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Earth Science India Volume-3(II), 2010

D. Muralidharan, Rolland Andrade, R. Rangarajan and U. Sathyanarayana

                Emergence of springs at surface or in shallow pits reported from discrete locations during the month of January 2005 in the southern Indian peninsular shield area had been an interesting post geo-hydrological phenomenon to investigate. Such freak incidences at places in the interior parts of a continental shield area were reported for the first time. Its connectivity with the 2004 mega thrust great (Mw 9.3) Sumatra earthquake and its multiple aftershocks are studied and analyzed. Resistivity 2D imaging and its hydrogeological modulations revealed perched aquifer conditions at shallow depth (<10 m). There is no geological or geophysical evidence of structurally controlled upward rise of deep groundwater in the area. Electrical conductivity of the emergent spring water and that of deeper (depth >50 m) groundwater support that the spring water is originated due to local effect by the 2004 mega thrust earthquake. The emergence of spring is attributed to ground movement and squeezing of pores in the saturated zone at shallow depth due the mega thrust Sumatra earthquake.

J. A. Olowofela1, O. D. Akinyemi1, R. Bello1 and A. A. Alabi

                The use of thermography for land mine detection has become a topic of great interest in recent years. The thermal properties and burial depth of the buried object also play a role in the thermal signature at the surface. The objective of this contribution is to determine the effect of burial depth on thermal signature of buried metallic object. The object used in this work is steel material buried at depth ranging from 1cm to 50cm. The two buried objects used in this work are steel of 12cm x 12cm surface area with thicknesses of 0.5cm and 3cm respectively. The soil where the objects were buried is mainly sandy. Soil above the buried objects and below it is assumed to be the same type of soil. This work was carried out in Abeokuta, Ogun State, Nigeria. There was a remarkable phase shift which increased with burial depth. A change in burial depth from 1cm to 10cm caused the maximum positive peak to shift from 46.50C to 38.00C and a change in burial depth from 40cm to 50cm, caused the maximum peak to shift from 30.00C to 29.00C. The burial depth of the buried objects has effect on the amplitude of the temperature at the surface and thus its thermal signature. It was also observed that the thickness of the buried objects has a significant effect on its thermal signature.

G. Vallinayagam and Naresh Kumar

              Occurrence of rhyolite with spheroidal structure is being reported first time in the Neoproterozoic Malani Igneous Suite (MIS) of Northwestern Peninsular India. MIS consists predominantly of felsic volcanic rocks, felsic plutonic rocks and minor amount of mafic rocks. A spheroidal rhyolite that is shaped like a sphere but is not perfectly round, especially an ellipsoid that is generated by concentric shells of different colours with different compositions revolving around one of its axes. The spheroidal rhyolite is exposed in an area of 200 sq.m. radius in the Nakora area. It is pale yellow to light brown colour, fine grained and consists essentially of quartz, alkali feldspar with accessories of altered ferromagnesian (arfvedsonite) and iron oxides (hematite and magnetite). Spheroidal structure is up to 5 m dimension and shows large number (up to 70) of concentric shells in a few cm thickness surrounding a nuclei. Nakora rhyolites display different hues viz. dark brown, light pink and pink but dark brown rhyolite is associated with pink colour spheroidal rhyolite where their contact is sharp. Geological setting and the petromineralogical characters of spheroidal rhyolite suggest that at early magmatic processes, the supersaturated liquid crystallized rapidly into relatively differential density silicate liquid phases and growth of crystals lead the formation of spheroidal structure in the studied rhyolite.

N.K. Samaila and G.P. Singh

              Present paper entails the study carried out on the fluvial Cretaceous Upper Bima Sandstone of the Upper Benue Trough. Compositional and textural changes due to diagenesis have altered the reservoir properties of the formation. Modal analyses reveal that these sandstones comprise of 71.21% quartz, 18.66% feldspars and 10.05% rock fragments. The average compactional porosity loss (COPL), cementational porosity loss (CEPL), and compaction index (ICOMPACT) in the Upper Bima Sandstone have been computed as 13.77%, 3.05% and 0.82 respectively. The sum of these values subtracted from the original porosity indicates that the initial porosity of the formation has been reduced to 18.18%. A cross plot of COPL versus CEPL shows that compaction is responsible for reducing the initial porosity of the sediments.

K. Bheemalingeswara

             Fifteen bulk stream sediment samples (minus 0.59mm size) from an area known for gold mineralization in Ramagiri Gold Fields, India are tested for gold. In addition, different size fractions (-0.590 + 0.259; -0.259 + 0.177 and -0.177) of the stream sediment are also analysed for gold. The data when compared suggests that the bulk samples data not only tally well with the previous stream sediment survey data but also provide additional anomalies for gold. The method suggested in this paper is bulk leach extractable gold (BLEG) using hot aqua regia and methyl isobutyl ketone solvents (MIBK-AR). The bulk leach extractable gold data of the new method seems do not suffer from iron oxide coatings, nugget effects, invisible gold etc. as compared to the data of different size fractions (coarse/ fine size fractions) of stream sediment sample. Hence it provides near total values for gold present in the sample. The proposed method differs from the widely used BLEG in terms of hot aqua regia treatment in place of cold cyanide solution. The procedure suggested in this paper is simple to use and it provides an alternative to the commonly used coarse/finer fractions or BLEG (using cyanide) methods in stream sediment surveys for Au particularly in areas where oxide/hydroxide coatings are conspicuous.

Devendraa Siingh, Sanjay Kumar and A. K. Singh

           The study of the thunderstorms has advanced rapidly during the past century and lots of efforts have been made towards the understanding of lightning, thunderstorms and their associated optical phenomena such as sprites, elves, blue get etc. Even though, thunderstorms and lightning are well understood, but our knowledge on sprites and associated phenomena, is limited. In this paper, we review the distribution of thunderstorm/lightning and their association with optical emissions. Detailed discussions on lightning generated sprites and various natural phenomena associated with them are also included. Recent results in this emerging field are summarized.

