processess. In spite of ongoing subduction of the Cocos plate, the TVF seems to owe its origin to rift-related processes as is the case of many other areas of the central and eastern MVB. A broader implication of the isotopic data from the MVB is that the basic assumption of geochronology of the same initial isotopic ratio seems to fall apart because none of the so far studied areas of the MVB shows a uniform Sr or Nd isotopic ratio. Indeed, the ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd ratios vary according to the rock-type for rocks of practically zero age.

11 Illus, 5 Tables, 75 Ref

010682   Thussu J L (Geological Survey Of India, , Central Region, Nagpur) : Impact of Environmental Hazards on Various Landforms in Haryana. J Indian Ass Envir Mgmt 2000, 27(2), 67-75.

Haryana State is located on vast stretches of Quaternary Alluvial Plains between the rocks of Delhi Supergroup in the south and west and Siwalik in the northeast. Based on geological, geomorphological and geochemical studies, it has been possible to conclude that the potential environmental hazards distinctly differ in each landform. The natural hazards, viz salinity, salt efflorescence, sand remobilization, badland and water-logging mainly affect the Central Alluvial Plains, while anthroprogenic hazards, viz mining, quarrying and waste disposal affect all the geomorphic landforms. Effective management controls have been suggested to mitigate the natural hazards and proper planning measures to control biotic hazards.

3 Illus, 19 Ref, 1 Table

010681   Suresh Chander;Sisodia C P (NO, , Geological Survey of India, AMSE Wing (Western Zone), GSI Complex, 15-16, Jhalana Dungri, Jaipur-302004) : Gold mineralisation in the palaeoproterozoic rocks of sanjela-manpur-dugocha belt, salumbar area Udaipur district, Rajasthan. J Geol Soc India 2003, 61(4), 463-70.

Ground re-evaluation of airborne electromagnetic and magnetic anomaly zones associated with geological and geochemical studies has brought to light the presence of two significant zones of gold mineralistion at Baratalav-Dugocha and Manpur-Lohagarh in Sanjela-Manpur-Dugocha belt of Salumbar area, Udaipur district, Rajasthan. The area exposes a Palaeoproterozoic carbonate dominated volcano-sedimentary sequence including quartzite, dolomite and meta-exhalite of the Debari Group forming a part of the Aravalli Supergroup. This sequence shows polyphase deformation and greenschist facies metamorphism and shows presence of shear zones trending in northwest-southeast direction in conformity with the general foliation trend of the rocks in the area. The shear zones are characterized by silicifiaction, brecciation, and hydrothermal alteration.Auriferous sulphide mineralisation occurs in the Jagpura Formation of the Debari Group in the Sanjela-Manpur-Dugocha belt. The Baratalav-Dugocha mineralised zone characterized by occurrence of gossan and presence of ancient workings is confined to a shear zone. Bedrock samples from a thick band of meta-exhalite within the dolomite horizen occurring northwest of Dugocha have analysed 1 to 4ppm of gold. The gold values in dolomite range between 0.10 ppm and 2.70 ppm in Baratalav and between 0.15 ppm and 8.52 ppm in Dugocha area. The Manpur-Lohagarh mineralised zone, characterised by linear ancient workings and gossans, also occurs in the proximity of a shear zone. Richer concentration of gold mineralisation can be expected along shear zones that are believed to have offered easy passage for gold-sulphide mineralising fluids.

5 Illus, 1 Tables, 7 Ref

010680   Sukhija B S;Nagabhushnam P;Reddy D V (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007) : Use of stable isotopes in groundwater hydrology. Indian J Geochem 2002, 17, 89-119.

