017158   Malik M I;Bhat M S (NO, , ) : Anthropogenic land use change detection in a Kashmir Himalayan watershed- a remote sensing and GIS approach. J Remote Sensing GIS 2014, 5(1), 34-42.

Watersheds are ubiquitous units that can be seen as the physical foundation of the nation. They have long been recognized as desirable units for planning and implementing developmental programs. Human impact on the watersheds is increasing day by day. The alteration of land use pattern in the Himalayan watersheds is increasing the vulnerability of these inherently fragile ecosystems. The study is conducted in a Himalayan watershed of Lidder catchment in Kashmir valley by integrating remote sensing, geographical information system (GIS), field survey and socio-economic data. The multi-temporal land use land cover (LULC) change detection is carried out using digital classification procedure. The results have revealed that agriculture and forest area has been encroached by horticulture and built-up area. High growth rate of population and maximization of economic returns from cultivable land are identified as the two main drivers of LULC change in the watershed. The study proposes that a comprehensive land use policy must be implemented to avoid unsustainable expansion of various land uses at the cost of natural land cover.

51 ref

017157   Kakodar A P;Alornekar A;D'Souza R;Thomas T R A;Divekar R;Nath I V A;Kavlekar D P;Ingole B S;Loka Bharathi P A (Biological Oceanography Div, National Institute of Oceanography, Council of Scientific & Industrial, Dona Paula, Goa-403 004, Email: loka@nio.org) : Biosearch: a glimpse intro marine biodiversity of Indian coastal waters. Indian J Geomar Sci 2013, 42(6), 745-8.

bioSearch is a database application developed to digitize marine biodiversity of Indian coastal waters. A user can obtain information on organism's binomial and common names, synonyms, taxonomy, morphology, ecology, economic importance, geographical distribution, images and reference literature. As on date 25 September 2013 bioSearch manages 19,760 records. It should be noted that the database is continuously being validated and updated. In this article we discuss structure, working and salient features of bioSearch (www.biosearch.in).

1 illus, 1 table, 9 ref

017156   Iyer S D;Das P;Kalangutkar N G;Mehta C M (NO, National Institute of Oceanography (CSIR), Sona Paula, Goa-403 004, Email: iyer@nio.org) : Seamounts-windows of opportnities and the Indian scenario. Curr Sci 2012, 102(10), 1382-91.

Seamounts are manifestations of crustal tectonics and volcanism, and are also sites of biodiversity and hydrothermal events. Although the population of seamounts is estimated to be in thousands, a large number of these have not been thoroughly studied. Globally, several seamounts are being exploited by the fishery industries, whereas a few have been demarcated for conservation and serve as underwater observatories. We provide a summary of the seamounts related to their discovery, distribution, nature and influence in the marine environment. In addition, we review the findings of seamounts in the Indian Ocean and the need to have a multi-disciplinary approach to explore them.

3 illus, 1 table, 91 ref

017155   Goswami P;Rakesh V;Patra G K;Prakash V S (NO, CSIR Centre for Mathematical Modelling and Computer Simulation, Wind Tunnel Road, Bangalore-560 037, Email: goswami@cmmacs.ernet.in) : Real-time quantitative rainfall forecasts at Hobli-level over Karnataka: evaluation for the winter monsoon 2010. Curr Sci 2012, 102(10), 1426-33.

Advance and accurate forecasts of rainfall can aid many sectors, from agriculture to disaster mitigation. However, given the tremendous spatial variability of rainfall, only forecasts at high resolution can serve users' needs. The skill of a dynamical forecast model depends on the resolution and varies from region to region. While such non-uniqueness poses challenges, they also provide avenues for improving skill; in particular, calibration and customization can improve region-specific skill. Here, Authors presents evaluation of rainfall forecast at hobli-level (a cluster of adjoining villages with average area of the order of 10 square kilometers) over Karnataka for the north-east monsoon (October-December) season of 2010, operationally implemented through collaboration between CSIR Centre for Mathematical Modelling and Computer Simulation (C-MMACS) and Karnataka State Natural Disaster Monitoring Centre (KSNDMC) for interactive evaluation. We have adopted and calibrated the Limited Area Model, called Weather Research and Forecasting (WRF) Model, using principles and methodologies developed at C-MMACS and elsewhere. Statistical evaluation of the forecasts is conducted against observations from the telemetric rain-gauge network established by KSNDMC based on large samples (90 forecasts for each of the 740 hoblis). The results shows that forecasts capture the observed spatio-temporal variability well enough to be useful. At the same time, certain areas of systematic bias are identified for further calibration to improve forecast skill. As a pioneering effort in the country to generate real time hobli-level forecasts validated against high-density observations, the results quantify realizable skill for the methodology. The forecasts are also disseminated by KSNDMC to various users on a daily basis.

5 illus, 9 tables, 11 ref

017154   Fuska J;Kubinsky D;Barek V;Halai P;Lenart R (NO, , ) : Tin model of water reservoir bottom and assessment of model accuracy. J Remote Sensing GIS 2014, 5(1), 27-33.

Natural and anthropogenic processes are causing changes in topography of water reservoir bed. These changes are connected to the income and outcome of the sediment to the water reservoir, so the water depth and total reservoir volume changes too. Knowledge of topography of the water reservoir bed and its changes can be useful for calculation of total actual amount of the sediment, for calculation of the actual volume of water in current water level, or it can be used for creation of area-capacity curves of the reservoir. This paper deals with the possibility of the creation of TIN (triangulated irregular network) model of the water reservoir bed and also for the assessment of the accuracy of the created TIN model. The idea of accuracy assessment is the evaluation of differences between modeled cross sections and the real elevations of the reservoir bed. Input data are the points collected with the GPS and depth measuring with the level staff (contact measuring) and the points collected with the GPS receiver and sonar during sailing in the reservoir (non-contact measuring). Then the data are processed in the ArcGIS 9.3 software and the TIN model of the reservoir bed is created. The cross sections of the model and the real elevations of the reservoir bed are created in the AutoCAD 2009 software. This method is demonstrated in the swimming pool in Topolcany. Bottom of the swimming pool is plain with good possibility to estimate real elevations of the points at its surface. The comparison of the modeled cross sections with the real bottom elevation offers evaluation of the accuracy of the method that can be obtained in the field work in the proper water reservoirs (fish ponds, irrigation reservoirs, etc.).

11 ref

017153   de Sousa T;Ingole B;de Sousa S;Bhosle S (Microbiology Dep, Goa Univ, Taleigao Plateau, Goa-403 206, Email: sarojbhosle@yahoo.com) : Seasonal variations of nitrate reducing and denitrifying bacteria utilizing hexadecane in Mandovi estuary, Goa, West coast of India. Indian J Geomar Sci 2013, 42(5), 587-92.

Mandovi estuary has a prolific population of heterotrophic bacteria due to the influx of nutrients including nitrate and organic hydrocarbons. Seasonal sampling at various locations along the estuary was carried out to isolate nitrate reducing and denitrifying bacteria capable of hexadecane utilization. Total viable counts of nitrate utilizing bacteria showed variations with seasonal changes. It ranged from 10³-10⁶ cfu/mL on nitrate reduction medium and 10¹-10⁵ cfu/ml on minimal media containing hexadecane as the sole carbon source. Highest bacterial counts were obtained during the monsoons. 22% of bacteria capable of hexadecane utilization were nitrate reducing and 12% were denitrifying. 29% of the hexadecane utilizing cultures isolated during the monsoons exhibited nitrate reducing activity. However, seasonal variations did not affect the frequency of the denitrifying hexadecane utilizers.

3 illus, 33 ref

017152   Bourgeon G;Nair K M;Ramesh B R;Seen D L (NO, , 3 rue de Guesclin, F-34000 Montpellier, France, Email: danny.lo_seen@cirad.fr) : Consequences of underestimating ancient deforestation in South India for global assessments of climatic change. Curr Sci 2012, 102(12), 1699-703.