Earth Science India Volume-3(I), 2010

Moulishree Joshi and B. S. Kotlia

           The fossil agamid lizards are reported from a Late Pleistocene locality (ca.0.74 ka in age) in the Narmada valley, central India. Although the fossil material is scanty, it is described keeping in view that, the fossil lizards are barely studied from south Asia, and secondly, this is the only report of fossil lizards from the Narmada valley. With the help of the jaw fragments and isolated teeth, the material is assigned to a new species, Agama schleichi sp.nov. The presence of lizards indicates dry/arid to semi-arid oscillations within otherwise warm/humid climatic conditions in the Narmada basin around the time of the Homo erectus, the only known Homo from India.

Soumyajit Mukherjee

          Thin-section studies of the rocks of the Zanskar Shear Zone led to document a top-to-SW ductile shearing; a top-to-NE shearing and finally a top-to-NE (down) shearing. Shape asymmetry and cleavage orientations of mineral fish reliably give the latter two shear senses. Although some of the fish reveal different phases of shearing, their specific orientations indicates simple shear. Type-1 flanking microstructures indicate the earliest top-to-SW shear. Boudins denote extension along the main foliation. Intrafolial folds demonstrate a top-to-NE shearing. A top-to-SW brittle shear is displayed by asymmetric trapezoid-shaped minerals. The brittle planes cut across rigid minerals. As in other shear zones, micas are found to be most susceptible to deformation.

Arun Kumar, M. Asif Khan and Abdul Muqtadir

         Historical Landsat Enhanced Thematic Mapper (ETM) data of the years 2000 and 2001 were used to numerically illustrate the distribution of mangroves that occur along the northern Saudi Arabian Red Sea coast from Sharm Zubair in the north to Al-Lith in the south. The distribution of mangroves is patchy and they do not occur as a continuous forest and are generally restricted to the low energy quieter environments like bays, narrow channels, and inland faces of offshore islands. However, they also occur in the intertidal environments. At certain locations they occupy very small area that could indicate depletion of mangroves. Due to rapid urbanization and industrialization of this region, traditional land use is changing and adversely impacting sustenance and growth of mangroves. There should be an inclusive policy that promotes economic development and protects mangroves also; this can be achieved as shown by Khan and Kumar (2009) on certain locations along the Arabian Gulf coast.

A.R. Bansal and V.P. Dimri

        The scaling spectral method for gravity and magnetic data is found useful for finding the depth values and statistical properties of the source distribution. The depth values calculated by scaling spectral method are close to the realistic values whereas white noise assumption of sources result in overestimations. The scaling spectral method has been applied to many parts of the world. The power spectrum corresponding to low wave number may be dominated by scaling properties alone rather than the depth values. The scaling distribution is useful for gridding the datasets,  delineating the lithological units and enhancing the information of sources. The long non-stationary profiles and larger areas may be divided into piecewise stationary profiles before applying the scaling spectral method. The values of scaling exponents from the field as well source indicate 3- D distribution of susceptibility and density.

S. S. Dugam

            In this paper, the relationship between daily meridional winds (v) at 200 hPa taken from NCEP/NCAR, over the domain (15°N to 25°N and 80°E to 95°E) at east coast of India and daily rainfall during the Indian Summer Monsoon (June-September) has been studied. Analysis is carried out for fifty three (1951-2003) years of data. The twenty days composite rainfall and meridional wind for the 10 drought and 8 flood monsoon years have been analyzed. The twenty days variations of the southerlies (northerlies) meridional wind in the upper troposphere during the monsoon at east coast the of India and twenty days rainfall activity goes hand in hand in drought (flood) monsoon years. From the analysis, it is observed that during the drought (flood) years southerlies (northerlies) persist over this domain in monsoon season.

K. Brindha and L. Elango

           The quality of groundwater is under constant threat due to urbanization. The purpose of this study is to understand the seasonal and temporal variations with special reference to bromide in groundwater and to determine the reasons behind the presence of this ion in groundwater. This study area is located at a distance of about 135 km towards ESE direction from Hyderabad. The concentration of bromide in groundwater of the study area was analyzed by collecting the groundwater samples from forty six wells once every two months from March 2008 to January 2009. Groundwater level and pH were measured in the field. The concentration of the minor ion namely bromide was determined by analyzing the groundwater samples in the laboratory using ion chromatograph. The bromide concentration ­ranged from below detection limit to 5.5 mg/l. The permissible limit for bromide in drinking water according to Indian standards specification is not mentioned. However, literature based on toxicity data puts forth 1 mg/l as the maximum admissible level of bromide. In this study, only a few groundwater samples had concentration of bromide above this limit. It is evident from this study that the groundwater quality is good with respect to bromide in this region. By the proper use of fertilizers and pesticides for agriculture, the groundwater quality can further be maintained in its current form or can be improved.

            The use of HVDC (High Voltage Direct Current) technology for transmission of bulk electrical power over long distances is more economical as compared to transmission in AC mode as the transmission losses in HVDC system are significantly lower. Besides, HVDC transmission has other advantages such as controllability, improved power system stability, and power modulation control. HVDC systems are designed to operate in bipolar mode, monopolar metallic return and monopolar ground return modes. A HVDC system requires specially designed earth electrode stations associated with the converter terminals of the HVDC transmission system. The earth electrodes provide an earth return circuit, facilitating the flow of current into the ground at the electrode stations. The design parameters of earth electrodes require consideration of the electrical conductivity structure of the subsurface in and around ground electrode sites. For a proper design, it is important to ensure that the site selected for the ground electrode has low near-surface resistivity. It is also necessary to ensure that the ground currents penetrate deep into the earth so that the grounding resistance/ potential rises in the vicinity of the electrode are within acceptable limits ensuring that the ground currents do not cause corrosion of buried pipelines and do not enter the neutrals of transformers installed in the close vicinity of the electrode station. Investigations using artificial source methods such as deep resistivity sounding pose logistic problems for these target depths. Magnetotelluric method is a very useful tool especially for the delineation of the electrical conductivity of the deep structure (up to 10 km depth) around the earth electrode site. We have carried out detailed investigations of some potential HVDC ground electrode sites employing magnetotelluric method to assess the suitability of these sites for the construction of Earth Electrode stations for India’s first ±800 kV, 6000MW HVDC multi-terminal transmission systems. MT method has been found to be a very useful tool for this purpose.