Groundwater, through a very small fraction of total water resources is a vital resource for human consumption, agriculture, industries etc. In order to have sustainable development of this resource, there is great need for understanding the groundwater system in different geologic, hydrologic climatic conditions as well as because of human interventions. The use of environmental stable and radioactive isotopes in groundwater is now a well established field which has been nurtured by physicists, chemist, geologists since last three to four decades. The isotope techniques have been particularly useful in qualitatively and quantitatively delineating the origin, source area of aquifers, the interconnection between acquifers, their linkage to surface water, hydrodynamic changes, source and dynamics of polluted water, paleorecharge in different climatic conditions and geothermal problems and even in mine hydrology studies. Describes the principles involved in the use of stable isotopes in groundwater hydrology and further demonstrates important applications by reviewing the stable isotope application in groundwater hydrology in the Indian context.

19 illus, 2 tables, 31 ref

010679   Srivastava R K (Geology Dep, Banaras Hindu University, Varanasi-221 005) : Carbon and oxygen isotope systematics in the igneous rocks: with special reference to Indian carbonatites. Indian J Geochem 2002, 17, 77-88.

Stables isotopes are important constituents of magmatic fluids, hence used to identify nature of fluids and fluid-rock interaction. In nature these isotopes are governed by the different fractionation processes, particularly isotopic exchange reactions, kinetic processes, and physio-chemical processes. Stable isotope, particularly carbon and oxygen, studies have widely been appliedto the problem of the origin of carbonatites. In magmatic carbonatites <100¹³C values range between -1 to -9 % and δ¹⁸O range between +5 and +12 %. δ¹³C concentration in carbonatites could reflect several parameters such as CO₂/H₂O ratio, C-bearing species in fluid, such as H₂CO₃ or HCO^3-, stc., and degrre of Equilibrium or Rayleigh fractionation. Similarly,there are magamtic or non-magmatic processes that can affect the concentration of δ¹⁸O. These process affect much on δ¹⁸O concentrations but has little effect on the δ¹³C values. Carbon and Oxygen isotopic concentrations in carbonatites from the Ambadungar, Samalpatti, and Sung Valley igneous complexes have been reviewed in the light of these different processes and possible resons for isotopic variation have been suggested. Enrichment of δ¹⁸O in the Ambadungar carbonatites is probably due to the influence of low-temperature hydrothermal solution. Rayleigh fractionation model together with exchange with high temperature magmatic fluids of high δ¹⁸O-content and hot fluid hydrothermal alteration are responsible for enrichment of stable isotopes in the Samalpatti carbonatites. δ¹³C and δ¹⁸O values in carboatite samles of the Sung VAlley complex are primary and do not show any isotopic fractionation, probably crystallized under plutonic conditions and reflect mantle (source) composition.

6 illus, 30 ref

010678   Somashekar R K;anand R;Garg B A K (Environmental Science Dep, Bangalore University, Jnana Bharathi, Bangalore-560 056) : Ground water potential and fluoride levels in the waters of Hosadurga taluk, Karnataka, India. Nat Envir Pollut Technol 2003, 2(1), 25-33.

Two hundred and nine ground water samples from the most preferred drinking water sources were collected from 32 Grampanchayats of Hosdurga Taluk, Chitradurga district in Karnataka and were analyzed for fluories, electrical conductivity and total hardness. The yield data, collected from the Zilla Panchayat office, Chjitradurga, revealed low yielding pattern in the study are. 34.76 percent of samples were found to contain excessive fluoride (<62>1.5 mg.L), 35.71 percent excessive EC (<62>3000) MF128><109>S/cm) and 9.81 per cent excessive total hardness (<62>600 mg/L as CaCO₃). the occurrence of fluorosis was common in children and adolescents, and cases of skeletal fluorosis were observed in the old age group. Based on the fluoride levels, 43.54 per cent of villages are rendered as safe, 22 per cent as fluoride deficit, 29.17 per cent slightly problematic and 5.25 per cent highly problematic. the distribution of fluoride is concentrated in the central portion of the taluk where the bedrock is gneiss and granite. Despite excessive fluorides in the low yielding areas (<62> 100 lph), appreceiable number of villages with yield between 4000 and 8000 lph also showed excessive fluorides. The taluk can be placed under medium problem category with a yield ranking of 2.96.