Land-cover changes occurring before 1800 are often ignored in the estimation of CO₂ emissions, probably because they are poorly documented in most tropical countries. India appears to be an exception to this rule. It was possible to reconstitute the main stages of the land-cover history for a large region of South India, and therefore to retrace the dynamics of CO₂ emissions during nearly 1000 years. It was then possible to demonstrate that 25% of the total emissions occurred before 1800, and are mistakenly considered as more recent emissions.

2 illus, 1 table, 29 ref

017151   Bansal B K;Verma M (Geoscience Div, Ministry of Earth Sciences, Prithvi Bhavan, Lodhi Road, New Delhi-110 003, Email: bansalbk@nic.in) : M 4.9 Delhi earthquake of 5 march 202. Curr Sci 2012, 102(12), 1704-8.

The occurrence of an M 4.9 event on 5 March 2012 at Delhi-Haryana border is a reminder about the active nature of different tectonic sources in and around Delhi. The earthquake was well recorded by local and regional networks of seismic stations and has generated good instrumentally recorded data. The epicentre of the earthquake falls near the surface expression of the Mahendragarh-Dehradun Fault (MDF), located to the northwest of Delhi. Peak ground acceleration recorded in the Delhi region varied from a minimum of 2.50 cm/s² to a maximum of 39.4 cm/s² on the transverse component at the Ridge Observatory and Jaffarpur stations respectively, located about 60 and 34 km away from the epicentre. The maximum velocity computed from acceleration time histories was 1.11 cm/s. According to the preliminary reports, a maximum intensity of VI, on the modified Mercalli intensity scale, was observed near the epicentral zone. Ground motion site amplification was not uniform; it varied between 3 and 6 at different sites. The recent earthquake is not just reminder that Delhi is vulnerable to local earthquakes; it also demonstrates site dependent amplification, calling for further studies.

3 illus, 2 tables, 6 ref

017150   Anooja S;Padmalal D;Maya K;Vishnu Mohan S; Baburaj B (NO, Centre for Earth Science Studies, Thiruvananthapuram-695 031, Email: drdpadmalal@gmail.com) : Heavy mineral contents and provenance of late quaternary sediments of southern Kerala, Southwest India. Indian J Geomar Sci 2013, 42(6), 749-57.

Deals with provenance and depositional history of the Late Quaternary sediments including heavy mineral placers in the coastal lands of Kollam district, SW India. Kollam coast is endowed with estuaries, old coastal plains with ridge-runnel systems and barrier beaches. Mineralogical analysis reveals that sediments in the estuarine basins that are seen entrenched over the Neogene sedimentary deposits were derived from dual sources. Heavy mineral residues of the upper estuarine zones are generally garnet bearing and are of alluvial origin. At the same time, sediments in the lower estuary are garnet-free and are derived from the nearby littoral zones during the tidal processes. Heavy mineralogical data together with statistical analysis discloses that the garnet and pyribole-free heavy mineral suite in the beaches and nearby coastal plains of the Kollam coast are primarily derived from denudation of the Neogene sedimentary deposits in the coastal lands. They are evolved during the rising phases of the sea level in the Late Quaternary period.

4 illus, 4 tables, 18 ref

016066   Wilson J J;Kitto M R (Faculty of Marine Science, Marine Biology Dep, King Abdulaziz Univ, P.O. Box 80207, Jeddah 21589, Saudi Arabia, Email: jeraldreef@gmail.com) : Marine sponge on evolving science - the need for a comprehensive systematic inventory for Peninsular India. Curr Sci 2012, 102(4), 545-6.

1 illus, 4 ref

016065   Valdiya K S (The Geodynamics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur Campus, Jakkur P.O., Bangalore, Email: valdiya@incasr.ac.in) : The tragedy of being a geologist. Curr Sci 2012, 102(4), 581-9.

The geologists, who toil hard for finding minerals for scientific research and industrial development, sources of water for multifarious needs, make sustained efforts to make India self-sufficient in energy and help select appropriate sites for dams, power plants, alignments of roads and tunnels, suggesting ways of overcoming problems of stability and natural hazards, go 'unwept, un-honoured and unsung'. Even the mainstream scientists have poor opinion of geologists as scientists and geology as a science. In the matters related to the wellness of the earth, the use of its bounties and assets, and the preservation of its environmental health, their opinions are not sought and their voices not hard by the powerful science councils, commissions and academies, and by the powers-that-be. The domineering presence for decades of the sets of same persons with blinkers and biases in committees for awarding and rewarding individual endeavours is responsible for elbowing out or marginalization of those foot soldiers who work in the field for months on end - away from homes in harsh and often perilous terrains. Is it true that just because they have not spent or do not spend long hours in laboratories and tapped the internet data make them unworthy or recognition?

5 illus, 22 ref

016064   Tripathi S K; (Uttarakhand Unit, Geological Survey of India, Industrial Area, Patel Nagar, Dehradun-248 001, Email: santoshktripathi63@gmail.com) : Preliminary post-disaster assessment of the landslide-affected areas in Uttarakhand- an aftermath of june 2013 disaster. Indian J Geosci 2012, 66(4), 193-202.

State of Uttarakhand in the northern Himalayas recently experienced a devastating flood- cum-landsliding event triggered by intense rainfall of about 300-350 mm between 16 and 17 June 2013 in the higher reaches of Bhagirathi, Mandakini, Alaknanda and Bhilangana valleys. This increased amount of rainfall drained the catchments and facilitated high flood discharge in all the trunk rivers which inundated and washed away almost everything along their routes. At many places the high flood discharge eroded the river banks comprising T₀ and T₁ level terraces and the colluvial fans. This increased amount of rainfall and erosion by the mighty streams triggered innumerable landslides; debris flows, etc. on valley slopes. All these landslides, coupled with flash floods cumulatively damaged roads, settlements and agricultural land at several locations resulting into heavy loss of life and property. The preliminary reconnaissance assessment of this disaster was carried out in the Bhagirathi-Bhilangana, Alaknanda and Mandakini valleys (including Kedarnath area) where the damages have been very severe. During this rapid assessment, 87 landslides were studied to understand the reasons of the slope instability and to suggest effective remedial measures at site. Geologically, the study area forms a part of Main Himalayan Belt and exposes the rocks of Central Crystalline Group that thrust over the Garhwal Group of rocks along northerly-dipping major tectonic discontinuity, the Main Central Thrust (MCT). Based on the material involved and the type of movement, majority (63 out of 87) of the landslides can be classified as debris slides (45) and debris flows (18) and the rest as debris-cum-rock slides (10), rock-cum-debris slides (7) and rock slides (7). Based on their temporal status, 14 incidences can be categorised as 'reactivation of older slides' and the rest as 'fresh' or "new" landslide incidences. The preliminary assessment has also revealed that majority of landslides are located either in the river terraces or in the road cuts that expose slope wash/debris cone deposits resting over steep slopes formed by the underlying bed rocks. The most important causes of the landslides include i) saturation of the slope-forming material due to incessant rainfall leading to loss of cohesion and ii) rise in the water level of Trunk Rivers and widening of the river channel together leading to toe saturation and toe-cutting along the river course. The scale of damage caused by the slope failures vis-a-vis floods attained alarming dimensions due to large-scale poorly planned utilisation of the of the active flood plains and river channels for various anthropogenic activities ignoring the possibilities of such higher rainfall events. Although the present study has been successful in bringing out the preliminary assessment of the recent landslides in some worst-affected areas but in Uttarakhand, many affected sectors/areas still remain to be traversed and studied. Therefore, further work along national and state highways and other roads leading to interior parts of the disaster-affected state (both Garhwal and Kumaon Himalayas) is necessary for making a more detailed and comprehensive study of the recent disaster which will also identify and prioritise the areas required for further detailed studies in future.

12 illus, 4 ref

016063   Sujeet Kumar;Mishra P K;Singh N L;Singh K K; Srivastava P (Environmental Science, Banaras Hindu Univ, Varanasi, Uttar Pradesh) : Water quality of river Varuna in Varanasi city, Uttar Pradesh, India. Asian J biochem pharm Res 2012, 2(2), 231-40.