          Although seventy percent of the Moon surface area is covered by meteoritic impact structures only 176 confirmed impact structures known on Earth hitherto. In India, the recently discovered Dhala impact structure, M.P. and the Lonar crater, Maharastra are the only two confirmed impact structures. The simple, complex and multi-ring impact structures are confirmed on the basis of mesoscopic and microscopic shock metamorphic features besides the physical and/or chemical signature(s) of the impactor (meteorite). The role of bolide impacts in the formation of mineral deposits and playing a crucial role in some of the major mass extinction events is also well known. The impact cratering process is considered responsible for the planetary evolution, landscape modification, and the presence of water and life on Earth.

Earth Science India Volume-2(III), 2009

         Gravity and magnetic surveys were conducted in an area about 5000 km² covering offshore region of the Qamar basin in the eastern part of Yemen. An attempt is made to address the gravity and magnetic signatures in term of structural features. In addition, seismic section (NIM-QAM-92-201) compiled by Nimir services limited, 1992 were used to illustrate subsurface structures in sedimentary sequences. Combined gravity and magnetic modeling along section QAM-92-201 by Geomodel 2.5D inversion technique suggest the thickness of sediment to vary from 3.2 to 5.3 km in the Qamar basin (offshore), and the basement rocks are divided into blocks because of existence of several faults extending from basement rocks to sedimentary rocks owing to strong tectonic activities. So the study area may be divided into several major blocks along the Qamar Gulf. It can be concluded that the sedimentary processes were affected by basement tectonics as

revealed by the seismic section.

          Rock mass are generally considered to be the most heterogeneous, complex and unpredictable geomaterials. It is difficult to fully understand its behavior under various loading conditions. In the present paper, an attempt has been made to calculate the maximum stresses at the crack tips (6m) after fracture developed in a rock specimen. Rock specimen was subjected to loading on servo-controlled auto feedback stiff testing system under compressional mode in a Brazilian cage. The fractured rock surface was considered for the determination of stresses all along the crack tips. The specimens were prepared and tested as per International Society of Rock Mechanics specifications for tensile strength determination. The specimen was placed under the Brazilian cage and subjected to compressional loading till it develop failure. The fracture mode followed the Griffith failure criteria. Various researchers have tried to calculate the stress at various point along the fracture plane and established relation with other physicomechanical properties, which is time taking and tedious job. In the present paper, a technique has been suggested to calculate maximum stresses at crack tips in a simple manner. The results can be used to establish the damage characteristic of the rock mass for improving safety and stability of existing structures and further help to improve production and productivity in mining and civil engineering constructions.

           Development of urban infrastructure along the west coast of the Arabian Gulf has caused major disturbance to the coastal environment and mangrove ecosystem during the past 40 years. The mangrove forests along this coastline have particularly been adversely impacted in most areas. Temporal Landsat MSS images of 1972-1973 and Landsat ETM images of 1999-2001 were used to detect changes in mangrove forests at 10 sites along the Arabian Gulf coast. The temporal changes in the mangrove covered areas were calculated using geometrically registered and radiometrically corrected historical Landsat images. Region masks were employed to isolate the unwanted area from the images. Normalized Difference Vegetation Indices (NDVI) were computed from the satellite images. The analysis of satellite images revealed massive losses of mangrove forests at six sites due mainly to the infrastructure development of coastal areas. The depletion of mangrove forests has been uneven in the region. Out of ten sites six sites showed varying degrees of reduction but in four sites 4, 8, 9 and 10 area covered by mangrove forests actually increased despite urban development. This was because areas of mangrove stands were left undisturbed during the development process. Although there are laws to protect mangrove forests in the region but they are not implemented effectively. This study shows the urgent need to protect mangrove ecosystem and consequently coastal marine habitats of region’s flora and fauna and natural protection from erosion from waves and currents.

             Assessment of groundwater prospects has been carried out for the Morar river basin in Gwalior district, Madhya Pradesh. Groundwater prospect of the basin has been delineated from the satellite data by the integration of geology, geomorphology, lineament and slope and classified as Excellent to poor groundwater potential zones using GIS. The results obtained from remotely sensed data cross checked with the bore well yield data and found in good agreement. This depicts the positive prospective zones in the study area for exploration of groundwater in future. Water level fluctuation map prepared from the pre- and post-monsoon water level data do not show any significant change except at some locations in alluvial area Net groundwater availability also calculated is about 63.634 MCM. The calculated annual draft of Groundwater from dug wells and tube wells for all users is 70.051 MCM revealing a deficit in groundwater storage in the Basin.

                This study is an attempt to analyse and highlight the present state of forests in Kashmir, which are under tremendous anthropogenic pressure. Extensive deforestation has resulted in harmful impacts on the overall environment especially on the health of the soil. The detailed studies were carried out in Kahmil Watershed of the Kashmir valley using Geo-spatial tools. The data of the Year 1974-75 and 2000 were used and changes in forest categories viz-a-viz soil erosion status have been analysed. The analysis revealed that the Kahmil watershed situated in the Kashmir valley is undergoing large scale deforestation. There has been a total loss of about 848 hectares of forest cover in about three decades. The most startling fact is the change in terms of density classes, where the change percentage is quite high. This deforestation has resulted in accelerated soil erosion. The area which was under the Moderate erosion class has reduced and that soil has further degraded and shifted to Moderate to severe class of erosion. Necessary remedial measuresshould be taken to check this deforestation and consequent soil erosion.

                Monitoring of hydrological data is pre-requisite for systematic and scientific designing of sub-surface drainage system for control water logging and salinity. In the present study, field experiments were conducted to determine various soil hydrological and physico-chemical properties (soil texture, color, permeability, infiltration, soil moisture characteristics, dry density, total dissolved solids, SAR, etc.) under saline soils around Gohana tehsil. The majority of the area is represented by silt loam texture with varying soil color having dominance of yellowish brown in top layer. The in-situ permeability was measured using Guelph Permeameter in the field and its values were found to vary from 0.01 to 0.69 m/d for silt loam. The SAR of the soil generally varied from 0.5 to 54. The infiltration data of area was fitted with Kostiakov’s type cumulative infiltration function (Y=a*tb) and its coefficient of determination (r2) varied from 0.956 to 0.998. The present data would be useful in planning of on farm land and water management strategies ultimately for enhancing the productivity of the land.