3 illus, 3 tables, 13 ref

010677   Sohoni P S;Karanth R V (Geology Dep, , Faculty of Science, M.S. University of Baroda) : Morphologic anatomy of normal faults in central kachchh mainland, Kachchh, Western India. J Geol Soc India 2003, 61(5), 513-28.

Kachchh region of western India has been a site for successive deformational events since the advent of Mesozoic leading to a considerable amount of structural deformation of the rocks. Faulting forms as one of the most conspicuous groups of structures that developed in Central Kachchh Mainland(CKM). Normal faults in particular are very well exposed throughout the region. These provides an avenue to study the geometry and morphology both in dip section and plan. Revolves around the geometru and morphology of normal faults exposed in late Cretaceous Bhuj Formation constituting an intercalating sequence of sandtones and shales. The observed morphology of faulting is quite varied; the most interesting being overstepsand bends. Both the extensional as well as the contractional offset of the faults have been observed and are analysed in detail. Several morphologic attributes recorded, include the pull-apart structures, fault refraction in the dip section, segmented fault scarps and conjugate faults. This note in general is aimed at documenting a variety of normal fault geometry occuring in Central Kachchh mainland and thereby focus on the fact that the zones of oversteps and bends are vulnerable to renewed faulting activity and may serve as potential sites for the earthquake foci in the future. Looking at the extent and type of deformation, it is envisaged that there must be several zones of oversteps and bends existing in Central Kachchh Mainland. A careful and proper documentation of such weak zones may go a long way to help proper urban planning and to evaluate perceptible seismic hazard in the area.

14 illus, 30 ref

010676   Singh P M;Singh K P;Singh K A (Geology Dep, Banaras Hindu University, Varanasi-221 005) : Petorgraphy and depositional environment of the permian coal deposite of Deoghar basin, Bihar. J Geol Soc India 2003, 61(4), 419-38.

An attempt has been made to carry out the petrographic characterzation of coals from the Deoghar basin and to reconstruct the palaeoenvironmental conditions of coal formation using macerals and microlithotypes as tools. For thils purpose, a large number of piller coal samples from the Karharbari and Barakar seams were collected and were subjected to detailed petrographic examination. The results indicate that the Karharbari coals are rich in inertinite whilethe Barakar coals are comparatively rich in vitrinite. The rank of Deoghar coals (as per ASTM system), on the basis of the mean of random vitrilnite reflectance, has been found to range between Sub-Bituminous 'B' and High Volatile 'C' Bituminous. The quantitative relationships of macerals, microlithotypes and mineral matter show that these coals have originated from the transitional plant communities in open to forest moor and under limmo-telmatic to limnic conditions. Moreover, the Karharbari coals have evolved under oxic moor conditions with sudden high flooding while the Barakar coals have evolved under comparatively wet moor conditions wiht intermittent moderate to high flooding. Low values of TPI and GI indicate periodic dryness in the basin.

8 illus, 7 tables, 22 ref

010675   Singh K P (NO, National Geophysical Research Institute, Uppal Road Hyderabad-500 007) : New approach for detection of hidden aquifer using DC resistivity data transforms. J Geol Soc India 2003, 61(5), 540-8.

Direct current resistivity is most commonly used as a potential toolin fining new resources of groundwater. This task is achieved by conducting Schlumberger and Wenner resistivity soundings. Usually, no signatures of the presence of a conducting layer/aquifer sandwiched between two resistive layers in the hard rock regions are observed in apparent resistivity curves. In such a difficult situation, detection of hidden aquifer employing one dimensional conventional approach of interpretation becomes a tedious job. A new non-conventional method based on apparent resistivity data transforms is attempted to overcome these difficulties. Assuming as many layers as the number of observations, and apparent resistivities as true resistivities, ratio of transverse resistance of the layer to total transverse resistance of all overlying layers(QOT) and ratio of longitudinal conductance of the layer to total longitudinal conductance of overlying layers (QLC) are computed. The plots of QLC and QOT against half current electrode spacing on bilogarithmic grap show sharp contrast at interfacesof layers. As a result, useful information about thickness of layers is extracted from these curves for inversion of observed data. The efficiency of this approach is tested on synthetic data and finally it is applied on field data to delineate hidden aquifer and to enhance the resolution of model parameters in interpretation. This approach is found very useful to identify the hidden aquifer when no a priori information is avilable.