Study was made to determine the surface water quality status of river Varuna in Varanasi City. Water quality assessment of river Varuna is done on the basis of 15 parameters at 32 different sampling sites between Kotwa (upstream of Varanasi City) and Aadikeshav Ghat (Ganga- Varuna Sangam). Appreciable deterioration in water quality of the river can be observed from upstream of Varanasi City to Ganga Varuna Sangam. Alarming depletion of dissolved oxygen level in river water is an indication of disposal of untreated sewage and industrial effluent. To assess the quality of water of river Varuna, each parameter was compared with the standard desirable limit of that parameters in surface water as prescribed by IS:2296.

11 ref

016062   Sridhar A R;Prasad A S S S R S;Sain K;Sarkar D (NO, CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: kalachandsain@yahoo.com) : Lithospheric structure across the western part of a Narmada-Son lineament from wide-angle seismic data. Curr Sci 2012, 102(3), 484-9.

Seismic refraction and wide-angle reflection data were acquired in early 1980s in analog form along a 260-km long Sendhwa-Sindad DSS profile over the Deccan Traps-covered area across the Narmada-Son Lineament. The data with 15 Hz high cut filter were later digitized and assembled into record sections which exhibit deep-travelling, identifiable, wide-angle refleeted phases by playing with gain. We have derived the lithospheric velocity structure in Central India by kinematic and dynamic modelling of these phases. The result shows two intra-crustal discontinuities, one at a depth of 14.5-16.5 km and the other at 26 km, where velocity jumps from 6.6 to 7.0 km/s. The sub-crustal lithosphere beneath a crust-mantle boundary at 39-41 km consists of two prominent low-velocity (7.0 km/s) zones bounded by high-velocity (8.0-8.2 km/s) layers.

7 illus, 26 ref

016061   Singh C P;Panigrahy S P;Thapliyal A;Kimothi M M;Soni P;Parihar J S (NO, Space Applications Centre (ISRO), Ahmedabad-380 015, Email: cpsingh@sac.isro.gov.in) : Monitoring the alpine treeline shift in parts of the Indian Himalayas using remote sensing. Curr Sci 2012, 102(4), 559-62.

2 illus, 2 tables, 14 ref

016060   Shrivastava J P;Mukhopadhyay S K;Pal S (Geology Dep, Delhi Univ, Delhi-110 007, Email: jpshrivastava.du@gmail.com ) : Chemico-mineralogical attributes of clays from bole horizons in the early cretaceous sylhet traps of Meghalaya: palaeoenvironmental inferences. Curr Sci 2012, 102(2), 332-8.

Reports chemico-mineralogical attributes of the clay minerals that occur in the bole horizons associated with the 116 Ma Early Cretaceous Sylhet Traps in Meghalaya. The boles are brick red, greyish-black and yellowish-brown in colour. They have been observed in drill cores between the flows and are exposed in the Mawlong-Tyrna section of the Meghalaya Plateau. Upper sharp contact and lower gradational contact suggest that bole horizons are palaeo-weathering surfaces developed in the time interval between successive eruptive cycles. X-ray diffraction of clay minerals of three bole horizons shows that a lower bole horizon is rich in palygorskite, whereas other two are rich in halloysite and kaolinite. Scanning electron micrographs show that palygorskite forms randomly oriented network of densely packed fibres; kaolinite is characterized by parallel platy texture and halloysite shows matrix-type structure with isometric, spheroidal microaggregates having intragranular porosity. PAAS normalized REE patterns of both Sylhet and Deccan Traps bole clays show overlapping REE patterns and HREE enrichment. Most of the clays show positive Ce anomalies, indicating oxidizing conditions during their formation. While dominance of kaolinite and halloysite suggests weathering of low Mg volcanic ash under humid tropical climate, occurrence of palygorskite suggests increase in the pH, H₄SiO₄ and Mg²⁺ ions in a peri-marine environment under semi-arid to arid conditions. Chemical indices of alteration show that similar alteration conditions for the formation of boles prevailed during early Cretaceous Sylhet and Late Cretaceous Deccan volcanism. Rainfall was probably a little higher during the formation of Sylhet bole horizons.

5 illus, 4 tables, 20 ref

016059   Sharma S (NO, G.B. Pant Institute of Himalayan Environment and Development, Kosi-Katarmal, Almora-263 643, Email: subrats@rediffmail.com) : Catastrophic hydrological event of 18 and 19 september 2010 in Uttarakhand, Indian Central Himalaya - an analysis of rainfall and slope failure. Curr Sci 2012, 102(2), 327-32.

Heavy rains on 18 and 19 September 2010 in the Ganga watershed associated with a regional monsoon event that occurred between Myanmar and Middle East caused disastrous landslips in Uttarakhand, Indian Central Himalaya and floods in the plains of Punjab, Uttar Pradesh and Delhi. Relation between quantum of rainfall per day and slope failure has been examined in the light of similar studies in other parts of Himalaya. The cloud movement and rainfall pattern during disaster dates have been studied using remote sensing data from Kalpana-1 weather satellite and weather station data from Uttarakhand. A system for advance warning system is suggested.

6 illus, 2 tables, 15 ref

016058   Sengupta N;Sengupta P;Sanyal S (Geology Dep, Calcutta Univ, 35 Ballygunge Circular Road, Kolkata-700 019, Email: nandinisg@yahoo.com) : Occurrence of fluorine-bearing minerals in granite and a plausible mode of transport of fluorine into hydrological system: an example from Jabalpur district, Madhya Pradesh, India. Indian J Geosci 2012, 66(4), 203-12.

Fluorite, a fluorine-bearing mineral present in different rock types can cause groundwater contamination through its dissolution as fluoride ion into aquifer. Bounded by roughly E-W-trending Son-Narmada north and south faults (SNNF and SNSF respectively), the areas in and around Jabalpur (Madhya Pradesh, central India) expose Palaeoproterozoic Mahakoshal Group of rocks including mica-schist, quartzite, dolomitic marble, minor mafic dykes and large elliptical granite plutons commonly known as Madan Mahal Granite (MMG). Part of the MMG is covered by unmetamorphosed Phanerozoic rock sequence including sandstone, limestone, clay, Deccan basalts and un/semi-consolidated sediments. Aquifers with high fluorine content present in the MMG and in the overlying sandstones are presumed to be the source of dental and skeletal fluorosis of the people of Jabalpur District. Integrating the extant geological and hydrological parameters, a model has been proposed to explain the high fluorine content in groundwater of Jabalpur District. This study shows that fluorite was developed in the MMG during Palaeoproterozoic deformation and metamorphism. Sedimentary rocks that are sourced from the MMG and host the major aquifers also contain fluorite. The proposed model visualises that groundwater became alkaline due to chemical interaction with feldspar. Because of enhanced solubility of F in alkaline water, groundwater that are buffered by feldspathic wall rocks leached large amount of F from fluorite present in the host rocks and become hazardous for human consumption. High heat flow of the region further aggravates F-solubility in ground water.

4 illus, 2 tables, 39 ref

016057   Satish Kumar;Pandey J P;Jha U;Sinha A K (NO, Birla Institute of Technology, Mesra, Ranchi) : Assessment of water quality of Subarnarekha river near Ranchi (Jharkhand) in the context of usage in the chemical and pharmaceutical industries. Pharmbit 2010, 21(1), 70-7.

Objective of this study was to evaluate water quality of the Subarnarekha River and assess its feasibility for usage in the chemical and pharmaceutical industries. Various National and International Agencies involved in water quality assessment and pollution control have defined water quality criteria for different uses of water considering different indicator parameters. In this study, water collected from different sampling location along entry and exit part of Subarnarekha river in Ranchi, Jharkhand were analysed for 26 (physical, chemical and biological) parameters. Most of the reported data were in compliance with IS 10500-1991 and WHO guidelines as well as CPCB, New Delhi for water quality criteria except turbidity, Fe and BOD. Water of Subarnarekha river is not fit for the chemical and pharmaceutical industries but after efficient filtration and disinfection process river water may be used for this purposes.