Comparison of the accuracy of SST estimates by artificial neural networks (ANN) and other quantitative methods using radiolarian data from the Antarctic and Pacific Oceans
Shyam M. Gupta and Björn A. Malmgren

            The quality of quantitative estimates of sea surface water temperatures (SSTs) is evaluated for different techniques, Imbrie-Kipp transfer functions (IKTF), the modern analog technique (MAT), weighted-averaging partial least squares (WAPLS) regression, the maximum likelihood (ML) method, and artificial neural networks (ANNs), based on radiolarian faunal abundance data from surface sediments from the Antarctic and Pacific Oceans. Recent studies have suggested that ANNs may represent one of the most optimum procedures for estimates of paleo-SSTs. We, therefore, employed ANNs together with these other methods to estimate SSTs during February-April (TFA) and August- October (TAO) at a mean water depth of 40 m, wherein radiolarian abundances generally coincide with chlorophyll-a maximum. We used CLIMAP’s modern Antarctic radiolarian core top data and Pisias et al.’s Pacific Ocean core top data for the analyses. A portion of the datasets (75%) was used for training of ten ANNs per season, and estimates of error rates (root-mean-square-errors of prediction, RMSEPs) were made from the remaining observations, constituting an independent holdback (HB) set. The same training and HB sets were used for estimates of RMSEPs for the other methods. For the ANNs the RMSEP in the Antarctic Ocean dataset is as low as ~1.3oC for both TFA and TAO. In comparison, RMSEPs for the other techniques for TFA are higher in ranging between 1.8 and 2.0°C, whereas those for TAO are similar (1.4-1.5°C). Correlation coefficients (r:s) between observed and predicted SSTs using the ANNs are 0.97 for both seasons. In the Pacific Ocean dataset, RMSEPs derived from the ANNs are considerably lower for both seasons, 1.5°C for TFA (1.8-2.2°C for the other methods), and 1.4°C for TAO (the other methods 1.7-1.9°C). ANN-derived correlation coefficients (r:s) between observed and predicted SSTs are 0.98 for both TFA and TAO in the Pacific Ocean. Comparison of residual (estimated-observed) SST maps suggests that MAT and ANN produced lesser geographic trends than those of the other methods.

Radon Time Series and Earthquake Signals—a Study by SSNTD at Matigara (Darjeeling), India
Dipak Ghosh, Argha Deb, Subrata Haldar, Swarup Ranjan Sahoo, Rosalima Sengupta

            A survey of radon concentration in the soil gas in order to get premonitory signal of arthquakes is being carried out by us since last 4 years in Kolkata, West Bengal, India—which is known to be situated at non-active fault zone and since last 2 years in an active fault zone—Jalpaiguri (26A32BN, 88 A46BE), West Bengal. In extension of our work we have started the experiment in another active fault zone: Matigara, Darjeeling (26º43' N, 88º23'E), West Bengal, India, to have more confirmatory signal. We present the description of signal of the terrestrial gas 222Radon observed for a period of more than one year at a depth of 70 cm in the soil using passive detector –Solid State Nuclear Track Detector (SSNTD). The time series of radon shows a distinctive anomalous fluctuation prior to seismic events that ccurred within 1000 km from the measuring site. The results are obtained at two fault zone sites are compared and the present analysis provides further evidence in favour of using radon signal as a precursor of earthquake.

Sun-Earth-cosmic connection to understand early warning of Earthquakes
Saumitra Mukherjee

              Muon detector has the potential to function as Nano Sensor to infer possible earthquake in earthquake prone areas. It has been observed that 30 to 36 hours before the occurrence of the earthquake the magnetic field (Kp) and electron flux (E-flux) of the Sun-Earth environment changes. Using Sun-Observatory-Heliospheric Observatory (SOHO) satellite data it is possible to monitor the fluctuation every 15 minutes interval. It has been observed that before the occurrence of earthquake, nanoparticle (muon) intensity reduces, while the atmospheric temperature rises along with the increase in Kp and E-flux values. After the earthquake the atmospheric temperature falls suddenly with the rise in cosmic rays and fall in Kp and E-flux values. It has been planned by IHY, NASA and UNBSS (United Nations Basic Space Sciences) to design and install basic hybrid SEVAN (Space Environment Viewing and Analysis Network) in 14 locations across the world. Cosmic Ray Division laboratory of Armenia will supply photomultiplier of similar standards to all these 14 locations including Jawaharlal Nehru University, New Delhi, India. These detectors will record and correlate the intensity of cosmic ray data to predict various environmental perturbations including earthquake. Based on this plan it was attempted to correlate Kp, Eflux and chages in environment in different locations across the world with variation of cosmic rays collected from existing muon detectors.

Microscopic examination of concrete with and without corrosion inhibitor
B.N. Singh, P.P. Abhilash, V. Kumar and M.A. Quraishi

             The present paper addresses the mineral constituents and microstructural behaviour of concrete with and without corrosion inhibitor (i.e. calcium stearate) observed under petrological microscope. Mineralogically and texturally, these concretes are largely similar but microstructurally they are quite distinct. The concrete samples without calcium stearate are characterized by the occurrence of microcracks, voids and carbonation leading to lower the strength and durability of concrete. However, these features are less abundant in the concrete with calcium stearate. The microcracks and voids are infilled with cementitious materials, if calcium stearate is used as admixture. Therefore, the use of calcium stearate in concrete can enhance the strength and durability properties of concrete.

Possibility of artificial recharge in overdeveloped miniwatersheds: A RS-GIS approach
Bhagyashri C. Maggirwar and Bhavana N. Umrikar

            The stress on groundwater has become a point of concern for planners and researchers. The groundwater pumping is exceeding the recharge due to increased dependency on roundwater to cater the needs of the growing population. Therefore, the assessment of groundwater potential and scope for artificial recharge in the overdeveloped watersheds is very crucial. GV-41 5/8 and 6/8 miniwatersheds are such overdeveloped areas where the groundwater occurring in unconfined / semi confined shallow aquifer needs to be augmented by undertaking suitable artificial recharge structures in order to ensure economically viable yields of wells vis-à-vis increase the groundwater availability on sustained basis. For the purpose of assessment of groundwater potential in GV-41 5/8 and 6/8 miniwatersheds, detailed hydrogeological surveys were carried out in Aurangabad District, Maharashtra and the database was also used to find out the feasibility of artificial recharge structures. The present study is an attempt to find out the possibility of artificial recharge considering the existing water harvesting structures using Remote Sensing and Geographical Information System  techniques (RS - GIS).