3 illus, 3 tables, 13 ref

010674   Sharma D D (NO, Reliance Industries Limited, Naroda Industrial Estate, Ahmedabad-382 330) : Review of coal resources in India and their exploitaition strategy. J Geol Soc India 2003, 61(4), 387-402.

The Gondwana coal reserves of 213 bt, are the reserves of Teritiary coals re-estimated at about 254 bt down to the depth of 1500 m. Gondwana coals of 213 bt have been futher sub-divided into shallow (mineable)of 149 bt and deeper (unmineable) of 64bt. The Tertiary coals of 254 by have also been further sub-divided into shallow (mineable) of 12 bt and deeper of 64 (unmineable) of 242 bt. Out of the 242 bt deeper (unmineable) Tertiary coals, 123 bt occur in Gujarat, 100 bt in Rajasthan and 19 bt in Tamilnadu. Out of 467 bt of reserves, 66% are deeper (unmineable), which need to be tapped by alternate means. Three pronged strategy for their exploration and exploitation is suggested. Mining; of shallow coals/lignites occurring at the depth of less than 300 m for power generation and idustrial uses. Underground Coal Gasification (UCG); of low rank coals (lignite to sub-bituminous) occurring at moderate unmineable depths of 300-600m, where seems are relatively thicker (<62>3m), persistent with competent overburden strata and without much aquifer inteference, and Coalbed Methane (CBM) Extraction; from deeper (600-1500m) unmineable coals of sub-bituminous to bituminous rank.

^iia7 illus, 6 tables, 8 ref

010673   Seneviratne G;Sompala K L A (NO, Inst of Fundamental Studies, Hantana Road, Kandy, Sri Lanka) : Litter controls on soil nitrous oxide emission. Curr Sci 2003, 84(4), 498-9.

1 illus, 1 table, 8 ref

010672   Sen S (NO, , Plot no. 10, Puranik Layout, Bharat Nagar, Nagpur-440 001) : The nature of earth's inner core-what the meteorites tend to tell us. J Geol Soc India 2003, 61(3), 364.

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010671   Selvaraj K;Ram Mohan V (Geology Dep, School of Earth and Atmospheric Sciences, University of Madras, A.C.College Campus, Chennai-600 025) : Textural variation and depositional environments of innershelf sediments, off Kalpakkam, Southeast coast of India. J Geol Soc India 2003, 61(4), 449-62.

Surface sediment samples collected from 42 locations up to a water depth of 53 m during pre-NE monsoon (September, 1995) and post-NE monsoon (April, 1996) seasons in the innershelf region, off Kalpakkam, were analysed for textural parameters, calcium carbonate and organic matter. Grain size distribution shows that the innershelf is carpeted with a mosaic of sand and silty sand with minor amounts of clay (0-4%). The analysed sediments are characteristically very poorly and poorly sorted, and dominantly positively skewed with very leptokurtic and very platykurtic nature. The occurrence of relict sediments in the form of coarse sand deposit around 19th km from the present shoreline has been identified as a palaeoshoreline. Bivariate plots of grain size parameters reveal that the sedimentary depositional environment is influenced dominantly by river/dune/beach conditions. A linear patch of coars sand with higher concentration of CaCo₃ (<62>15%) and very low organic matter (<60>0.4%) at a depth around 50-53 m confirms the existence of the palaeoshoreline, formed probably during Holocene low sea level. SEM photomicrographs also support the occurrence of energy enviroment related to shoreline.

10 illus, tables, 58 ref

010670   Schweig E;Gomberg J;Petersen M;Ellis M;Boding P;Mayrose L;Rastogi B.K. (NO, U.S. Geological Survey, Memphis, TN-38152, USA) : The mw 7.7 Bhuj earthquake: Global lessons for earthquake hazard in intra-plate regions. J Geol Soc India 2003, 61(3), 277-82.