5 tables, 17 ref

016056   Satheesh S K (Centre for Atmospheric and Oceanic Sciences and Divecha Centre for Cli, Indian Institute of Science, Bangalore-560 012, Email: satheesh@caos.iisc.ernet.in) : Atmospheric chemistry and climate. Curr Sci 2012, 102(3), 426-39.

Atmospheric chemistry is a branch of atmospheric science where major focus is the composition of the Earth's atmosphere. Knowledge of atmospheric com-position is essential due to its interaction with (solar and terrestrial) radiation and interactions of atmospheric species (gaseous and particulate matter) with living organisms. Since atmospheric chemistry covers a vast range of topics, in this article the focus is on the chemistry of atmospheric aerosols with special emphasis on the Indian region. I present a review of the current state of knowledge of aerosol chemistry in India and propose future directions.

8 illus, 2 tables, 117 ref

016055   Sahay V K (NO, Maheshwari Mining Pvt. Ltd., Bole Sub-City, Addis Ababa, Ethiopia, Email: vinay.sahay2geologist.com) : Case study of spatial geometry of modern fluvial meandering channel bar deposits using remote sensing and GIS. Indian J Geosci 2012, 66(4), 247-54.

This paper presents the result of a study on a modern fluvial meandering channel bar deposit of Wardha basin in India, based on remote sensing and GIS. In this study, 28 channel bar deposits and their geometry have been documented. The geometries of channel bar deposits documented are crescent-shaped, curved crescent-shaped, linear, curved linear, tabular, V-shaped, inverted L-shaped, U-shaped and globular. In the studied part of the Wardha meandering river channel, the crescent-shaped and linear bar deposits are relatively common than the other shapes. If this finding can be generalised then it can be expected that in a meandering type of fluvial system the probability of getting crescent-shaped and linear bar deposits and their sub-types is high. This work reports V-type geometry of a meandering channel bar deposit for the first time. The correlation coefficient (R²) results suggest that the width and length of channel bar deposits are least correlatable. Two fan deposits have also been found in the study area. The fluvial fan deposits are of lobate shape and sandy in composition. This work further emphasises the importance of remote sensing, as a relatively low-cost tool, in exploring and understanding the modern natural processes and their products for exploitation of natural resources occurring in ancient channel bar deposits. Remote sensing studies provide useful information on shape and size of the channel bar deposits, from modern fluvial systems, which can be utilised as an input for more efficient characterisation arid development of hydrocarbon reservoirs occurring in ancient fluvial channel bar deposits.

7 illus, 1 table, 10 ref

016054   Roy A B (Geology Dep, Presidency Univ, Kolkata-700 073, Email: ashitbaranroy@gmail.com) : Indian shield: insight into the pristine size, shape and tectonic framework. Indian J Geosci 2012, 66(4), 181-92.

Indian Shield which receives wide reference in literature occupied much wider area than the exposed Precambrian terrane of Peninsular India prior to its decimation during successive Phanerozoic events that started with the Jurassic break-up of Gondwanaland. Relying on the information from the Peninsular India, it is possible to trace out not only the history of destruction, but also the clue to divide this Precambrian crustal block into two major tectonic blocks: Precambrian continental core or Proto-India, and the accreted charnockitic terranes. Proto-India, belonging to two major domains: Aravalli-Bundelkhand and the Gondwana, can be further subdivided into six smaller units which are described as the fundamental nuclei or Protocontinents. These are: (1) Dharwar, (2) Bastar, (3) Singhbhum, (4) Rajmahal, (5) Bundelkhand and (6) Aravalli. The two accreted terranes which were added subsequently to the Proto-India include the Eastern Ghats Belt and the Southern Granulite Belts. The combined Precambrian crustal blocks of Proto-India and the accreted terranes constituted the Indian Shield. The Joins that separate or suture the Protocontinents as well as the 'accreted' terranes, are marked by different features, such as fault trace (as between the Aravalli and the Bundelkhand), thrust or ductile shear zone (as between Eastern Ghats Belt and the Dharwar, Bastar and Singhbhum to its west, and between Dharwar and Southern Granulite Belt), or Lineaments like Narmada-Son, Godavari or Mahanadi which follow coal-bearing, Gondwana rift basins. It is suggested that the invariable occurrence of Gondwana rift basins along some Joins resulted at the time of Gondwana break-up when there was an abortive attempt to fragment the Indian Shield, resulting in the opening of intracratonic continental basins along pre-exiting weak zones marked by Joins.

6 illus, 84 ref

016053   Ray D;Rajan S;Ravindra R (NO, National Centre for Antarctic and Ocean Research, Goa-403 804, Email: dwijesh@rediffmail.com) : Role of subducting component and sub-arc mantle in arc petrogenesis: Andaman volcanic arc. Curr Sci 2012, 102(4), 605-9.

Geochemical proxies, especially the trace element ratios of arc lavas from Barren and Narcondam Islands of the Andaman-Nicobar Islands group, display dissimilar characteristics. Narcondam lavas (mostly andesitic) are typically characterized by high Ba/La, Ba/Nb and Th/Nd ratios, reflective of the imprint of substantial subduction component in the form of sediment fluid and melt. On the other hand, Barren lavas (mostly basaltic) show relatively high Ba/Th ratios, indicative of fluid-induced subduction component, mainly signature-inducing fluid component, de-rived from altered ocean crust.

5 illus, 2 tables, 23 ref

016052   Rana R S;Bhagat R M;Kalia V;Lal H;Sen V (Centre for Geo-Informatics Research and Training, CSK Himachal Pradesh Agriculture University, Palampur, Email: 176 062) : Indigenous perceptions of Climate change vis-a-vis Mountain Agricultural activities in Himachal Pradesh, India. Indian J Tradl Knowledge 2013, 12(4), 596-604.

The study assesses the effects of climatic and socioeconomic changes on the livelihoods of rural agricultural communities in the Himachal Pradesh of India. The farmers' perceptions on locally idealized traditional weather cycles with climate change are analyzed and compared for different agro climatic zones of Himachal Pradesh. Climate change is described by farmers as temporal displacement of weather cycles, reflecting changes in crop enterprises and livelihood options. Increasing temperature during summers, prolonged summers, delayed onset and uneven distribution of SW monsoon, delayed onset of winter, short winter periods, temperature above normal during winters, decreasing snowfall during winters, delayed snowfall and shorter winters, low temperature spells at high altitudes during winters and unpredictable rainfalls were the main experiences of the farmers regarding climate change across the elevation zones. Farmers' perceptions clearly indicated a shift in crop production in the low and mid hill regions, from crops requiring high moisture, like basmati rice and sugarcane, to those tolerating lower water like maize and local paddy rice. In addition, a shift of the apple growing belt to higher altitudes was noted, with former apple production areas replaced by vegetable crops. The study concludes that climate variability has a clear impact on crop productivity. In all elevations, farmers opined that a shift of labor earlier engaged in agriculture, to other enterprises is primarily due to handsome earnings in other enterprises, reflecting reduction in profits from agriculture and increase in vulnerability in climate dependent agricultural systems. Farmers in marginal areas are more vulnerable than small and large farmers from sub tropical climates in the mid hills to sub temperate climates at higher elevations.

5 illus, 3 tables, 12 ref

016051   Onwualu J N;Ukaegbu V U;Okengwu K O (Geology Dep, University of Port Harcourt, Port Harcourt, Nigeria) : Source region inhomogeneity in igneous suite of Ishiagu, Southern Benue Trough, Nigeria. Archiv appl Sci Res 2012, 4(2), 923-34.