Assessment and impacts of surface water environment in and around Jabalpur city, Madhya Pradesh, India
Medha Jha and Sanjay Tignath

             The physical, chemical and biological characteristics of surface water in and around Jabalpur city, M.P. have been studied to evaluate the suitability of water for irrigation and domestic uses. Samples of water were collected from various localities such as Narmada and Pariyat water supply system, various ghats of Narmada river, various tals and tanks, main drains of the city such as Omti nala and Moti nala and were analyzed for pH, electrical conductivity, temperature, dissolved oxygen, five days Biological oxygen demand , fecal coliform , turbidity, total solids, nitrates and phosphates.Water quality indices “WQI” developed in 1970 by the U.S. National sanitation foundation were calculated for these water samples. The results conclude that the water quality of water supply systems, various ghats of Narmada River is of medium quality and can be used for domestic use after suitable treatment. The water quality of various tanks and drains falls in the range of bad quality waters by index rating and can be used for irrigational purposes .This study is helpful to environmental planning and pollution control measures applicable to the area.

Hydro-meteorological disasters and climate change: conceptual issues and data needs for integrating adaptation into environment - development framework
Anil K. Gupta, Sreeja S. Nair and Vinay K. Sehgal

             Integrating Risk Reduction to the Environment and Development Framework at local and regional levels has now emerged as the core strategy for minimizing hazards and managing disasters. This strategy calls for a ‘paradigm shif by treating disaster management and climate change as developmental issues interlinked to each other and requiring common management approaches’. Disaster management comprises of (1) disaster risk management and (2) emergency organization for protecting natural, built and socio-economic environments from impacts at temporal and spatial scales. Damage and losses due to extreme events depend upon the magnitude and intensity of hazardous event along with the vulnerability of population, habitat, resources, and developmental settings, as against the capacity to withstand the risk. Designing the approach for convergence of Climate Change Adaptation and Disaster Risk Reduction (DRR) and mainstreaming towards development, it required an analysis of various components of environment-development complex that are to
be put into adaptation agenda. Availability of suitable, accurate and proper data is crucial for any assessment, planning or decision task. The present paper presents an effort of cross-sectional probe into various conceptual issues relating to hydro-meteorological disasters, climate-change impacts and disaster risks, issues for adaptation nd convergence, disaster risk reduction framework in India and examples of data needs at different stages for their better management.

Earth Science India Volume-2(I), 2009

Radiolarian abundance - a monsoon proxy responding to the Earth’s orbital forcing: Inferences on the mid-Brunhes climate shift

Shyam Murti Gupta

           Radiolarian fluxes from the sediment traps moored in the southern Bay of Bengal suggested that radiolarians were invariably higher at times of higher sea surface temperature (SST >28oC) and moderately lower salinity (~33.5 psu) during the summers of 1991-93. It implied that higher SSTs due to summer heat and lower salinity due to rains might have affected the radiolarian fluxes during the monsoon. Hence, the down core radiolarian-yield in the unit weight as the percentage abundance may shed light on monsoon-sensitive radiolarian production through the geological past. It is tested in a well-dated radiolarian ooze-bearing sediment core collected from the central Indian Ocean in the southwest of the trap site. Radiolarian tests/g dry bulk sediment (Rads/g) yield from the sediment samples at every 4750 years (4.75 ka) time interval (δt) produced a time series for the last 485000 years (485-ka) during the late Quaternary. Rads/g was higher during the upper last 200-ka record than the lower section of the core implying higher radiolarian production in the upper part than in the lower part of the core. Blackman-Tukey and maximum entropy spectral analyses of the Rads/g time series revealed multiple cycles at ~126-, 95-ka due to the Earth’s orbital eccentricity, ~54-, 41-, and 31-ka due to axial tilt, 23-, 19-, and 17-ka due to changes in the precession of equinoxes, besides the 15-, 13- and 11-ka sub- Milankovitch cycles. The spectral results are further verified by multi-taper method using 90% reshaped spectrum, adaptive narrowband and high-resolution harmonic signals with robust noise and the statistical significance test (F-test), and the >90-99% significant cyclic components are reconstructed to visualize the variation in their amplitude through time. The reconstructed harmonic components revealed a conspicuous change in the trend of the amplitudes of ~95-, 54-, 41-, 31-, 17-, 15-, 13- and 11-ka cycles suggesting an effect of the mid-Brunhes epoch climate shift at around ~300-350-ka before present. The results substantiates the existence of multiple cycles at the eccentricity (126-, and 95-ka), tilt (~54-, 41-, and 31-ka) and precession (23-, 19-, and 17-ka) and sub-orbital bands (~15-, and 13-ka) as proposed by Berger (1977) in the astronomical data, which strengthens growing belief of multiple orbital cycles reported from pollens (Mommersteeg et al, 1995) and the radiolarian assemblages (Gupta, 2003) suggesting the cyclic changes in the summer-monsoon productivity during the Late Quaternary in the Central Indian Ocean sediments.

Seasonal and inter-annual variability of Chlorophyll – a in the Arabian Sea from SeaWiFS data

Rajeev Mudgal1, Mihir K. Dash2and P. C. Pandey2

Dynamics of a  river system– the case of the Kosi river in north Bihar

Rajiv Sinha

Taxonomic placement of a holectypoid echinoid genus Srivastava and Singh, 2001  

D. K. Srivastava

Earth Science India Vol.1 (IV), October, 2008

Granite Series Evaluation of Early Ordovician Kyrdem Granitoids and Enclaves, Meghalaya Plateau, Northeast India: Implication on Oxidation Condition of Interacting Mafic-Felsic Magma System

Santosh Kumar and Kh. Mohon Singh

           Early Ordovician (479±26 Ma) Kyrdem granitoids (KG) and their enclaves in Meghalaya plateau have been evaluated in terms of magnetic susceptibility (MS) and whole rock composition in order to understand the redox condition of comingled mafic and felsic melts. KG (MS=15.56-31.55×10^-3SI) and microgranular enclaves (ME) (MS=24.47-32.09×10^-3SI) are moderately to strongly oxidized, magnetite series granites formed in a late- to post-tectonic calc-alkaline, mafic-felsic magma interacting environment. Oxidizing nature of bulk KG melt was locally reduced to ilmenite series (0.26×10^-3 SI) granite near the margin of the KG pluton as a result of reaction with pelitic country-rocks occurred at shallow emplacement level.