The Mw 7.7 Bhuj earthquake occurred in the Kachchh District of the State of Gujrat, India on 26 January 2001, and was one of the most damaging intraplate earthquake ever recorded. This earthquake is in many ways similar to the three great New Madrid earthquakes that occured in the Central United States in 1811-1812. An Indo-US team ia studying the similarities and differences of these sequences in order to learn lessons of earthquake hazard in intraplate regions. Some preliminary conclusion from the study are presented. Both the Kutch and New Madrid regions have rift type geotectonic setting. In both regions the strain rates are of the order of 10^-9/yr and attenuation of seismic waves are inferred from observations of intensity and liquefaction are low. These strain rates predict recurrence intervals for Bhuj or New Madrid sized earthquakes of several thousand years or more. In contrast, intervals estimated from paleoseismic studies and from other independent data are signoificantly shorter, probably hundreds of years. All these observations together may suggest that earthquakes relax high ambient stresses that are locally concentrated by rheologic heterogeneites, rather than loading by plate-tectonic forces. The latter model generally underlies basic assumptions made in earthquake hazard assessment, that the long-term average rate of energy released by earthquakes is determined by the tectonic rate, which thus implies an inherent average periodicity of earthquake occurrence. Interpreting the observetions in terms of the former model therfore may require re-examining the basic assumptions of hazard assessment.

1 illus, 31 ref

010669   Satish Kumar M;Santosh M (Biology and Geoscience Dep, Faculty of Science, Shizuoka University, Ohya, Shizuoka-422 8529 Japan) : Carbon isotope geochemistryof the precambrian continental crust in Southern India. Indian J Geochem 2002, 17, 57-76.

The Precambrian terrain of southern India offers an ideal section of continental crust for studies relating to the early Earth's geochmical evolution. This terrain shows a large spread in age, diversity in rock types, has unique geochemical features and multiple tectonothermal history. Summarizes the different modes of occurrence of carbon and its geochemical cycle in the Archaean to Proterozoic metamorphic terrains of southern India. For our discussion, evaluates data generated using state of the art tool of microscale carbon isotope analyses in differentiating the varied forms of carbon in the lower continental crust and its evolution through time. A decade of research on the stable isotopes of carbon in southern Indian Precambrian rocks has hielded valuable information not only on crustal carbon but also on carbon input from the mantle. Research has revealed the role of mantle carbon in modifying the carbon budget of deep crustal rocks. Evidence for this was imaged from the carbon isotope studies of fluid inclusions in minerals and from the investigations of fluid precipitated graphite. The evolution of crustal carbon through time is recorded in the biogenic carbon isotope signatures on graphite preserved in high-grade supracrustal rocks of the Early Proterozoic. Fluids transport material and ha, and also exert significant control on deformation. Carbon and oxygen isotope studies of fluid-altered metamorphic rocks unravel the fluid-rocks history of the continental crust. Another significant application of carbon isotope studies is to elucidate the metamorphic conditions of the crustal rocks, by the application of carbon isotope exchange between calcite and graphite. Evidence for ultrahigh tempreature metamorphism was reported from marbles of isotope of southern India based on carbon isotope thermometry. Demonstrates that in addition to the clues that carbon isotopes studies provide in environmental and paleoclimatic studies in the Holocene, they also significantly aid in understanding the Earth's early evolutionary history.

4 Illus, 48 Ref

010668   Saraswati P K (Earth Science Dep, IIT, Bombay, Powai, Mumbai-400 076) : Oxygen and carbon isotopic studies of calcareous microfossils. Indian J Geochem 2002, 17, 47-56.

The oxygen and carbon isotopic composition of the skeletal carbonates of microfossils provide important data for palaeoclimatic and palaeobiologic interpretation. The variation in isotopic composition is influenced by climate and global sea-level change and as a result the isotopic signals are of significance in global stratigraphic correlation. Reviews the application of stable isotopic date of calcareous microfossils in reconstructing the ancient climate, in correlation of strata and in understanding the palaeoecology and palaeobiology of calcareous microfossils.