Intermediate -basic intrusive and volcanic form structurally-controlled topographic features in Ishiagu area of Afikpo basin, southern Benue trough of Nigeria. Petrogenesis of the rocks was studied using major, trace and ree. Interpretation of data confirm the division of the rocks into three groups (Syenodiorite, basalt and pyroclastics). Basalt occurs along horizontal contact of syenodiorite with overlying pyroclastics .These rocks intruded the Albian sediment. Petrogenetic modeling suggests that the rocks are not cogenetic and represent various stages of crystallization from three different and genetically unrelated magma. The extent of variation can be related to (i) magmatism originating from mantle, (ii), crystal fractionation, (iii), magma mixing and /or mingling, (iv), varying degree of partial melt, (v), assimilation and contamination, (vi),batch melting ,(vii) hydrothermal alteration. These processes could operate alone or simultaneously. They will be evaluated on the basis of observations that have been made on the igneous suite. Different mechanisms will be considered particularly i, ii, iii, iv, vi.

40 ref

016050   Narke S Y;Kore N S (Geography Dep, Jamkhed Mahavidyalaya, Jamkhed, Email: sunilnarke23@gmail.com) : Development potentialities of towns: a case study of Ahmednagar district. Ultra Scient phys Sci-Sect B 2013, 25(1), 69-74.

Evaluates the development potentialities of the towns of Ahmednagar district. The entire paper is based on secondary source of data. Data has been processed by applying quantitative techniques such as mean, standard Deviation, Centrality Index etc. For this research purpose a tahsil unit of urban centre is considered. A comparative rank order as per population and cumulative potentiality score reveals that Ahmednagar, Sangamner, Shrirampur, Rahuri and Kopargaon are stood first, second, third, fourth and fifth rank respectively.

3 tables, 4 ref

016049   Naidu P D;Patil J S;Narale D D;Anil A C (NO, National Institute of Oceanography (CSIR), Dona Paula, Goa-403 004, Email: divakar@nio.org) : First look at the dinoflagellate cysts abundance in the Bay of Bengal: implications on late quaternary productivity and climate change. Curr Sci 2012, 102(3), 495-9.

Abundance and composition of dinoflagellate cysts in a sediment core (SK218/1) from the Bay of Bengal were examined for the last 23 kyr. Cyst abundance at this site varied from 20 to 153 cysts/g dry wt, which is far less than that reported from other oceans. The Hololocene harboured higher number of cysts (74-153 cysts/g dry wt) than the last glacial period (up to 67 cysts/g dry wt). Although cyst abundance is low at this site, the cyst composition and its abundance between Holocene and last glacial period reflect the affinity to climate change between these two periods, like other regions. Greater abundance of heterotroph and autotroph cysts and higher species diversity were noticed during Holocene than in the last glacial period, which supports earlier observations depicting higher productivity during the Holocene than in the last glacial period in the southwest monsoon-influenced regions of the Indian Ocean.

2 illus, 1 table, 33 ref

016048   Mukherjee P;Rakshit P (Geodata and Database Div, Geological Survey of India, Central Headquarters, 27, J.L. Nehru Road, Kolkata-700 016, Email: pralaymukherjee@gmail.com) : Late quaternary climatic vicissitudes as deciphered from study of lacustrine sediments of Sambhar lake, Rajasthan, India. Indian J Geosci 2012, 66(4), 213-4.

The Sambhar salt lake is one of the exclusive ephemeral endorheic saline basins in Rajasthan having considerable thickness of Quaternary deposits and is one of the premier salt- producing areas of Rajasthan. The Quaternary sedimentology of Sambhar Lake has been studied with the aid of hand auger drilling to understand palaeoclimatic changes in and around Sambhar Lake. A dense network of relict drainage around Sambhar reflects abundant supply of water and sediments during wetter phases. Gradual drying up of the drainage took place in response to climate change. The Sambhar playa core sediments indicate variation in major oxide composition (in certain geochemical variants) through vertical geological sections commensurate with climate change in late Holocene period. Palynofloral assemblage has also been proved helpful in deciphering palaeoclimate. The sedimentary unit lying at the bottom of the studied sedimentary package comprises predominantly blackish silt-clay which have yielded high percentage of pollen varieties depicting sub-humid limnic condition where as the successive younger unit shows a change in lithofacies represented by greyish, greenish fine to very fine sand and silt comprising a fair percentage of anemophilous pollen considered to be transported from far off distances possibly under arid condition. The evidence of desiccation of the lake ecosystem is manifested by the presence of low algal and fungal spore in the upper part of the sedimentary sequence. So a change in climatic condition is however postulated from the study of Quaternary lacustrine sediments.

5 illus, 2 tables, 25 ref

016047   Mukherjee D (Palaeontology Div, Central Headquarters, Geological Survey of India, 15 Kyd Street, Kolkata-700 016, Email: debahuti.mukherjeegsi@gmail.com) : Diverse invertebrate assemblage from the upper Maastrichtian of Meghalaya and its biogeographic significance. Indian J Geosci 2012, 66(4), 233-46.

Upper Maastrichtian sediments of Meghalaya represented by the Mahadek and the lower part of Langpar Formation reveal a diverse assemblage of invertebrate taxa belonging to echinoids, gastropods, bivalves and ammonites. The echinoids recovered from the Mahadek and Langpar formations reveal a wide taxonomic diversity belonging to five families - Holectypoida, Cideroida, Cassiduloida, Holasteroida and Spatangoida represented by Conulus, Globator, Galerites, Offaster, Stygmatopygus, Micraster. The gastropods in the Mahadek and Langpar formations belong to five families, viz. Ampullinidae, Naticiidae, Neritidae, Mitriidae, and Euomphalidae having the genera: Ampulina, Natica, Nerita, Mitra and Discohelix. The heteromorphic ammonite genus Eubaculites has been recorded in the earthy limestone horizon of the Langpar Formation along with a fragmentary specimen of Glyptoxoceras. The nautiloid Cymatoceras is also present in the Mahadek and lower Langpar Formation. Biogeographic distribution of the Meghalaya invertebrates reveals remarkable faunal similarity with Poland, Middle-East countries and North Africa especially the echinoid and gastropod taxa suggesting a Tethyan connection.

8 illus, 2 tables, 19 ref

016046   Mishra P K;Rai S C (Geography Dep, Delhi School of Economics, University of Delhi, Delhi-110 007, Email: raisc1958@rediffmail.com) : Use of indigenous soil and water conservation practices among farmers in Sikkim Himalaya. Indian J Tradl Knowledge 2013, 12(3), 454-64.

This paper analyses indigenous soil and water conservation practices in a watershed of Sikkim Himalaya based on information collected through a questionnaire survey. Information used in the analysis were obtained through a survey of 150 farmers in 3 ecological zones (low, mid and high), group discussions, key informant interviews, and field observation conducted during 2009-10. Farmers have adopted several conservation practices passed on to them by their forefathers. Farmers in all ecological zones have practiced several structural and biological land management practices to conserve soil and water. Adoption of terrace cultivation, construction of retention walls, bunds, construction and maintenance of waterways, mixed cropping, crop rotation, mulching, agroforestry, and use of farm yard manure are found significantly higher in all ecological zones of the watershed. This indicates that the farmers have very high belief in indigenous techniques of conservation. Findings are discussed in the context of conservation programmes within the watershed. The findings of this study have important policy implications for sustainable land management in the region.

3 illus, 4 tables, 24 ref

016045   Mahadevaswamy G;Nagaraju D (Studies in Geology Dep, Manasagangotri Mysore Univ, Mysore-570 006) : Determination of specific yield in Kuderu micro water shed of Chamarajanagar and Nanjanagud taluks, Karnataka. J Ecotoxic envir Monit 2011, 21(3-4), 341-5.

An attempt has bean made to compute the specific yield of water table aquifer of granitic formation in Kuderu micro watershed having an area of 58 sq km. of Chamarajanagar and Mysore district, Karnataka during February to March-2009 using Water Balance Equation. Total ground water extracted in the water shed has bean estimated as 0.00930 mcm. Adhoc norms for recharge due to ground water irrigation has bean considered based on the type of crop (paddy or non paddy) and depth of water table below ground level, which worked out as 0.00232 mcm. (25%of total volume of water extracted in the area). The volume of aquifer de watered was calculated by multiplying the area of water shed (1.75 sq.km.) and the average water level fluctuation (0.72 m.), which is 1.26 mcm. The Specific Yield of phreatic aquifer in granitic terrain of micro watershed was calculated using Water Balance Equation and the value of 0.55% was arrived as per the studies.