New Trends in Gondwana Palaeobotany

A.K. Srivastava

           Discoveries of insect wings, insect activities in fossil flora and microbial association with plant fossils have helped to understand the interrelationship of plants and insects and role of mico-organisms in Gondwana flora.

Speleothems from the Himalaya and the Monsoon: A Preliminary Study

V. C. Tewari

            Speleothems (stalagmites, stalactites) have great potential for the records of past climate, environment and monsoon on a global scale particularly in the Asian region. Speleothems are found in all parts of the world and grow continuously through many glacial – interglacial cycles and their stable isotopic ratios and annual growth bands are useful for decadal to seasonal variations in rainfall. Some important speleothems from the Himalayan region such as Sahastradhara, Dehradun; Brahmakhal, Uttarkashi; Bhagirathi valley, Garhwal and Mawasmai caves from the Meghalaya have been studied. In the present paper, the oxygen and carbon isotope ratios from the Sahastradhara, Brahmakhal, Nagni  and Pratapnagar speleothems and cave drip water  has been recorded for the first time. The significance of speleothems and their relationship with the monsoon is discussed.

Marine ¹⁴C Reservoir Age and Suess Effect in the Indian Ocean

Koushik Dutta

       Apparent radiocarbon (¹⁴C) ages of marine biogenic samples that derive their carbon from surface seawater dissolved inorganic carbon are on the average about 400 years older than contemporary terrestrial woods or global atmospheric CO₂. This age offset is due to mixing of old carbon from the deep ocean and is referred to marine ¹⁴C reservoir effect. Both regional and temporal variations of ocean circulation pattern causes significant spatial and temporal variations in marine ¹⁴C reservoir ages and hence of biogenic surface marine samples. Knowledge of reservoir age is very important to accurately calibrate ¹⁴C-ages of biogenic carbonates and sediment organic matter from marine sediments that are frequently used in paleoceanographic studies. Here the concept of marine ¹⁴C reservoir ages and their quantification are discussed and data for the Indian Ocean region are reviewed. Regional variations of marine ¹⁴C reservoir ages and fossil fuel Suess effect for the Indian Ocean and the South China Sea are analyzed.

Recently Studied Sedimentary Records from the Eastern Arabian Sea: Implications to Holocene Monsoonal Variability

Rajesh Agnihotri and Siby Kurian

            Deep insight into exact mechanism(s) controlling past monsoonal variability on inter-annual to millennial time scales is a pre-requisite for developing predictive capability of monsoon on timescales relevant to human life. Reliable monsoon predictions developed by climate modelers play a crucial role for making country’s future economic programme. Basic data input to generally applied monsoon models is instrumental rainfall data, beyond which search for monsoon variability relies upon proxy records stored in various natural repositories such as tree rings, corals, cave deposits, lake and marine sediments. While tree rings, cave deposits and corals are capable of yielding paleo-monsoonal information on extremely high temporal resolution, continental margin sediments depositing in the Arabian Sea have provided relatively coarser but longer proxy records of monsoonal variability. Here we review some of such recently studied sedimentary records from precipitation dominated eastern Arabian Sea in an attempt to comprehend past monsoonal variability in Indian as well as global context. We also focus upon different proxies used so far in the Arabian Sea, their fidelity, limitations and future scope of using novel proxies for a better understanding of past monsoonal variability especially in the anthropocene epoch.

Variation in Erythemal UV Dose for Indian Cities as Observed from Global Ozone Monitoring Experiment Data

Nandita D. Ganguly

Variation in Erythemal UV Dose (EUVD) for five Indian cities and their expected critical limits has been studied using the data obtained from Global Ozone Monitoring Experiment (GOME). The EUVD values are found to be higher and peak earlier at places located at lower latitudes than at higher latitudes. They are higher during summer / monsoon compared to winter. Seasonal variation in EUVD is more pronounced at higher latitudes compared to lower latitudes. EUVD variations show a negative correlation with solar activity and are observed to be well within the statistically calculated critical limits for these five Indian cities.

Use of Interactions between NAO and MJO for the Prediction of Dry and Wet Spell in Monsoon Season

S.S.Dugam

           The Indian summer monsoon exhibits prominent 30-40 day fluctuations with “active” periods of heavy rain interrupted by dry periods i.e. “Breaks”. The circulation anomalies associated with active/break monsoon cover the entire Indian Ocean remote tropics and North Pacific Ocean. A prolonged dry/wet period will result in severe drought/flooding, which have profound influences on the south Asia water cycle, agriculture and societal activity of more than one billion people. The atmospheric general circulation models have great difficulty in simulating the Intra-seasonal oscillation (ISO). Therefore, it is necessary to study the empirical relationship between various atmospheric processes, which are responsible for the ISO. In this paper, the analysis of North Atlantic Oscillation Index (NAOI) and Madden Julian Oscillation Index (MJOI) on daily scale is carried out in relation to daily Indian summer monsoon rainfall (June-September). The analysis is carried out for the period 1979-2001. Since the potential predictability limit for monsoon break is about 20 days, the 20 days running lag/lead correlation analysis between the NAOI and MJOI is found out for each year. It is observed that 20-day lag relationship between NAO and MJO is inverse and significant (0.1 level) and this relationship remains negative throughout the break monsoon period and in active phase it reverses. This twenty days lag relationship between NAO and MJO is potential predictor for break/ active monsoon conditions over the Indian region. The analysis is verified for major drought year 2002.