4 illus, 23 ref

010667   Santosh Kumar (Geology Dep, Kumanun University, Nainital-263 002) : Pearce Element Ratios Applied to Model Basic Rock Members of Phenai Mata Igneous Complex, Baroda District, Gujarat. J Geol Soc India 2003, 61(5), 565-72.

Pearce element ratio (PER) diagrams were constructed for tholeiitic gabroo, alkali gabroo, dolerite and tholeiitic basalt of Phenai Mata igneous complex (PMIC) identifying potassium as a conserved element particularly during the course of basic magma(s) differentiation series. The observed variations among the tholeiitic basalts, dolerites, tholeiitic and gabroos of PMIC on PER diagrams appear to be commonly controlled by the fractional crystallization of plagioclase, clinopyroxene and olivine in variable proportion. Tholeiitic basalts and tholeiitic gabroos of PMIC could be derived from the same parental magma but proportion of crystallizing phases and even assemblages differ as reflected by their different slopes on PER diagrams. The different intercepts with a common slope for tholeiitic gabroos and dolerites however strongly suggest their similarly involved differentiation mechanism but different parentage probably formed by slight contamination of episodic tholeiitic magma by an alkaline one, which subsequentlty experienced the same differentiation mechanism.

3 illus, 1 table, 27 ref

010666   Sajeev R;Subramanian V (School of Environmental Science, Jawaharlal Nehru University, New Delhi-110 067) : Land use/land cover changes in Ashtamudi Wetland Region of Kerala-a study using remote sensing and GIS. J Geol Soc India 2003, 61(5), 573-80.

Ashtamudi estuary, the second lartest wetland ecosystem of Kerala is the deepest among all the estuaries of Kerala. This wetland is under severs environmental stress due to large-scale land use / land cover conversions that occurred in and around it for the past several decades. Ashtamudi is one of the 21 notified wetlands of paramount importance in India needing special conservation measures. Land use/land cover conversions in Ashtamudi wetland region from 1967 to 1997 is quantified using the technique of Remote Sensing and Geographic Information System (GIS). Survey of India topographic map, hard copies of IRS-1A LISS-IC LISS III images are used. Shows that increasing population density, change in family system, extensive coconut husk retting and deposition of husk waste along the margin of the estuary, solid waste deposition form factories, reclamation of the estuary by local population and low profit obtained from paddy cultivation are mainly responsible for the large-scale land use/land cover conversions in the wetland region. The study tries to correlate unscientific land use/land cover conversions in the wetland region with its environmental degradation.

5 illus, 2 tables, 9 ref

010665   Rao A T;Venkata Rao M;Srinivasa Rao K;Deva Verma D;Dhananjaya Rao E N (Geology Dep, Andhra University, Visakapatnam-530 003) : Geochemistry and sedimentation of carbonate rocks from the Umpavalli area, eastern ghats granulite belt, India: Implications for genesis of high - grade terrains.. Indian J Geochem 2002, 17, 121-42.

The Umpavalli carbonate rocks show deviation of chemical composition such as Mg/Ca ratios in many cases, depletion of Fe, Mn, Cr, Ni and Co and enrichment in Zr, and <6>87Sr/⁸⁶Sr isotopic ratio than that of most sedimentary carbonates from greenstone belts. The Sr isotopic composition in the carbonates is distinctly higher than those of contemporary mantle and seawater, which can be attributed to the dominant buffering of the water in the basin by continental flux via rivers. However, sedimentary carbonates from greenstone belts were generally mantle flux buffered. We envisage that the high-grade terrain of Umpavaliarea and the Eastern chats Granulite Belt as a whole formed in a continental marginal setting which is different from back-arc(or rift-type) setting of greenstone belts.

3 illus, 4 tables, 46 ref

010664   Ramakrishna T L (45, 5th Cross, II Floor Malleswaram, Banglore-560 003, , ) : Standardisation of the nomenclature of commercial dimension stones. J Geol Soc India 2003, 61(3), 365-6.

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