1 illus, 2 tables, 5 ref

016044   Madhan R;Dabholkar N;Navelkar G;Desa E; Afzulpurkar S;Mascarenhas A;Prabhudesai S (NO, National Institute of Oceangraphy (CSIR), Dona Paula, Goa-403 004, Email: madhan@nio.org) : Autonomous profiling device to monitor remote water bodies. Curr Sci 2012, 102(2), 169-76.

In tropical climates, most freshwater reservoirs, dams and lakes are prone to annual summer stratification during which bottom water layers near the bed become hypoxic (<60> 2 ml/l) with very low concentrations of dissolved oxygen (DO). This has serious implications to human health, and requires frequent and effective monitoring, particularly during summer months (March-May) when water consumption is highest. These water bodies are frequently located in remote areas away from human habitation, making it logistically difficult to access and monitor their water column properties on a regular basis. The need for monitoring temporal changes in freshwater ecosystems is addressed in this note through the description of a patented technology - Autonomous Vertical Profiler (AVP) designed and developed at the National Institute of Oceanography (NIO), Goa, for use in both coastal and freshwater bodies. The AVP was used in experiments to satellite transmit complete time and location referenced high-resolution profiles of temperature, phytoplankton concentration, turbidity and DO from the remote Tillari Dam - a freshwater reservoir near Dodamarg, Maharashtra, India. The profiles were received without errors at the Marine Instrumentation Laboratory at NIO. The benefits of in situ time-series profiling with AVP captured the onset of developing hypoxia in early April 2011 over a 9-day unsupervised profiling experiment. A similar 5-day experiment in February 2011 tracked diurnal changes in phytoplankton concentrations through night and day, suggesting a possible interplay between recycled production and photoinhibition.

8 illus, 1 table, 17 ref

016043   Karabulut S;Tezel O;Ozcep F;Imre N (NO, Division of Seismology, Istanbul, Turkiye, Email: savask@istanbul.edu.tr) : A geophysical study on soil conditions in flood-affected selimpasa area, Istanbul, Turkey. Curr Sci 2012, 102(2), 320-6.

Multi-channel analysis of surface waves (MASW) and micrometer array measurements (MAM) have been carried out in the flood-prone areas of Selimpasa, Kavakli, Ortakoy and Kadikoy in Turkey to understand several soil problems, especially soil amplification during earthquakes. In the region, there are now more than 80 geotechnical boreholes with SPT and laboratory test data, as also MASW-MAM geophysical measurements at more than 100 locations. All these data have been evaluated to classify the soils according to Eurocode 8, determine soil amplification and finally to obtain a microzonation map. According to the Eurocode soil classification system, there are D, B and C type soils in the area of study. In the final microzonation map, the study area is divided into three sub-regions based on shear wave (Vs) velocities - sub-region A (Vs velocities higher than 420 m/s), sub-region B (Vs velocities between 360 and 420 m/s) and sub-region C (Vs velocities lower than 360 m/s). Results show that there are clear relationships between Vs 30 and flood damage effect. Vs 30: 180 m/s is characteristic of zone with D type soil, which is transported alluvial soil. Vs 30 <60> 180 zones define the limits of the areas affected by floods in the study region.

8 illus, 2 tables, 35 ref

016042   Josheph B;Thrivikramaji K P;Joseph S J (Geology Dep, Government College, Kottayam, Kerala) : Development of soil profiles in contrasting climates: a case study from southern India. Pollut Res 2012, 31(2), 247-50.

Formation of soil profiles is a complex process involving several factors viz., climate, parent rock, relief, organic activity and time and therefore results in diverse profiles. Among these, climate plays the dominant role. Development of soil profiles and their constituent horizons (in terms of their thickness) formed under two contrasting climatic set up, viz., tropical humid (Neyyar basin, Kerala) and semi-arid (Tambraparni basin, Tamil Nadu), with similar geological setting in southern India are detailed in this study.

4 illus, 1 table, 8 ref

016041   Gutierrez R M;Baculi R;Pastor N;Puma-at T; Balangcod T (Biology Dep, College of Science, University of the Philippines, Baguio, Email: rosegutz@gmail.com) : Antibacterial potential of some medicinal plants of the Cordillera Region, Philippines. Indian J Tradl Knowledge 2013, 12(4), 630-7.

Since plants have been the source of a large percentage of prescription drugs, it is very important that the antimicrobial properties of medicinal plants be investigated because these plants could be a resource for new and alternative treatment for some common infectious diseases. Eleven medicinal plants of the Cordillera Region, in the Philippines were evaluated for their antimicrobial properties by the standard disc diffusion assay method using test bacterial organisms: Escherichia coli, Bacillus subtilis, Staphyloccocus aureus and Proteus vulgaris, while test fungal organisms used were Candida albicans and Aspergillus flavus. Only four plants namely, Agathis dammara, Eupatorium triplenerve, Citrus aurantifolia and Tithonia divserifolia were found to have antibacterial properties. The Minimum Inhibitory Concentrations (MICs) of these plant extracts against the four test organisms were also determined. Results of MIC determination revealed that the gram positive organisms, Bacillus subtilis and Staphylococcus aureus, were more sensitive to the four plant extracts, since they scored the lowest value of MIC which ranged from 62.5 to 125 μg/ml. The gram negative organisms Escherichia coli and Proteus vulgaris scored higher MIC values ranging from 62.5 - 250 μg/ml. Phytochemical screening of the four plants with antibacterial activities were also undertaken.

3 tables, 36 ref

016040   Chowdhuri S N;Mishra O P;Majumdar R K (NO, Geological Survey of India, Central Geophysics Div, 27 J.L. Nehru Road, Kolkata-700 016, Email: sumitchowdhuri@rocketmail.com) : Oblate particle motion for high site response characteristics in Agartala city, India. Indian J Geosci 2012, 66(4), 225-32.

Site characteristic is well explained by H/V ratio (Nakamura, 1989) from the fundamental peak of Rayleigh waves and is related to the ellipticity of Raleigh waves. Also, the vibration characteristics of horizontal and vertical motions behave differently in soft-ground and hard-ground condition. Therefore it is attempted to study the nature of polarization associated with particle motion induced within the subsoil. A site response (SR) study was carried out using digital microearthquake recorders with short period SS-1 seismometers, covering 70 sites in and around Agartala City. It is observed that estimated SR from H/V increases from edges to middle of the Haora River valley. This reflects that site response (by H/V ratio) is influenced by impedance contrast and different nature of particle motions within the valley zone. The higher order of SR depends upon the ellipticity of the particle motion which is further influenced by high frequency range of predominant frequencies of the subsoil. We tried to identify the causative factors in such vibrations. Therefore it is an attempt to classify the strength of polarization of three-dimensional particle motion derived from ambient noise or Rayleigh wave spectra. Negative strength of the polarization attributes a flat ellipsoid/oblate particle motion due to prograde motion of Rayleigh wave for a surface layer with low velocities.

4 illus, 1 table, 19 ref

016039   Bhambri R;Bolch T;Chaujar R K (Center for Glaciology, Wadia Institute of Himalayan Geology, Dehradun-248 001, Email: rchaujar@gmail.com) : Frontal recession of Gangotri glacier, Garhwal Himalayas, from 1965 to 2006, measured through high-resolution remote sensing data. Curr Sci 2012, 102(3), 489-94.