Earth Science India Vol.1 (III), July, 2008

Chemical Characteristics of Water Soluble Components of Fine Particulate Matter, PM_2.5, at Delhi, India

Suresh Tiwari , Manoj K. Srivastava , and Deewan S. Bisht

              Aerosol samples in the size range up to 2.5 µ m were collected from January to December 2005 at New Delhi, India, as a pilot experiment and analysed for organic [O xalate and Formate ] and inorganic [ Sulfate, Ammonium, Nitrate, Potassium, Chloride, Sodium, Calcium and Magnesium] chemical components. Initial results show that the annual mean PM _2.5 concentration was 98.7 µg/m 3 , which varied between 38 to 285µg/m 3 . The water soluble inorganic fraction constituted only 9% of PM 2.5 with SO 4 2- , NH 4 + and NO 3 - being the dominant ions followed by potassium. Annual cycle shows higher concentration of PM 2.5 during winter season [October to January] and the lowest during monsoon. It is attributed to the enhanced production of aerosols and prevailing meteorological conditions. The PM _2.5 /PM ₁₀ ratio [0.86] coupled with the HySPLIT air-mass back trajectories indicated that PM _2.5 at was dominated by fine particles, when the winds passed through the eastern azimuth, where many industries and major thermal power plants are located.

Cosmic Rays and Earth's Atmospheric Processes : A review

Devendraa Siingh

The modulation of cosmic ray flux incident on the Earth's upper atmosphere by solar activity results in changing the global electrical properties of the atmosphere, which is, in turn, believed to affect weather and climate. In this review paper an attempt has been made to summarize the present understanding of Earth's atmospheric processes, which are affected by Cosmic rays.

Sediment characteristics and Heavy Mineral Distribution in Tamiraparani Estuary and off Tuticorin, Tamil Nadu- SEM Studies

M. Suresh Gandhi, A. Solai, K. Chandrasekaran and V. Rammohan

           The study area Tamiraparani located between latitudes 8° 25? and 9° 13? N, and longitudes 77° 10? to 78° 10? E along the south- east coast of India. All samples were collected between Pre-monsoon July 2003 and Post-monsoon February 2004 . The heavy mineral assemblage of the study region is governed by the distribution of different type of minerals. However, the assemblage is restricted to the dominance of few selective minerals like garnet (colourless), garnet (pink), zircon, rutile, chlorite, etc. From the SEM studies, it is observed that, the grains are sub-angular with various surface solution features, rounded crescent like pits, straight net like sutures; v-shaped pits are noticed in pre- and post-monsoon samples. The coarser nature of the grain may be due to the influence of river activities. The weathered surface futures also noticed in few samples. The sediment texture, mineral and SEM studies, clearly indicate that in pre-monsoon the erosional activities are predominant than the post-monsoon. In both the monsoons, sediments transport from river and estuary towards the beach and marine. In pre-monsoon whatever sediment deposited were transported and shifted due to longshore current action. But, in the post-monsoon, it is depositional environment where the sediments deposited due to the multi-source like riverine and marine influence is observed.

Small-scale deformational structures as significant shear-sense indicators: An example from Almora Crystalline Zone, Kumaun Lesser Himalaya

K. K. Agarwal and R. Bali

             Small-scale deformational structures e.g. folds, asymmetric boudins, thin veins in an en-echelon pattern, small-scale duplex, shear zones and shear bands are the most common structural elements used as reliable shear-sense indicators in crystalline rocks. Most of these structures are observed in the Almora Crystalline Zone (ACZ) in Kumaun Lesser Himalaya, which is disposed in the form of a huge asymmetric synform. The shear-sense observed on the northern and southern flanks is found to be – top to north and top to south respectively.

SFARF: Software for Classification of Fourier Shape of the Folds Around Tamadhaun, District Almora, Uttarakhand

H. Thomas , S. Sujata and A. Chandel

            Fourier (harmonic) analysis is a very simplified graphical method of plotting fold shapes in two dimensions. The authors have developed software (SFARF) to directly assign the class of fold shapes on the basis of the value of the ratio b3 / b1 (Fourier Coefficient). The various fold forms obtained by the software around Tamadhaun area reveal that fold developed in quartzite occurring in the study area is varying in the range between sine-waves and parabolas to almost sine-wave, whereas the folds which are developed in phyllite and schist rocks are statistically between sine-waves to almost chevron.

Climate change and its future impact on the Indo-Gangetic Plain (IGP )

H.S.Saini

           The Indo-Gangetic plain (IGP) is an environmentally sensitive, socially significant and economically strategic domain of India where landscape, hydrology and fertility are threatened by climate warming and anthropogenic pressure. Irregular availability of water is going to be thebiggest hazard in future. In case of increased water supply, the piedmont zone and river lowlands are threatened by erosion and sedimentation while in case of decreased water supply, the upland surface is endangered by salinization, desertification and drying-up of aquifers. Decline in food production will be the major problem. In order to make assessments of the environmental changes, concerted efforts should be initiated to understand the geological past and model the future. A pre-requisite is to develop a high resolution history of climate variation and their impact on landscape and ecology from the geological and historical recordsof IGP during the past 25 ka. Such data can help in the evaluation of forecasting scenarios, and thereby assist in developing mitigation plans regarding the environment. Artificially induced recyclingof the water can be one of the possible ways to maintain a minimum availability of water.

Earth Science India Vol.1 (II), April, 2008

Lateral Zonation Around Archean Nucleus of the Dharwar Craton (India): Its Deformation, Segmentation and Subsequent  Breakup

O.P. PANDEY  and P.K. AGRAWAL

Regional scale variation of the nature of geological units across the earliest evolved regions of the earth may contain fundamental information about continental evolution. Among the Archean blocks, the Indian shield appears to possess certain unique geotectonic and geodynamical characteristics which provide an opportunity to understand its multi-stage crustal evolution both in space and time. Our study of the south Indian shield reveals segmentation and a secular and progressive lateral zonation of the continental lithosphere around Dharwar nucleus since mid-Archean. However, its cratonic nucleus seems to have ultimately broken due to successive crustal remobilization and foundering of the rheologically and tectonically weak Archean lithosphere. Such weakness were caused by (i) episodic plume induced tectonothermal events since 2.7 Ga, and (ii) asthenospheric convective processes associated with a new rifting phase triggered by Marion plume activity along the India's western margin at about 90 Ma. The Antongil block of northeast Madagascar seems to correspond to the broken segment of the western Dharwar craton.