Reports in this communication the length fluctuation and frontal area changes at the snout of Gangotri Glacier based on high-resolution satellite data from 1965 to 2006. Glacial outlines were mapped from de-classified imageries from Corona (1965, 1968), Hexagon (1980) and Indian satellites IRS PAN (2001) and Cartosat-1 (2006). The results show that Gangotri Glacier exhibited retreat up to 819 ± 14 m and lost 0.41 ± 0.03 sq. km (<126> 0.01 sq. km year^-1) at its front from 1965 to 2006. The retreat rates are lower than those previously reported using coarse-resolution remote sensing data and the Survey of India topography map. The results of the present study are supported by in-situ field survey conducted by the Geological Survey of India.

4 illus, 4 tables, 45 ref

016038   Bhagat S N (NO, Geological Survey of India, N C-II Block, Pushpa Bhavan, Madangir Road, New Delhi-110 062, Email: snbhagat2004@yahoo.co.in) : EPMA study of galena from lower Vindhyan rocks of Choraiya area, Damoh district, Madhya Pradesh, India. Indian J Geosci 2012, 66(4), 255-8.

3 illus, 1 table, 5 ref

016037   Baul T K;Atique Ullah K M;Tiwari K R;McDonald M A (Institute of Forestry and Environmental Sciences, University of Chitta, , Chittagong-4331, Bangladesh, Email: tarit_ifescu@yahoo.com) : People's local knowledge of climate change in the Middle-Hills of Nepal. Indian J Tradl Knowledge 2013, 12(4), 585-95.

In the Pokhare Khola watershed of Dhading district in the Middle-ills of Nepal, almost all farmers perceived that summers are becoming hotter and longer while 81% of interviewed farmers responded that winters are becoming warmer and shorter. During the period of 1978 - 2008, the overall temperature has risen about 0.20C. Summer temperatures have fluctuated, but mean winter temperature has generally increased over this time. Meteorological data corroborates the farmers' perceptions. Annual and monsoon season rainfall was highly variable over the last 30 years, with the lowest mean monsoon rainfall (212 mm) in 1990 and the highest (646 mm) in 1999. Farmers observed that duration of the rainy season has decreased from four to two months. The reduction in wheat (Triticum aestivum L.) production due to shorter winters and insufficient post-monsoon rain was evident. Changes in annual rainfall pattern and resulting water shortages also lowered the millet [Eleusine coracana (L.) Gaertn.] production. The appearance of advancing phenological development in trees (flowering 10 - 25 days earlier), and earlier ripening of some crops were often cited as impacts of change in climate. Household survey and interview, group discussions, participatory rural appraisal (PRA) tools, viz. trend analysis, and problem ranking were conducted to gather the observations and experiences on climate change perceived by local people. Moreover, local meteorological data was analyzed to see the trend of changes in rainfall and temperature.

8 illus, 1 table, 39 ref

016036   Barthakur P;Das R K (Geology Dep, Pragjyotish College, Guwahati-781 009) : Grain size and texture of the sandstones occurring in and around Mawsinram, Meghalaya. Ultra Scient phys Sci-Sect B 2013, 25(1), 121-46.

Grain size analyses and textural studies have been made from four types of sandstones occurring in and around Mawsinram, Meghalaya. For this purpose, statistical parameters of the grain size distribution have been determined. The nature of cumulative and frequency curves shows mostly bimodality in nature. It indicates mixing of the sediments mostly under sand and silt modes. Moreover, it shows the variation in the kinetic energy of the depositing agents which reflect the diversity in the grain size of source materials and different modes of transportation of sediments. The univariant plots of size parameters reflect the distance of provenance, fluctuation in the velocity of the depositing media and higher hydrodynamic energy conditions of the transporting medium. The bivariant plots of the samples of sandstones indicate sedimentation processes took place both under river and marine conditions. Log probability plots show dominance of saltation followed by suspension and rolling. The C-M patterns of four types of sandstones show that the sediments were carried dominantly by graded suspension alongwith rolling. The sandstones are of sand and silty sand under textural classification.

13 illus, 3 tables, 32 ref

016035   Antony Ravindran A (Manonmaniam Sundaranar University, , Thoothukudi) : Azimuthal square array method and grounwater potential zone in hard rock area in Thoothukudi district, Tamilnadu. Archiv appl Sci Res 2012, 4(2), 971-9.

Aim of the study is find out the groundwater potential in the granite and quartzite terrain in the Thoothukudi District using Azimuthal Square Array (DC) electrical resistivity method. The case study carried out in Mangalagiri (Quartzite terrain), Kovilpatti(Quartzite, weathered gneiss), Chandragiri (Weahtered gneiss and granite rock) is occurred in the geological formation of Archaen age. The Square array electrical resistivity methods were carried out in field using CRM-500 electrical resistivity meter, wire spool, electrodes with square array configuration. The depth of penetration `a' is equal to the length of electrode spacing. The collected resistivity data was processed by the formula and calculate the apparent resistivity, anisotropy and lithostratigraphy of the study area. The fault zone direction was identified in the study area by using the azimuthal polar plots and curve matching techniques. The obtained apparent resistivity is ranging from 1-50,soil and Caliche deposits, quartzite 50-100 Ohm.m and freshwater apparent resistivity 100-120 ohm.m.

11 ref

016034   Ali I;Olatunjia S;Nwankwoa L I;Akoshilea C O; Johnsonb L M;Edino F (Physics Dep, University of Ilorin, Ilorin, Nigeria) : Geomagnetic modeling of potential hydrocarbon traps in the lower Niger Delta, Offshore West Africa. Archiv appl Sci Res 2012, 4(2), 863-74.

A renewed interest to continually search for hydrocarbon prospects in the deep offshore West Africa climaxed after the discovery of a rewarding oil prospects around the deep offshore basin of Mauritania. However, recent statistics showed that, viable prospects along this region are increasingly becoming difficult to locate and that, future success will greatly depend on identifying `structural and stratigraphic traps' within prospective areas. In this study, digitised aeromagnetic data covering part of Niger Delta was processed and gridded to generate the residual map as well as the depth to basement maps. On these maps, potential areas for hydrocarbon traps were delineated accordingly. Oasis Montaj geophysical software was used throughout the data processing and analysis. The average thickness of the sediments or depth to basement varies from 0 km on the outcrops to as much as 10.7 km within the study area, large enough for hydrocarbon accumulation. In addition to that, eleven intrusives were mapped from 2.5D forward and inverse modeling, with lateral extents of 1.5 km - 6.0 km. The presence of these intrusives made parts of the study area less favourable for hydrocarbon exploration. The structurally low areas were also outlined from the depth to basement maps. Interestingly, most of the oil producing fields were reportedly located within the structurally low areas of the basin. Hence, it is recommended that a detailed seismic prospecting be carried out around the structurally low areas in `the new frontiers'.

19 ref

015159   Zaidi W A;Khurshid S;Alvi S H (GIS Laboratory, Faculty of Science, Mauritius Univ, Reduit, Mauritius, Email: wasizaidi.geology@gmail.com) : Groundwater quality studies in parts of Delhi, India using geospatial technology. J appl Geochem 2014, 16(1), 11-7.

Information derived from the different hydrogeomorphological layers in parts of national capital Delhi (India) shows that the intermountain valley fill and alluvial plains are in excellent condition for groundwater extraction, however the water quality in the intermountain valley fill deposits is not good hence care should be taken at the time of choosing the well site. The Aeolian sandy plain intermountain basin and buried pediment provide a good opportunity for groundwater prospect in the area and among all these intermountain basins and buried pediment units have limited size, area and therefore these two units have only limited possible groundwater development. The other units show poor to moderate opportunity for groundwater development in some blocks, but places near to fault planes and joints in the hills of Delhi and the denudated hills in Mewat and Gurgaon districts show moderate chances of groundwater prospects. The GIS technology is very useful for the preparation of Geological, Hydrogeomorphological and groundwater quality prospecting area mapping and management plan on a scientific basis. The information generated on prospects of Geology, Geomorphology and Groundwater quality in the map will be helpful for the planners and decision makers and also feasible for groundwater quality, development and management.