Some Observations on the Thrust Geometry of the Siwalik Rocks of the Outer Himalaya , India

A. R. Bhattacharya and K. K. Agarwal

The rocks of the Siwalik Supergroup of the Outer Himalaya have been found to show a complicated system of thrust geometry in their internal domain. The structures which the lithic layers commonly show include the following: duplex, imbricate fan system, thrust propagation structures, fault propagation folds, pop-up structures, antiformal stack, snakehead anticline, snakehead duplex, overstep thrust system and the related types. Occurrence of these structures suggests, amongst others, the active role, and/or reactivation, of the anisotropy planes of the rocks during deformation, and that the deformation was progressive in nature. Development of most of these structures may have involved addition of mass to the moving thrust complexes. Presence of the above structures possibly indicates that the Siwalik strata, in general, may have undergone structural thickening in their internal domain during the overall deformation of these rocks.

Brissid echinoid Eupatagus L. Agassiz, 1847 from the Khuiala Formation, Jaisalmer district, Rajasthan, India

D. K. Srivastava and Hukam Singh

The spatangoid genus Eupatagus L. Agassiz, 1847 is recorded, for the first time, from the sediments of the Khuiala Formation (Early Eocene) exposed near Habur, Jaisalmer district, Rajasthan, India. The specimens are placed in a new species characterised by its large, oval test with mild frontal sinus; convex aboral surface; flat oral surface; anteriorly eccentric ethmolytic apical system; anteriorly eccentric kidney- shaped peristome; long, petaloid ambulacral petals; longitudinally oval periproct at the posterior truncation and imperforate, non crenulated tubercles.       

Earth Science India Vol.1 (I), January, 2008

Basement Rocks of the Kumaun - Garhwal Himalaya: Some Implications for Himalayan Tectonics

A. R. Bhattacharya

            The Himalayan orogenic belt is characterized by the presence of basement rocks. These rocks got involved in the evolution of the mountain belt and, as such, have played a great role in the structural architecture and tectonic framework of the orogen. These rocks have evolved from depth due to concentration of compressive stresses generated by plate collision and rose vertically up because of buoyancy up to the surface and were then pushed southwards over the less- or un-metamorphosed , younger rocks of the sedimentary belt of the Lesser Himalaya. In order to make room for such a vast chunk of the basement, the sedimentary pile had to undergo large scale deformation sympathetically. As such, the present tectonic setting, structural architecture and deformation pattern of the upper crustal rocks of the Himalaya owe much to the rise of the basement rocks during evolutionary stages of the Himalaya. The paper examines some aspects of the tectonics and structural framework of the Himalaya as related to the basement rocks in the Kumaun - Garhwal sectors.

Fluvial Palaeohydrological Studies in Western India: A Synthesis

Alpa Sridhar

          The river basins of India are important repository of the late Quaternary hydrological and climatic changes. The long term (millennial scale) and short term (centennial scale) hydrological changes in these river basins can be reconstructed through the records of platform alterations and sediment deposits that occur during the rare extreme flood events. The status of fluvial palaeohydrological studies in western India and the future prospects are discussed in this synthesis. Almost continuous palaeoflood records spanning two thousand years is available from the bedrock rivers on western India, whereas older events dating back to ~ 5 ka have also been documented from the alluvial reaches. Though bedrock gorges are considered to be ideal sites for the preservation of palaeoflood deposits and related discharge estimations, the alluvial reaches of the rivers in western India owing to their unique geomorphic set up are equally promising. Regime-based palaeodischarge estimations for the average flows in these alluvial reaches would be significant in providing a regional history of the hydrological changes that have occurred in the river basins of western India.

Geothermal Energy Resources and Their Potential in India

P.N.Razdan, R.K. Agarwal and Rajan Singh

              Geothermal Energy is the vast reservoir of heat energy in the earth’s interior, whose surface manifestations are the volcanoes, fumaroles, geysers, steaming grounds and hot springs. About 300 thermal springs are known to occur in India, falling in orogenic (Himalayan) as well as non-orogenic (Peninsular) province. Thirty one areas have been examined in detail and finally, shallow drilling has been done in sixteen areas. The temperatures of these springs range from 35°C to the boiling point of water. On the basis of enthalpy characteristics the geothermal systems in India, are classified into medium (100°C-200°C)-and low enthalpy (<100°C) geothermal energy resources/systems. Medium enthalpy geothermal energy systems are associated with younger intrusive granites (as in Himalayas), major tectonic features/lineaments and rifts and grabens. The Low enthalpy geothermal energy systems are associated with Tertiary tectonism and neo-tectonic activity. The primary and most important aspect of geothermal system is to understand the heat source and its capacity for exploitation. Studies carried out, so far, have clearly pointed that adequate geothermal potential in respect of direct heat utilization and power generation does exist at several geothermal sites.  Reservoir simulation studies have suggested the possibility of generating over 3 MW electric power in Puga (J&K) field, if deeper levels are probed at least up to the depth of 500 m. The paper provides an overview on various geothermal fields of India and the status of exploration for future studies.

Synthetic Minerals for Electronic Applications

P. S. Anjana, Sherin Thomas, M. T. Sebastian and J. James

         Several of the mineral phases used for our common use are available in nature. However, the purity of the natural mineral phases, their consistency of properties, structure, morphology and availability make them unsuitable for large scale continuous use in electronic and other applications. Therefore, several inorganic minerals are synthesized to tailor their properties for specific applications. These minerals, though similar in their structural characteristics to the naturally occurring minerals, gives flexibility in controlling their purity, and crystallographic characteristics. This in turn helps to develop newer and improved applications like electronic and magnetic devices for communication. This article has concentrated on of some of the major synthetic materials used for electronic applications with special ephasis on their mineralogical aspects, structure, preparation and uses. The minerals covered include: quartz, synthetic Berlinite, synthetic Perovskites, synthetic halites, synthetic pyrites, synthetic rutiles, synthetic pyrochlores, synthetic spinels, synthetic sphalerites, synthetic wurtzites, synthetic corundum.