4 illus, 2 tables, 4 ref

015158   Uniyal A;Shah P N;Chandra Prakash;Gangwar D S;Dhar S;Mishra S P;Sharma S;Malik G S (NO, Remote Sensing Applications, Centre-Uttar Pradesh, Sector-G, Jankipuram, Kursi Road, Lucknow-226 021, Email: aniruddhauniyal@yahoo.com) : Anthropogenically induced mass movements along the Dharasu-Yamunotri route. Curr Sci 2012, 102(6), 828-9.

2 illus, 1 ref

015157   Umamaheswar K;Bisht B S;Zakaulla S;Rai A K (NO, Atomic Minerals Directorate for Exploration and Research, Atomic Energ, Hyderabad, Email: umamaheswark252@gmail.com) : Cuddapah uranium province, Andhra Pradesh role of basement granites, tectonism and geochemistry. J appl Geochem 2014, 16(1), 33-44.

The Cuddapah Uranium Province encompasses two economically viable genetic types of uranium deposits as the carbonate-hosted stratabound uranium deposits around Tummalapalle-Rachakuntapalle area, and the unconformity-proximal type in basement granitoids and overlying Srisailam/Banganapalle quartzite in the Lambapur-Peddagattu-Chitrial-Koppunuru area. Besides, the basin characteristically hosts important occurrences, of fracture controlled uranium mineralisation in Gulcheru quartzite near Gandi and in basement granitoid around Lakkireddipalle-Rayachoti; shear-controlled along the thrusted eastern margin of Cuddapah basin in basic metavolcanics and schists at Gudarukoppu and Kasturigattu. In the northern part of the basin, uranium deposits of Lambapur, Peddagattu, Chitrial, and Koppunuru area characteristically show association of ore bodies along structures formed by intersection of prominent basement fractures with the unconformity separating Srisailam and Palnad sediments from the basement. In the southwestern part of the basin, potential carbonate-hosted, stratabound uranium mineralisation extends over a 160 km long belt from Chelumpalli to Maddimadugu with large-tonnage, low-grade, uranium deposits in Tummallapalle-Rachakuntapalle area. The unconformity-proximal and fracture controlled deposits/prospects characteristically share a common source for uranium, repeated tectonism, weathering of the basement granitoids and episodic, epigenetic hydrothermal processes of uranium mineralisation. This paper evaluates the role of granitoids spatially and temporally associated with uranium mineralisation in making the Cuddapah Basin a unique uranium province.

3 illus, 36 ref

015156   Sukumaran P V (NO, , 'Sukrutham', Ambika Road, Kotekar Post, Mangalore-575 022, Email: pvs341950@gmail.com) : Need to explore for rare earth minerals. Curr Sci 2012, 102(6), 839-41.

Rare earth elements (REEs) are strategic metals with critical applications in modern technology, and with no satisfactory substitutes. REE minerals do not occur concentrated in geological environments unlike those of base metals or iron ores and their geological exploration is often a daunting task. Mining, beneficiation and metallurgy of REEs constitute a complex process with adverse environmental impacts. The world REE market today is controlled by the Peoples Republic of China, which is moving ahead to impose a total export embargo on these metals by the year 2012. As a consequence, the entire world is vigorously exploring for REE minerals in an effort to counter China's threat. There are many favourable geological milieus in our country for REE mineralization which should be targeted for exploration.

^ssc13 ref

015155   Sujatha D;Ramana D V (NO, CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad, Email: sujathadantu@rediffmail.com) : Statistical approach to investigate baseline concentration of major/trace elements in soils in and around Medak and Sangareddy, Medak district, Andhra Pradesh. J appl Geochem 2014, 16(1), 18-32.

Study was carried out in and around Medak and Sangareddy to determine the baseline levels of ten major (Si, Al, Ca, Fe, K, Mn, Mg, Na, P and Ti) and fourteen trace elements (As, Ba, Co, Cr, Cu, Mo, Ni, Pb, Rb, Sr, V, Y, Zn and Zr) on ninety-five representative soil samples comprising of topsoil (0-25 cms) and subsoil (90-115 cms). The reference or the baseline values for different elements in the study area were calculated following two procedures (1) as the expected range (ER) = GM/GD² - GMxGD², where GM is the geometric mean and GD is the geometric deviation, and (2) probability plots taking the concentrations between 5th and 95th percentiles. The data sets were studied by means of histograms in order to verify the general assumption, which states that trace element distribution in soils follows the lognormal law. Results reveal that the concentrations of Mo and K show normal distribution while the concentrations of Co, Zn, Zr and Na show lognormal distribution, the concentrations of Ca, Cu, Sr, Ti and V show neither normal nor lognormal distribution in both the cases of topsoil and subsoil. Logarithmic transformation was found to have over transformed most of the data sets, changing their skewness from positive to negative values.

4 illus, 2 tables, 20 ref

015154   Sridhar P N;Ali M M;Rao M V;Nagamani P V (NO, National Remote Sensing Centre, ISRO, Hyderabad-500 037, Email: sridhar_pn@nrsc.gov.in) : Photosynthetically active radiation, a critical parameter for mass coral bleaching in the north Indian ocean. Curr Sci 2012, 102(1), 114-18.

The Gulf of Mannar (GOM) and Kadamat Island (KI) are two major coral reefs that were severely bleached en masse in the North Indian Ocean (N1O) during 1998. Mass coral bleaching took place once again in NIO during 2002, which severely affected the GOM corals but not the Kl corals. This contrasting phenomenon prompted us to re-examine parameters such as surface sea temperature (SST), photosynthetically active radiation (PAR), hotspots, heat content, sea-surface height anomaly (SSHA) and North Indian Ocean Dipole (NIOD) events. The analysis indicates that the above mass bleaching events are associated with high PAR (47 Einstein/m²/day) with minimum SST of 30°C, which was probably critical for mass bleaching in NIO during 1998 and 2002. However, the above bleaching events do not show any direct link with SSHA, hotspots and NIOD.

5 illus, 2 tables, 28 ref

015153   Singh A K;Singh R (NO, , CMPDI) : Slope stability: mitigating risk in dragline dump slopes. Wat Energy int 2012, 69(4), 36-41.

8 illus, 3 tables, 4 ref

015152   Senthilkumar S;Aruna M;Malathi D;Sivakumar R; Gowtham B (Geology Dep, Presidency College, Chennai, Email: kumarramsiva@rediff.com) : Hydrogeochemistry of Mailam block of Tindivanam taluk, Villupuram district, Tamil Nadu. J appl Geochem 2014, 16(1), 64-80.

Geochemical signatures of groundwater in the Hardrock Aquifer of Mailam block which forms a part of Tindivanam Taluk, Villupuram district, Tamil Nadu, India, were used to identify the chemical processes that control hydrochemistry. The study area covering an area of 285 sq.km which lies in the northern part of Tamil Nadu forms a part of Tondiyar basin. The area also includes a number of rainfed tanks and streams. It serves as a source for groundwater to irrigate the area. The present study is about geochemical characterization of groundwater, its suitability for drinking, domestic and irrigational purposes. About 32 groundwater samples were collected for this purpose from the study area and all the samples underwent geochemical analysis for various water quality parameters such as pH, Electrical conductivity (EC), TDS, and major ion concentrations Na, K, Ca, Mg, Cl, HCO3, SO4. All the analytical values were computed by employing HYCH (a computer programme) for ionic balance of analytical values. Based on HYCH output all the groundwater samples were evaluated for suitability for drinking, domestic and agricultural purposes. The geographic information system-based spatial distribution map of different major elements was prepared using ArcGIS 9.2. In comparison with WHO(1993) and IS-10500(1991) for the permissible limit of drinking water, a majority of the ground water samples in the study area fall within the maximum permissible limit. Some on the basis of TDS and due to hardness of the groundwater did not meet the permissible limit for domestic purposes. Other chemical parameters such as Sodium Adsorption Ratio, percentage of sodium etc. which were calculated to determine the suitability of groundwater for irrigational purposes were found to be good. In the Gibb's diagram, majority of the samples fall under rock dominance field and little under Evaporation field.

9 tables, 4 tables, 23 ref